System: Simplify save state booting

Fixes memory card warning messages on load state.

src/core/host_interface.cpp

@@ -82,13 +82,13 @@ void HostInterface::CreateAudioStream()
 
 bool HostInterface::BootSystem(const SystemBootParameters& parameters)
 {
-  if (parameters.filename.empty())
-    Log_InfoPrintf("Boot Filename: <BIOS/Shell>");
-  else
-    Log_InfoPrintf("Boot Filename: %s", parameters.filename.c_str());
-
-  if (!parameters.state_filename.empty())
-    Log_InfoPrintf("Save State Filename: %s", parameters.filename.c_str());
+  if (!parameters.state_stream)
+  {
+    if (parameters.filename.empty())
+      Log_InfoPrintf("Boot Filename: <BIOS/Shell>");
+    else
+      Log_InfoPrintf("Boot Filename: %s", parameters.filename.c_str());
+  }
 
   if (!AcquireHostDisplay())
   {
@@ -111,9 +111,6 @@ bool HostInterface::BootSystem(const SystemBootParameters& parameters)
     return false;
   }
 
-  if (!parameters.state_filename.empty())
-    LoadState(parameters.state_filename.c_str());
-
   OnSystemCreated();
 
   m_paused = m_settings.start_paused;
@@ -475,18 +472,9 @@ bool HostInterface::LoadState(const char* filename)
   else
   {
     SystemBootParameters boot_params;
+    boot_params.state_stream = std::move(stream);
     if (!BootSystem(boot_params))
-    {
-      ReportFormattedError("Failed to boot system to load state from '%s'.", filename);
       return false;
-    }
-
-    if (!m_system->LoadState(stream.get()))
-    {
-      ReportFormattedError("Failed to load state. The log may contain more information. Shutting down system.");
-      DestroySystem();
-      return false;
-    }
   }
 
   m_system->ResetPerformanceCounters();
@@ -1219,19 +1207,13 @@ void HostInterface::RecreateSystem()
   DestroySystem();
 
   SystemBootParameters boot_params;
+  boot_params.state_stream = std::move(stream);
   if (!BootSystem(boot_params))
   {
     ReportError("Failed to boot system after recreation.");
     return;
   }
 
-  if (!m_system->LoadState(stream.get()))
-  {
-    ReportError("Failed to load state after system recreation. Shutting down.");
-    DestroySystem();
-    return;
-  }
-
   m_system->ResetPerformanceCounters();
   PauseSystem(was_paused);
 }

src/core/save_state_version.h

@@ -2,7 +2,7 @@
 #include "types.h"
 
 static constexpr u32 SAVE_STATE_MAGIC = 0x43435544;
-static constexpr u32 SAVE_STATE_VERSION = 35;
+static constexpr u32 SAVE_STATE_VERSION = 36;
 
 #pragma pack(push, 4)
 struct SAVE_STATE_HEADER
@@ -18,6 +18,9 @@ struct SAVE_STATE_HEADER
   char title[MAX_TITLE_LENGTH];
   char game_code[MAX_GAME_CODE_LENGTH];
 
+  u32 media_filename_length;
+  u32 offset_to_media_filename;
+  
   u32 screenshot_width;
   u32 screenshot_height;
   u32 screenshot_size;

src/core/system.cpp

@@ -37,6 +37,13 @@ SystemBootParameters::SystemBootParameters() = default;
 
 SystemBootParameters::SystemBootParameters(std::string filename_) : filename(filename_) {}
 
+SystemBootParameters::SystemBootParameters(const SystemBootParameters& copy)
+  : filename(copy.filename), override_fast_boot(copy.override_fast_boot), override_fullscreen(copy.override_fullscreen)
+{
+  // only exists for qt, we can't copy the state stream
+  Assert(!copy.state_stream);
+}
+
 SystemBootParameters::~SystemBootParameters() = default;
 
 System::System(HostInterface* host_interface) : m_host_interface(host_interface)
@@ -130,6 +137,9 @@ void System::SetCPUExecutionMode(CPUExecutionMode mode)
 
 bool System::Boot(const SystemBootParameters& params)
 {
+  if (params.state_stream)
+    return DoLoadState(params.state_stream.get(), true);
+
   // Load CD image up and detect region.
   std::unique_ptr<CDImage> media;
   bool exe_boot = false;
@@ -318,34 +328,6 @@ bool System::DoState(StateWrapper& sw)
   sw.Do(&m_internal_frame_number);
   sw.Do(&m_global_tick_counter);
 
-  std::string media_filename = m_cdrom->GetMediaFileName();
-  sw.Do(&media_filename);
-
-  bool media_is_bad = false;
-  if (sw.IsReading())
-  {
-    std::unique_ptr<CDImage> media;
-    if (!media_filename.empty())
-    {
-      media = CDImage::Open(media_filename.c_str());
-      if (!media)
-      {
-        Log_ErrorPrintf("Failed to open CD image from save state: '%s'. Disc will be removed.", media_filename.c_str());
-        media_is_bad = true;
-      }
-    }
-
-    UpdateRunningGame(media_filename.c_str(), media.get());
-    if (GetSettings().HasAnyPerGameMemoryCards())
-      UpdateMemoryCards();
-
-    m_cdrom->Reset();
-    if (media)
-      m_cdrom->InsertMedia(std::move(media));
-    else
-      m_cdrom->RemoveMedia();
-  }
-
   if (!sw.DoMarker("CPU") || !m_cpu->DoState(sw))
     return false;
 
