Revert "Virtual Filesystem (#597)"

This reverts commit 77c684c1140f6bf3fb7d4560d06d2efb1a2ee5e2.

src/common/file_util.cpp

@@ -2,7 +2,6 @@
 // Licensed under GPLv2 or any later version
 // Refer to the license.txt file included.
 
-#include <sstream>
 #include "common/assert.h"
 #include "common/common_funcs.h"
 #include "common/common_paths.h"
@@ -387,7 +386,7 @@ u64 GetSize(FILE* f) {
 bool CreateEmptyFile(const std::string& filename) {
     LOG_TRACE(Common_Filesystem, "{}", filename);
 
-    if (!FileUtil::IOFile(filename, "wb").IsOpen()) {
+    if (!FileUtil::IOFile(filename, "wb")) {
         LOG_ERROR(Common_Filesystem, "failed {}: {}", filename, GetLastErrorMsg());
         return false;
     }
@@ -751,7 +750,7 @@ size_t WriteStringToFile(bool text_file, const std::string& str, const char* fil
 size_t ReadFileToString(bool text_file, const char* filename, std::string& str) {
     IOFile file(filename, text_file ? "r" : "rb");
 
-    if (!file.IsOpen())
+    if (!file)
         return false;
 
     str.resize(static_cast<u32>(file.GetSize()));
@@ -800,57 +799,6 @@ void SplitFilename83(const std::string& filename, std::array<char, 9>& short_nam
     }
 }
 
-std::vector<std::string> SplitPathComponents(const std::string& filename) {
-    auto copy(filename);
-    std::replace(copy.begin(), copy.end(), '\\', '/');
-    std::vector<std::string> out;
-
-    std::stringstream stream(filename);
-    std::string item;
-    while (std::getline(stream, item, '/'))
-        out.push_back(std::move(item));
-
-    return out;
-}
-
-std::string GetParentPath(const std::string& path) {
-    auto out = path;
-    const auto name_bck_index = out.find_last_of('\\');
-    const auto name_fwd_index = out.find_last_of('/');
-    size_t name_index;
-    if (name_bck_index == std::string::npos || name_fwd_index == std::string::npos)
-        name_index = std::min<size_t>(name_bck_index, name_fwd_index);
-    else
-        name_index = std::max<size_t>(name_bck_index, name_fwd_index);
-
-    return out.erase(name_index);
-}
-
-std::string GetFilename(std::string path) {
-    std::replace(path.begin(), path.end(), '\\', '/');
-    auto name_index = path.find_last_of('/');
-    if (name_index == std::string::npos)
-        return "";
-    return path.substr(name_index + 1);
-}
-
-std::string GetExtensionFromFilename(const std::string& name) {
-    size_t index = name.find_last_of('.');
-    if (index == std::string::npos)
-        return "";
-
-    return name.substr(index + 1);
-}
-
-std::string RemoveTrailingSlash(const std::string& path) {
-    if (path.empty())
-        return path;
-    if (path.back() == '\\' || path.back() == '/')
-        return path.substr(0, path.size() - 1);
-
-    return path;
-}
-
 IOFile::IOFile() {}
 
 IOFile::IOFile(const std::string& filename, const char openmode[], int flags) {
@@ -872,6 +820,7 @@ IOFile& IOFile::operator=(IOFile&& other) noexcept {
 
 void IOFile::Swap(IOFile& other) noexcept {
     std::swap(m_file, other.m_file);
+    std::swap(m_good, other.m_good);
 }
 
 bool IOFile::Open(const std::string& filename, const char openmode[], int flags) {
@@ -888,15 +837,16 @@ bool IOFile::Open(const std::string& filename, const char openmode[], int flags)
     m_file = fopen(filename.c_str(), openmode);
 #endif
 
-    return IsOpen();
+    m_good = IsOpen();
+    return m_good;
 }
 
 bool IOFile::Close() {
     if (!IsOpen() || 0 != std::fclose(m_file))
-        return false;
+        m_good = false;
 
     m_file = nullptr;
-    return true;
+    return m_good;
 }
 
 u64 IOFile::GetSize() const {
@@ -906,8 +856,11 @@ u64 IOFile::GetSize() const {
     return 0;
 }
 
-bool IOFile::Seek(s64 off, int origin) const {
-    return IsOpen() && 0 == fseeko(m_file, off, origin);
+bool IOFile::Seek(s64 off, int origin) {
+    if (!IsOpen() || 0 != fseeko(m_file, off, origin))
+        m_good = false;
+
+    return m_good;
 }
 
 u64 IOFile::Tell() const {
@@ -918,20 +871,26 @@ u64 IOFile::Tell() const {
 }
 
 bool IOFile::Flush() {
-    return IsOpen() && 0 == std::fflush(m_file);
+    if (!IsOpen() || 0 != std::fflush(m_file))
+        m_good = false;
+
+    return m_good;
 }
 
 bool IOFile::Resize(u64 size) {
-    return IsOpen() && 0 ==
+    if (!IsOpen() || 0 !=
 #ifdef _WIN32
-                           // ector: _chsize sucks, not 64-bit safe
-                           // F|RES: changed to _chsize_s. i think it is 64-bit safe
-                           _chsize_s(_fileno(m_file), size)
+                         // ector: _chsize sucks, not 64-bit safe
+                         // F|RES: changed to _chsize_s. i think it is 64-bit safe
+                         _chsize_s(_fileno(m_file), size)
 #else
-                           // TODO: handle 64bit and growing
-                           ftruncate(fileno(m_file), size)
+                         // TODO: handle 64bit and growing
+                         ftruncate(fileno(m_file), size)
 #endif
-        ;
+    )
+        m_good = false;
+
+    return m_good;
 }
 
 } // namespace FileUtil

src/common/file_util.h

@@ -150,31 +150,6 @@ size_t ReadFileToString(bool text_file, const char* filename, std::string& str);
 void SplitFilename83(const std::string& filename, std::array<char, 9>& short_name,
                      std::array<char, 4>& extension);
 
-// Splits the path on '/' or '\' and put the components into a vector
-// i.e. "C:\Users\Yuzu\Documents\save.bin" becomes {"C:", "Users", "Yuzu", "Documents", "save.bin" }
-std::vector<std::string> SplitPathComponents(const std::string& filename);
-
-// Gets all of the text prior to the last '/' or '\' in the path.
-std::string GetParentPath(const std::string& path);
-
-// Gets the filename of the path
-std::string GetFilename(std::string path);
-
-// Gets the extension of the filename
-std::string GetExtensionFromFilename(const std::string& name);
-
-// Removes the final '/' or '\' if one exists
-std::string RemoveTrailingSlash(const std::string& path);
-
-// Creates a new vector containing indices [first, last) from the original.
-template <typename T>
-std::vector<T> SliceVector(const std::vector<T>& vector, size_t first, size_t last) {
-    if (first >= last)
-        return {};
-    last = std::min<size_t>(last, vector.size());
-    return std::vector<T>(vector.begin() + first, vector.begin() + first + last);
-}
-
 // simple wrapper for cstdlib file functions to
 // hopefully will make error checking easier
 // and make forgetting an fclose() harder
@@ -197,27 +172,41 @@ public:
     bool Close();
 
     template <typename T>
-    size_t ReadArray(T* data, size_t length) const {
+    size_t ReadArray(T* data, size_t length) {
         static_assert(std::is_trivially_copyable<T>(),
                       "Given array does not consist of trivially copyable objects");
 
-        if (!IsOpen())
+        if (!IsOpen()) {
+            m_good = false;
             return -1;
+        }
 
-        return std::fread(data, sizeof(T), length, m_file);
+        size_t items_read = std::fread(data, sizeof(T), length, m_file);
+        if (items_read != length)
+            m_good = false;
+
+        return items_read;
     }
 
     template <typename T>
     size_t WriteArray(const T* data, size_t length) {
         static_assert(std::is_trivially_copyable<T>(),
                       "Given array does not consist of trivially copyable objects");
-        if (!IsOpen())
+
+        if (!IsOpen()) {
+            m_good = false;
             return -1;
-        return std::fwrite(data, sizeof(T), length, m_file);
+        }
+
+        size_t items_written = std::fwrite(data, sizeof(T), length, m_file);
+        if (items_written != length)
+            m_good = false;
+
+        return items_written;
     }
 
     template <typename T>
-    size_t ReadBytes(T* data, size_t length) const {
+    size_t ReadBytes(T* data, size_t length) {
         static_assert(std::is_trivially_copyable<T>(), "T must be trivially copyable");
         return ReadArray(reinterpret_cast<char*>(data), length);
     }
@@ -242,7 +231,15 @@ public:
         return nullptr != m_file;
     }
 
-    bool Seek(s64 off, int origin) const;
+    // m_good is set to false when a read, write or other function fails
+    bool IsGood() const {
+        return m_good;
+    }
+    explicit operator bool() const {
+        return IsGood();
+    }
+
+    bool Seek(s64 off, int origin);
     u64 Tell() const;
     u64 GetSize() const;
     bool Resize(u64 size);
@@ -250,11 +247,13 @@ public:
 
     // clear error state
     void Clear() {
+        m_good = true;
         std::clearerr(m_file);
     }
 
 private:
     std::FILE* m_file = nullptr;
+    bool m_good = true;
 };
 
 } // namespace FileUtil

src/core/CMakeLists.txt

@@ -8,9 +8,9 @@ add_library(core STATIC
     core_cpu.h
     core_timing.cpp
     core_timing.h
-    file_sys/content_archive.cpp
-    file_sys/content_archive.h
     file_sys/directory.h
+    file_sys/disk_filesystem.cpp
+    file_sys/disk_filesystem.h
     file_sys/errors.h
     file_sys/filesystem.cpp
     file_sys/filesystem.h
@@ -20,13 +20,15 @@ add_library(core STATIC
     file_sys/path_parser.h
     file_sys/program_metadata.cpp
     file_sys/program_metadata.h
+    file_sys/romfs_factory.cpp
+    file_sys/romfs_factory.h
+    file_sys/romfs_filesystem.cpp
+    file_sys/romfs_filesystem.h
+    file_sys/savedata_factory.cpp
+    file_sys/savedata_factory.h
+    file_sys/sdmc_factory.cpp
+    file_sys/sdmc_factory.h
     file_sys/storage.h
-    file_sys/vfs.cpp
-    file_sys/vfs.h
-    file_sys/vfs_offset.cpp
-    file_sys/vfs_offset.h
-    file_sys/vfs_real.cpp
-    file_sys/vfs_real.h
     frontend/emu_window.cpp
     frontend/emu_window.h
     frontend/framebuffer_layout.cpp

src/core/core.cpp

@@ -19,7 +19,6 @@
 #include "core/loader/loader.h"
 #include "core/memory_setup.h"
 #include "core/settings.h"
-#include "file_sys/vfs_real.h"
 #include "video_core/video_core.h"
 
 namespace Core {
@@ -85,7 +84,7 @@ System::ResultStatus System::SingleStep() {
 }
 
 System::ResultStatus System::Load(EmuWindow* emu_window, const std::string& filepath) {
-    app_loader = Loader::GetLoader(std::make_shared<FileSys::RealVfsFile>(filepath));
+    app_loader = Loader::GetLoader(filepath);
 
     if (!app_loader) {
         LOG_CRITICAL(Core, "Failed to obtain loader for {}!", filepath);

src/core/file_sys/content_archive.cpp

@@ -1,164 +0,0 @@
-// Copyright 2018 yuzu emulator team
-// Licensed under GPLv2 or any later version
-// Refer to the license.txt file included.
-
-#include "common/logging/log.h"
-#include "core/file_sys/content_archive.h"
-#include "core/file_sys/vfs_offset.h"
-#include "core/loader/loader.h"
-
-namespace FileSys {
-
-// Media offsets in headers are stored divided by 512. Mult. by this to get real offset.
-constexpr u64 MEDIA_OFFSET_MULTIPLIER = 0x200;
-
-constexpr u64 SECTION_HEADER_SIZE = 0x200;
-constexpr u64 SECTION_HEADER_OFFSET = 0x400;
-
-constexpr u32 IVFC_MAX_LEVEL = 6;
-
-enum class NCASectionFilesystemType : u8 { PFS0 = 0x2, ROMFS = 0x3 };
-
-struct NCASectionHeaderBlock {
-    INSERT_PADDING_BYTES(3);
-    NCASectionFilesystemType filesystem_type;
-    u8 crypto_type;
-    INSERT_PADDING_BYTES(3);
-};
-static_assert(sizeof(NCASectionHeaderBlock) == 0x8, "NCASectionHeaderBlock has incorrect size.");
-
-struct PFS0Superblock {
-    NCASectionHeaderBlock header_block;
-    std::array<u8, 0x20> hash;
-    u32_le size;
-    INSERT_PADDING_BYTES(4);
-    u64_le hash_table_offset;
-    u64_le hash_table_size;
-    u64_le pfs0_header_offset;
-    u64_le pfs0_size;
-    INSERT_PADDING_BYTES(432);
-};
-static_assert(sizeof(PFS0Superblock) == 0x200, "PFS0Superblock has incorrect size.");
-
-struct IVFCLevel {
-    u64_le offset;
-    u64_le size;
-    u32_le block_size;
-    u32_le reserved;
-};
-static_assert(sizeof(IVFCLevel) == 0x18, "IVFCLevel has incorrect size.");
-
-struct RomFSSuperblock {
-    NCASectionHeaderBlock header_block;
-    u32_le magic;
-    u32_le magic_number;
-    INSERT_PADDING_BYTES(8);
-    std::array<IVFCLevel, 6> levels;
-    INSERT_PADDING_BYTES(64);
-};
-static_assert(sizeof(RomFSSuperblock) == 0xE8, "RomFSSuperblock has incorrect size.");
-
-NCA::NCA(VirtualFile file_) : file(file_) {
-    if (sizeof(NCAHeader) != file->ReadObject(&header))
-        LOG_CRITICAL(Loader, "File reader errored out during header read.");
-
-    if (!IsValidNCA(header)) {
-        status = Loader::ResultStatus::ErrorInvalidFormat;
-        return;
-    }
-
-    std::ptrdiff_t number_sections =
-        std::count_if(std::begin(header.section_tables), std::end(header.section_tables),
-                      [](NCASectionTableEntry entry) { return entry.media_offset > 0; });
-
-    for (std::ptrdiff_t i = 0; i < number_sections; ++i) {
-        // Seek to beginning of this section.
-        NCASectionHeaderBlock block{};
-        if (sizeof(NCASectionHeaderBlock) !=
-            file->ReadObject(&block, SECTION_HEADER_OFFSET + i * SECTION_HEADER_SIZE))
-            LOG_CRITICAL(Loader, "File reader errored out during header read.");
-
-        if (block.filesystem_type == NCASectionFilesystemType::ROMFS) {
-            RomFSSuperblock sb{};
-            if (sizeof(RomFSSuperblock) !=
-                file->ReadObject(&sb, SECTION_HEADER_OFFSET + i * SECTION_HEADER_SIZE))
-                LOG_CRITICAL(Loader, "File reader errored out during header read.");
-
-            const size_t romfs_offset =
-                header.section_tables[i].media_offset * MEDIA_OFFSET_MULTIPLIER +
-                sb.levels[IVFC_MAX_LEVEL - 1].offset;
-            const size_t romfs_size = sb.levels[IVFC_MAX_LEVEL - 1].size;
-            files.emplace_back(std::make_shared<OffsetVfsFile>(file, romfs_size, romfs_offset));
-            romfs = files.back();
-        } else if (block.filesystem_type == NCASectionFilesystemType::PFS0) {
-            PFS0Superblock sb{};
-            // Seek back to beginning of this section.
-            if (sizeof(PFS0Superblock) !=
-                file->ReadObject(&sb, SECTION_HEADER_OFFSET + i * SECTION_HEADER_SIZE))
-                LOG_CRITICAL(Loader, "File reader errored out during header read.");
-
-            u64 offset = (static_cast<u64>(header.section_tables[i].media_offset) *
-                          MEDIA_OFFSET_MULTIPLIER) +
-                         sb.pfs0_header_offset;
-            u64 size = MEDIA_OFFSET_MULTIPLIER * (header.section_tables[i].media_end_offset -
-                                                  header.section_tables[i].media_offset);
-            auto npfs = std::make_shared<PartitionFilesystem>(
-                std::make_shared<OffsetVfsFile>(file, size, offset));
-
-            if (npfs->GetStatus() == Loader::ResultStatus::Success) {
-                dirs.emplace_back(npfs);
-                if (IsDirectoryExeFS(dirs.back()))
-                    exefs = dirs.back();
-            }
-        }
-    }
-
-    status = Loader::ResultStatus::Success;
-}
-
-Loader::ResultStatus NCA::GetStatus() const {
-    return status;
-}
-
-std::vector<std::shared_ptr<VfsFile>> NCA::GetFiles() const {
-    if (status != Loader::ResultStatus::Success)
-        return {};
-    return files;
-}
-
-std::vector<std::shared_ptr<VfsDirectory>> NCA::GetSubdirectories() const {
-    if (status != Loader::ResultStatus::Success)
-        return {};
-    return dirs;
-}
-
-std::string NCA::GetName() const {
-    return file->GetName();
-}
-
-std::shared_ptr<VfsDirectory> NCA::GetParentDirectory() const {
-    return file->GetContainingDirectory();
-}
-
-NCAContentType NCA::GetType() const {
-    return header.content_type;
-}
-
-u64 NCA::GetTitleId() const {
-    if (status != Loader::ResultStatus::Success)
-        return {};
-    return header.title_id;
-}
-
-VirtualFile NCA::GetRomFS() const {
-    return romfs;
-}
-
-VirtualDir NCA::GetExeFS() const {
-    return exefs;
-}
-
-bool NCA::ReplaceFileWithSubdirectory(VirtualFile file, VirtualDir dir) {
-    return false;
-}
-} // namespace FileSys

src/core/file_sys/content_archive.h

@@ -1,89 +0,0 @@
-// Copyright 2018 yuzu emulator team
-// Licensed under GPLv2 or any later version
-// Refer to the license.txt file included.
-
-#pragma once
-
-#include "common/common_funcs.h"
-#include "common/common_types.h"
-#include "common/swap.h"
-#include "core/file_sys/partition_filesystem.h"
-
-namespace FileSys {
-
-enum class NCAContentType : u8 { Program = 0, Meta = 1, Control = 2, Manual = 3, Data = 4 };
-
-struct NCASectionTableEntry {
-    u32_le media_offset;
-    u32_le media_end_offset;
-    INSERT_PADDING_BYTES(0x8);
-};
-static_assert(sizeof(NCASectionTableEntry) == 0x10, "NCASectionTableEntry has incorrect size.");
-
-struct NCAHeader {
-    std::array<u8, 0x100> rsa_signature_1;
-    std::array<u8, 0x100> rsa_signature_2;
-    u32_le magic;
-    u8 is_system;
-    NCAContentType content_type;
-    u8 crypto_type;
-    u8 key_index;
-    u64_le size;
-    u64_le title_id;
-    INSERT_PADDING_BYTES(0x4);
-    u32_le sdk_version;
-    u8 crypto_type_2;
-    INSERT_PADDING_BYTES(15);
-    std::array<u8, 0x10> rights_id;
-    std::array<NCASectionTableEntry, 0x4> section_tables;
-    std::array<std::array<u8, 0x20>, 0x4> hash_tables;
-    std::array<std::array<u8, 0x10>, 0x4> key_area;
-    INSERT_PADDING_BYTES(0xC0);
-};
-static_assert(sizeof(NCAHeader) == 0x400, "NCAHeader has incorrect size.");
-
-static bool IsDirectoryExeFS(std::shared_ptr<FileSys::VfsDirectory> pfs) {
-    // According to switchbrew, an exefs must only contain these two files:
-    return pfs->GetFile("main") != nullptr && pfs->GetFile("main.npdm") != nullptr;
-}
-
-static bool IsValidNCA(const NCAHeader& header) {
-    return header.magic == Common::MakeMagic('N', 'C', 'A', '2') ||
-           header.magic == Common::MakeMagic('N', 'C', 'A', '3');
-}
-
-// An implementation of VfsDirectory that represents a Nintendo Content Archive (NCA) conatiner.
-// After construction, use GetStatus to determine if the file is valid and ready to be used.
-class NCA : public ReadOnlyVfsDirectory {
-public:
-    explicit NCA(VirtualFile file);
-    Loader::ResultStatus GetStatus() const;
-
-    std::vector<std::shared_ptr<VfsFile>> GetFiles() const override;
-    std::vector<std::shared_ptr<VfsDirectory>> GetSubdirectories() const override;
-    std::string GetName() const override;
-    std::shared_ptr<VfsDirectory> GetParentDirectory() const override;
-
-    NCAContentType GetType() const;
-    u64 GetTitleId() const;
-
-    VirtualFile GetRomFS() const;
-    VirtualDir GetExeFS() const;
-
-protected:
-    bool ReplaceFileWithSubdirectory(VirtualFile file, VirtualDir dir) override;
-
-private:
-    std::vector<VirtualDir> dirs;
-    std::vector<VirtualFile> files;
-
-    VirtualFile romfs = nullptr;
-    VirtualDir exefs = nullptr;
-    VirtualFile file;
-
-    NCAHeader header{};
-
-    Loader::ResultStatus status{};
-};
-
-} // namespace FileSys

