piwalker/melonDS
1
0
Fork 0
mirror of https://github.com/melonDS-emu/melonDS.git synced 2024-11-14 13:27:41 -07:00
Code Issues Actions 3 Packages Projects Releases Wiki Activity

more weirdness

Browse Source
This commit is contained in:
Jaklyy 2024-06-09 07:25:42 -04:00
parent b846c6f100
commit be60c68aeb
1 changed files with 29 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

38
src/ARM.cpp
View File

@ -288,11 +288,19 @@ void ARM::SetupCodeMem(u32 addr)
void ARMv5::BuggedJumpTo32(const u32 addr)
{
// ldrd to pc
// behavior seems to be related to if a bugged 8/16 bit write has prefetch aborted (does any p.abort work?)
// switching to thumb mode only seems to work the first time after one of the above aborts?
// writing to pc seems to fail entirely if an abort hasn't occured and thumb interworking is in v4 mode
if (BuggyJump == 1)
{
BuggyJump = 2;
JumpTo(addr);
}
else if ((BuggyJump == 0) && (CP15Control & (1<<15)))
{
return; // checkme
}
else
{
JumpTo(addr & ~0x1);
@ -301,15 +309,27 @@ void ARMv5::BuggedJumpTo32(const u32 addr)
void ARMv5::BuggedJumpTo(const u32 addr)
{
if ((BuggyJump == 0) && (addr & 0x3))
// 16 and 8 bit loads (signed instructions included) to pc
// if they're misaligned they'll prefetch abort
// but they can only prefetch abort once, every time afterwards will succeed (more testing needed)
// if the lsb is set they will try to switch to thumb state, though it'll fail if they haven't prefetch aborted yet
// they work as expected if thumb interwork is set to v4 mode
if (BuggyJump == 0)
{
BuggyJump = 1;
PrefetchAbort(); // checkme
}
else
{
JumpTo(addr);
if (CP15Control & (1<<15))
{
JumpTo(addr & ~1);
return;
}
else if (addr & 0x3)
{
if (addr & 0x1) CPSR |= 0x20;
BuggyJump = 1;
PrefetchAbort();
return;
}
}
JumpTo(addr);
}
void ARMv5::JumpTo(u32 addr, bool restorecpsr)
@ -382,12 +402,12 @@ void ARMv5::JumpTo(u32 addr, bool restorecpsr)
void ARMv4::BuggedJumpTo32(const u32 addr)
{
JumpTo(addr); // todo
JumpTo(addr & ~1); // todo
}
void ARMv4::BuggedJumpTo(const u32 addr)
{
JumpTo(addr); // todo
JumpTo(addr & ~1); // todo
}
void ARMv4::JumpTo(u32 addr, bool restorecpsr)