@@ -385,9 +367,6 @@ bool System::DoState(StateWrapper& sw)
   if (!sw.DoMarker("Events") || !DoEventsState(sw))
     return false;
 
-  if (media_is_bad)
-    m_cdrom->RemoveMedia(true);
-
   return !sw.HasError();
 }
 
@@ -413,6 +392,11 @@ void System::Reset()
 }
 
 bool System::LoadState(ByteStream* state)
+{
+  return DoLoadState(state, false);
+}
+
+bool System::DoLoadState(ByteStream* state, bool init_components)
 {
   SAVE_STATE_HEADER header;
   if (!state->Read2(&header, sizeof(header)))
@@ -428,6 +412,49 @@ bool System::LoadState(ByteStream* state)
     return false;
   }
 
+  std::string media_filename;
+  std::unique_ptr<CDImage> media;
+  if (header.media_filename_length > 0)
+  {
+    media_filename.resize(header.media_filename_length);
+    if (!state->SeekAbsolute(header.offset_to_media_filename) ||
+        !state->Read2(media_filename.data(), header.media_filename_length))
+    {
+      return false;
+    }
+
+    media = CDImage::Open(media_filename.c_str());
+    if (!media)
+    {
+      m_host_interface->ReportFormattedError("Failed to open CD image from save state: '%s'.", media_filename.c_str());
+      return false;
+    }
+  }
+
+  UpdateRunningGame(media_filename.c_str(), media.get());
+
+  if (init_components)
+  {
+    InitializeComponents();
+    UpdateControllers();
+    UpdateMemoryCards();
+
+    if (media)
+      m_cdrom->InsertMedia(std::move(media));
+  }
+  else
+  {
+    m_cdrom->Reset();
+    if (media)
+      m_cdrom->InsertMedia(std::move(media));
+    else
+      m_cdrom->RemoveMedia();
+
+    // ensure the correct card is loaded
+    if (GetSettings().HasAnyPerGameMemoryCards())
+      UpdateMemoryCards();
+  }
+
   if (header.data_compression_type != 0)
   {
     m_host_interface->ReportFormattedError("Unknown save state compression type %u", header.data_compression_type);
@@ -455,6 +482,12 @@ bool System::SaveState(ByteStream* state)
   StringUtil::Strlcpy(header.title, m_running_game_title.c_str(), sizeof(header.title));
   StringUtil::Strlcpy(header.game_code, m_running_game_code.c_str(), sizeof(header.game_code));
 
+  std::string media_filename = m_cdrom->GetMediaFileName();
+  header.offset_to_media_filename = static_cast<u32>(state->GetPosition());
+  header.media_filename_length = static_cast<u32>(media_filename.length());
+  if (!media_filename.empty() && !state->Write2(media_filename.data(), header.media_filename_length))
+    return false;
+
   // save screenshot
   {
     const u32 screenshot_width = 128;

src/core/system.h

@@ -32,12 +32,13 @@ struct SystemBootParameters
 {
   SystemBootParameters();
   SystemBootParameters(std::string filename_);
+  SystemBootParameters(const SystemBootParameters& copy);
   ~SystemBootParameters();
 
   std::string filename;
-  std::string state_filename;
   std::optional<bool> override_fast_boot;
   std::optional<bool> override_fullscreen;
+  std::unique_ptr<ByteStream> state_stream;
 };
 
 class System
@@ -143,6 +144,7 @@ public:
 private:
   System(HostInterface* host_interface);
 
+  bool DoLoadState(ByteStream* stream, bool init_components);
   bool DoState(StateWrapper& sw);
   bool CreateGPU(GPURenderer renderer);
 

src/frontend-common/common_host_interface.cpp

@@ -1,6 +1,7 @@
 #include "common_host_interface.h"
 #include "common/assert.h"
 #include "common/audio_stream.h"
+#include "common/byte_stream.h"
 #include "common/file_system.h"
 #include "common/log.h"
 #include "common/string_util.h"
@@ -289,9 +290,22 @@ bool CommonHostInterface::ParseCommandLineParameters(int argc, char* argv[],
 
     std::unique_ptr<SystemBootParameters> boot_params = std::make_unique<SystemBootParameters>();
     boot_params->filename = std::move(boot_filename);
-    boot_params->state_filename = std::move(state_filename);
     boot_params->override_fast_boot = std::move(force_fast_boot);
     boot_params->override_fullscreen = std::move(force_fullscreen);
+
+    if (!state_filename.empty())
+    {
+      std::unique_ptr<ByteStream> state_stream =
+        FileSystem::OpenFile(state_filename.c_str(), BYTESTREAM_OPEN_READ | BYTESTREAM_OPEN_STREAMED);
+      if (!state_stream)
+      {
+        Log_ErrorPrintf("Failed to open save state file '%s'", state_filename.c_str());
+        return false;
+      }
+
+      boot_params->state_stream = std::move(state_stream);
+    }
+
     *out_boot_params = std::move(boot_params);
   }