src/core/file_sys/disk_filesystem.cpp

@@ -0,0 +1,237 @@
+// Copyright 2018 yuzu emulator team
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include <cstring>
+#include <memory>
+#include "common/common_types.h"
+#include "common/logging/log.h"
+#include "core/file_sys/disk_filesystem.h"
+#include "core/file_sys/errors.h"
+
+namespace FileSys {
+
+static std::string ModeFlagsToString(Mode mode) {
+    std::string mode_str;
+    u32 mode_flags = static_cast<u32>(mode);
+
+    // Calculate the correct open mode for the file.
+    if ((mode_flags & static_cast<u32>(Mode::Read)) &&
+        (mode_flags & static_cast<u32>(Mode::Write))) {
+        if (mode_flags & static_cast<u32>(Mode::Append))
+            mode_str = "a+";
+        else
+            mode_str = "r+";
+    } else {
+        if (mode_flags & static_cast<u32>(Mode::Read))
+            mode_str = "r";
+        else if (mode_flags & static_cast<u32>(Mode::Append))
+            mode_str = "a";
+        else if (mode_flags & static_cast<u32>(Mode::Write))
+            mode_str = "w";
+    }
+
+    mode_str += "b";
+
+    return mode_str;
+}
+
+std::string Disk_FileSystem::GetName() const {
+    return "Disk";
+}
+
+ResultVal<std::unique_ptr<StorageBackend>> Disk_FileSystem::OpenFile(const std::string& path,
+                                                                     Mode mode) const {
+
+    // Calculate the correct open mode for the file.
+    std::string mode_str = ModeFlagsToString(mode);
+
+    std::string full_path = base_directory + path;
+    auto file = std::make_shared<FileUtil::IOFile>(full_path, mode_str.c_str());
+
+    if (!file->IsOpen()) {
+        return ERROR_PATH_NOT_FOUND;
+    }
+
+    return MakeResult<std::unique_ptr<StorageBackend>>(
+        std::make_unique<Disk_Storage>(std::move(file)));
+}
+
+ResultCode Disk_FileSystem::DeleteFile(const std::string& path) const {
+    if (!FileUtil::Exists(path)) {
+        return ERROR_PATH_NOT_FOUND;
+    }
+
+    FileUtil::Delete(path);
+
+    return RESULT_SUCCESS;
+}
+
+ResultCode Disk_FileSystem::RenameFile(const std::string& src_path,
+                                       const std::string& dest_path) const {
+    const std::string full_src_path = base_directory + src_path;
+    const std::string full_dest_path = base_directory + dest_path;
+
+    if (!FileUtil::Exists(full_src_path)) {
+        return ERROR_PATH_NOT_FOUND;
+    }
+    // TODO(wwylele): Use correct error code
+    return FileUtil::Rename(full_src_path, full_dest_path) ? RESULT_SUCCESS : ResultCode(-1);
+}
+
+ResultCode Disk_FileSystem::DeleteDirectory(const Path& path) const {
+    LOG_WARNING(Service_FS, "(STUBBED) called");
+    // TODO(wwylele): Use correct error code
+    return ResultCode(-1);
+}
+
+ResultCode Disk_FileSystem::DeleteDirectoryRecursively(const Path& path) const {
+    LOG_WARNING(Service_FS, "(STUBBED) called");
+    // TODO(wwylele): Use correct error code
+    return ResultCode(-1);
+}
+
+ResultCode Disk_FileSystem::CreateFile(const std::string& path, u64 size) const {
+    LOG_WARNING(Service_FS, "(STUBBED) called");
+
+    std::string full_path = base_directory + path;
+    if (size == 0) {
+        FileUtil::CreateEmptyFile(full_path);
+        return RESULT_SUCCESS;
+    }
+
+    FileUtil::IOFile file(full_path, "wb");
+    // Creates a sparse file (or a normal file on filesystems without the concept of sparse files)
+    // We do this by seeking to the right size, then writing a single null byte.
+    if (file.Seek(size - 1, SEEK_SET) && file.WriteBytes("", 1) == 1) {
+        return RESULT_SUCCESS;
+    }
+
+    LOG_ERROR(Service_FS, "Too large file");
+    // TODO(Subv): Find out the correct error code
+    return ResultCode(-1);
+}
+
+ResultCode Disk_FileSystem::CreateDirectory(const std::string& path) const {
+    // TODO(Subv): Perform path validation to prevent escaping the emulator sandbox.
+    std::string full_path = base_directory + path;
+
+    if (FileUtil::CreateDir(full_path)) {
+        return RESULT_SUCCESS;
+    }
+
+    LOG_CRITICAL(Service_FS, "(unreachable) Unknown error creating {}", full_path);
+    // TODO(wwylele): Use correct error code
+    return ResultCode(-1);
+}
+
+ResultCode Disk_FileSystem::RenameDirectory(const Path& src_path, const Path& dest_path) const {
+    LOG_WARNING(Service_FS, "(STUBBED) called");
+    // TODO(wwylele): Use correct error code
+    return ResultCode(-1);
+}
+
+ResultVal<std::unique_ptr<DirectoryBackend>> Disk_FileSystem::OpenDirectory(
+    const std::string& path) const {
+
+    std::string full_path = base_directory + path;
+
+    if (!FileUtil::IsDirectory(full_path)) {
+        // TODO(Subv): Find the correct error code for this.
+        return ResultCode(-1);
+    }
+
+    auto directory = std::make_unique<Disk_Directory>(full_path);
+    return MakeResult<std::unique_ptr<DirectoryBackend>>(std::move(directory));
+}
+
+u64 Disk_FileSystem::GetFreeSpaceSize() const {
+    LOG_WARNING(Service_FS, "(STUBBED) called");
+    return 0;
+}
+
+ResultVal<FileSys::EntryType> Disk_FileSystem::GetEntryType(const std::string& path) const {
+    std::string full_path = base_directory + path;
+    if (!FileUtil::Exists(full_path)) {
+        return ERROR_PATH_NOT_FOUND;
+    }
+
+    if (FileUtil::IsDirectory(full_path))
+        return MakeResult(EntryType::Directory);
+
+    return MakeResult(EntryType::File);
+}
+
+ResultVal<size_t> Disk_Storage::Read(const u64 offset, const size_t length, u8* buffer) const {
+    LOG_TRACE(Service_FS, "called offset={}, length={}", offset, length);
+    file->Seek(offset, SEEK_SET);
+    return MakeResult<size_t>(file->ReadBytes(buffer, length));
+}
+
+ResultVal<size_t> Disk_Storage::Write(const u64 offset, const size_t length, const bool flush,
+                                      const u8* buffer) const {
+    LOG_WARNING(Service_FS, "(STUBBED) called");
+    file->Seek(offset, SEEK_SET);
+    size_t written = file->WriteBytes(buffer, length);
+    if (flush) {
+        file->Flush();
+    }
+    return MakeResult<size_t>(written);
+}
+
+u64 Disk_Storage::GetSize() const {
+    return file->GetSize();
+}
+
+bool Disk_Storage::SetSize(const u64 size) const {
+    file->Resize(size);
+    file->Flush();
+    return true;
+}
+
+Disk_Directory::Disk_Directory(const std::string& path) {
+    unsigned size = FileUtil::ScanDirectoryTree(path, directory);
+    directory.size = size;
+    directory.isDirectory = true;
+    children_iterator = directory.children.begin();
+}
+
+u64 Disk_Directory::Read(const u64 count, Entry* entries) {
+    u64 entries_read = 0;
+
+    while (entries_read < count && children_iterator != directory.children.cend()) {
+        const FileUtil::FSTEntry& file = *children_iterator;
+        const std::string& filename = file.virtualName;
+        Entry& entry = entries[entries_read];
+
+        LOG_TRACE(Service_FS, "File {}: size={} dir={}", filename, file.size, file.isDirectory);
+
+        // TODO(Link Mauve): use a proper conversion to UTF-16.
+        for (size_t j = 0; j < FILENAME_LENGTH; ++j) {
+            entry.filename[j] = filename[j];
+            if (!filename[j])
+                break;
+        }
+
+        if (file.isDirectory) {
+            entry.file_size = 0;
+            entry.type = EntryType::Directory;
+        } else {
+            entry.file_size = file.size;
+            entry.type = EntryType::File;
+        }
+
+        ++entries_read;
+        ++children_iterator;
+    }
+    return entries_read;
+}
+
+u64 Disk_Directory::GetEntryCount() const {
+    // We convert the children iterator into a const_iterator to allow template argument deduction
+    // in std::distance.
+    std::vector<FileUtil::FSTEntry>::const_iterator current = children_iterator;
+    return std::distance(current, directory.children.end());
+}
+
+} // namespace FileSys

src/core/file_sys/disk_filesystem.h

@@ -0,0 +1,84 @@
+// Copyright 2018 yuzu emulator team
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <cstddef>
+#include <memory>
+#include <string>
+#include "common/common_types.h"
+#include "common/file_util.h"
+#include "core/file_sys/directory.h"
+#include "core/file_sys/filesystem.h"
+#include "core/file_sys/storage.h"
+#include "core/hle/result.h"
+
+namespace FileSys {
+
+class Disk_FileSystem : public FileSystemBackend {
+public:
+    explicit Disk_FileSystem(std::string base_directory)
+        : base_directory(std::move(base_directory)) {}
+
+    std::string GetName() const override;
+
+    ResultVal<std::unique_ptr<StorageBackend>> OpenFile(const std::string& path,
+                                                        Mode mode) const override;
+    ResultCode DeleteFile(const std::string& path) const override;
+    ResultCode RenameFile(const std::string& src_path, const std::string& dest_path) const override;
+    ResultCode DeleteDirectory(const Path& path) const override;
+    ResultCode DeleteDirectoryRecursively(const Path& path) const override;
+    ResultCode CreateFile(const std::string& path, u64 size) const override;
+    ResultCode CreateDirectory(const std::string& path) const override;
+    ResultCode RenameDirectory(const Path& src_path, const Path& dest_path) const override;
+    ResultVal<std::unique_ptr<DirectoryBackend>> OpenDirectory(
+        const std::string& path) const override;
+    u64 GetFreeSpaceSize() const override;
+    ResultVal<EntryType> GetEntryType(const std::string& path) const override;
+
+protected:
+    std::string base_directory;
+};
+
+class Disk_Storage : public StorageBackend {
+public:
+    explicit Disk_Storage(std::shared_ptr<FileUtil::IOFile> file) : file(std::move(file)) {}
+
+    ResultVal<size_t> Read(u64 offset, size_t length, u8* buffer) const override;
+    ResultVal<size_t> Write(u64 offset, size_t length, bool flush, const u8* buffer) const override;
+    u64 GetSize() const override;
+    bool SetSize(u64 size) const override;
+    bool Close() const override {
+        return false;
+    }
+    void Flush() const override {}
+
+private:
+    std::shared_ptr<FileUtil::IOFile> file;
+};
+
+class Disk_Directory : public DirectoryBackend {
+public:
+    explicit Disk_Directory(const std::string& path);
+
+    ~Disk_Directory() override {
+        Close();
+    }
+
+    u64 Read(const u64 count, Entry* entries) override;
+    u64 GetEntryCount() const override;
+
+    bool Close() const override {
+        return true;
+    }
+
+protected:
+    FileUtil::FSTEntry directory;
+
+    // We need to remember the last entry we returned, so a subsequent call to Read will continue
+    // from the next one. This iterator will always point to the next unread entry.
+    std::vector<FileUtil::FSTEntry>::iterator children_iterator;
+};
+
+} // namespace FileSys

src/core/file_sys/filesystem.h

@@ -66,4 +66,136 @@ private:
     std::u16string u16str;
 };
 
+/// Parameters of the archive, as specified in the Create or Format call.
+struct ArchiveFormatInfo {
+    u32_le total_size;         ///< The pre-defined size of the archive.
+    u32_le number_directories; ///< The pre-defined number of directories in the archive.
+    u32_le number_files;       ///< The pre-defined number of files in the archive.
+    u8 duplicate_data;         ///< Whether the archive should duplicate the data.
+};
+static_assert(std::is_pod<ArchiveFormatInfo>::value, "ArchiveFormatInfo is not POD");
+
+class FileSystemBackend : NonCopyable {
+public:
+    virtual ~FileSystemBackend() {}
+
+    /**
+     * Get a descriptive name for the archive (e.g. "RomFS", "SaveData", etc.)
+     */
+    virtual std::string GetName() const = 0;
+
+    /**
+     * Create a file specified by its path
+     * @param path Path relative to the Archive
+     * @param size The size of the new file, filled with zeroes
+     * @return Result of the operation
+     */
+    virtual ResultCode CreateFile(const std::string& path, u64 size) const = 0;
+
+    /**
+     * Delete a file specified by its path
+     * @param path Path relative to the archive
+     * @return Result of the operation
+     */
+    virtual ResultCode DeleteFile(const std::string& path) const = 0;
+
+    /**
+     * Create a directory specified by its path
+     * @param path Path relative to the archive
+     * @return Result of the operation
+     */
+    virtual ResultCode CreateDirectory(const std::string& path) const = 0;
+
+    /**
+     * Delete a directory specified by its path
+     * @param path Path relative to the archive
+     * @return Result of the operation
+     */
+    virtual ResultCode DeleteDirectory(const Path& path) const = 0;
+
+    /**
+     * Delete a directory specified by its path and anything under it
+     * @param path Path relative to the archive
+     * @return Result of the operation
+     */
+    virtual ResultCode DeleteDirectoryRecursively(const Path& path) const = 0;
+
+    /**
+     * Rename a File specified by its path
+     * @param src_path Source path relative to the archive
+     * @param dest_path Destination path relative to the archive
+     * @return Result of the operation
+     */
+    virtual ResultCode RenameFile(const std::string& src_path,
+                                  const std::string& dest_path) const = 0;
+
+    /**
+     * Rename a Directory specified by its path
+     * @param src_path Source path relative to the archive
+     * @param dest_path Destination path relative to the archive
+     * @return Result of the operation
+     */
+    virtual ResultCode RenameDirectory(const Path& src_path, const Path& dest_path) const = 0;
+
+    /**
+     * Open a file specified by its path, using the specified mode
+     * @param path Path relative to the archive
+     * @param mode Mode to open the file with
+     * @return Opened file, or error code
+     */
+    virtual ResultVal<std::unique_ptr<StorageBackend>> OpenFile(const std::string& path,
+                                                                Mode mode) const = 0;
+
+    /**
+     * Open a directory specified by its path
+     * @param path Path relative to the archive
+     * @return Opened directory, or error code
+     */
+    virtual ResultVal<std::unique_ptr<DirectoryBackend>> OpenDirectory(
+        const std::string& path) const = 0;
+
+    /**
+     * Get the free space
+     * @return The number of free bytes in the archive
+     */
+    virtual u64 GetFreeSpaceSize() const = 0;
+
+    /**
+     * Get the type of the specified path
+     * @return The type of the specified path or error code
+     */
+    virtual ResultVal<EntryType> GetEntryType(const std::string& path) const = 0;
+};
+
+class FileSystemFactory : NonCopyable {
+public:
+    virtual ~FileSystemFactory() {}
+
+    /**
+     * Get a descriptive name for the archive (e.g. "RomFS", "SaveData", etc.)
+     */
+    virtual std::string GetName() const = 0;
+
+    /**
+     * Tries to open the archive of this type with the specified path
+     * @param path Path to the archive
+     * @return An ArchiveBackend corresponding operating specified archive path.
+     */
+    virtual ResultVal<std::unique_ptr<FileSystemBackend>> Open(const Path& path) = 0;
+
+    /**
+     * Deletes the archive contents and then re-creates the base folder
+     * @param path Path to the archive
+     * @return ResultCode of the operation, 0 on success
+     */
+    virtual ResultCode Format(const Path& path) = 0;
+
+    /**
+     * Retrieves the format info about the archive with the specified path
+     * @param path Path to the archive
+     * @return Format information about the archive or error code
+     */
+    virtual ResultVal<ArchiveFormatInfo> GetFormatInfo(const Path& path) const = 0;
+};
+
 } // namespace FileSys

src/core/file_sys/partition_filesystem.cpp

@@ -6,30 +6,29 @@
 #include "common/file_util.h"
 #include "common/logging/log.h"
 #include "core/file_sys/partition_filesystem.h"
-#include "core/file_sys/vfs_offset.h"
 #include "core/loader/loader.h"
 
 namespace FileSys {
 
-PartitionFilesystem::PartitionFilesystem(std::shared_ptr<VfsFile> file) {
+Loader::ResultStatus PartitionFilesystem::Load(const std::string& file_path, size_t offset) {
+    FileUtil::IOFile file(file_path, "rb");
+    if (!file.IsOpen())
+        return Loader::ResultStatus::Error;
+
     // At least be as large as the header
-    if (file->GetSize() < sizeof(Header)) {
-        status = Loader::ResultStatus::Error;
-        return;
-    }
+    if (file.GetSize() < sizeof(Header))
+        return Loader::ResultStatus::Error;
 
+    file.Seek(offset, SEEK_SET);
     // For cartridges, HFSs can get very large, so we need to calculate the size up to
     // the actual content itself instead of just blindly reading in the entire file.
     Header pfs_header;
-    if (sizeof(Header) != file->ReadObject(&pfs_header)) {
-        status = Loader::ResultStatus::Error;
-        return;
-    }
+    if (!file.ReadBytes(&pfs_header, sizeof(Header)))
+        return Loader::ResultStatus::Error;
 
     if (pfs_header.magic != Common::MakeMagic('H', 'F', 'S', '0') &&
         pfs_header.magic != Common::MakeMagic('P', 'F', 'S', '0')) {
-        status = Loader::ResultStatus::ErrorInvalidFormat;
-        return;
+        return Loader::ResultStatus::ErrorInvalidFormat;
     }
 
     bool is_hfs = pfs_header.magic == Common::MakeMagic('H', 'F', 'S', '0');
@@ -39,86 +38,99 @@ PartitionFilesystem::PartitionFilesystem(std::shared_ptr<VfsFile> file) {
         sizeof(Header) + (pfs_header.num_entries * entry_size) + pfs_header.strtab_size;
 
     // Actually read in now...
-    std::vector<u8> file_data = file->ReadBytes(metadata_size);
+    file.Seek(offset, SEEK_SET);
+    std::vector<u8> file_data(metadata_size);
 
-    if (file_data.size() != metadata_size) {
-        status = Loader::ResultStatus::Error;
-        return;
-    }
+    if (!file.ReadBytes(file_data.data(), metadata_size))
+        return Loader::ResultStatus::Error;
 
-    size_t total_size = file_data.size();
-    if (total_size < sizeof(Header)) {
-        status = Loader::ResultStatus::Error;
-        return;
-    }
+    Loader::ResultStatus result = Load(file_data);
+    if (result != Loader::ResultStatus::Success)
+        LOG_ERROR(Service_FS, "Failed to load PFS from file {}!", file_path);
+
+    return result;
+}
 
-    memcpy(&pfs_header, file_data.data(), sizeof(Header));
+Loader::ResultStatus PartitionFilesystem::Load(const std::vector<u8>& file_data, size_t offset) {
+    size_t total_size = file_data.size() - offset;
+    if (total_size < sizeof(Header))
+        return Loader::ResultStatus::Error;
+
+    memcpy(&pfs_header, &file_data[offset], sizeof(Header));
     if (pfs_header.magic != Common::MakeMagic('H', 'F', 'S', '0') &&
         pfs_header.magic != Common::MakeMagic('P', 'F', 'S', '0')) {
-        status = Loader::ResultStatus::ErrorInvalidFormat;
-        return;
+        return Loader::ResultStatus::ErrorInvalidFormat;
     }
 
     is_hfs = pfs_header.magic == Common::MakeMagic('H', 'F', 'S', '0');
 
-    size_t entries_offset = sizeof(Header);
+    size_t entries_offset = offset + sizeof(Header);
+    size_t entry_size = is_hfs ? sizeof(HFSEntry) : sizeof(PFSEntry);
     size_t strtab_offset = entries_offset + (pfs_header.num_entries * entry_size);
-    content_offset = strtab_offset + pfs_header.strtab_size;
     for (u16 i = 0; i < pfs_header.num_entries; i++) {
-        FSEntry entry;
-
-        memcpy(&entry, &file_data[entries_offset + (i * entry_size)], sizeof(FSEntry));
-        std::string name(
-            reinterpret_cast<const char*>(&file_data[strtab_offset + entry.strtab_offset]));
+        FileEntry entry;
 
-        pfs_files.emplace_back(
-            std::make_shared<OffsetVfsFile>(file, entry.size, content_offset + entry.offset, name));
+        memcpy(&entry.fs_entry, &file_data[entries_offset + (i * entry_size)], sizeof(FSEntry));
+        entry.name = std::string(reinterpret_cast<const char*>(
+            &file_data[strtab_offset + entry.fs_entry.strtab_offset]));
+        pfs_entries.push_back(std::move(entry));
     }
 
-    status = Loader::ResultStatus::Success;
-}
+    content_offset = strtab_offset + pfs_header.strtab_size;
 
-Loader::ResultStatus PartitionFilesystem::GetStatus() const {
-    return status;
+    return Loader::ResultStatus::Success;
 }
 
-std::vector<std::shared_ptr<VfsFile>> PartitionFilesystem::GetFiles() const {
-    return pfs_files;
+u32 PartitionFilesystem::GetNumEntries() const {
+    return pfs_header.num_entries;
 }
 
-std::vector<std::shared_ptr<VfsDirectory>> PartitionFilesystem::GetSubdirectories() const {
-    return {};
+u64 PartitionFilesystem::GetEntryOffset(u32 index) const {
+    if (index > GetNumEntries())
+        return 0;
+
+    return content_offset + pfs_entries[index].fs_entry.offset;
 }
 
-std::string PartitionFilesystem::GetName() const {
-    return is_hfs ? "HFS0" : "PFS0";
+u64 PartitionFilesystem::GetEntrySize(u32 index) const {
+    if (index > GetNumEntries())
+        return 0;
+
+    return pfs_entries[index].fs_entry.size;
 }
 
-std::shared_ptr<VfsDirectory> PartitionFilesystem::GetParentDirectory() const {
-    // TODO(DarkLordZach): Add support for nested containers.
-    return nullptr;
+std::string PartitionFilesystem::GetEntryName(u32 index) const {
+    if (index > GetNumEntries())
+        return "";
+
+    return pfs_entries[index].name;
 }
 
-void PartitionFilesystem::PrintDebugInfo() const {
-    LOG_DEBUG(Service_FS, "Magic:                  {:.4}", pfs_header.magic);
-    LOG_DEBUG(Service_FS, "Files:                  {}", pfs_header.num_entries);
+u64 PartitionFilesystem::GetFileOffset(const std::string& name) const {
     for (u32 i = 0; i < pfs_header.num_entries; i++) {
-        LOG_DEBUG(Service_FS, " > File {}:              {} (0x{:X} bytes, at 0x{:X})", i,
-                  pfs_files[i]->GetName(), pfs_files[i]->GetSize(),
-                  dynamic_cast<OffsetVfsFile*>(pfs_files[i].get())->GetOffset());
+        if (pfs_entries[i].name == name)
+            return content_offset + pfs_entries[i].fs_entry.offset;
     }
-}
 
-bool PartitionFilesystem::ReplaceFileWithSubdirectory(VirtualFile file, VirtualDir dir) {
-    auto iter = std::find(pfs_files.begin(), pfs_files.end(), file);
-    if (iter == pfs_files.end())
-        return false;
+    return 0;
+}
 
-    pfs_files[iter - pfs_files.begin()] = pfs_files.back();
-    pfs_files.pop_back();
+u64 PartitionFilesystem::GetFileSize(const std::string& name) const {
+    for (u32 i = 0; i < pfs_header.num_entries; i++) {
+        if (pfs_entries[i].name == name)
+            return pfs_entries[i].fs_entry.size;
+    }
 
