sgilissen/llamaplayer
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

System: Rewrite EXE override/loading

Browse Source 
Relies on POST=7 as a kernel initialization indicator, instead of
patching the BIOS.

Fixes EXE loading with OpenBIOS and PS2 BIOS, and fast boot getting
baked into save states.
This commit is contained in:
Stenzek
2024-07-28 16:16:05 +10:00
parent 7b99fcbbf3
commit 6fe0c986fa
13 changed files with 327 additions and 322 deletions
Download Patch File Download Diff File Expand all files Collapse all files

45
src/core/bios.cpp
View File

@ -19,6 +19,7 @@ Log_SetChannel(BIOS);
namespace BIOS {
static const ImageInfo* GetInfoForHash(const std::span<u8> image, const ImageInfo::Hash& hash);
static void PatchBIOS(u8* image, u32 image_size, u32 address, u32 value, u32 mask = UINT32_C(0xFFFFFFFF));
static constexpr ImageInfo::Hash MakeHashFromString(const char str[])
{
@ -255,54 +256,16 @@ bool BIOS::PatchBIOSFastBoot(u8* image, u32 image_size)
return true;
}
bool BIOS::PatchBIOSForEXE(u8* image, u32 image_size, u32 r_pc, u32 r_gp, u32 r_sp, u32 r_fp)
{
#define PATCH(offset, value) PatchBIOS(image, image_size, (offset), (value))
// pc has to be done first because we can't load it in the delay slot
PATCH(0xBFC06FF0, UINT32_C(0x3C080000) | r_pc >> 16); // lui $t0, (r_pc >> 16)
PATCH(0xBFC06FF4, UINT32_C(0x35080000) | (r_pc & UINT32_C(0xFFFF))); // ori $t0, $t0, (r_pc & 0xFFFF)
PATCH(0xBFC06FF8, UINT32_C(0x3C1C0000) | r_gp >> 16); // lui $gp, (r_gp >> 16)
PATCH(0xBFC06FFC, UINT32_C(0x379C0000) | (r_gp & UINT32_C(0xFFFF))); // ori $gp, $gp, (r_gp & 0xFFFF)
if (r_sp != 0)
{
PATCH(0xBFC07000, UINT32_C(0x3C1D0000) | r_sp >> 16); // lui $sp, (r_sp >> 16)
PATCH(0xBFC07004, UINT32_C(0x37BD0000) | (r_sp & UINT32_C(0xFFFF))); // ori $sp, $sp, (r_sp & 0xFFFF)
}
else
{
PATCH(0xBFC07000, UINT32_C(0x00000000)); // nop
PATCH(0xBFC07004, UINT32_C(0x00000000)); // nop
}
if (r_fp != 0)
{
PATCH(0xBFC07008, UINT32_C(0x3C1E0000) | r_fp >> 16); // lui $fp, (r_fp >> 16)
PATCH(0xBFC0700C, UINT32_C(0x01000008)); // jr $t0
PATCH(0xBFC07010, UINT32_C(0x37DE0000) | (r_fp & UINT32_C(0xFFFF))); // ori $fp, $fp, (r_fp & 0xFFFF)
}
else
{
PATCH(0xBFC07008, UINT32_C(0x00000000)); // nop
PATCH(0xBFC0700C, UINT32_C(0x01000008)); // jr $t0
PATCH(0xBFC07010, UINT32_C(0x00000000)); // nop
}
#undef PATCH
return true;
}
bool BIOS::IsValidPSExeHeader(const PSEXEHeader& header, u32 file_size)
bool BIOS::IsValidPSExeHeader(const PSEXEHeader& header, size_t file_size)
{
static constexpr char expected_id[] = {'P', 'S', '-', 'X', ' ', 'E', 'X', 'E'};
if (std::memcmp(header.id, expected_id, sizeof(expected_id)) != 0)
if (file_size < sizeof(expected_id) || std::memcmp(header.id, expected_id, sizeof(expected_id)) != 0)
return false;
if ((header.file_size + sizeof(PSEXEHeader)) > file_size)
{
WARNING_LOG("Incorrect file size in PS-EXE header: {} bytes should not be greater than {} bytes", header.file_size,
static_cast<unsigned>(file_size - sizeof(PSEXEHeader)));
file_size - sizeof(PSEXEHeader));
}
return true;