From 3effa1238f67e3f61141830a932a076f1fe9326d Mon Sep 17 00:00:00 2001
From: Connor McLaughlin <stenzek@gmail.com>
Date: Thu, 12 Mar 2020 13:51:53 +1000
Subject: [PATCH] CDROM: Return correct SCEx string based on disc region

Fixes SCEI/SCEE displaying as SCEE in BIOS.
---
 src/core/cdrom.cpp  | 52 ++++++++++++++++++++++++++++++---------------
 src/core/cdrom.h    |  3 ++-
 src/core/system.cpp |  3 ++-
 3 files changed, 39 insertions(+), 19 deletions(-)

diff --git a/src/core/cdrom.cpp b/src/core/cdrom.cpp
index 88fc17b89..a8b4d1d9e 100644
--- a/src/core/cdrom.cpp
+++ b/src/core/cdrom.cpp
@@ -3,6 +3,7 @@
 #include "common/log.h"
 #include "common/state_wrapper.h"
 #include "dma.h"
+#include "game_list.h"
 #include "imgui.h"
 #include "interrupt_controller.h"
 #include "settings.h"
@@ -153,6 +154,11 @@ void CDROM::InsertMedia(std::unique_ptr<CDImage> media)
   if (HasMedia())
     RemoveMedia();
 
+  // set the region from the system area of the disc
+  m_disc_region = GameList::GetRegionForImage(media.get());
+  Log_InfoPrintf("Inserting new media, disc region: %s, console region: %s", Settings::GetDiscRegionName(m_disc_region),
+                 Settings::GetConsoleRegionName(m_system->GetRegion()));
+
   m_reader.SetMedia(std::move(media));
 }
 
@@ -165,6 +171,7 @@ void CDROM::RemoveMedia()
   m_reader.RemoveMedia();
 
   m_secondary_status.shell_open = true;
+  m_disc_region = DiscRegion::Other;
 
   // If the drive was doing anything, we need to abort the command.
   if (m_drive_state != DriveState::Idle)
@@ -586,17 +593,10 @@ void CDROM::ExecuteCommand()
     case Command::GetID:
     {
       Log_DebugPrintf("CDROM GetID command");
-      if (!HasMedia())
-      {
-        SendErrorResponse(STAT_ERROR, 0x80);
-      }
-      else
-      {
-        SendACKAndStat();
+      SendACKAndStat();
 
-        m_drive_state = DriveState::ReadingID;
-        m_drive_event->Schedule(18000);
-      }
+      m_drive_state = DriveState::ReadingID;
+      m_drive_event->Schedule(18000);
 
       EndCommand();
       return;
@@ -1291,20 +1291,38 @@ void CDROM::DoChangeSessionComplete()
 
 void CDROM::DoIDRead()
 {
-  // TODO: This should depend on the disc type/region...
-
   Log_DebugPrintf("ID read complete");
   m_drive_state = DriveState::Idle;
   m_drive_event->Deactivate();
   m_secondary_status.ClearActiveBits();
-  m_secondary_status.motor_on = true;
+  m_secondary_status.motor_on = HasMedia();
   m_sector_buffer.clear();
 
-  static constexpr u8 response2[] = {0x00, 0x20, 0x00, 0x53, 0x43, 0x45, 0x41}; // last byte is 0x49 for EU
+  // TODO: Audio CD.
+  u8 stat_byte = m_secondary_status.bits;
+  u8 flags_byte = 0;
+  if (!HasMedia())
+  {
+    flags_byte |= (1 << 6); // Disc Missing
+  }
+  else if (m_disc_region == DiscRegion::Other)
+  {
+    stat_byte |= STAT_ID_ERROR;
+    flags_byte |= (1 << 7); // Unlicensed
+  }
+
   m_async_response_fifo.Clear();
-  m_async_response_fifo.Push(m_secondary_status.bits);
-  m_async_response_fifo.PushRange(response2, countof(response2));
-  SetAsyncInterrupt(Interrupt::Complete);
+  m_async_response_fifo.Push(stat_byte);
+  m_async_response_fifo.Push(flags_byte);
+  m_async_response_fifo.Push(0x20); // TODO: Disc type from TOC
+  m_async_response_fifo.Push(0x00); // TODO: Session info?
+
+  static constexpr u32 REGION_STRING_LENGTH = 4;
+  static constexpr std::array<std::array<u8, REGION_STRING_LENGTH>, static_cast<size_t>(DiscRegion::Count)>
+    region_strings = {{{'S', 'C', 'E', 'I'}, {'S', 'C', 'E', 'A'}, {'S', 'C', 'E', 'E'}, {0, 0, 0, 0}}};
+  m_async_response_fifo.PushRange(region_strings[static_cast<u8>(m_disc_region)].data(), REGION_STRING_LENGTH);
+
+  SetAsyncInterrupt((flags_byte != 0) ? Interrupt::Error : Interrupt::Complete);
 }
 
 void CDROM::DoTOCRead()
diff --git a/src/core/cdrom.h b/src/core/cdrom.h
index 2b11883f0..bab35be2e 100644
--- a/src/core/cdrom.h
+++ b/src/core/cdrom.h
@@ -1,10 +1,10 @@
 #pragma once
+#include "cdrom_async_reader.h"
 #include "common/bitfield.h"
 #include "common/cd_image.h"
 #include "common/cd_xa.h"
 #include "common/fifo_queue.h"
 #include "common/heap_array.h"
-#include "cdrom_async_reader.h"
 #include "types.h"
 #include <array>
 #include <string>
@@ -239,6 +239,7 @@ private:
 
   Command m_command = Command::None;
   DriveState m_drive_state = DriveState::Idle;
+  DiscRegion m_disc_region = DiscRegion::Other;
 
   StatusRegister m_status = {};
   SecondaryStatusRegister m_secondary_status = {};
diff --git a/src/core/system.cpp b/src/core/system.cpp
index 6555d556f..1ddf6b5e2 100644
--- a/src/core/system.cpp
+++ b/src/core/system.cpp
@@ -207,7 +207,8 @@ bool System::Boot(const SystemBootParameters& params)
   UpdateRunningGame(params.filename.c_str(), media.get());
 
   // Insert CD, and apply fastboot patch if enabled.
-  m_cdrom->InsertMedia(std::move(media));
+  if (media)
+    m_cdrom->InsertMedia(std::move(media));
   if (m_cdrom->HasMedia() &&
       (params.override_fast_boot.has_value() ? params.override_fast_boot.value() : GetSettings().bios_patch_fast_boot))
   {