-    pfs_dirs.emplace_back(dir);
+    return 0;
+}
 
-    return true;
+void PartitionFilesystem::Print() const {
+    LOG_DEBUG(Service_FS, "Magic:                  {}", pfs_header.magic);
+    LOG_DEBUG(Service_FS, "Files:                  {}", pfs_header.num_entries);
+    for (u32 i = 0; i < pfs_header.num_entries; i++) {
+        LOG_DEBUG(Service_FS, " > File {}:              {} (0x{:X} bytes, at 0x{:X})", i,
+                  pfs_entries[i].name.c_str(), pfs_entries[i].fs_entry.size,
+                  GetFileOffset(pfs_entries[i].name));
+    }
 }
 } // namespace FileSys

src/core/file_sys/partition_filesystem.h

@@ -10,7 +10,6 @@
 #include "common/common_funcs.h"
 #include "common/common_types.h"
 #include "common/swap.h"
-#include "core/file_sys/vfs.h"
 
 namespace Loader {
 enum class ResultStatus;
@@ -22,19 +21,19 @@ namespace FileSys {
  * Helper which implements an interface to parse PFS/HFS filesystems.
  * Data can either be loaded from a file path or data with an offset into it.
  */
-class PartitionFilesystem : public ReadOnlyVfsDirectory {
+class PartitionFilesystem {
 public:
-    explicit PartitionFilesystem(std::shared_ptr<VfsFile> file);
-    Loader::ResultStatus GetStatus() const;
+    Loader::ResultStatus Load(const std::string& file_path, size_t offset = 0);
+    Loader::ResultStatus Load(const std::vector<u8>& file_data, size_t offset = 0);
 
-    std::vector<std::shared_ptr<VfsFile>> GetFiles() const override;
-    std::vector<std::shared_ptr<VfsDirectory>> GetSubdirectories() const override;
-    std::string GetName() const override;
-    std::shared_ptr<VfsDirectory> GetParentDirectory() const override;
-    void PrintDebugInfo() const;
+    u32 GetNumEntries() const;
+    u64 GetEntryOffset(u32 index) const;
+    u64 GetEntrySize(u32 index) const;
+    std::string GetEntryName(u32 index) const;
+    u64 GetFileOffset(const std::string& name) const;
+    u64 GetFileSize(const std::string& name) const;
 
-protected:
-    bool ReplaceFileWithSubdirectory(VirtualFile file, VirtualDir dir) override;
+    void Print() const;
 
 private:
     struct Header {
@@ -73,14 +72,16 @@ private:
 
 #pragma pack(pop)
 
-    Loader::ResultStatus status;
+    struct FileEntry {
+        FSEntry fs_entry;
+        std::string name;
+    };
 
     Header pfs_header;
     bool is_hfs;
     size_t content_offset;
 
-    std::vector<VirtualFile> pfs_files;
-    std::vector<VirtualDir> pfs_dirs;
+    std::vector<FileEntry> pfs_entries;
 };
 
 } // namespace FileSys

src/core/file_sys/program_metadata.cpp

@@ -9,30 +9,41 @@
 
 namespace FileSys {
 
-Loader::ResultStatus ProgramMetadata::Load(VirtualFile file) {
-    size_t total_size = static_cast<size_t>(file->GetSize());
-    if (total_size < sizeof(Header))
+Loader::ResultStatus ProgramMetadata::Load(const std::string& file_path) {
+    FileUtil::IOFile file(file_path, "rb");
+    if (!file.IsOpen())
         return Loader::ResultStatus::Error;
 
-    // TODO(DarkLordZach): Use ReadObject when Header/AcidHeader becomes trivially copyable.
-    std::vector<u8> npdm_header_data = file->ReadBytes(sizeof(Header));
-    if (sizeof(Header) != npdm_header_data.size())
-        return Loader::ResultStatus::Error;
-    std::memcpy(&npdm_header, npdm_header_data.data(), sizeof(Header));
+    std::vector<u8> file_data(file.GetSize());
 
-    std::vector<u8> acid_header_data = file->ReadBytes(sizeof(AcidHeader), npdm_header.acid_offset);
-    if (sizeof(AcidHeader) != acid_header_data.size())
+    if (!file.ReadBytes(file_data.data(), file_data.size()))
         return Loader::ResultStatus::Error;
-    std::memcpy(&acid_header, acid_header_data.data(), sizeof(AcidHeader));
 
-    if (sizeof(AciHeader) != file->ReadObject(&aci_header, npdm_header.aci_offset))
-        return Loader::ResultStatus::Error;
+    Loader::ResultStatus result = Load(file_data);
+    if (result != Loader::ResultStatus::Success)
+        LOG_ERROR(Service_FS, "Failed to load NPDM from file {}!", file_path);
 
-    if (sizeof(FileAccessControl) != file->ReadObject(&acid_file_access, acid_header.fac_offset))
-        return Loader::ResultStatus::Error;
-    if (sizeof(FileAccessHeader) != file->ReadObject(&aci_file_access, aci_header.fah_offset))
+    return result;
+}
+
+Loader::ResultStatus ProgramMetadata::Load(const std::vector<u8> file_data, size_t offset) {
+    size_t total_size = static_cast<size_t>(file_data.size() - offset);
+    if (total_size < sizeof(Header))
         return Loader::ResultStatus::Error;
 
+    size_t header_offset = offset;
+    memcpy(&npdm_header, &file_data[offset], sizeof(Header));
+
+    size_t aci_offset = header_offset + npdm_header.aci_offset;
+    size_t acid_offset = header_offset + npdm_header.acid_offset;
+    memcpy(&aci_header, &file_data[aci_offset], sizeof(AciHeader));
+    memcpy(&acid_header, &file_data[acid_offset], sizeof(AcidHeader));
+
+    size_t fac_offset = acid_offset + acid_header.fac_offset;
+    size_t fah_offset = aci_offset + aci_header.fah_offset;
+    memcpy(&acid_file_access, &file_data[fac_offset], sizeof(FileAccessControl));
+    memcpy(&aci_file_access, &file_data[fah_offset], sizeof(FileAccessHeader));
+
     return Loader::ResultStatus::Success;
 }
 

src/core/file_sys/program_metadata.h

@@ -10,7 +10,6 @@
 #include "common/bit_field.h"
 #include "common/common_types.h"
 #include "common/swap.h"
-#include "partition_filesystem.h"
 
 namespace Loader {
 enum class ResultStatus;
@@ -38,7 +37,8 @@ enum class ProgramFilePermission : u64 {
  */
 class ProgramMetadata {
 public:
-    Loader::ResultStatus Load(VirtualFile file);
+    Loader::ResultStatus Load(const std::string& file_path);
+    Loader::ResultStatus Load(const std::vector<u8> file_data, size_t offset = 0);
 
     bool Is64BitProgram() const;
     ProgramAddressSpaceType GetAddressSpaceType() const;
@@ -51,7 +51,6 @@ public:
     void Print() const;
 
 private:
-    // TODO(DarkLordZach): BitField is not trivially copyable.
     struct Header {
         std::array<char, 4> magic;
         std::array<u8, 8> reserved;
@@ -78,7 +77,6 @@ private:
 
     static_assert(sizeof(Header) == 0x80, "NPDM header structure size is wrong");
 
-    // TODO(DarkLordZach): BitField is not trivially copyable.
     struct AcidHeader {
         std::array<u8, 0x100> signature;
         std::array<u8, 0x100> nca_modulus;

src/core/file_sys/romfs_factory.cpp

@@ -0,0 +1,38 @@
+// Copyright 2018 yuzu emulator team
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include <algorithm>
+#include <memory>
+#include "common/common_types.h"
+#include "common/logging/log.h"
+#include "core/file_sys/romfs_factory.h"
+#include "core/file_sys/romfs_filesystem.h"
+
+namespace FileSys {
+
+RomFS_Factory::RomFS_Factory(Loader::AppLoader& app_loader) {
+    // Load the RomFS from the app
+    if (Loader::ResultStatus::Success != app_loader.ReadRomFS(romfs_file, data_offset, data_size)) {
+        LOG_ERROR(Service_FS, "Unable to read RomFS!");
+    }
+}
+
+ResultVal<std::unique_ptr<FileSystemBackend>> RomFS_Factory::Open(const Path& path) {
+    auto archive = std::make_unique<RomFS_FileSystem>(romfs_file, data_offset, data_size);
+    return MakeResult<std::unique_ptr<FileSystemBackend>>(std::move(archive));
+}
+
+ResultCode RomFS_Factory::Format(const Path& path) {
+    LOG_ERROR(Service_FS, "Unimplemented Format archive {}", GetName());
+    // TODO(bunnei): Find the right error code for this
+    return ResultCode(-1);
+}
+
+ResultVal<ArchiveFormatInfo> RomFS_Factory::GetFormatInfo(const Path& path) const {
+    LOG_ERROR(Service_FS, "Unimplemented GetFormatInfo archive {}", GetName());
+    // TODO(bunnei): Find the right error code for this
+    return ResultCode(-1);
+}
+
+} // namespace FileSys

src/core/file_sys/romfs_factory.h

@@ -0,0 +1,35 @@
+// Copyright 2018 yuzu emulator team
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <memory>
+#include <string>
+#include <vector>
+#include "common/common_types.h"
+#include "core/file_sys/filesystem.h"
+#include "core/hle/result.h"
+#include "core/loader/loader.h"
+
+namespace FileSys {
+
+/// File system interface to the RomFS archive
+class RomFS_Factory final : public FileSystemFactory {
+public:
+    explicit RomFS_Factory(Loader::AppLoader& app_loader);
+
+    std::string GetName() const override {
+        return "ArchiveFactory_RomFS";
+    }
+    ResultVal<std::unique_ptr<FileSystemBackend>> Open(const Path& path) override;
+    ResultCode Format(const Path& path) override;
+    ResultVal<ArchiveFormatInfo> GetFormatInfo(const Path& path) const override;
+
+private:
+    std::shared_ptr<FileUtil::IOFile> romfs_file;
+    u64 data_offset;
+    u64 data_size;
+};
+
+} // namespace FileSys

src/core/file_sys/romfs_filesystem.cpp

@@ -0,0 +1,110 @@
+// Copyright 2018 yuzu emulator team
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include <cstring>
+#include <memory>
+#include "common/common_types.h"
+#include "common/logging/log.h"
+#include "core/file_sys/romfs_filesystem.h"
+
+namespace FileSys {
+
+std::string RomFS_FileSystem::GetName() const {
+    return "RomFS";
+}
+
+ResultVal<std::unique_ptr<StorageBackend>> RomFS_FileSystem::OpenFile(const std::string& path,
+                                                                      Mode mode) const {
+    return MakeResult<std::unique_ptr<StorageBackend>>(
+        std::make_unique<RomFS_Storage>(romfs_file, data_offset, data_size));
+}
+
+ResultCode RomFS_FileSystem::DeleteFile(const std::string& path) const {
+    LOG_CRITICAL(Service_FS, "Attempted to delete a file from an ROMFS archive ({}).", GetName());
+    // TODO(bunnei): Use correct error code
+    return ResultCode(-1);
+}
+
+ResultCode RomFS_FileSystem::RenameFile(const std::string& src_path,
+                                        const std::string& dest_path) const {
+    LOG_CRITICAL(Service_FS, "Attempted to rename a file within an ROMFS archive ({}).", GetName());
+    // TODO(wwylele): Use correct error code
+    return ResultCode(-1);
+}
+
+ResultCode RomFS_FileSystem::DeleteDirectory(const Path& path) const {
+    LOG_CRITICAL(Service_FS, "Attempted to delete a directory from an ROMFS archive ({}).",
+                 GetName());
+    // TODO(wwylele): Use correct error code
+    return ResultCode(-1);
+}
+
+ResultCode RomFS_FileSystem::DeleteDirectoryRecursively(const Path& path) const {
+    LOG_CRITICAL(Service_FS, "Attempted to delete a directory from an ROMFS archive ({}).",
+                 GetName());
+    // TODO(wwylele): Use correct error code
+    return ResultCode(-1);
+}
+
+ResultCode RomFS_FileSystem::CreateFile(const std::string& path, u64 size) const {
+    LOG_CRITICAL(Service_FS, "Attempted to create a file in an ROMFS archive ({}).", GetName());
+    // TODO(bunnei): Use correct error code
+    return ResultCode(-1);
+}
+
+ResultCode RomFS_FileSystem::CreateDirectory(const std::string& path) const {
+    LOG_CRITICAL(Service_FS, "Attempted to create a directory in an ROMFS archive ({}).",
+                 GetName());
+    // TODO(wwylele): Use correct error code
+    return ResultCode(-1);
+}
+
+ResultCode RomFS_FileSystem::RenameDirectory(const Path& src_path, const Path& dest_path) const {
+    LOG_CRITICAL(Service_FS, "Attempted to rename a file within an ROMFS archive ({}).", GetName());
+    // TODO(wwylele): Use correct error code
+    return ResultCode(-1);
+}
+
+ResultVal<std::unique_ptr<DirectoryBackend>> RomFS_FileSystem::OpenDirectory(
+    const std::string& path) const {
+    LOG_WARNING(Service_FS, "Opening Directory in a ROMFS archive");
+    return MakeResult<std::unique_ptr<DirectoryBackend>>(std::make_unique<ROMFSDirectory>());
+}
+
+u64 RomFS_FileSystem::GetFreeSpaceSize() const {
+    LOG_WARNING(Service_FS, "Attempted to get the free space in an ROMFS archive");
+    return 0;
+}
+
+ResultVal<FileSys::EntryType> RomFS_FileSystem::GetEntryType(const std::string& path) const {
+    LOG_CRITICAL(Service_FS, "Called within an ROMFS archive (path {}).", path);
+    // TODO(wwylele): Use correct error code
+    return ResultCode(-1);
+}
+
+ResultVal<size_t> RomFS_Storage::Read(const u64 offset, const size_t length, u8* buffer) const {
+    LOG_TRACE(Service_FS, "called offset={}, length={}", offset, length);
+    romfs_file->Seek(data_offset + offset, SEEK_SET);
+    size_t read_length = (size_t)std::min((u64)length, data_size - offset);
+
+    return MakeResult<size_t>(romfs_file->ReadBytes(buffer, read_length));
+}
+
+ResultVal<size_t> RomFS_Storage::Write(const u64 offset, const size_t length, const bool flush,
+                                       const u8* buffer) const {
+    LOG_ERROR(Service_FS, "Attempted to write to ROMFS file");
+    // TODO(Subv): Find error code
+    return MakeResult<size_t>(0);
+}
+
+u64 RomFS_Storage::GetSize() const {
+    return data_size;
+}
+
+bool RomFS_Storage::SetSize(const u64 size) const {
+    LOG_ERROR(Service_FS, "Attempted to set the size of an ROMFS file");
+    return false;
+}
+
+} // namespace FileSys

src/core/file_sys/romfs_filesystem.h

@@ -0,0 +1,85 @@
+// Copyright 2018 yuzu emulator team
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <cstddef>
+#include <memory>
+#include <string>
+#include <vector>
+#include "common/common_types.h"
+#include "common/file_util.h"
+#include "core/file_sys/directory.h"
+#include "core/file_sys/filesystem.h"
+#include "core/file_sys/storage.h"
+#include "core/hle/result.h"
+
+namespace FileSys {
+
+/**
+ * Helper which implements an interface to deal with Switch .istorage ROMFS images used in some
+ * archives This should be subclassed by concrete archive types, which will provide the input data
+ * (load the raw ROMFS archive) and override any required methods
+ */
+class RomFS_FileSystem : public FileSystemBackend {
+public:
+    RomFS_FileSystem(std::shared_ptr<FileUtil::IOFile> file, u64 offset, u64 size)
+        : romfs_file(file), data_offset(offset), data_size(size) {}
+
+    std::string GetName() const override;
+
+    ResultVal<std::unique_ptr<StorageBackend>> OpenFile(const std::string& path,
+                                                        Mode mode) const override;
+    ResultCode DeleteFile(const std::string& path) const override;
+    ResultCode RenameFile(const std::string& src_path, const std::string& dest_path) const override;
+    ResultCode DeleteDirectory(const Path& path) const override;
+    ResultCode DeleteDirectoryRecursively(const Path& path) const override;
+    ResultCode CreateFile(const std::string& path, u64 size) const override;
+    ResultCode CreateDirectory(const std::string& path) const override;
+    ResultCode RenameDirectory(const Path& src_path, const Path& dest_path) const override;
+    ResultVal<std::unique_ptr<DirectoryBackend>> OpenDirectory(
+        const std::string& path) const override;
+    u64 GetFreeSpaceSize() const override;
+    ResultVal<EntryType> GetEntryType(const std::string& path) const override;
+
+protected:
+    std::shared_ptr<FileUtil::IOFile> romfs_file;
+    u64 data_offset;
+    u64 data_size;
+};
+
+class RomFS_Storage : public StorageBackend {
+public:
+    RomFS_Storage(std::shared_ptr<FileUtil::IOFile> file, u64 offset, u64 size)
+        : romfs_file(file), data_offset(offset), data_size(size) {}
+
+    ResultVal<size_t> Read(u64 offset, size_t length, u8* buffer) const override;
+    ResultVal<size_t> Write(u64 offset, size_t length, bool flush, const u8* buffer) const override;
+    u64 GetSize() const override;
+    bool SetSize(u64 size) const override;
+    bool Close() const override {
+        return false;
+    }
+    void Flush() const override {}
+
+private:
+    std::shared_ptr<FileUtil::IOFile> romfs_file;
+    u64 data_offset;
+    u64 data_size;
+};
+
+class ROMFSDirectory : public DirectoryBackend {
+public:
+    u64 Read(const u64 count, Entry* entries) override {
+        return 0;
+    }
+    u64 GetEntryCount() const override {
+        return 0;
+    }
+    bool Close() const override {
+        return false;
+    }
+};
+
+} // namespace FileSys

src/core/file_sys/savedata_factory.cpp

@@ -0,0 +1,54 @@
+// Copyright 2018 yuzu emulator team
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include <memory>
+#include "common/common_types.h"
+#include "common/logging/log.h"
+#include "core/core.h"
+#include "core/file_sys/disk_filesystem.h"
+#include "core/file_sys/savedata_factory.h"
+#include "core/hle/kernel/process.h"
+
+namespace FileSys {
+
+SaveData_Factory::SaveData_Factory(std::string nand_directory)
+    : nand_directory(std::move(nand_directory)) {}
+
+ResultVal<std::unique_ptr<FileSystemBackend>> SaveData_Factory::Open(const Path& path) {
+    std::string save_directory = GetFullPath();
+    // Return an error if the save data doesn't actually exist.
+    if (!FileUtil::IsDirectory(save_directory)) {
+        // TODO(Subv): Find out correct error code.
+        return ResultCode(-1);
+    }
+
+    auto archive = std::make_unique<Disk_FileSystem>(save_directory);
+    return MakeResult<std::unique_ptr<FileSystemBackend>>(std::move(archive));
+}
+
+ResultCode SaveData_Factory::Format(const Path& path) {
+    LOG_WARNING(Service_FS, "Format archive {}", GetName());
+    // Create the save data directory.
+    if (!FileUtil::CreateFullPath(GetFullPath())) {
+        // TODO(Subv): Find the correct error code.
+        return ResultCode(-1);
+    }
+
+    return RESULT_SUCCESS;
+}
+
+ResultVal<ArchiveFormatInfo> SaveData_Factory::GetFormatInfo(const Path& path) const {
+    LOG_ERROR(Service_FS, "Unimplemented GetFormatInfo archive {}", GetName());
+    // TODO(bunnei): Find the right error code for this
+    return ResultCode(-1);
+}
+
+std::string SaveData_Factory::GetFullPath() const {
+    u64 title_id = Core::CurrentProcess()->program_id;
+    // TODO(Subv): Somehow obtain this value.
+    u32 user = 0;
+    return fmt::format("{}save/{:016X}/{:08X}/", nand_directory, title_id, user);
+}
+
+} // namespace FileSys

src/core/file_sys/savedata_factory.h

@@ -0,0 +1,33 @@
+// Copyright 2018 yuzu emulator team
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <memory>
+#include <string>
+#include "common/common_types.h"
+#include "core/file_sys/filesystem.h"
+#include "core/hle/result.h"
+
+namespace FileSys {
+
+/// File system interface to the SaveData archive
+class SaveData_Factory final : public FileSystemFactory {
+public:
+    explicit SaveData_Factory(std::string nand_directory);
+
+    std::string GetName() const override {
+        return "SaveData_Factory";
+    }
+    ResultVal<std::unique_ptr<FileSystemBackend>> Open(const Path& path) override;
+    ResultCode Format(const Path& path) override;
+    ResultVal<ArchiveFormatInfo> GetFormatInfo(const Path& path) const override;
+
+private:
+    std::string nand_directory;
+
+    std::string GetFullPath() const;
+};
+
+} // namespace FileSys

src/core/file_sys/sdmc_factory.cpp

@@ -0,0 +1,39 @@
+// Copyright 2018 yuzu emulator team
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include <memory>
+#include "common/common_types.h"
+#include "common/logging/log.h"
+#include "common/string_util.h"
+#include "core/core.h"
+#include "core/file_sys/disk_filesystem.h"
+#include "core/file_sys/sdmc_factory.h"
+
+namespace FileSys {
+
+SDMC_Factory::SDMC_Factory(std::string sd_directory) : sd_directory(std::move(sd_directory)) {}
+
+ResultVal<std::unique_ptr<FileSystemBackend>> SDMC_Factory::Open(const Path& path) {
+    // Create the SD Card directory if it doesn't already exist.
+    if (!FileUtil::IsDirectory(sd_directory)) {
+        FileUtil::CreateFullPath(sd_directory);
+    }
+
+    auto archive = std::make_unique<Disk_FileSystem>(sd_directory);
+    return MakeResult<std::unique_ptr<FileSystemBackend>>(std::move(archive));
+}
+
+ResultCode SDMC_Factory::Format(const Path& path) {
+    LOG_ERROR(Service_FS, "Unimplemented Format archive {}", GetName());
+    // TODO(Subv): Find the right error code for this
+    return ResultCode(-1);
+}
+
+ResultVal<ArchiveFormatInfo> SDMC_Factory::GetFormatInfo(const Path& path) const {
+    LOG_ERROR(Service_FS, "Unimplemented GetFormatInfo archive {}", GetName());
+    // TODO(bunnei): Find the right error code for this
+    return ResultCode(-1);
+}
+
+} // namespace FileSys

src/core/file_sys/sdmc_factory.h

@@ -0,0 +1,31 @@
+// Copyright 2018 yuzu emulator team
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <memory>
+#include <string>
+#include "common/common_types.h"
+#include "core/file_sys/filesystem.h"
+#include "core/hle/result.h"
+
+namespace FileSys {
+
+/// File system interface to the SDCard archive
+class SDMC_Factory final : public FileSystemFactory {
+public:
+    explicit SDMC_Factory(std::string sd_directory);
+
+    std::string GetName() const override {
+        return "SDMC_Factory";
+    }
+    ResultVal<std::unique_ptr<FileSystemBackend>> Open(const Path& path) override;
+    ResultCode Format(const Path& path) override;
+    ResultVal<ArchiveFormatInfo> GetFormatInfo(const Path& path) const override;
+
+private:
+    std::string sd_directory;
+};
+
+} // namespace FileSys

