service: Remove remaining uses of BufferDescriptor*.

src/core/hle/service/acc/acc_u0.cpp

@@ -66,8 +66,7 @@ void ACC_U0::GetUserExistence(Kernel::HLERequestContext& ctx) {
 
 void ACC_U0::ListAllUsers(Kernel::HLERequestContext& ctx) {
     constexpr std::array<u128, 10> user_ids{DEFAULT_USER_ID};
-    const auto& output_buffer = ctx.BufferDescriptorC()[0];
-    Memory::WriteBlock(output_buffer.Address(), user_ids.data(), user_ids.size());
+    ctx.WriteBuffer(user_ids.data(), user_ids.size());
     IPC::ResponseBuilder rb{ctx, 2};
     rb.Push(RESULT_SUCCESS);
     LOG_DEBUG(Service_ACC, "called");

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

@@ -306,11 +306,11 @@ private:
 
         u64 offset = rp.Pop<u64>();
 
-        const auto& output_buffer = ctx.BufferDescriptorC()[0];
+        const size_t size{ctx.GetWriteBufferSize()};
 
-        ASSERT(offset + output_buffer.Size() <= buffer.size());
+        ASSERT(offset + size <= buffer.size());
 
-        Memory::WriteBlock(output_buffer.Address(), buffer.data() + offset, output_buffer.Size());
+        ctx.WriteBuffer(buffer.data() + offset, size);
 
         IPC::ResponseBuilder rb{ctx, 2};
 

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

@@ -33,12 +33,10 @@ private:
         IPC::RequestParser rp{ctx};
         const s64 offset = rp.Pop<s64>();
         const s64 length = rp.Pop<s64>();
-        const auto& descriptor = ctx.BufferDescriptorB()[0];
 
         LOG_DEBUG(Service_FS, "called, offset=0x%llx, length=0x%llx", offset, length);
 
         // Error checking
-        ASSERT_MSG(length == descriptor.Size(), "unexpected size difference");
         if (length < 0) {
             IPC::ResponseBuilder rb{ctx, 2};
             rb.Push(ResultCode(ErrorModule::FS, ErrorDescription::InvalidLength));
@@ -60,7 +58,7 @@ private:
         }
 
         // Write the data to memory
-        Memory::WriteBlock(descriptor.Address(), output.data(), descriptor.Size());
+        ctx.WriteBuffer(output);
 
         IPC::ResponseBuilder rb{ctx, 2};
         rb.Push(RESULT_SUCCESS);

src/core/hle/service/nvdrv/interface.cpp

@@ -14,9 +14,8 @@ namespace Nvidia {
 void NVDRV::Open(Kernel::HLERequestContext& ctx) {
     LOG_DEBUG(Service_NVDRV, "called");
 
-    auto buffer = ctx.BufferDescriptorA()[0];
-
-    std::string device_name = Memory::ReadCString(buffer.Address(), buffer.Size());
+    const auto& buffer = ctx.ReadBuffer();
+    std::string device_name(buffer.begin(), buffer.end());
 
     u32 fd = nvdrv->Open(device_name);
     IPC::ResponseBuilder rb{ctx, 4};

src/core/hle/service/set/set.cpp

@@ -17,9 +17,7 @@ void SET::GetAvailableLanguageCodes(Kernel::HLERequestContext& ctx) {
     u32 id = rp.Pop<u32>();
     constexpr std::array<u8, 13> lang_codes{};
 
-    const auto& output_buffer = ctx.BufferDescriptorC()[0];
-
-    Memory::WriteBlock(output_buffer.Address(), lang_codes.data(), lang_codes.size());
+    ctx.WriteBuffer(lang_codes.data(), lang_codes.size());
 
     IPC::ResponseBuilder rb{ctx, 2};