From 0e2276fc7af769e3d22533a5474e031df20b4dec Mon Sep 17 00:00:00 2001
From: Albert Liu <45282415+ggrtk@users.noreply.github.com>
Date: Fri, 25 Dec 2020 07:33:33 -0800
Subject: [PATCH] BIOS: Add support for loading PS2 BIOSes

---
 src/core/bios.cpp           | 6 ++++--
 src/core/bios.h             | 3 ++-
 src/core/host_interface.cpp | 4 ++--
 src/core/host_interface.h   | 2 +-
 4 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/src/core/bios.cpp b/src/core/bios.cpp
index 9a86d3e73..3a47775f3 100644
--- a/src/core/bios.cpp
+++ b/src/core/bios.cpp
@@ -101,9 +101,11 @@ std::optional<Image> LoadImageFromFile(const char* filename)
   const u32 size = static_cast<u32>(std::ftell(fp.get()));
   std::fseek(fp.get(), 0, SEEK_SET);
 
-  if (size != BIOS_SIZE)
+  // Apparently some PS1/PS2 BIOS revisions found on the PS3 are neither 512KB nor 4MB, so just check within this range
+  if (size < BIOS_SIZE || size > BIOS_SIZE_PS2)
   {
-    Log_ErrorPrintf("BIOS image '%s' mismatch, expecting %u bytes, got %u bytes", filename, BIOS_SIZE, size);
+    Log_ErrorPrintf("BIOS image '%s' mismatch, expecting between %u and %u bytes, got %u bytes", filename, BIOS_SIZE,
+                    BIOS_SIZE_PS2, size);
     return std::nullopt;
   }
 
diff --git a/src/core/bios.h b/src/core/bios.h
index ee298399f..3367407f0 100644
--- a/src/core/bios.h
+++ b/src/core/bios.h
@@ -9,7 +9,8 @@ namespace BIOS {
 enum : u32
 {
   BIOS_BASE = 0x1FC00000,
-  BIOS_SIZE = 0x80000
+  BIOS_SIZE = 0x80000,
+  BIOS_SIZE_PS2 = 0x400000
 };
 
 using Image = std::vector<u8>;
diff --git a/src/core/host_interface.cpp b/src/core/host_interface.cpp
index 4092ecc19..c946bbdd7 100644
--- a/src/core/host_interface.cpp
+++ b/src/core/host_interface.cpp
@@ -304,7 +304,7 @@ std::optional<std::vector<u8>> HostInterface::FindBIOSImageInDirectory(ConsoleRe
 
   for (const FILESYSTEM_FIND_DATA& fd : results)
   {
-    if (fd.Size != BIOS::BIOS_SIZE)
+    if (fd.Size < BIOS::BIOS_SIZE || fd.Size > BIOS::BIOS_SIZE_PS2)
     {
       Log_WarningPrintf("Skipping '%s': incorrect size", fd.FileName.c_str());
       continue;
@@ -353,7 +353,7 @@ HostInterface::FindBIOSImagesInDirectory(const char* directory)
 
   for (FILESYSTEM_FIND_DATA& fd : files)
   {
-    if (fd.Size != BIOS::BIOS_SIZE)
+    if (fd.Size < BIOS::BIOS_SIZE || fd.Size > BIOS::BIOS_SIZE_PS2)
       continue;
 
     std::string full_path(
diff --git a/src/core/host_interface.h b/src/core/host_interface.h
index c984f7d91..557c8d1b6 100644
--- a/src/core/host_interface.h
+++ b/src/core/host_interface.h
@@ -126,7 +126,7 @@ public:
   std::optional<std::vector<u8>> GetBIOSImage(ConsoleRegion region);
 
   /// Searches for a BIOS image for the specified region in the specified directory. If no match is found, the first
-  /// 512KB BIOS image will be used.
+  /// BIOS image within 512KB and 4MB will be used.
   std::optional<std::vector<u8>> FindBIOSImageInDirectory(ConsoleRegion region, const char* directory);
 
   /// Returns a list of filenames and descriptions for BIOS images in a directory.