src/core/file_sys/vfs.cpp

@@ -1,187 +0,0 @@
-// Copyright 2018 yuzu emulator team
-// Licensed under GPLv2 or any later version
-// Refer to the license.txt file included.
-
-#include <algorithm>
-#include <numeric>
-#include "common/file_util.h"
-#include "core/file_sys/vfs.h"
-
-namespace FileSys {
-
-VfsFile::~VfsFile() = default;
-
-std::string VfsFile::GetExtension() const {
-    return FileUtil::GetExtensionFromFilename(GetName());
-}
-
-VfsDirectory::~VfsDirectory() = default;
-
-boost::optional<u8> VfsFile::ReadByte(size_t offset) const {
-    u8 out{};
-    size_t size = Read(&out, 1, offset);
-    if (size == 1)
-        return out;
-
-    return boost::none;
-}
-
-std::vector<u8> VfsFile::ReadBytes(size_t size, size_t offset) const {
-    std::vector<u8> out(size);
-    size_t read_size = Read(out.data(), size, offset);
-    out.resize(read_size);
-    return out;
-}
-
-std::vector<u8> VfsFile::ReadAllBytes() const {
-    return ReadBytes(GetSize());
-}
-
-bool VfsFile::WriteByte(u8 data, size_t offset) {
-    return Write(&data, 1, offset) == 1;
-}
-
-size_t VfsFile::WriteBytes(std::vector<u8> data, size_t offset) {
-    return Write(data.data(), data.size(), offset);
-}
-
-std::shared_ptr<VfsFile> VfsDirectory::GetFileRelative(const std::string& path) const {
-    auto vec = FileUtil::SplitPathComponents(path);
-    vec.erase(std::remove_if(vec.begin(), vec.end(), [](const auto& str) { return str.empty(); }),
-              vec.end());
-    if (vec.empty())
-        return nullptr;
-    if (vec.size() == 1)
-        return GetFile(vec[0]);
-    auto dir = GetSubdirectory(vec[0]);
-    for (size_t i = 1; i < vec.size() - 1; ++i) {
-        if (dir == nullptr)
-            return nullptr;
-        dir = dir->GetSubdirectory(vec[i]);
-    }
-    if (dir == nullptr)
-        return nullptr;
-    return dir->GetFile(vec.back());
-}
-
-std::shared_ptr<VfsFile> VfsDirectory::GetFileAbsolute(const std::string& path) const {
-    if (IsRoot())
-        return GetFileRelative(path);
-
-    return GetParentDirectory()->GetFileAbsolute(path);
-}
-
-std::shared_ptr<VfsDirectory> VfsDirectory::GetDirectoryRelative(const std::string& path) const {
-    auto vec = FileUtil::SplitPathComponents(path);
-    vec.erase(std::remove_if(vec.begin(), vec.end(), [](const auto& str) { return str.empty(); }),
-              vec.end());
-    if (vec.empty())
-        // return std::shared_ptr<VfsDirectory>(this);
-        return nullptr;
-    auto dir = GetSubdirectory(vec[0]);
-    for (size_t i = 1; i < vec.size(); ++i) {
-        dir = dir->GetSubdirectory(vec[i]);
-    }
-    return dir;
-}
-
-std::shared_ptr<VfsDirectory> VfsDirectory::GetDirectoryAbsolute(const std::string& path) const {
-    if (IsRoot())
-        return GetDirectoryRelative(path);
-
-    return GetParentDirectory()->GetDirectoryAbsolute(path);
-}
-
-std::shared_ptr<VfsFile> VfsDirectory::GetFile(const std::string& name) const {
-    const auto& files = GetFiles();
-    const auto iter = std::find_if(files.begin(), files.end(),
-                                   [&name](const auto& file1) { return name == file1->GetName(); });
-    return iter == files.end() ? nullptr : *iter;
-}
-
-std::shared_ptr<VfsDirectory> VfsDirectory::GetSubdirectory(const std::string& name) const {
-    const auto& subs = GetSubdirectories();
-    const auto iter = std::find_if(subs.begin(), subs.end(),
-                                   [&name](const auto& file1) { return name == file1->GetName(); });
-    return iter == subs.end() ? nullptr : *iter;
-}
-
-bool VfsDirectory::IsRoot() const {
-    return GetParentDirectory() == nullptr;
-}
-
-size_t VfsDirectory::GetSize() const {
-    const auto& files = GetFiles();
-    const auto file_total =
-        std::accumulate(files.begin(), files.end(), 0ull,
-                        [](const auto& f1, const auto& f2) { return f1 + f2->GetSize(); });
-
-    const auto& sub_dir = GetSubdirectories();
-    const auto subdir_total =
-        std::accumulate(sub_dir.begin(), sub_dir.end(), 0ull,
-                        [](const auto& f1, const auto& f2) { return f1 + f2->GetSize(); });
-
-    return file_total + subdir_total;
-}
-
-bool VfsDirectory::DeleteSubdirectoryRecursive(const std::string& name) {
-    auto dir = GetSubdirectory(name);
-    if (dir == nullptr)
-        return false;
-
-    bool success = true;
-    for (const auto& file : dir->GetFiles()) {
-        if (!DeleteFile(file->GetName()))
-            success = false;
-    }
-
-    for (const auto& sdir : dir->GetSubdirectories()) {
-        if (!dir->DeleteSubdirectoryRecursive(sdir->GetName()))
-            success = false;
-    }
-
-    return success;
-}
-
-bool VfsDirectory::Copy(const std::string& src, const std::string& dest) {
-    const auto f1 = GetFile(src);
-    auto f2 = CreateFile(dest);
-    if (f1 == nullptr || f2 == nullptr)
-        return false;
-
-    if (!f2->Resize(f1->GetSize())) {
-        DeleteFile(dest);
-        return false;
-    }
-
-    return f2->WriteBytes(f1->ReadAllBytes()) == f1->GetSize();
-}
-
-bool ReadOnlyVfsDirectory::IsWritable() const {
-    return false;
-}
-
-bool ReadOnlyVfsDirectory::IsReadable() const {
-    return true;
-}
-
-std::shared_ptr<VfsDirectory> ReadOnlyVfsDirectory::CreateSubdirectory(const std::string& name) {
-    return nullptr;
-}
-
-std::shared_ptr<VfsFile> ReadOnlyVfsDirectory::CreateFile(const std::string& name) {
-    return nullptr;
-}
-
-bool ReadOnlyVfsDirectory::DeleteSubdirectory(const std::string& name) {
-    return false;
-}
-
-bool ReadOnlyVfsDirectory::DeleteFile(const std::string& name) {
-    return false;
-}
-
-bool ReadOnlyVfsDirectory::Rename(const std::string& name) {
-    return false;
-}
-} // namespace FileSys

src/core/file_sys/vfs.h

@@ -1,220 +0,0 @@
-// Copyright 2018 yuzu emulator team
-// Licensed under GPLv2 or any later version
-// Refer to the license.txt file included.
-
-#pragma once
-
-#include <memory>
-#include <string>
-#include <type_traits>
-#include <vector>
-#include "boost/optional.hpp"
-#include "common/common_types.h"
-#include "common/file_util.h"
-
-namespace FileSys {
-struct VfsFile;
-struct VfsDirectory;
-
-// Convenience typedefs to use VfsDirectory and VfsFile
-using VirtualDir = std::shared_ptr<FileSys::VfsDirectory>;
-using VirtualFile = std::shared_ptr<FileSys::VfsFile>;
-
-// A class representing a file in an abstract filesystem.
-struct VfsFile : NonCopyable {
-    virtual ~VfsFile();
-
-    // Retrieves the file name.
-    virtual std::string GetName() const = 0;
-    // Retrieves the extension of the file name.
-    virtual std::string GetExtension() const;
-    // Retrieves the size of the file.
-    virtual size_t GetSize() const = 0;
-    // Resizes the file to new_size. Returns whether or not the operation was successful.
-    virtual bool Resize(size_t new_size) = 0;
-    // Gets a pointer to the directory containing this file, returning nullptr if there is none.
-    virtual std::shared_ptr<VfsDirectory> GetContainingDirectory() const = 0;
-
-    // Returns whether or not the file can be written to.
-    virtual bool IsWritable() const = 0;
-    // Returns whether or not the file can be read from.
-    virtual bool IsReadable() const = 0;
-
-    // The primary method of reading from the file. Reads length bytes into data starting at offset
-    // into file. Returns number of bytes successfully read.
-    virtual size_t Read(u8* data, size_t length, size_t offset = 0) const = 0;
-    // The primary method of writing to the file. Writes length bytes from data starting at offset
-    // into file. Returns number of bytes successfully written.
-    virtual size_t Write(const u8* data, size_t length, size_t offset = 0) = 0;
-
-    // Reads exactly one byte at the offset provided, returning boost::none on error.
-    virtual boost::optional<u8> ReadByte(size_t offset = 0) const;
-    // Reads size bytes starting at offset in file into a vector.
-    virtual std::vector<u8> ReadBytes(size_t size, size_t offset = 0) const;
-    // Reads all the bytes from the file into a vector. Equivalent to 'file->Read(file->GetSize(),
-    // 0)'
-    virtual std::vector<u8> ReadAllBytes() const;
-
-    // Reads an array of type T, size number_elements starting at offset.
-    // Returns the number of bytes (sizeof(T)*number_elements) read successfully.
-    template <typename T>
-    size_t ReadArray(T* data, size_t number_elements, size_t offset = 0) const {
-        static_assert(std::is_trivially_copyable<T>::value,
-                      "Data type must be trivially copyable.");
-
-        return Read(reinterpret_cast<u8*>(data), number_elements * sizeof(T), offset);
-    }
-
-    // Reads size bytes into the memory starting at data starting at offset into the file.
-    // Returns the number of bytes read successfully.
-    template <typename T>
-    size_t ReadBytes(T* data, size_t size, size_t offset = 0) const {
-        static_assert(std::is_trivially_copyable<T>::value,
-                      "Data type must be trivially copyable.");
-        return Read(reinterpret_cast<u8*>(data), size, offset);
-    }
-
-    // Reads one object of type T starting at offset in file.
-    // Returns the number of bytes read successfully (sizeof(T)).
-    template <typename T>
-    size_t ReadObject(T* data, size_t offset = 0) const {
-        static_assert(std::is_trivially_copyable<T>::value,
-                      "Data type must be trivially copyable.");
-        return Read(reinterpret_cast<u8*>(data), sizeof(T), offset);
-    }
-
-    // Writes exactly one byte to offset in file and retuns whether or not the byte was written
-    // successfully.
-    virtual bool WriteByte(u8 data, size_t offset = 0);
-    // Writes a vector of bytes to offset in file and returns the number of bytes successfully
-    // written.
-    virtual size_t WriteBytes(std::vector<u8> data, size_t offset = 0);
-
-    // Writes an array of type T, size number_elements to offset in file.
-    // Returns the number of bytes (sizeof(T)*number_elements) written successfully.
-    template <typename T>
-    size_t WriteArray(T* data, size_t number_elements, size_t offset = 0) {
-        static_assert(std::is_trivially_copyable<T>::value,
-                      "Data type must be trivially copyable.");
-
-        return Write(data, number_elements * sizeof(T), offset);
-    }
-
-    // Writes size bytes starting at memory location data to offset in file.
-    // Returns the number of bytes written successfully.
-    template <typename T>
-    size_t WriteBytes(T* data, size_t size, size_t offset = 0) {
-        static_assert(std::is_trivially_copyable<T>::value,
-                      "Data type must be trivially copyable.");
-        return Write(reinterpret_cast<u8*>(data), size, offset);
-    }
-
-    // Writes one object of type T to offset in file.
-    // Returns the number of bytes written successfully (sizeof(T)).
-    template <typename T>
-    size_t WriteObject(const T& data, size_t offset = 0) {
-        static_assert(std::is_trivially_copyable<T>::value,
-                      "Data type must be trivially copyable.");
-        return Write(&data, sizeof(T), offset);
-    }
-
-    // Renames the file to name. Returns whether or not the operation was successsful.
-    virtual bool Rename(const std::string& name) = 0;
-};
-
-// A class representing a directory in an abstract filesystem.
-struct VfsDirectory : NonCopyable {
-    virtual ~VfsDirectory();
-
-    // Retrives the file located at path as if the current directory was root. Returns nullptr if
-    // not found.
-    virtual std::shared_ptr<VfsFile> GetFileRelative(const std::string& path) const;
-    // Calls GetFileRelative(path) on the root of the current directory.
-    virtual std::shared_ptr<VfsFile> GetFileAbsolute(const std::string& path) const;
-
-    // Retrives the directory located at path as if the current directory was root. Returns nullptr
-    // if not found.
-    virtual std::shared_ptr<VfsDirectory> GetDirectoryRelative(const std::string& path) const;
-    // Calls GetDirectoryRelative(path) on the root of the current directory.
-    virtual std::shared_ptr<VfsDirectory> GetDirectoryAbsolute(const std::string& path) const;
-
-    // Returns a vector containing all of the files in this directory.
-    virtual std::vector<std::shared_ptr<VfsFile>> GetFiles() const = 0;
-    // Returns the file with filename matching name. Returns nullptr if directory dosen't have a
-    // file with name.
-    virtual std::shared_ptr<VfsFile> GetFile(const std::string& name) const;
-
-    // Returns a vector containing all of the subdirectories in this directory.
-    virtual std::vector<std::shared_ptr<VfsDirectory>> GetSubdirectories() const = 0;
-    // Returns the directory with name matching name. Returns nullptr if directory dosen't have a
-    // directory with name.
-    virtual std::shared_ptr<VfsDirectory> GetSubdirectory(const std::string& name) const;
-
-    // Returns whether or not the directory can be written to.
-    virtual bool IsWritable() const = 0;
-    // Returns whether of not the directory can be read from.
-    virtual bool IsReadable() const = 0;
-
-    // Returns whether or not the directory is the root of the current file tree.
-    virtual bool IsRoot() const;
-
-    // Returns the name of the directory.
-    virtual std::string GetName() const = 0;
-    // Returns the total size of all files and subdirectories in this directory.
-    virtual size_t GetSize() const;
-    // Returns the parent directory of this directory. Returns nullptr if this directory is root or
-    // has no parent.
-    virtual std::shared_ptr<VfsDirectory> GetParentDirectory() const = 0;
-
-    // Creates a new subdirectory with name name. Returns a pointer to the new directory or nullptr
-    // if the operation failed.
-    virtual std::shared_ptr<VfsDirectory> CreateSubdirectory(const std::string& name) = 0;
-    // Creates a new file with name name. Returns a pointer to the new file or nullptr if the
-    // operation failed.
-    virtual std::shared_ptr<VfsFile> CreateFile(const std::string& name) = 0;
-
-    // Deletes the subdirectory with name and returns true on success.
-    virtual bool DeleteSubdirectory(const std::string& name) = 0;
-    // Deletes all subdirectories and files of subdirectory with name recirsively and then deletes
-    // the subdirectory. Returns true on success.
-    virtual bool DeleteSubdirectoryRecursive(const std::string& name);
-    // Returnes whether or not the file with name name was deleted successfully.
-    virtual bool DeleteFile(const std::string& name) = 0;
-
-    // Returns whether or not this directory was renamed to name.
-    virtual bool Rename(const std::string& name) = 0;
-
-    // Returns whether or not the file with name src was successfully copied to a new file with name
-    // dest.
-    virtual bool Copy(const std::string& src, const std::string& dest);
-
-    // Interprets the file with name file instead as a directory of type directory.
-    // The directory must have a constructor that takes a single argument of type
-    // std::shared_ptr<VfsFile>. Allows to reinterpret container files (i.e NCA, zip, XCI, etc) as a
-    // subdirectory in one call.
-    template <typename Directory>
-    bool InterpretAsDirectory(const std::string& file) {
-        auto file_p = GetFile(file);
-        if (file_p == nullptr)
-            return false;
-        return ReplaceFileWithSubdirectory(file, std::make_shared<Directory>(file_p));
-    }
-
-protected:
-    // Backend for InterpretAsDirectory.
-    // Removes all references to file and adds a reference to dir in the directory's implementation.
-    virtual bool ReplaceFileWithSubdirectory(VirtualFile file, VirtualDir dir) = 0;
-};
-
-// A convenience partial-implementation of VfsDirectory that stubs out methods that should only work
-// if writable. This is to avoid redundant empty methods everywhere.
-struct ReadOnlyVfsDirectory : public VfsDirectory {
-    bool IsWritable() const override;
-    bool IsReadable() const override;
-    std::shared_ptr<VfsDirectory> CreateSubdirectory(const std::string& name) override;
-    std::shared_ptr<VfsFile> CreateFile(const std::string& name) override;
-    bool DeleteSubdirectory(const std::string& name) override;
-    bool DeleteFile(const std::string& name) override;
-    bool Rename(const std::string& name) override;
-};
-} // namespace FileSys

src/core/file_sys/vfs_offset.cpp

@@ -1,92 +0,0 @@
-// Copyright 2018 yuzu emulator team
-// Licensed under GPLv2 or any later version
-// Refer to the license.txt file included.
-
-#include "core/file_sys/vfs_offset.h"
-
-namespace FileSys {
-
-OffsetVfsFile::OffsetVfsFile(std::shared_ptr<VfsFile> file_, size_t size_, size_t offset_,
-                             const std::string& name_)
-    : file(file_), offset(offset_), size(size_), name(name_) {}
-
-std::string OffsetVfsFile::GetName() const {
-    return name.empty() ? file->GetName() : name;
-}
-
-size_t OffsetVfsFile::GetSize() const {
-    return size;
-}
-
-bool OffsetVfsFile::Resize(size_t new_size) {
-    if (offset + new_size < file->GetSize()) {
-        size = new_size;
-    } else {
-        auto res = file->Resize(offset + new_size);
-        if (!res)
-            return false;
-        size = new_size;
-    }
-
-    return true;
-}
-
-std::shared_ptr<VfsDirectory> OffsetVfsFile::GetContainingDirectory() const {
-    return file->GetContainingDirectory();
-}
-
-bool OffsetVfsFile::IsWritable() const {
-    return file->IsWritable();
-}
-
-bool OffsetVfsFile::IsReadable() const {
-    return file->IsReadable();
-}
-
-size_t OffsetVfsFile::Read(u8* data, size_t length, size_t r_offset) const {
-    return file->Read(data, TrimToFit(length, r_offset), offset + r_offset);
-}
-
-size_t OffsetVfsFile::Write(const u8* data, size_t length, size_t r_offset) {
-    return file->Write(data, TrimToFit(length, r_offset), offset + r_offset);
-}
-
-boost::optional<u8> OffsetVfsFile::ReadByte(size_t r_offset) const {
-    if (r_offset < size)
-        return file->ReadByte(offset + r_offset);
-
-    return boost::none;
-}
-
-std::vector<u8> OffsetVfsFile::ReadBytes(size_t r_size, size_t r_offset) const {
-    return file->ReadBytes(TrimToFit(r_size, r_offset), offset + r_offset);
-}
-
-std::vector<u8> OffsetVfsFile::ReadAllBytes() const {
-    return file->ReadBytes(size, offset);
-}
-
-bool OffsetVfsFile::WriteByte(u8 data, size_t r_offset) {
-    if (r_offset < size)
-        return file->WriteByte(data, offset + r_offset);
-
-    return false;
-}
-
-size_t OffsetVfsFile::WriteBytes(std::vector<u8> data, size_t r_offset) {
-    return file->Write(data.data(), TrimToFit(data.size(), r_offset), offset + r_offset);
-}
-
-bool OffsetVfsFile::Rename(const std::string& name) {
-    return file->Rename(name);
-}
-
-size_t OffsetVfsFile::GetOffset() const {
-    return offset;
-}
-
-size_t OffsetVfsFile::TrimToFit(size_t r_size, size_t r_offset) const {
-    return std::max<size_t>(std::min<size_t>(size - r_offset, r_size), 0);
-}
-
-} // namespace FileSys

src/core/file_sys/vfs_offset.h

@@ -1,46 +0,0 @@
-// Copyright 2018 yuzu emulator team
-// Licensed under GPLv2 or any later version
-// Refer to the license.txt file included.
-
-#pragma once
-
-#include "core/file_sys/vfs.h"
-
-namespace FileSys {
-
-// An implementation of VfsFile that wraps around another VfsFile at a certain offset.
-// Similar to seeking to an offset.
-// If the file is writable, operations that would write past the end of the offset file will expand
-// the size of this wrapper.
-struct OffsetVfsFile : public VfsFile {
-    OffsetVfsFile(std::shared_ptr<VfsFile> file, size_t size, size_t offset = 0,
-                  const std::string& new_name = "");
-
-    std::string GetName() const override;
-    size_t GetSize() const override;
-    bool Resize(size_t new_size) override;
-    std::shared_ptr<VfsDirectory> GetContainingDirectory() const override;
-    bool IsWritable() const override;
-    bool IsReadable() const override;
-    size_t Read(u8* data, size_t length, size_t offset) const override;
-    size_t Write(const u8* data, size_t length, size_t offset) override;
-    boost::optional<u8> ReadByte(size_t offset) const override;
-    std::vector<u8> ReadBytes(size_t size, size_t offset) const override;
-    std::vector<u8> ReadAllBytes() const override;
-    bool WriteByte(u8 data, size_t offset) override;
-    size_t WriteBytes(std::vector<u8> data, size_t offset) override;
-
-    bool Rename(const std::string& name) override;
-
-    size_t GetOffset() const;
-
-private:
-    size_t TrimToFit(size_t r_size, size_t r_offset) const;
-
-    std::shared_ptr<VfsFile> file;
-    size_t offset;
-    size_t size;
-    std::string name;
-};
-
-} // namespace FileSys

src/core/file_sys/vfs_real.cpp

@@ -1,168 +0,0 @@
-// Copyright 2018 yuzu emulator team
-// Licensed under GPLv2 or any later version
-// Refer to the license.txt file included.
-
-#include "common/common_paths.h"
-#include "common/logging/log.h"
-#include "core/file_sys/vfs_real.h"
-
-namespace FileSys {
-
-static std::string PermissionsToCharArray(Mode perms) {
-    std::string out;
-    switch (perms) {
-    case Mode::Read:
-        out += "r";
-        break;
-    case Mode::Write:
-        out += "r+";
-        break;
-    case Mode::Append:
-        out += "a";
-        break;
-    }
-    return out + "b";
-}
-
-RealVfsFile::RealVfsFile(const std::string& path_, Mode perms_)
-    : backing(path_, PermissionsToCharArray(perms_).c_str()), path(path_),
-      parent_path(FileUtil::GetParentPath(path_)),
-      path_components(FileUtil::SplitPathComponents(path_)),
-      parent_components(FileUtil::SliceVector(path_components, 0, path_components.size() - 1)),
-      perms(perms_) {}
-
-std::string RealVfsFile::GetName() const {
-    return path_components.back();
-}
-
-size_t RealVfsFile::GetSize() const {
-    return backing.GetSize();
-}
-
-bool RealVfsFile::Resize(size_t new_size) {
-    return backing.Resize(new_size);
-}
-
-std::shared_ptr<VfsDirectory> RealVfsFile::GetContainingDirectory() const {
-    return std::make_shared<RealVfsDirectory>(parent_path, perms);
-}
-
-bool RealVfsFile::IsWritable() const {
-    return perms == Mode::Append || perms == Mode::Write;
-}
-
-bool RealVfsFile::IsReadable() const {
-    return perms == Mode::Read || perms == Mode::Write;
-}
-
-size_t RealVfsFile::Read(u8* data, size_t length, size_t offset) const {
-    if (!backing.Seek(offset, SEEK_SET))
-        return 0;
-    return backing.ReadBytes(data, length);
-}
-
-size_t RealVfsFile::Write(const u8* data, size_t length, size_t offset) {
-    if (!backing.Seek(offset, SEEK_SET))
-        return 0;
-    return backing.WriteBytes(data, length);
-}
-
-bool RealVfsFile::Rename(const std::string& name) {
-    const auto out = FileUtil::Rename(GetName(), name);
-    path = parent_path + DIR_SEP + name;
-    path_components = parent_components;
-    path_components.push_back(name);
-    backing = FileUtil::IOFile(path, PermissionsToCharArray(perms).c_str());
-    return out;
-}
-
-RealVfsDirectory::RealVfsDirectory(const std::string& path_, Mode perms_)
-    : path(FileUtil::RemoveTrailingSlash(path_)), parent_path(FileUtil::GetParentPath(path)),
-      path_components(FileUtil::SplitPathComponents(path)),
-      parent_components(FileUtil::SliceVector(path_components, 0, path_components.size() - 1)),
-      perms(perms_) {
-    if (!FileUtil::Exists(path) && (perms == Mode::Write || perms == Mode::Append))
-        FileUtil::CreateDir(path);
-    unsigned size;
-    if (perms != Mode::Append) {
-        FileUtil::ForeachDirectoryEntry(
-            &size, path,
-            [this](unsigned* entries_out, const std::string& directory,
-                   const std::string& filename) {
-                std::string full_path = directory + DIR_SEP + filename;
-                if (FileUtil::IsDirectory(full_path))
-                    subdirectories.emplace_back(
-                        std::make_shared<RealVfsDirectory>(full_path, perms));
-                else
-                    files.emplace_back(std::make_shared<RealVfsFile>(full_path, perms));
-                return true;
-            });
-    }
-}
-
-std::vector<std::shared_ptr<VfsFile>> RealVfsDirectory::GetFiles() const {
-    return std::vector<std::shared_ptr<VfsFile>>(files);
-}
-
-std::vector<std::shared_ptr<VfsDirectory>> RealVfsDirectory::GetSubdirectories() const {
-    return std::vector<std::shared_ptr<VfsDirectory>>(subdirectories);
-}
-
-bool RealVfsDirectory::IsWritable() const {
-    return perms == Mode::Write || perms == Mode::Append;
-}
-
-bool RealVfsDirectory::IsReadable() const {
-    return perms == Mode::Read || perms == Mode::Write;
-}
-
-std::string RealVfsDirectory::GetName() const {
-    return path_components.back();
-}
-
-std::shared_ptr<VfsDirectory> RealVfsDirectory::GetParentDirectory() const {
-    if (path_components.size() <= 1)
-        return nullptr;
-
-    return std::make_shared<RealVfsDirectory>(parent_path, perms);
-}
-
-std::shared_ptr<VfsDirectory> RealVfsDirectory::CreateSubdirectory(const std::string& name) {
-    if (!FileUtil::CreateDir(path + DIR_SEP + name))
-        return nullptr;
-    subdirectories.emplace_back(std::make_shared<RealVfsDirectory>(path + DIR_SEP + name, perms));
-    return subdirectories.back();
-}
-
-std::shared_ptr<VfsFile> RealVfsDirectory::CreateFile(const std::string& name) {
-    if (!FileUtil::CreateEmptyFile(path + DIR_SEP + name))
-        return nullptr;
-    files.emplace_back(std::make_shared<RealVfsFile>(path + DIR_SEP + name, perms));
-    return files.back();
-}
-
-bool RealVfsDirectory::DeleteSubdirectory(const std::string& name) {
-    return FileUtil::DeleteDirRecursively(path + DIR_SEP + name);
-}
-
-bool RealVfsDirectory::DeleteFile(const std::string& name) {
-    return FileUtil::Delete(path + DIR_SEP + name);
-}
-
-bool RealVfsDirectory::Rename(const std::string& name) {
-    return FileUtil::Rename(path, parent_path + DIR_SEP + name);
-}
-
-bool RealVfsDirectory::ReplaceFileWithSubdirectory(VirtualFile file, VirtualDir dir) {
-    auto iter = std::find(files.begin(), files.end(), file);
-    if (iter == files.end())
-        return false;
-
-    files[iter - files.begin()] = files.back();
-    files.pop_back();
-
-    subdirectories.emplace_back(dir);
-
-    return true;
-}
-} // namespace FileSys

src/core/file_sys/vfs_real.h

@@ -1,65 +0,0 @@
-// Copyright 2018 yuzu emulator team
-// Licensed under GPLv2 or any later version
-// Refer to the license.txt file included.
-
-#pragma once
-
-#include "common/file_util.h"
-#include "core/file_sys/filesystem.h"
-#include "core/file_sys/vfs.h"
-
-namespace FileSys {
-
-// An implmentation of VfsFile that represents a file on the user's computer.
-struct RealVfsFile : public VfsFile {
-    RealVfsFile(const std::string& name, Mode perms = Mode::Read);
-
-    std::string GetName() const override;
-    size_t GetSize() const override;
-    bool Resize(size_t new_size) override;
-    std::shared_ptr<VfsDirectory> GetContainingDirectory() const override;
-    bool IsWritable() const override;
-    bool IsReadable() const override;
-    size_t Read(u8* data, size_t length, size_t offset) const override;
-    size_t Write(const u8* data, size_t length, size_t offset) override;
-    bool Rename(const std::string& name) override;
-
-private:
-    FileUtil::IOFile backing;
-    std::string path;
-    std::string parent_path;
-    std::vector<std::string> path_components;
-    std::vector<std::string> parent_components;
-    Mode perms;
-};
-
-// An implementation of VfsDirectory that represents a directory on the user's computer.
-struct RealVfsDirectory : public VfsDirectory {
-    RealVfsDirectory(const std::string& path, Mode perms);
-
-    std::vector<std::shared_ptr<VfsFile>> GetFiles() const override;
-    std::vector<std::shared_ptr<VfsDirectory>> GetSubdirectories() const override;
-    bool IsWritable() const override;
-    bool IsReadable() const override;
-    std::string GetName() const override;
-    std::shared_ptr<VfsDirectory> GetParentDirectory() const override;
-    std::shared_ptr<VfsDirectory> CreateSubdirectory(const std::string& name) override;
-    std::shared_ptr<VfsFile> CreateFile(const std::string& name) override;
-    bool DeleteSubdirectory(const std::string& name) override;
-    bool DeleteFile(const std::string& name) override;
-    bool Rename(const std::string& name) override;
-
-protected:
-    bool ReplaceFileWithSubdirectory(VirtualFile file, VirtualDir dir) override;
-
-private:
-    std::string path;
-    std::string parent_path;
-    std::vector<std::string> path_components;
-    std::vector<std::string> parent_components;
-    Mode perms;
-    std::vector<std::shared_ptr<VfsFile>> files;
-    std::vector<std::shared_ptr<VfsDirectory>> subdirectories;
-};
-
-} // namespace FileSys

src/core/hle/service/am/am.cpp

@@ -621,7 +621,7 @@ void IApplicationFunctions::EnsureSaveData(Kernel::HLERequestContext& ctx) {
     IPC::ResponseBuilder rb{ctx, 4};
 
     FileSys::Path unused;
-    auto savedata = FileSystem::OpenFileSystem(FileSystem::Type::SaveData);
+    auto savedata = FileSystem::OpenFileSystem(FileSystem::Type::SaveData, unused);
     if (savedata.Failed()) {
         // Create the save data and return an error indicating that the operation was performed.
         FileSystem::FormatFileSystem(FileSystem::Type::SaveData);

src/core/hle/service/filesystem/filesystem.cpp

@@ -2,221 +2,36 @@
 // Licensed under GPLv2 or any later version
 // Refer to the license.txt file included.
 
-#include "boost/container/flat_map.hpp"
-#include "common/assert.h"
-#include "common/common_paths.h"
+#include <boost/container/flat_map.hpp>
 #include "common/file_util.h"
-#include "core/core.h"
-#include "core/file_sys/errors.h"
 #include "core/file_sys/filesystem.h"
-#include "core/file_sys/vfs.h"
-#include "core/file_sys/vfs_offset.h"
-#include "core/file_sys/vfs_real.h"
-#include "core/hle/kernel/process.h"
+#include "core/file_sys/savedata_factory.h"
+#include "core/file_sys/sdmc_factory.h"
 #include "core/hle/service/filesystem/filesystem.h"
 #include "core/hle/service/filesystem/fsp_srv.h"
 
 namespace Service::FileSystem {
 
-// Size of emulated sd card free space, reported in bytes.
-// Just using 32GB because thats reasonable
-// TODO(DarkLordZach): Eventually make this configurable in settings.
-constexpr u64 EMULATED_SD_REPORTED_SIZE = 32000000000;
-
-static FileSys::VirtualDir GetDirectoryRelativeWrapped(FileSys::VirtualDir base,
-                                                       const std::string& dir_name) {
-    if (dir_name == "." || dir_name == "" || dir_name == "/" || dir_name == "\\")
-        return base;
-
-    return base->GetDirectoryRelative(dir_name);
-}
-
-VfsDirectoryServiceWrapper::VfsDirectoryServiceWrapper(FileSys::VirtualDir backing_)
-    : backing(backing_) {}
-
-std::string VfsDirectoryServiceWrapper::GetName() const {
-    return backing->GetName();
-}
-
-ResultCode VfsDirectoryServiceWrapper::CreateFile(const std::string& path, u64 size) const {
-    auto dir = GetDirectoryRelativeWrapped(backing, FileUtil::GetParentPath(path));
-    auto file = dir->CreateFile(FileUtil::GetFilename(path));
-    if (file == nullptr)
-        return ResultCode(-1);
-    if (!file->Resize(size))
-        return ResultCode(-1);
-    return RESULT_SUCCESS;
-}
-
-ResultCode VfsDirectoryServiceWrapper::DeleteFile(const std::string& path) const {
-    auto dir = GetDirectoryRelativeWrapped(backing, FileUtil::GetParentPath(path));
-    if (!backing->DeleteFile(FileUtil::GetFilename(path)))
-        return ResultCode(-1);
-    return RESULT_SUCCESS;
-}
-
-ResultCode VfsDirectoryServiceWrapper::CreateDirectory(const std::string& path) const {
-    auto dir = GetDirectoryRelativeWrapped(backing, FileUtil::GetParentPath(path));
-    if (dir == nullptr && FileUtil::GetFilename(FileUtil::GetParentPath(path)).empty())
-        dir = backing;
-    auto new_dir = dir->CreateSubdirectory(FileUtil::GetFilename(path));
-    if (new_dir == nullptr)
-        return ResultCode(-1);
-    return RESULT_SUCCESS;
-}
-
-ResultCode VfsDirectoryServiceWrapper::DeleteDirectory(const std::string& path) const {
-    auto dir = GetDirectoryRelativeWrapped(backing, FileUtil::GetParentPath(path));
-    if (!dir->DeleteSubdirectory(FileUtil::GetFilename(path)))
-        return ResultCode(-1);
-    return RESULT_SUCCESS;
-}
-
-ResultCode VfsDirectoryServiceWrapper::DeleteDirectoryRecursively(const std::string& path) const {
-    auto dir = GetDirectoryRelativeWrapped(backing, FileUtil::GetParentPath(path));
-    if (!dir->DeleteSubdirectoryRecursive(FileUtil::GetFilename(path)))
-        return ResultCode(-1);
-    return RESULT_SUCCESS;
-}
-
-ResultCode VfsDirectoryServiceWrapper::RenameFile(const std::string& src_path,
-                                                  const std::string& dest_path) const {
-    auto src = backing->GetFileRelative(src_path);
-    if (FileUtil::GetParentPath(src_path) == FileUtil::GetParentPath(dest_path)) {
-        // Use more-optimized vfs implementation rename.
-        if (src == nullptr)
-            return FileSys::ERROR_PATH_NOT_FOUND;
-        if (!src->Rename(FileUtil::GetFilename(dest_path)))
-            return ResultCode(-1);
-        return RESULT_SUCCESS;
-    }
-
-    // Move by hand -- TODO(DarkLordZach): Optimize
-    auto c_res = CreateFile(dest_path, src->GetSize());
-    if (c_res != RESULT_SUCCESS)
-        return c_res;
-
-    auto dest = backing->GetFileRelative(dest_path);
-    ASSERT_MSG(dest != nullptr, "Newly created file with success cannot be found.");
-
-    ASSERT_MSG(dest->WriteBytes(src->ReadAllBytes()) == src->GetSize(),
-               "Could not write all of the bytes but everything else has succeded.");
-
-    if (!src->GetContainingDirectory()->DeleteFile(FileUtil::GetFilename(src_path)))
-        return ResultCode(-1);
-
-    return RESULT_SUCCESS;
-}
-
-ResultCode VfsDirectoryServiceWrapper::RenameDirectory(const std::string& src_path,
-                                                       const std::string& dest_path) const {
-    auto src = GetDirectoryRelativeWrapped(backing, src_path);
-    if (FileUtil::GetParentPath(src_path) == FileUtil::GetParentPath(dest_path)) {
-        // Use more-optimized vfs implementation rename.
-        if (src == nullptr)
-            return FileSys::ERROR_PATH_NOT_FOUND;
-        if (!src->Rename(FileUtil::GetFilename(dest_path)))
-            return ResultCode(-1);
-        return RESULT_SUCCESS;
-    }
-
-    // TODO(DarkLordZach): Implement renaming across the tree (move).
-    ASSERT_MSG(false,
-               "Could not rename directory with path \"{}\" to new path \"{}\" because parent dirs "
-               "don't match -- UNIMPLEMENTED",
-               src_path, dest_path);
-
-    return ResultCode(-1);
-}
-
-ResultVal<FileSys::VirtualFile> VfsDirectoryServiceWrapper::OpenFile(const std::string& path,
-                                                                     FileSys::Mode mode) const {
-    auto file = backing->GetFileRelative(path);
-    if (file == nullptr)
-        return FileSys::ERROR_PATH_NOT_FOUND;
-
-    if ((static_cast<u32>(mode) & static_cast<u32>(FileSys::Mode::Append)) != 0) {
-        return MakeResult<FileSys::VirtualFile>(
-            std::make_shared<FileSys::OffsetVfsFile>(file, 0, file->GetSize()));
-    }
-
-    return MakeResult<FileSys::VirtualFile>(file);
-}
-
-ResultVal<FileSys::VirtualDir> VfsDirectoryServiceWrapper::OpenDirectory(const std::string& path) {
-    auto dir = GetDirectoryRelativeWrapped(backing, path);
-    if (dir == nullptr)
-        return ResultCode(-1);
-    return MakeResult(dir);
-}
-
-u64 VfsDirectoryServiceWrapper::GetFreeSpaceSize() const {
-    if (backing->IsWritable())
-        return EMULATED_SD_REPORTED_SIZE;
-
-    return 0;
-}
-
-ResultVal<FileSys::EntryType> VfsDirectoryServiceWrapper::GetEntryType(
-    const std::string& path) const {
-    auto dir = GetDirectoryRelativeWrapped(backing, FileUtil::GetParentPath(path));
-    if (dir == nullptr)
-        return ResultCode(-1);
-    auto filename = FileUtil::GetFilename(path);
-    if (dir->GetFile(filename) != nullptr)
-        return MakeResult(FileSys::EntryType::File);
-    if (dir->GetSubdirectory(filename) != nullptr)
-        return MakeResult(FileSys::EntryType::Directory);
-    return ResultCode(-1);
-}
-
-// A deferred filesystem for nand save data.
-// This must be deferred because the directory is dependent on title id, which is not set at
-// registration time.
-struct SaveDataDeferredFilesystem : DeferredFilesystem {
-protected:
-    FileSys::VirtualDir CreateFilesystem() override {
-        u64 title_id = Core::CurrentProcess()->program_id;
-        // TODO(DarkLordZach): Users
-        u32 user_id = 0;
-        std::string nand_directory = fmt::format(
-            "{}save/{:016X}/{:08X}/", FileUtil::GetUserPath(D_NAND_IDX), title_id, user_id);
-
-        auto savedata =
-            std::make_shared<FileSys::RealVfsDirectory>(nand_directory, FileSys::Mode::Write);
-        return savedata;
-    }
-};
-
 /**
  * Map of registered file systems, identified by type. Once an file system is registered here, it
  * is never removed until UnregisterFileSystems is called.
  */
-static boost::container::flat_map<Type, std::unique_ptr<DeferredFilesystem>> filesystem_map;
-static FileSys::VirtualFile filesystem_romfs = nullptr;
+static boost::container::flat_map<Type, std::unique_ptr<FileSys::FileSystemFactory>> filesystem_map;
 
-ResultCode RegisterFileSystem(std::unique_ptr<DeferredFilesystem>&& factory, Type type) {
+ResultCode RegisterFileSystem(std::unique_ptr<FileSys::FileSystemFactory>&& factory, Type type) {
     auto result = filesystem_map.emplace(type, std::move(factory));
 
     bool inserted = result.second;
     ASSERT_MSG(inserted, "Tried to register more than one system with same id code");
 
     auto& filesystem = result.first->second;
-    LOG_DEBUG(Service_FS, "Registered file system with id code 0x{:08X}", static_cast<u32>(type));
-    return RESULT_SUCCESS;
-}
-
-ResultCode RegisterRomFS(FileSys::VirtualFile filesystem) {
-    ASSERT_MSG(filesystem_romfs == nullptr,
-               "Tried to register more than one system with same id code");
-
-    filesystem_romfs = filesystem;
     LOG_DEBUG(Service_FS, "Registered file system {} with id code 0x{:08X}", filesystem->GetName(),
-              static_cast<u32>(Type::RomFS));
+              static_cast<u32>(type));
     return RESULT_SUCCESS;
 }
 
-ResultVal<FileSys::VirtualDir> OpenFileSystem(Type type) {
+ResultVal<std::unique_ptr<FileSys::FileSystemBackend>> OpenFileSystem(Type type,
+                                                                      FileSys::Path& path) {
     LOG_TRACE(Service_FS, "Opening FileSystem with type={}", static_cast<u32>(type));
 
     auto itr = filesystem_map.find(type);
@@ -225,13 +40,7 @@ ResultVal<FileSys::VirtualDir> OpenFileSystem(Type type) {
         return ResultCode(-1);
     }
 
-    return MakeResult(itr->second->Get());
-}
-
-ResultVal<FileSys::VirtualFile> OpenRomFS() {
-    if (filesystem_romfs == nullptr)
-        return ResultCode(-1);
-    return MakeResult(filesystem_romfs);
+    return itr->second->Open(path);
 }
 
 ResultCode FormatFileSystem(Type type) {
@@ -243,21 +52,21 @@ ResultCode FormatFileSystem(Type type) {
         return ResultCode(-1);
     }
 
-    return itr->second->Get()->GetParentDirectory()->DeleteSubdirectory(
-               itr->second->Get()->GetName())
-               ? RESULT_SUCCESS
-               : ResultCode(-1);
+    FileSys::Path unused;
+    return itr->second->Format(unused);
 }
 
 void RegisterFileSystems() {
     filesystem_map.clear();
-    filesystem_romfs = nullptr;
 
+    std::string nand_directory = FileUtil::GetUserPath(D_NAND_IDX);
     std::string sd_directory = FileUtil::GetUserPath(D_SDMC_IDX);
-    auto sdcard = std::make_shared<FileSys::RealVfsDirectory>(sd_directory, FileSys::Mode::Write);
-    RegisterFileSystem(std::make_unique<DeferredFilesystem>(sdcard), Type::SDMC);
 
-    RegisterFileSystem(std::make_unique<SaveDataDeferredFilesystem>(), Type::SaveData);
+    auto savedata = std::make_unique<FileSys::SaveData_Factory>(std::move(nand_directory));
+    RegisterFileSystem(std::move(savedata), Type::SaveData);
+
+    auto sdcard = std::make_unique<FileSys::SDMC_Factory>(std::move(sd_directory));
+    RegisterFileSystem(std::move(sdcard), Type::SDMC);
 }
 
 void InstallInterfaces(SM::ServiceManager& service_manager) {

src/core/hle/service/filesystem/filesystem.h

@@ -6,8 +6,6 @@
 
 #include <memory>
 #include "common/common_types.h"
-#include "core/file_sys/filesystem.h"
-#include "core/file_sys/vfs.h"
 #include "core/hle/result.h"
 
 namespace FileSys {
@@ -31,136 +29,12 @@ enum class Type {
     SDMC = 3,
 };
 
-// A class that wraps a VfsDirectory with methods that return ResultVal and ResultCode instead of
-// pointers and booleans. This makes using a VfsDirectory with switch services much easier and
-// avoids repetitive code.
-class VfsDirectoryServiceWrapper {
-public:
-    explicit VfsDirectoryServiceWrapper(FileSys::VirtualDir backing);
-
-    /**
-     * Get a descriptive name for the archive (e.g. "RomFS", "SaveData", etc.)
-     */
-    std::string GetName() const;
-
-    /**
-     * Create a file specified by its path
-     * @param path Path relative to the Archive
-     * @param size The size of the new file, filled with zeroes
-     * @return Result of the operation
-     */
-    ResultCode CreateFile(const std::string& path, u64 size) const;
-
-    /**
-     * Delete a file specified by its path
-     * @param path Path relative to the archive
-     * @return Result of the operation
-     */
-    ResultCode DeleteFile(const std::string& path) const;
-
-    /**
-     * Create a directory specified by its path
-     * @param path Path relative to the archive
-     * @return Result of the operation
-     */
-    ResultCode CreateDirectory(const std::string& path) const;
-
-    /**
-     * Delete a directory specified by its path
-     * @param path Path relative to the archive
-     * @return Result of the operation
-     */
-    ResultCode DeleteDirectory(const std::string& path) const;
-
-    /**
-     * Delete a directory specified by its path and anything under it
-     * @param path Path relative to the archive
-     * @return Result of the operation
-     */
-    ResultCode DeleteDirectoryRecursively(const std::string& path) const;
-
-    /**
-     * Rename a File specified by its path
-     * @param src_path Source path relative to the archive
-     * @param dest_path Destination path relative to the archive
-     * @return Result of the operation
-     */
-    ResultCode RenameFile(const std::string& src_path, const std::string& dest_path) const;
-
-    /**
-     * Rename a Directory specified by its path
-     * @param src_path Source path relative to the archive
-     * @param dest_path Destination path relative to the archive
-     * @return Result of the operation
-     */
-    ResultCode RenameDirectory(const std::string& src_path, const std::string& dest_path) const;
-
-    /**
-     * Open a file specified by its path, using the specified mode
-     * @param path Path relative to the archive
-     * @param mode Mode to open the file with
-     * @return Opened file, or error code
-     */
-    ResultVal<FileSys::VirtualFile> OpenFile(const std::string& path, FileSys::Mode mode) const;
-
-    /**
-     * Open a directory specified by its path
-     * @param path Path relative to the archive
-     * @return Opened directory, or error code
-     */
-    ResultVal<FileSys::VirtualDir> OpenDirectory(const std::string& path);
-
-    /**
-     * Get the free space
-     * @return The number of free bytes in the archive
-     */
-    u64 GetFreeSpaceSize() const;
-
-    /**
-     * Get the type of the specified path
-     * @return The type of the specified path or error code
-     */
-    ResultVal<FileSys::EntryType> GetEntryType(const std::string& path) const;
-
-private:
-    FileSys::VirtualDir backing;
-};
-
-// A class that deferres the creation of a filesystem until a later time.
-// This is useful if construction depends on a variable not known when the filesystem is registered.
-// Construct this with a filesystem (VirtualDir) to avoid the deferrence feature or override the
-//     CreateFilesystem method which will be called on first use.
-struct DeferredFilesystem {
-    DeferredFilesystem() = default;
-
-    explicit DeferredFilesystem(FileSys::VirtualDir vfs_directory) : fs(std::move(vfs_directory)) {}
-
-    FileSys::VirtualDir Get() {
-        if (fs == nullptr)
-            fs = CreateFilesystem();
-
-        return fs;
-    }
-
-    virtual ~DeferredFilesystem() = default;
-
-protected:
-    virtual FileSys::VirtualDir CreateFilesystem() {
-        return fs;
-    }
-
-private:
-    FileSys::VirtualDir fs;
-};
-
 /**
  * Registers a FileSystem, instances of which can later be opened using its IdCode.
  * @param factory FileSystem backend interface to use
  * @param type Type used to access this type of FileSystem
  */
-ResultCode RegisterFileSystem(std::unique_ptr<DeferredFilesystem>&& fs, Type type);
-
-ResultCode RegisterRomFS(FileSys::VirtualFile fs);
+ResultCode RegisterFileSystem(std::unique_ptr<FileSys::FileSystemFactory>&& factory, Type type);
 
 /**
  * Opens a file system
@@ -168,9 +42,8 @@ ResultCode RegisterRomFS(FileSys::VirtualFile fs);
  * @param path Path to the file system, used with Binary paths
  * @return FileSys::FileSystemBackend interface to the file system
  */
-ResultVal<FileSys::VirtualDir> OpenFileSystem(Type type);
-
-ResultVal<FileSys::VirtualFile> OpenRomFS();
+ResultVal<std::unique_ptr<FileSys::FileSystemBackend>> OpenFileSystem(Type type,
+                                                                      FileSys::Path& path);
 
 /**
  * Formats a file system

src/core/hle/service/filesystem/fsp_srv.cpp

@@ -19,8 +19,8 @@ namespace Service::FileSystem {
 
 class IStorage final : public ServiceFramework<IStorage> {
 public:
-    IStorage(FileSys::VirtualFile backend_)
-        : ServiceFramework("IStorage"), backend(std::move(backend_)) {
+    IStorage(std::unique_ptr<FileSys::StorageBackend>&& backend)
+        : ServiceFramework("IStorage"), backend(std::move(backend)) {
         static const FunctionInfo functions[] = {
             {0, &IStorage::Read, "Read"}, {1, nullptr, "Write"},   {2, nullptr, "Flush"},
             {3, nullptr, "SetSize"},      {4, nullptr, "GetSize"}, {5, nullptr, "OperateRange"},
@@ -29,7 +29,7 @@ public:
     }
 
 private:
-    FileSys::VirtualFile backend;
+    std::unique_ptr<FileSys::StorageBackend> backend;
 
     void Read(Kernel::HLERequestContext& ctx) {
         IPC::RequestParser rp{ctx};
@@ -51,8 +51,8 @@ private:
         }
 
         // Read the data from the Storage backend
-        std::vector<u8> output = backend->ReadBytes(length, offset);
-        auto res = MakeResult<size_t>(output.size());
+        std::vector<u8> output(length);
+        ResultVal<size_t> res = backend->Read(offset, length, output.data());
         if (res.Failed()) {
             IPC::ResponseBuilder rb{ctx, 2};
             rb.Push(res.Code());
@@ -69,8 +69,8 @@ private:
 
 class IFile final : public ServiceFramework<IFile> {
 public:
-    explicit IFile(FileSys::VirtualFile backend_)
-        : ServiceFramework("IFile"), backend(std::move(backend_)) {
+    explicit IFile(std::unique_ptr<FileSys::StorageBackend>&& backend)
+        : ServiceFramework("IFile"), backend(std::move(backend)) {
         static const FunctionInfo functions[] = {
             {0, &IFile::Read, "Read"},       {1, &IFile::Write, "Write"},
             {2, &IFile::Flush, "Flush"},     {3, &IFile::SetSize, "SetSize"},
@@ -80,7 +80,7 @@ public:
     }
 
 private:
-    FileSys::VirtualFile backend;
+    std::unique_ptr<FileSys::StorageBackend> backend;
 
     void Read(Kernel::HLERequestContext& ctx) {
         IPC::RequestParser rp{ctx};
@@ -103,8 +103,8 @@ private:
         }
 
         // Read the data from the Storage backend
-        std::vector<u8> output = backend->ReadBytes(length, offset);
-        auto res = MakeResult<size_t>(output.size());
+        std::vector<u8> output(length);
+        ResultVal<size_t> res = backend->Read(offset, length, output.data());
         if (res.Failed()) {
             IPC::ResponseBuilder rb{ctx, 2};
             rb.Push(res.Code());
@@ -139,10 +139,9 @@ private:
             return;
         }
 
-        std::vector<u8> data = ctx.ReadBuffer();
-        data.resize(length);
         // Write the data to the Storage backend
-        auto res = MakeResult<size_t>(backend->WriteBytes(data, offset));
+        std::vector<u8> data = ctx.ReadBuffer();
+        ResultVal<size_t> res = backend->Write(offset, length, true, data.data());
         if (res.Failed()) {
             IPC::ResponseBuilder rb{ctx, 2};
             rb.Push(res.Code());
@@ -155,8 +154,7 @@ private:
 
     void Flush(Kernel::HLERequestContext& ctx) {
         LOG_DEBUG(Service_FS, "called");
-
-        // Exists for SDK compatibiltity -- No need to flush file.
+        backend->Flush();
 
         IPC::ResponseBuilder rb{ctx, 2};
         rb.Push(RESULT_SUCCESS);
@@ -165,7 +163,7 @@ private:
     void SetSize(Kernel::HLERequestContext& ctx) {
         IPC::RequestParser rp{ctx};
         const u64 size = rp.Pop<u64>();
-        backend->Resize(size);
+        backend->SetSize(size);
         LOG_DEBUG(Service_FS, "called, size={}", size);
 
         IPC::ResponseBuilder rb{ctx, 2};
@@ -182,38 +180,19 @@ private:
     }
 };
 
-template <typename T>
-static void BuildEntryIndex(std::vector<FileSys::Entry>& entries, const std::vector<T>& new_data,
-                            FileSys::EntryType type) {
-    for (const auto& new_entry : new_data) {
-        FileSys::Entry entry;
-        entry.filename[0] = '\0';
-        std::strncat(entry.filename, new_entry->GetName().c_str(), FileSys::FILENAME_LENGTH - 1);
-        entry.type = type;
-        entry.file_size = new_entry->GetSize();
-        entries.emplace_back(std::move(entry));
-    }
-}
-
 class IDirectory final : public ServiceFramework<IDirectory> {
 public:
-    explicit IDirectory(FileSys::VirtualDir backend_)
-        : ServiceFramework("IDirectory"), backend(std::move(backend_)) {
+    explicit IDirectory(std::unique_ptr<FileSys::DirectoryBackend>&& backend)
+        : ServiceFramework("IDirectory"), backend(std::move(backend)) {
         static const FunctionInfo functions[] = {
             {0, &IDirectory::Read, "Read"},
             {1, &IDirectory::GetEntryCount, "GetEntryCount"},
         };
         RegisterHandlers(functions);
-
-        // Build entry index now to save time later.
-        BuildEntryIndex(entries, backend->GetFiles(), FileSys::File);
-        BuildEntryIndex(entries, backend->GetSubdirectories(), FileSys::Directory);
     }
 
 private:
-    FileSys::VirtualDir backend;
-    std::vector<FileSys::Entry> entries;
-    u64 next_entry_index = 0;
+    std::unique_ptr<FileSys::DirectoryBackend> backend;
 
     void Read(Kernel::HLERequestContext& ctx) {
         IPC::RequestParser rp{ctx};
@@ -224,31 +203,26 @@ private:
         // Calculate how many entries we can fit in the output buffer
         u64 count_entries = ctx.GetWriteBufferSize() / sizeof(FileSys::Entry);
 
-        // Cap at total number of entries.
-        u64 actual_entries = std::min(count_entries, entries.size() - next_entry_index);
-
         // Read the data from the Directory backend
-        std::vector<FileSys::Entry> entry_data(entries.begin() + next_entry_index,
-                                               entries.begin() + next_entry_index + actual_entries);
-
-        next_entry_index += actual_entries;
+        std::vector<FileSys::Entry> entries(count_entries);
+        u64 read_entries = backend->Read(count_entries, entries.data());
 
         // Convert the data into a byte array
-        std::vector<u8> output(entry_data.size() * sizeof(FileSys::Entry));
-        std::memcpy(output.data(), entry_data.data(), output.size());
+        std::vector<u8> output(entries.size() * sizeof(FileSys::Entry));
+        std::memcpy(output.data(), entries.data(), output.size());
 
         // Write the data to memory
         ctx.WriteBuffer(output);
 
         IPC::ResponseBuilder rb{ctx, 4};
         rb.Push(RESULT_SUCCESS);
-        rb.Push(actual_entries);
+        rb.Push(read_entries);
     }
 
     void GetEntryCount(Kernel::HLERequestContext& ctx) {
         LOG_DEBUG(Service_FS, "called");
 
-        u64 count = entries.size() - next_entry_index;
+        u64 count = backend->GetEntryCount();
 
         IPC::ResponseBuilder rb{ctx, 4};
         rb.Push(RESULT_SUCCESS);
@@ -258,7 +232,7 @@ private:
 
 class IFileSystem final : public ServiceFramework<IFileSystem> {
 public:
-    explicit IFileSystem(FileSys::VirtualDir backend)
+    explicit IFileSystem(std::unique_ptr<FileSys::FileSystemBackend>&& backend)
         : ServiceFramework("IFileSystem"), backend(std::move(backend)) {
         static const FunctionInfo functions[] = {
             {0, &IFileSystem::CreateFile, "CreateFile"},
@@ -293,7 +267,7 @@ public:
         LOG_DEBUG(Service_FS, "called file {} mode 0x{:X} size 0x{:08X}", name, mode, size);
 
         IPC::ResponseBuilder rb{ctx, 2};
-        rb.Push(backend.CreateFile(name, size));
+        rb.Push(backend->CreateFile(name, size));
     }
 
     void DeleteFile(Kernel::HLERequestContext& ctx) {
@@ -305,7 +279,7 @@ public:
         LOG_DEBUG(Service_FS, "called file {}", name);
 
         IPC::ResponseBuilder rb{ctx, 2};
-        rb.Push(backend.DeleteFile(name));
+        rb.Push(backend->DeleteFile(name));
     }
 
     void CreateDirectory(Kernel::HLERequestContext& ctx) {
@@ -317,7 +291,7 @@ public:
         LOG_DEBUG(Service_FS, "called directory {}", name);
 
         IPC::ResponseBuilder rb{ctx, 2};
-        rb.Push(backend.CreateDirectory(name));
+        rb.Push(backend->CreateDirectory(name));
     }
 
     void RenameFile(Kernel::HLERequestContext& ctx) {
@@ -335,7 +309,7 @@ public:
         LOG_DEBUG(Service_FS, "called file '{}' to file '{}'", src_name, dst_name);
 
         IPC::ResponseBuilder rb{ctx, 2};
-        rb.Push(backend.RenameFile(src_name, dst_name));
+        rb.Push(backend->RenameFile(src_name, dst_name));
     }
 
     void OpenFile(Kernel::HLERequestContext& ctx) {
@@ -348,14 +322,14 @@ public:
 
         LOG_DEBUG(Service_FS, "called file {} mode {}", name, static_cast<u32>(mode));
 
-        auto result = backend.OpenFile(name, mode);
+        auto result = backend->OpenFile(name, mode);
         if (result.Failed()) {
             IPC::ResponseBuilder rb{ctx, 2};
             rb.Push(result.Code());
             return;
         }
 
-        IFile file(result.Unwrap());
+        auto file = std::move(result.Unwrap());
 
         IPC::ResponseBuilder rb{ctx, 2, 0, 1};
         rb.Push(RESULT_SUCCESS);
@@ -373,14 +347,14 @@ public:
 
         LOG_DEBUG(Service_FS, "called directory {} filter {}", name, filter_flags);
 
-        auto result = backend.OpenDirectory(name);
+        auto result = backend->OpenDirectory(name);
         if (result.Failed()) {
             IPC::ResponseBuilder rb{ctx, 2};
             rb.Push(result.Code());
             return;
         }
 
-        IDirectory directory(result.Unwrap());
+        auto directory = std::move(result.Unwrap());
 
         IPC::ResponseBuilder rb{ctx, 2, 0, 1};
         rb.Push(RESULT_SUCCESS);
@@ -395,7 +369,7 @@ public:
 
         LOG_DEBUG(Service_FS, "called file {}", name);
 
-        auto result = backend.GetEntryType(name);
+        auto result = backend->GetEntryType(name);
         if (result.Failed()) {
             IPC::ResponseBuilder rb{ctx, 2};
             rb.Push(result.Code());
@@ -415,7 +389,7 @@ public:
     }
 
 private:
-    VfsDirectoryServiceWrapper backend;
+    std::unique_ptr<FileSys::FileSystemBackend> backend;
 };
 
 FSP_SRV::FSP_SRV() : ServiceFramework("fsp-srv") {
@@ -516,7 +490,8 @@ void FSP_SRV::TryLoadRomFS() {
     if (romfs) {
         return;
     }
-    auto res = OpenRomFS();
+    FileSys::Path unused;
+    auto res = OpenFileSystem(Type::RomFS, unused);
     if (res.Succeeded()) {
         romfs = std::move(res.Unwrap());
     }
@@ -532,7 +507,8 @@ void FSP_SRV::Initialize(Kernel::HLERequestContext& ctx) {
 void FSP_SRV::MountSdCard(Kernel::HLERequestContext& ctx) {
     LOG_DEBUG(Service_FS, "called");
 
-    IFileSystem filesystem(OpenFileSystem(Type::SDMC).Unwrap());
+    FileSys::Path unused;
+    auto filesystem = OpenFileSystem(Type::SDMC, unused).Unwrap();
 
     IPC::ResponseBuilder rb{ctx, 2, 0, 1};
     rb.Push(RESULT_SUCCESS);
@@ -555,7 +531,8 @@ void FSP_SRV::CreateSaveData(Kernel::HLERequestContext& ctx) {
 void FSP_SRV::MountSaveData(Kernel::HLERequestContext& ctx) {
     LOG_WARNING(Service_FS, "(STUBBED) called");
 
-    IFileSystem filesystem(OpenFileSystem(Type::SaveData).Unwrap());
+    FileSys::Path unused;
+    auto filesystem = OpenFileSystem(Type::SaveData, unused).Unwrap();
 
     IPC::ResponseBuilder rb{ctx, 2, 0, 1};
     rb.Push(RESULT_SUCCESS);
@@ -582,11 +559,18 @@ void FSP_SRV::OpenDataStorageByCurrentProcess(Kernel::HLERequestContext& ctx) {
         return;
     }
 
-    IStorage storage(romfs);
+    // Attempt to open a StorageBackend interface to the RomFS
+    auto storage = romfs->OpenFile({}, {});
+    if (storage.Failed()) {
+        LOG_CRITICAL(Service_FS, "no storage interface available!");
+        IPC::ResponseBuilder rb{ctx, 2};
+        rb.Push(storage.Code());
+        return;
+    }
 
     IPC::ResponseBuilder rb{ctx, 2, 0, 1};
     rb.Push(RESULT_SUCCESS);
-    rb.PushIpcInterface<IStorage>(std::move(storage));
+    rb.PushIpcInterface<IStorage>(std::move(storage.Unwrap()));
 }
 
 void FSP_SRV::OpenRomStorage(Kernel::HLERequestContext& ctx) {

src/core/hle/service/filesystem/fsp_srv.h

@@ -29,7 +29,7 @@ private:
     void OpenDataStorageByCurrentProcess(Kernel::HLERequestContext& ctx);
     void OpenRomStorage(Kernel::HLERequestContext& ctx);
 
-    FileSys::VirtualFile romfs;
+    std::unique_ptr<FileSys::FileSystemBackend> romfs;
 };
 
 } // namespace Service::FileSystem

src/core/loader/deconstructed_rom_directory.cpp

@@ -4,10 +4,11 @@
 
 #include <cinttypes>
 #include "common/common_funcs.h"
+#include "common/common_paths.h"
 #include "common/file_util.h"
 #include "common/logging/log.h"
 #include "common/string_util.h"
-#include "core/file_sys/content_archive.h"
+#include "core/file_sys/romfs_factory.h"
 #include "core/hle/kernel/process.h"
 #include "core/hle/kernel/resource_limit.h"
 #include "core/hle/service/filesystem/filesystem.h"
@@ -45,11 +46,55 @@ static std::string FindRomFS(const std::string& directory) {
     return filepath_romfs;
 }
 
-AppLoader_DeconstructedRomDirectory::AppLoader_DeconstructedRomDirectory(FileSys::VirtualFile file)
-    : AppLoader(std::move(file)) {}
+AppLoader_DeconstructedRomDirectory::AppLoader_DeconstructedRomDirectory(FileUtil::IOFile&& file,
+                                                                         std::string filepath)
+    : AppLoader(std::move(file)), filepath(std::move(filepath)) {}
+
+FileType AppLoader_DeconstructedRomDirectory::IdentifyType(FileUtil::IOFile& file,
+                                                           const std::string& filepath) {
+    bool is_main_found{};
+    bool is_npdm_found{};
+    bool is_rtld_found{};
+    bool is_sdk_found{};
+
+    const auto callback = [&](unsigned* num_entries_out, const std::string& directory,
+                              const std::string& virtual_name) -> bool {
+        // Skip directories
+        std::string physical_name = directory + virtual_name;
+        if (FileUtil::IsDirectory(physical_name)) {
+            return true;
+        }
+
+        // Verify filename
+        if (Common::ToLower(virtual_name) == "main") {
+            is_main_found = true;
+        } else if (Common::ToLower(virtual_name) == "main.npdm") {
+            is_npdm_found = true;
+            return true;
+        } else if (Common::ToLower(virtual_name) == "rtld") {
+            is_rtld_found = true;
+        } else if (Common::ToLower(virtual_name) == "sdk") {
+            is_sdk_found = true;
+        } else {
+            // Continue searching
+            return true;
+        }
+
+        // Verify file is an NSO
+        FileUtil::IOFile file(physical_name, "rb");
+        if (AppLoader_NSO::IdentifyType(file, physical_name) != FileType::NSO) {
+            return false;
+        }
+
+        // We are done if we've found and verified all required NSOs
+        return !(is_main_found && is_npdm_found && is_rtld_found && is_sdk_found);
+    };
+
+    // Search the directory recursively, looking for the required modules
+    const std::string directory = filepath.substr(0, filepath.find_last_of("/\\")) + DIR_SEP;
+    FileUtil::ForeachDirectoryEntry(nullptr, directory, callback);
 
-FileType AppLoader_DeconstructedRomDirectory::IdentifyType(const FileSys::VirtualFile& file) {
-    if (FileSys::IsDirectoryExeFS(file->GetContainingDirectory())) {
+    if (is_main_found && is_npdm_found && is_rtld_found && is_sdk_found) {
         return FileType::DeconstructedRomDirectory;
     }
 
@@ -61,13 +106,14 @@ ResultStatus AppLoader_DeconstructedRomDirectory::Load(
     if (is_loaded) {
         return ResultStatus::ErrorAlreadyLoaded;
     }
+    if (!file.IsOpen()) {
+        return ResultStatus::Error;
+    }
 
-    const FileSys::VirtualDir dir = file->GetContainingDirectory();
-    const FileSys::VirtualFile npdm = dir->GetFile("main.npdm");
-    if (npdm == nullptr)
-        return ResultStatus::ErrorInvalidFormat;
+    const std::string directory = filepath.substr(0, filepath.find_last_of("/\\")) + DIR_SEP;
+    const std::string npdm_path = directory + DIR_SEP + "main.npdm";
 
-    ResultStatus result = metadata.Load(npdm);
+    ResultStatus result = metadata.Load(npdm_path);
     if (result != ResultStatus::Success) {
         return result;
     }
@@ -82,10 +128,9 @@ ResultStatus AppLoader_DeconstructedRomDirectory::Load(
     VAddr next_load_addr{Memory::PROCESS_IMAGE_VADDR};
     for (const auto& module : {"rtld", "main", "subsdk0", "subsdk1", "subsdk2", "subsdk3",
                                "subsdk4", "subsdk5", "subsdk6", "subsdk7", "sdk"}) {
+        const std::string path = directory + DIR_SEP + module;
         const VAddr load_addr = next_load_addr;
-        const FileSys::VirtualFile module_file = dir->GetFile(module);
-        if (module_file != nullptr)
-            next_load_addr = AppLoader_NSO::LoadModule(module_file, load_addr);
+        next_load_addr = AppLoader_NSO::LoadModule(path, load_addr);
         if (next_load_addr) {
             LOG_DEBUG(Loader, "loaded module {} @ 0x{:X}", module, load_addr);
         } else {
@@ -102,20 +147,42 @@ ResultStatus AppLoader_DeconstructedRomDirectory::Load(
                  metadata.GetMainThreadStackSize());
 
     // Find the RomFS by searching for a ".romfs" file in this directory
-    const auto& files = dir->GetFiles();
-    const auto romfs_iter =
-        std::find_if(files.begin(), files.end(), [](const FileSys::VirtualFile& file) {
-            return file->GetName().find(".romfs") != std::string::npos;
-        });
-
-    // TODO(DarkLordZach): Identify RomFS if its a subdirectory.
-    const auto romfs = (romfs_iter == files.end()) ? nullptr : *romfs_iter;
+    filepath_romfs = FindRomFS(directory);
 
-    if (romfs != nullptr)
-        Service::FileSystem::RegisterRomFS(romfs);
+    // Register the RomFS if a ".romfs" file was found
+    if (!filepath_romfs.empty()) {
+        Service::FileSystem::RegisterFileSystem(std::make_unique<FileSys::RomFS_Factory>(*this),
+                                                Service::FileSystem::Type::RomFS);
+    }
 
     is_loaded = true;
     return ResultStatus::Success;
 }
 
+ResultStatus AppLoader_DeconstructedRomDirectory::ReadRomFS(
+    std::shared_ptr<FileUtil::IOFile>& romfs_file, u64& offset, u64& size) {
+
+    if (filepath_romfs.empty()) {
+        LOG_DEBUG(Loader, "No RomFS available");
+        return ResultStatus::ErrorNotUsed;
+    }
+
+    // We reopen the file, to allow its position to be independent
+    romfs_file = std::make_shared<FileUtil::IOFile>(filepath_romfs, "rb");
+    if (!romfs_file->IsOpen()) {
+        return ResultStatus::Error;
+    }
+
+    offset = 0;
+    size = romfs_file->GetSize();
+
+    LOG_DEBUG(Loader, "RomFS offset:           0x{:016X}", offset);
+    LOG_DEBUG(Loader, "RomFS size:             0x{:016X}", size);
+
+    // Reset read pointer
+    file.Seek(0, SEEK_SET);
+
+    return ResultStatus::Success;
+}
+
 } // namespace Loader

src/core/loader/deconstructed_rom_directory.h

@@ -20,22 +20,28 @@ namespace Loader {
  */
 class AppLoader_DeconstructedRomDirectory final : public AppLoader {
 public:
-    explicit AppLoader_DeconstructedRomDirectory(FileSys::VirtualFile main_file);
+    AppLoader_DeconstructedRomDirectory(FileUtil::IOFile&& file, std::string filepath);
 
     /**
      * Returns the type of the file
-     * @param file std::shared_ptr<VfsFile> open file
+     * @param file FileUtil::IOFile open file
+     * @param filepath Path of the file that we are opening.
      * @return FileType found, or FileType::Error if this loader doesn't know it
      */
-    static FileType IdentifyType(const FileSys::VirtualFile& file);
+    static FileType IdentifyType(FileUtil::IOFile& file, const std::string& filepath);
 
     FileType GetFileType() override {
-        return IdentifyType(file);
+        return IdentifyType(file, filepath);
     }
 
     ResultStatus Load(Kernel::SharedPtr<Kernel::Process>& process) override;
 
+    ResultStatus ReadRomFS(std::shared_ptr<FileUtil::IOFile>& romfs_file, u64& offset,
+                           u64& size) override;
+
 private:
+    std::string filepath_romfs;
+    std::string filepath;
     FileSys::ProgramMetadata metadata;
 };
 

src/core/loader/elf.cpp

@@ -365,17 +365,20 @@ SectionID ElfReader::GetSectionByName(const char* name, int firstSection) const
 
 namespace Loader {
 
-AppLoader_ELF::AppLoader_ELF(FileSys::VirtualFile file) : AppLoader(std::move(file)) {}
+AppLoader_ELF::AppLoader_ELF(FileUtil::IOFile&& file, std::string filename)
+    : AppLoader(std::move(file)), filename(std::move(filename)) {}
 
-FileType AppLoader_ELF::IdentifyType(const FileSys::VirtualFile& file) {
+FileType AppLoader_ELF::IdentifyType(FileUtil::IOFile& file, const std::string&) {
     static constexpr u16 ELF_MACHINE_ARM{0x28};
 
     u32 magic = 0;
-    if (4 != file->ReadObject(&magic))
+    file.Seek(0, SEEK_SET);
+    if (1 != file.ReadArray<u32>(&magic, 1))
         return FileType::Error;
 
     u16 machine = 0;
-    if (2 != file->ReadObject(&machine, 18))
+    file.Seek(18, SEEK_SET);
+    if (1 != file.ReadArray<u16>(&machine, 1))
         return FileType::Error;
 
     if (Common::MakeMagic('\x7f', 'E', 'L', 'F') == magic && ELF_MACHINE_ARM == machine)
@@ -388,13 +391,20 @@ ResultStatus AppLoader_ELF::Load(Kernel::SharedPtr<Kernel::Process>& process) {
     if (is_loaded)
         return ResultStatus::ErrorAlreadyLoaded;
 
-    std::vector<u8> buffer = file->ReadAllBytes();
-    if (buffer.size() != file->GetSize())
+    if (!file.IsOpen())
+        return ResultStatus::Error;
+
+    // Reset read pointer in case this file has been read before.
+    file.Seek(0, SEEK_SET);
+
+    size_t size = file.GetSize();
+    std::unique_ptr<u8[]> buffer(new u8[size]);
+    if (file.ReadBytes(&buffer[0], size) != size)
         return ResultStatus::Error;
 
     ElfReader elf_reader(&buffer[0]);
     SharedPtr<CodeSet> codeset = elf_reader.LoadInto(Memory::PROCESS_IMAGE_VADDR);
-    codeset->name = file->GetName();
+    codeset->name = filename;
 
     process->LoadModule(codeset, codeset->entrypoint);
     process->svc_access_mask.set();

src/core/loader/elf.h

@@ -16,20 +16,24 @@ namespace Loader {
 /// Loads an ELF/AXF file
 class AppLoader_ELF final : public AppLoader {
 public:
-    explicit AppLoader_ELF(FileSys::VirtualFile file);
+    AppLoader_ELF(FileUtil::IOFile&& file, std::string filename);
 
     /**
      * Returns the type of the file
-     * @param file std::shared_ptr<VfsFile> open file
+     * @param file FileUtil::IOFile open file
+     * @param filepath Path of the file that we are opening.
      * @return FileType found, or FileType::Error if this loader doesn't know it
      */
-    static FileType IdentifyType(const FileSys::VirtualFile& file);
+    static FileType IdentifyType(FileUtil::IOFile& file, const std::string& filepath);
 
     FileType GetFileType() override {
-        return IdentifyType(file);
+        return IdentifyType(file, filename);
     }
 
     ResultStatus Load(Kernel::SharedPtr<Kernel::Process>& process) override;
+
+private:
+    std::string filename;
 };
 
 } // namespace Loader

src/core/loader/loader.cpp

@@ -6,7 +6,6 @@
 #include <string>
 #include "common/logging/log.h"
 #include "common/string_util.h"
-#include "core/file_sys/vfs_real.h"
 #include "core/hle/kernel/process.h"
 #include "core/loader/deconstructed_rom_directory.h"
 #include "core/loader/elf.h"
@@ -22,11 +21,11 @@ const std::initializer_list<Kernel::AddressMapping> default_address_mappings = {
     {0x1F000000, 0x600000, false}, // entire VRAM
 };
 
-FileType IdentifyFile(FileSys::VirtualFile file) {
+FileType IdentifyFile(FileUtil::IOFile& file, const std::string& filepath) {
     FileType type;
 
 #define CHECK_TYPE(loader)                                                                         \
-    type = AppLoader_##loader::IdentifyType(file);                                                 \
+    type = AppLoader_##loader::IdentifyType(file, filepath);                                       \
     if (FileType::Error != type)                                                                   \
         return type;
 
@@ -42,22 +41,25 @@ FileType IdentifyFile(FileSys::VirtualFile file) {
 }
 
 FileType IdentifyFile(const std::string& file_name) {
-    return IdentifyFile(FileSys::VirtualFile(std::make_shared<FileSys::RealVfsFile>(file_name)));
-}
+    FileUtil::IOFile file(file_name, "rb");
+    if (!file.IsOpen()) {
+        LOG_ERROR(Loader, "Failed to load file {}", file_name);
+        return FileType::Unknown;
+    }
 
-FileType GuessFromFilename(const std::string& name) {
-    if (name == "main")
-        return FileType::DeconstructedRomDirectory;
+    return IdentifyFile(file, file_name);
+}
 
-    const std::string extension = Common::ToLower(FileUtil::GetExtensionFromFilename(name));
+FileType GuessFromExtension(const std::string& extension_) {
+    std::string extension = Common::ToLower(extension_);
 
-    if (extension == "elf")
+    if (extension == ".elf")
         return FileType::ELF;
-    if (extension == "nro")
+    else if (extension == ".nro")
         return FileType::NRO;
-    if (extension == "nso")
+    else if (extension == ".nso")
         return FileType::NSO;
-    if (extension == "nca")
+    else if (extension == ".nca")
         return FileType::NCA;
 
     return FileType::Unknown;
@@ -91,47 +93,58 @@ const char* GetFileTypeString(FileType type) {
  * @param filepath the file full path (with name)
  * @return std::unique_ptr<AppLoader> a pointer to a loader object;  nullptr for unsupported type
  */
-static std::unique_ptr<AppLoader> GetFileLoader(FileSys::VirtualFile file, FileType type) {
+static std::unique_ptr<AppLoader> GetFileLoader(FileUtil::IOFile&& file, FileType type,
+                                                const std::string& filename,
+                                                const std::string& filepath) {
     switch (type) {
 
     // Standard ELF file format.
     case FileType::ELF:
-        return std::make_unique<AppLoader_ELF>(std::move(file));
+        return std::make_unique<AppLoader_ELF>(std::move(file), filename);
 
     // NX NSO file format.
     case FileType::NSO:
-        return std::make_unique<AppLoader_NSO>(std::move(file));
+        return std::make_unique<AppLoader_NSO>(std::move(file), filepath);
 
     // NX NRO file format.
     case FileType::NRO:
-        return std::make_unique<AppLoader_NRO>(std::move(file));
+        return std::make_unique<AppLoader_NRO>(std::move(file), filepath);
 
     // NX NCA file format.
     case FileType::NCA:
-        return std::make_unique<AppLoader_NCA>(std::move(file));
+        return std::make_unique<AppLoader_NCA>(std::move(file), filepath);
 
     // NX deconstructed ROM directory.
     case FileType::DeconstructedRomDirectory:
-        return std::make_unique<AppLoader_DeconstructedRomDirectory>(std::move(file));
+        return std::make_unique<AppLoader_DeconstructedRomDirectory>(std::move(file), filepath);
 
     default:
         return nullptr;
     }
 }
 
-std::unique_ptr<AppLoader> GetLoader(FileSys::VirtualFile file) {
-    FileType type = IdentifyFile(file);
-    FileType filename_type = GuessFromFilename(file->GetName());
+std::unique_ptr<AppLoader> GetLoader(const std::string& filename) {
+    FileUtil::IOFile file(filename, "rb");
+    if (!file.IsOpen()) {
+        LOG_ERROR(Loader, "Failed to load file {}", filename);
+        return nullptr;
+    }
+
+    std::string filename_filename, filename_extension;
+    Common::SplitPath(filename, nullptr, &filename_filename, &filename_extension);
+
+    FileType type = IdentifyFile(file, filename);
+    FileType filename_type = GuessFromExtension(filename_extension);
 
     if (type != filename_type) {
-        LOG_WARNING(Loader, "File {} has a different type than its extension.", file->GetName());
+        LOG_WARNING(Loader, "File {} has a different type than its extension.", filename);
         if (FileType::Unknown == type)
             type = filename_type;
     }
 
-    LOG_DEBUG(Loader, "Loading file {} as {}...", file->GetName(), GetFileTypeString(type));
+    LOG_DEBUG(Loader, "Loading file {} as {}...", filename, GetFileTypeString(type));
 
-    return GetFileLoader(std::move(file), type);
+    return GetFileLoader(std::move(file), type, filename_filename, filename);
 }
 
 } // namespace Loader

src/core/loader/loader.h

@@ -13,7 +13,6 @@
 #include <boost/optional.hpp>
 #include "common/common_types.h"
 #include "common/file_util.h"
-#include "core/file_sys/vfs.h"
 #include "core/hle/kernel/kernel.h"
 
 namespace Kernel {
@@ -37,9 +36,10 @@ enum class FileType {
 /**
  * Identifies the type of a bootable file based on the magic value in its header.
  * @param file open file
+ * @param filepath Path of the file that we are opening.
  * @return FileType of file
  */
-FileType IdentifyFile(FileSys::VirtualFile file);
+FileType IdentifyFile(FileUtil::IOFile& file, const std::string& filepath);
 
 /**
  * Identifies the type of a bootable file based on the magic value in its header.
@@ -50,12 +50,12 @@ FileType IdentifyFile(FileSys::VirtualFile file);
 FileType IdentifyFile(const std::string& file_name);
 
 /**
- * Guess the type of a bootable file from its name
- * @param name String name of bootable file
+ * Guess the type of a bootable file from its extension
+ * @param extension String extension of bootable file
  * @return FileType of file. Note: this will return FileType::Unknown if it is unable to determine
  * a filetype, and will never return FileType::Error.
  */
-FileType GuessFromFilename(const std::string& name);
+FileType GuessFromExtension(const std::string& extension);
 
 /**
  * Convert a FileType into a string which can be displayed to the user.
@@ -79,7 +79,7 @@ enum class ResultStatus {
 /// Interface for loading an application
 class AppLoader : NonCopyable {
 public:
-    AppLoader(FileSys::VirtualFile file) : file(std::move(file)) {}
+    AppLoader(FileUtil::IOFile&& file) : file(std::move(file)) {}
     virtual ~AppLoader() {}
 
     /**
@@ -154,20 +154,26 @@ public:
     /**
      * Get the RomFS of the application
      * Since the RomFS can be huge, we return a file reference instead of copying to a buffer
-     * @param file The file containing the RomFS
+     * @param romfs_file The file containing the RomFS
+     * @param offset The offset the romfs begins on
+     * @param size The size of the romfs
      * @return ResultStatus result of function
      */
-    virtual ResultStatus ReadRomFS(FileSys::VirtualFile& dir) {
+    virtual ResultStatus ReadRomFS(std::shared_ptr<FileUtil::IOFile>& romfs_file, u64& offset,
+                                   u64& size) {
         return ResultStatus::ErrorNotImplemented;
     }
 
     /**
      * Get the update RomFS of the application
      * Since the RomFS can be huge, we return a file reference instead of copying to a buffer
-     * @param file The file containing the RomFS
+     * @param romfs_file The file containing the RomFS
+     * @param offset The offset the romfs begins on
+     * @param size The size of the romfs
      * @return ResultStatus result of function
      */
-    virtual ResultStatus ReadUpdateRomFS(FileSys::VirtualFile& file) {
+    virtual ResultStatus ReadUpdateRomFS(std::shared_ptr<FileUtil::IOFile>& romfs_file, u64& offset,
+                                         u64& size) {
         return ResultStatus::ErrorNotImplemented;
     }
 
@@ -181,7 +187,7 @@ public:
     }
 
 protected:
-    FileSys::VirtualFile file;
+    FileUtil::IOFile file;
     bool is_loaded = false;
 };
 
@@ -196,6 +202,6 @@ extern const std::initializer_list<Kernel::AddressMapping> default_address_mappi
  * @param filename String filename of bootable file
  * @return best loader for this file
  */
-std::unique_ptr<AppLoader> GetLoader(FileSys::VirtualFile file);
+std::unique_ptr<AppLoader> GetLoader(const std::string& filename);
 
 } // namespace Loader

src/core/loader/nca.cpp

@@ -4,11 +4,13 @@
 
 #include <vector>
 
+#include "common/common_funcs.h"
 #include "common/file_util.h"
 #include "common/logging/log.h"
+#include "common/swap.h"
 #include "core/core.h"
-#include "core/file_sys/content_archive.h"
 #include "core/file_sys/program_metadata.h"
+#include "core/file_sys/romfs_factory.h"
 #include "core/hle/kernel/process.h"
 #include "core/hle/kernel/resource_limit.h"
 #include "core/hle/service/filesystem/filesystem.h"
@@ -18,15 +20,208 @@
 
 namespace Loader {
 
-AppLoader_NCA::AppLoader_NCA(FileSys::VirtualFile file) : AppLoader(file) {}
+// Media offsets in headers are stored divided by 512. Mult. by this to get real offset.
+constexpr u64 MEDIA_OFFSET_MULTIPLIER = 0x200;
 
-FileType AppLoader_NCA::IdentifyType(const FileSys::VirtualFile& file) {
-    // TODO(DarkLordZach): Assuming everything is decrypted. Add crypto support.
-    FileSys::NCAHeader header{};
-    if (sizeof(FileSys::NCAHeader) != file->ReadObject(&header))
+constexpr u64 SECTION_HEADER_SIZE = 0x200;
+constexpr u64 SECTION_HEADER_OFFSET = 0x400;
+
+enum class NcaContentType : u8 { Program = 0, Meta = 1, Control = 2, Manual = 3, Data = 4 };
+
+enum class NcaSectionFilesystemType : u8 { PFS0 = 0x2, ROMFS = 0x3 };
+
+struct NcaSectionTableEntry {
+    u32_le media_offset;
+    u32_le media_end_offset;
+    INSERT_PADDING_BYTES(0x8);
+};
+static_assert(sizeof(NcaSectionTableEntry) == 0x10, "NcaSectionTableEntry has incorrect size.");
+
+struct NcaHeader {
+    std::array<u8, 0x100> rsa_signature_1;
+    std::array<u8, 0x100> rsa_signature_2;
+    u32_le magic;
+    u8 is_system;
+    NcaContentType content_type;
+    u8 crypto_type;
+    u8 key_index;
+    u64_le size;
+    u64_le title_id;
+    INSERT_PADDING_BYTES(0x4);
+    u32_le sdk_version;
+    u8 crypto_type_2;
+    INSERT_PADDING_BYTES(15);
+    std::array<u8, 0x10> rights_id;
+    std::array<NcaSectionTableEntry, 0x4> section_tables;
+    std::array<std::array<u8, 0x20>, 0x4> hash_tables;
+    std::array<std::array<u8, 0x10>, 0x4> key_area;
+    INSERT_PADDING_BYTES(0xC0);
+};
+static_assert(sizeof(NcaHeader) == 0x400, "NcaHeader has incorrect size.");
+
+struct NcaSectionHeaderBlock {
+    INSERT_PADDING_BYTES(3);
+    NcaSectionFilesystemType filesystem_type;
+    u8 crypto_type;
+    INSERT_PADDING_BYTES(3);
+};
+static_assert(sizeof(NcaSectionHeaderBlock) == 0x8, "NcaSectionHeaderBlock has incorrect size.");
+
+struct Pfs0Superblock {
+    NcaSectionHeaderBlock header_block;
+    std::array<u8, 0x20> hash;
+    u32_le size;
+    INSERT_PADDING_BYTES(4);
+    u64_le hash_table_offset;
+    u64_le hash_table_size;
+    u64_le pfs0_header_offset;
+    u64_le pfs0_size;
+    INSERT_PADDING_BYTES(432);
+};
+static_assert(sizeof(Pfs0Superblock) == 0x200, "Pfs0Superblock has incorrect size.");
+
+static bool IsValidNca(const NcaHeader& header) {
+    return header.magic == Common::MakeMagic('N', 'C', 'A', '2') ||
+           header.magic == Common::MakeMagic('N', 'C', 'A', '3');
+}
+
+// TODO(DarkLordZach): Add support for encrypted.
+class Nca final {
+    std::vector<FileSys::PartitionFilesystem> pfs;
+    std::vector<u64> pfs_offset;
+
+    u64 romfs_offset = 0;
+    u64 romfs_size = 0;
+
+    boost::optional<u8> exefs_id = boost::none;
+
+    FileUtil::IOFile file;
+    std::string path;
+
+    u64 GetExeFsFileOffset(const std::string& file_name) const;
+    u64 GetExeFsFileSize(const std::string& file_name) const;
+
+public:
+    ResultStatus Load(FileUtil::IOFile&& file, std::string path);
+
+    FileSys::PartitionFilesystem GetPfs(u8 id) const;
+
+    u64 GetRomFsOffset() const;
+    u64 GetRomFsSize() const;
+
+    std::vector<u8> GetExeFsFile(const std::string& file_name);
+};
+
+static bool IsPfsExeFs(const FileSys::PartitionFilesystem& pfs) {
+    // According to switchbrew, an exefs must only contain these two files:
+    return pfs.GetFileSize("main") > 0 && pfs.GetFileSize("main.npdm") > 0;
+}
+
+ResultStatus Nca::Load(FileUtil::IOFile&& in_file, std::string in_path) {
+    file = std::move(in_file);
+    path = in_path;
+    file.Seek(0, SEEK_SET);
+    std::array<u8, sizeof(NcaHeader)> header_array{};
+    if (sizeof(NcaHeader) != file.ReadBytes(header_array.data(), sizeof(NcaHeader)))
+        LOG_CRITICAL(Loader, "File reader errored out during header read.");
+
+    NcaHeader header{};
+    std::memcpy(&header, header_array.data(), sizeof(NcaHeader));
+    if (!IsValidNca(header))
+        return ResultStatus::ErrorInvalidFormat;
+
+    int number_sections =
+        std::count_if(std::begin(header.section_tables), std::end(header.section_tables),
+                      [](NcaSectionTableEntry entry) { return entry.media_offset > 0; });
+
+    for (int i = 0; i < number_sections; ++i) {
+        // Seek to beginning of this section.
+        file.Seek(SECTION_HEADER_OFFSET + i * SECTION_HEADER_SIZE, SEEK_SET);
+        std::array<u8, sizeof(NcaSectionHeaderBlock)> array{};
+        if (sizeof(NcaSectionHeaderBlock) !=
+            file.ReadBytes(array.data(), sizeof(NcaSectionHeaderBlock)))
+            LOG_CRITICAL(Loader, "File reader errored out during header read.");
+
+        NcaSectionHeaderBlock block{};
+        std::memcpy(&block, array.data(), sizeof(NcaSectionHeaderBlock));
+
+        if (block.filesystem_type == NcaSectionFilesystemType::ROMFS) {
+            romfs_offset = header.section_tables[i].media_offset * MEDIA_OFFSET_MULTIPLIER;
+            romfs_size =
+                header.section_tables[i].media_end_offset * MEDIA_OFFSET_MULTIPLIER - romfs_offset;
+        } else if (block.filesystem_type == NcaSectionFilesystemType::PFS0) {
+            Pfs0Superblock sb{};
+            // Seek back to beginning of this section.
+            file.Seek(SECTION_HEADER_OFFSET + i * SECTION_HEADER_SIZE, SEEK_SET);
+            if (sizeof(Pfs0Superblock) != file.ReadBytes(&sb, sizeof(Pfs0Superblock)))
+                LOG_CRITICAL(Loader, "File reader errored out during header read.");
+
+            u64 offset = (static_cast<u64>(header.section_tables[i].media_offset) *
+                          MEDIA_OFFSET_MULTIPLIER) +
+                         sb.pfs0_header_offset;
+            FileSys::PartitionFilesystem npfs{};
+            ResultStatus status = npfs.Load(path, offset);
+
+            if (status == ResultStatus::Success) {
+                pfs.emplace_back(std::move(npfs));
+                pfs_offset.emplace_back(offset);
+            }
+        }
+    }
+
+    for (size_t i = 0; i < pfs.size(); ++i) {
+        if (IsPfsExeFs(pfs[i]))
+            exefs_id = i;
+    }
+
+    return ResultStatus::Success;
+}
+
+FileSys::PartitionFilesystem Nca::GetPfs(u8 id) const {
+    return pfs[id];
+}
+
+u64 Nca::GetExeFsFileOffset(const std::string& file_name) const {
+    if (exefs_id == boost::none)
+        return 0;
+    return pfs[*exefs_id].GetFileOffset(file_name) + pfs_offset[*exefs_id];
+}
+
+u64 Nca::GetExeFsFileSize(const std::string& file_name) const {
+    if (exefs_id == boost::none)
+        return 0;
+    return pfs[*exefs_id].GetFileSize(file_name);
+}
+
+u64 Nca::GetRomFsOffset() const {
+    return romfs_offset;
+}
+
+u64 Nca::GetRomFsSize() const {
+    return romfs_size;
+}
+
+std::vector<u8> Nca::GetExeFsFile(const std::string& file_name) {
+    std::vector<u8> out(GetExeFsFileSize(file_name));
+    file.Seek(GetExeFsFileOffset(file_name), SEEK_SET);
+    file.ReadBytes(out.data(), GetExeFsFileSize(file_name));
+    return out;
+}
+
+AppLoader_NCA::AppLoader_NCA(FileUtil::IOFile&& file, std::string filepath)
+    : AppLoader(std::move(file)), filepath(std::move(filepath)) {}
+
+FileType AppLoader_NCA::IdentifyType(FileUtil::IOFile& file, const std::string&) {
+    file.Seek(0, SEEK_SET);
+    std::array<u8, 0x400> header_enc_array{};
+    if (0x400 != file.ReadBytes(header_enc_array.data(), 0x400))
         return FileType::Error;
 
-    if (IsValidNCA(header) && header.content_type == FileSys::NCAContentType::Program)
+    // TODO(DarkLordZach): Assuming everything is decrypted. Add crypto support.
+    NcaHeader header{};
+    std::memcpy(&header, header_enc_array.data(), sizeof(NcaHeader));
+
+    if (IsValidNca(header) && header.content_type == NcaContentType::Program)
         return FileType::NCA;
 
     return FileType::Error;
@@ -36,22 +231,17 @@ ResultStatus AppLoader_NCA::Load(Kernel::SharedPtr<Kernel::Process>& process) {
     if (is_loaded) {
         return ResultStatus::ErrorAlreadyLoaded;
     }
+    if (!file.IsOpen()) {
+        return ResultStatus::Error;
+    }
 
-    nca = std::make_unique<FileSys::NCA>(file);
-    ResultStatus result = nca->GetStatus();
+    nca = std::make_unique<Nca>();
+    ResultStatus result = nca->Load(std::move(file), filepath);
     if (result != ResultStatus::Success) {
         return result;
     }
 
-    if (nca->GetType() != FileSys::NCAContentType::Program)
-        return ResultStatus::ErrorInvalidFormat;
-
-    auto exefs = nca->GetExeFS();
-
-    if (exefs == nullptr)
-        return ResultStatus::ErrorInvalidFormat;
-
-    result = metadata.Load(exefs->GetFile("main.npdm"));
+    result = metadata.Load(nca->GetExeFsFile("main.npdm"));
     if (result != ResultStatus::Success) {
         return result;
     }
@@ -66,8 +256,7 @@ ResultStatus AppLoader_NCA::Load(Kernel::SharedPtr<Kernel::Process>& process) {
     for (const auto& module : {"rtld", "main", "subsdk0", "subsdk1", "subsdk2", "subsdk3",
                                "subsdk4", "subsdk5", "subsdk6", "subsdk7", "sdk"}) {
         const VAddr load_addr = next_load_addr;
-
-        next_load_addr = AppLoader_NSO::LoadModule(exefs->GetFile(module), load_addr);
+        next_load_addr = AppLoader_NSO::LoadModule(module, nca->GetExeFsFile(module), load_addr);
         if (next_load_addr) {
             LOG_DEBUG(Loader, "loaded module {} @ 0x{:X}", module, load_addr);
         } else {
@@ -83,11 +272,28 @@ ResultStatus AppLoader_NCA::Load(Kernel::SharedPtr<Kernel::Process>& process) {
     process->Run(Memory::PROCESS_IMAGE_VADDR, metadata.GetMainThreadPriority(),
                  metadata.GetMainThreadStackSize());
 
+    if (nca->GetRomFsSize() > 0)
+        Service::FileSystem::RegisterFileSystem(std::make_unique<FileSys::RomFS_Factory>(*this),
+                                                Service::FileSystem::Type::RomFS);
+
     is_loaded = true;
+    return ResultStatus::Success;
+}
+
+ResultStatus AppLoader_NCA::ReadRomFS(std::shared_ptr<FileUtil::IOFile>& romfs_file, u64& offset,
+                                      u64& size) {
+    if (nca->GetRomFsSize() == 0) {
+        LOG_DEBUG(Loader, "No RomFS available");
+        return ResultStatus::ErrorNotUsed;
+    }
+
+    romfs_file = std::make_shared<FileUtil::IOFile>(filepath, "rb");
+
+    offset = nca->GetRomFsOffset();
+    size = nca->GetRomFsSize();
 
-    const auto romfs = nca->GetRomFS();
-    if (romfs != nullptr)
-        Service::FileSystem::RegisterRomFS(romfs);
+    LOG_DEBUG(Loader, "RomFS offset:           0x{:016X}", offset);
+    LOG_DEBUG(Loader, "RomFS size:             0x{:016X}", size);
 
     return ResultStatus::Success;
 }

src/core/loader/nca.h

@@ -6,37 +6,44 @@
 
 #include <string>
 #include "common/common_types.h"
-#include "core/file_sys/content_archive.h"
+#include "core/file_sys/partition_filesystem.h"
 #include "core/file_sys/program_metadata.h"
 #include "core/hle/kernel/kernel.h"
 #include "core/loader/loader.h"
 
 namespace Loader {
 
+class Nca;
+
 /// Loads an NCA file
 class AppLoader_NCA final : public AppLoader {
 public:
-    explicit AppLoader_NCA(FileSys::VirtualFile file);
+    AppLoader_NCA(FileUtil::IOFile&& file, std::string filepath);
 
     /**
      * Returns the type of the file
-     * @param file std::shared_ptr<VfsFile> open file
+     * @param file FileUtil::IOFile open file
+     * @param filepath Path of the file that we are opening.
      * @return FileType found, or FileType::Error if this loader doesn't know it
      */
-    static FileType IdentifyType(const FileSys::VirtualFile& file);
+    static FileType IdentifyType(FileUtil::IOFile& file, const std::string& filepath);
 
     FileType GetFileType() override {
-        return IdentifyType(file);
+        return IdentifyType(file, filepath);
     }
 
     ResultStatus Load(Kernel::SharedPtr<Kernel::Process>& process) override;
 
+    ResultStatus ReadRomFS(std::shared_ptr<FileUtil::IOFile>& romfs_file, u64& offset,
+                           u64& size) override;
+
     ~AppLoader_NCA();
 
 private:
+    std::string filepath;
     FileSys::ProgramMetadata metadata;
 
-    std::unique_ptr<FileSys::NCA> nca;
+    std::unique_ptr<Nca> nca;
 };
 
 } // namespace Loader

src/core/loader/nro.cpp

@@ -47,12 +47,14 @@ struct ModHeader {
 };
 static_assert(sizeof(ModHeader) == 0x1c, "ModHeader has incorrect size.");
 
-AppLoader_NRO::AppLoader_NRO(FileSys::VirtualFile file) : AppLoader(file) {}
+AppLoader_NRO::AppLoader_NRO(FileUtil::IOFile&& file, std::string filepath)
+    : AppLoader(std::move(file)), filepath(std::move(filepath)) {}
 
-FileType AppLoader_NRO::IdentifyType(const FileSys::VirtualFile& file) {
+FileType AppLoader_NRO::IdentifyType(FileUtil::IOFile& file, const std::string&) {
     // Read NSO header
     NroHeader nro_header{};
-    if (sizeof(NroHeader) != file->ReadObject(&nro_header)) {
+    file.Seek(0, SEEK_SET);
+    if (sizeof(NroHeader) != file.ReadBytes(&nro_header, sizeof(NroHeader))) {
         return FileType::Error;
     }
     if (nro_header.magic == Common::MakeMagic('N', 'R', 'O', '0')) {
@@ -65,10 +67,16 @@ static constexpr u32 PageAlignSize(u32 size) {
     return (size + Memory::PAGE_MASK) & ~Memory::PAGE_MASK;
 }
 
-bool AppLoader_NRO::LoadNro(FileSys::VirtualFile file, VAddr load_base) {
+bool AppLoader_NRO::LoadNro(const std::string& path, VAddr load_base) {
+    FileUtil::IOFile file(path, "rb");
+    if (!file.IsOpen()) {
+        return {};
+    }
+
     // Read NSO header
     NroHeader nro_header{};
-    if (sizeof(NroHeader) != file->ReadObject(&nro_header)) {
+    file.Seek(0, SEEK_SET);
+    if (sizeof(NroHeader) != file.ReadBytes(&nro_header, sizeof(NroHeader))) {
         return {};
     }
     if (nro_header.magic != Common::MakeMagic('N', 'R', 'O', '0')) {
@@ -77,9 +85,10 @@ bool AppLoader_NRO::LoadNro(FileSys::VirtualFile file, VAddr load_base) {
 
     // Build program image
     Kernel::SharedPtr<Kernel::CodeSet> codeset = Kernel::CodeSet::Create("");
-    std::vector<u8> program_image = file->ReadBytes(PageAlignSize(nro_header.file_size));
-    if (program_image.size() != PageAlignSize(nro_header.file_size))
-        return {};
+    std::vector<u8> program_image;
+    program_image.resize(PageAlignSize(nro_header.file_size));
+    file.Seek(0, SEEK_SET);
+    file.ReadBytes(program_image.data(), nro_header.file_size);
 
     for (int i = 0; i < nro_header.segments.size(); ++i) {
         codeset->segments[i].addr = nro_header.segments[i].offset;
@@ -102,7 +111,7 @@ bool AppLoader_NRO::LoadNro(FileSys::VirtualFile file, VAddr load_base) {
     program_image.resize(static_cast<u32>(program_image.size()) + bss_size);
 
     // Load codeset for current process
-    codeset->name = file->GetName();
+    codeset->name = path;
     codeset->memory = std::make_shared<std::vector<u8>>(std::move(program_image));
     Core::CurrentProcess()->LoadModule(codeset, load_base);
 
@@ -113,11 +122,14 @@ ResultStatus AppLoader_NRO::Load(Kernel::SharedPtr<Kernel::Process>& process) {
     if (is_loaded) {
         return ResultStatus::ErrorAlreadyLoaded;
     }
+    if (!file.IsOpen()) {
+        return ResultStatus::Error;
+    }
 
     // Load NRO
     static constexpr VAddr base_addr{Memory::PROCESS_IMAGE_VADDR};
 
-    if (!LoadNro(file, base_addr)) {
+    if (!LoadNro(filepath, base_addr)) {
         return ResultStatus::ErrorInvalidFormat;
     }
 

src/core/loader/nro.h

@@ -15,23 +15,26 @@ namespace Loader {
 /// Loads an NRO file
 class AppLoader_NRO final : public AppLoader, Linker {
 public:
-    AppLoader_NRO(FileSys::VirtualFile file);
+    AppLoader_NRO(FileUtil::IOFile&& file, std::string filepath);
 
     /**
      * Returns the type of the file
-     * @param file std::shared_ptr<VfsFile> open file
+     * @param file FileUtil::IOFile open file
+     * @param filepath Path of the file that we are opening.
      * @return FileType found, or FileType::Error if this loader doesn't know it
      */
-    static FileType IdentifyType(const FileSys::VirtualFile& file);
+    static FileType IdentifyType(FileUtil::IOFile& file, const std::string& filepath);
 
     FileType GetFileType() override {
-        return IdentifyType(file);
+        return IdentifyType(file, filepath);
     }
 
     ResultStatus Load(Kernel::SharedPtr<Kernel::Process>& process) override;
 
 private:
-    bool LoadNro(FileSys::VirtualFile file, VAddr load_base);
+    bool LoadNro(const std::string& path, VAddr load_base);
+
+    std::string filepath;
 };
 
 } // namespace Loader

src/core/loader/nso.cpp

@@ -37,7 +37,6 @@ struct NsoHeader {
     std::array<u32_le, 3> segments_compressed_size;
 };
 static_assert(sizeof(NsoHeader) == 0x6c, "NsoHeader has incorrect size.");
-static_assert(std::is_trivially_copyable_v<NsoHeader>, "NsoHeader isn't trivially copyable.");
 
 struct ModHeader {
     u32_le magic;
@@ -50,11 +49,15 @@ struct ModHeader {
 };
 static_assert(sizeof(ModHeader) == 0x1c, "ModHeader has incorrect size.");
 
-AppLoader_NSO::AppLoader_NSO(FileSys::VirtualFile file) : AppLoader(std::move(file)) {}
+AppLoader_NSO::AppLoader_NSO(FileUtil::IOFile&& file, std::string filepath)
+    : AppLoader(std::move(file)), filepath(std::move(filepath)) {}
 
-FileType AppLoader_NSO::IdentifyType(const FileSys::VirtualFile& file) {
+FileType AppLoader_NSO::IdentifyType(FileUtil::IOFile& file, const std::string&) {
     u32 magic = 0;
-    file->ReadObject(&magic);
+    file.Seek(0, SEEK_SET);
+    if (1 != file.ReadArray<u32>(&magic, 1)) {
+        return FileType::Error;
+    }
 
     if (Common::MakeMagic('N', 'S', 'O', '0') == magic) {
         return FileType::NSO;
@@ -95,27 +98,80 @@ static constexpr u32 PageAlignSize(u32 size) {
     return (size + Memory::PAGE_MASK) & ~Memory::PAGE_MASK;
 }
 
-VAddr AppLoader_NSO::LoadModule(FileSys::VirtualFile file, VAddr load_base) {
-    if (file == nullptr)
+VAddr AppLoader_NSO::LoadModule(const std::string& name, const std::vector<u8>& file_data,
+                                VAddr load_base) {
+    if (file_data.size() < sizeof(NsoHeader))
         return {};
 
-    if (file->GetSize() < sizeof(NsoHeader))
+    NsoHeader nso_header;
+    std::memcpy(&nso_header, file_data.data(), sizeof(NsoHeader));
+
+    if (nso_header.magic != Common::MakeMagic('N', 'S', 'O', '0'))
         return {};
 
-    NsoHeader nso_header{};
-    if (sizeof(NsoHeader) != file->ReadObject(&nso_header))
+    // Build program image
+    Kernel::SharedPtr<Kernel::CodeSet> codeset = Kernel::CodeSet::Create("");
+    std::vector<u8> program_image;
+    for (int i = 0; i < nso_header.segments.size(); ++i) {
+        std::vector<u8> compressed_data(nso_header.segments_compressed_size[i]);
+        for (int j = 0; j < nso_header.segments_compressed_size[i]; ++j)
+            compressed_data[j] = file_data[nso_header.segments[i].offset + j];
+        std::vector<u8> data = DecompressSegment(compressed_data, nso_header.segments[i]);
+        program_image.resize(nso_header.segments[i].location);
+        program_image.insert(program_image.end(), data.begin(), data.end());
+        codeset->segments[i].addr = nso_header.segments[i].location;
+        codeset->segments[i].offset = nso_header.segments[i].location;
+        codeset->segments[i].size = PageAlignSize(static_cast<u32>(data.size()));
+    }
+
+    // MOD header pointer is at .text offset + 4
+    u32 module_offset;
+    std::memcpy(&module_offset, program_image.data() + 4, sizeof(u32));
+
+    // Read MOD header
+    ModHeader mod_header{};
+    // Default .bss to size in segment header if MOD0 section doesn't exist
+    u32 bss_size{PageAlignSize(nso_header.segments[2].bss_size)};
+    std::memcpy(&mod_header, program_image.data() + module_offset, sizeof(ModHeader));
+    const bool has_mod_header{mod_header.magic == Common::MakeMagic('M', 'O', 'D', '0')};
+    if (has_mod_header) {
+        // Resize program image to include .bss section and page align each section
+        bss_size = PageAlignSize(mod_header.bss_end_offset - mod_header.bss_start_offset);
+    }
+    codeset->data.size += bss_size;
+    const u32 image_size{PageAlignSize(static_cast<u32>(program_image.size()) + bss_size)};
+    program_image.resize(image_size);
+
+    // Load codeset for current process
+    codeset->name = name;
+    codeset->memory = std::make_shared<std::vector<u8>>(std::move(program_image));
+    Core::CurrentProcess()->LoadModule(codeset, load_base);
+
+    return load_base + image_size;
+}
+
+VAddr AppLoader_NSO::LoadModule(const std::string& path, VAddr load_base) {
+    FileUtil::IOFile file(path, "rb");
+    if (!file.IsOpen()) {
         return {};
+    }
 
-    if (nso_header.magic != Common::MakeMagic('N', 'S', 'O', '0'))
+    // Read NSO header
+    NsoHeader nso_header{};
+    file.Seek(0, SEEK_SET);
+    if (sizeof(NsoHeader) != file.ReadBytes(&nso_header, sizeof(NsoHeader))) {
+        return {};
+    }
+    if (nso_header.magic != Common::MakeMagic('N', 'S', 'O', '0')) {
         return {};
+    }
 
     // Build program image
     Kernel::SharedPtr<Kernel::CodeSet> codeset = Kernel::CodeSet::Create("");
     std::vector<u8> program_image;
     for (int i = 0; i < nso_header.segments.size(); ++i) {
-        const std::vector<u8> compressed_data =
-            file->ReadBytes(nso_header.segments_compressed_size[i], nso_header.segments[i].offset);
-        std::vector<u8> data = DecompressSegment(compressed_data, nso_header.segments[i]);
+        std::vector<u8> data =
+            ReadSegment(file, nso_header.segments[i], nso_header.segments_compressed_size[i]);
         program_image.resize(nso_header.segments[i].location);
         program_image.insert(program_image.end(), data.begin(), data.end());
         codeset->segments[i].addr = nso_header.segments[i].location;
@@ -142,7 +198,7 @@ VAddr AppLoader_NSO::LoadModule(FileSys::VirtualFile file, VAddr load_base) {
     program_image.resize(image_size);
 
     // Load codeset for current process
-    codeset->name = file->GetName();
+    codeset->name = path;
     codeset->memory = std::make_shared<std::vector<u8>>(std::move(program_image));
     Core::CurrentProcess()->LoadModule(codeset, load_base);
 
@@ -153,10 +209,13 @@ ResultStatus AppLoader_NSO::Load(Kernel::SharedPtr<Kernel::Process>& process) {
     if (is_loaded) {
         return ResultStatus::ErrorAlreadyLoaded;
     }
+    if (!file.IsOpen()) {
+        return ResultStatus::Error;
+    }
 
     // Load module
-    LoadModule(file, Memory::PROCESS_IMAGE_VADDR);
-    LOG_DEBUG(Loader, "loaded module {} @ 0x{:X}", file->GetName(), Memory::PROCESS_IMAGE_VADDR);
+    LoadModule(filepath, Memory::PROCESS_IMAGE_VADDR);
+    LOG_DEBUG(Loader, "loaded module {} @ 0x{:X}", filepath, Memory::PROCESS_IMAGE_VADDR);
 
     process->svc_access_mask.set();
     process->address_mappings = default_address_mappings;

src/core/loader/nso.h

@@ -15,22 +15,29 @@ namespace Loader {
 /// Loads an NSO file
 class AppLoader_NSO final : public AppLoader, Linker {
 public:
-    explicit AppLoader_NSO(FileSys::VirtualFile file);
+    AppLoader_NSO(FileUtil::IOFile&& file, std::string filepath);
 
     /**
      * Returns the type of the file
-     * @param file std::shared_ptr<VfsFile> open file
+     * @param file FileUtil::IOFile open file
+     * @param filepath Path of the file that we are opening.
      * @return FileType found, or FileType::Error if this loader doesn't know it
      */
-    static FileType IdentifyType(const FileSys::VirtualFile& file);
+    static FileType IdentifyType(FileUtil::IOFile& file, const std::string& filepath);
 
     FileType GetFileType() override {
-        return IdentifyType(file);
+        return IdentifyType(file, filepath);
     }
 
-    static VAddr LoadModule(FileSys::VirtualFile file, VAddr load_base);
+    static VAddr LoadModule(const std::string& name, const std::vector<u8>& file_data,
+                            VAddr load_base);
+
+    static VAddr LoadModule(const std::string& path, VAddr load_base);
 
     ResultStatus Load(Kernel::SharedPtr<Kernel::Process>& process) override;
+
+private:
+    std::string filepath;
 };
 
 } // namespace Loader

src/yuzu/game_list.cpp

@@ -12,7 +12,6 @@
 #include "common/common_paths.h"
 #include "common/logging/log.h"
 #include "common/string_util.h"
-#include "core/file_sys/vfs_real.h"
 #include "core/loader/loader.h"
 #include "game_list.h"
 #include "game_list_p.h"
@@ -405,8 +404,7 @@ void GameListWorker::AddFstEntriesToGameList(const std::string& dir_path, unsign
         bool is_dir = FileUtil::IsDirectory(physical_name);
         if (!is_dir &&
             (HasSupportedFileExtension(physical_name) || IsExtractedNCAMain(physical_name))) {
-            std::unique_ptr<Loader::AppLoader> loader =
-                Loader::GetLoader(std::make_shared<FileSys::RealVfsFile>(physical_name));
+            std::unique_ptr<Loader::AppLoader> loader = Loader::GetLoader(physical_name);
             if (!loader)
                 return true;