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Workaround bug in Kurohyou 2 (uninitialized data.)

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The game calls scePsmfGetEPWithTimestamp(), but without any chapters.
This means nothing is written to its pointer.  But it takes the value
there anyway.

It happens that the value there is 0, but only because something wrote it
to the stack before the call.  It seems like scePsmfVerifyPsmf() is the
one writing it, since it has a different value shortly before that call.

So, as a workaround, just write some 0s into the stack.  Games without
bugs should not care.  Hard to predict what will happen to another buggy
game.
This commit is contained in:
Unknown W. Brackets 2014-03-02 01:15:00 -08:00
parent d2ce324c52
commit 87a07d7355
2 changed files with 9 additions and 6 deletions
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2
Core/HLE/sceKernelModule.cpp
View file

@ -1046,7 +1046,7 @@ Module *__KernelLoadELFFromPtr(const u8 *ptr, u32 loadAddress, std::string *erro
for (int i = 0; i < entry->numFuncs; ++i) {
// This is the id of the import.
func.nid = nidDataPtr[i];
// This is the address to write the j abnd delay slot to.
// This is the address to write the j and delay slot to.
func.stubAddr = entry->firstSymAddr + i * 8;
module->ImportFunc(func);
}

13
Core/HLE/scePsmf.cpp
View file

@ -728,6 +728,9 @@ u32 scePsmfVerifyPsmf(u32 psmfAddr)
ERROR_LOG(ME, "scePsmfVerifyPsmf(%08x): bad version %08x", psmfAddr, version);
return ERROR_PSMF_NOT_FOUND;
}
// Kurohyou 2 (at least the demo) uses an uninitialized value that happens to be zero on the PSP.
// It appears to be written by scePsmfVerifyPsmf(), so we write some bytes into the stack here.
Memory::Memset(currentMIPS->r[MIPS_REG_SP] - 0x20, 0, 0x20);
DEBUG_LOG(ME, "scePsmfVerifyPsmf(%08x)", psmfAddr);
return 0;
}
@ -800,13 +803,13 @@ u32 scePsmfGetEPWithId(u32 psmfStruct, int epid, u32 entryAddr)
Psmf *psmf = getPsmf(psmfStruct);
if (!psmf) {
ERROR_LOG(ME, "scePsmfGetEPWithId(%08x, %i, %08x): invalid psmf", psmfStruct, epid, entryAddr);
return ERROR_PSMF_NOT_FOUND;
return ERROR_PSMF_NOT_INITIALIZED;
}
DEBUG_LOG(ME, "scePsmfGetEPWithId(%08x, %i, %08x)", psmfStruct, epid, entryAddr);
if (epid < 0 || epid >= (int)psmf->EPMap.size()) {
ERROR_LOG(ME, "scePsmfGetEPWithId(%08x, %i): invalid id", psmfStruct, epid);
return ERROR_PSMF_INVALID_ID;
return ERROR_PSMF_NOT_FOUND;
}
if (Memory::IsValidAddress(entryAddr)) {
Memory::WriteStruct(entryAddr, &psmf->EPMap[epid]);
@ -819,19 +822,19 @@ u32 scePsmfGetEPWithTimestamp(u32 psmfStruct, u32 ts, u32 entryAddr)
Psmf *psmf = getPsmf(psmfStruct);
if (!psmf) {
ERROR_LOG(ME, "scePsmfGetEPWithTimestamp(%08x, %i, %08x): invalid psmf", psmfStruct, ts, entryAddr);
return ERROR_PSMF_NOT_FOUND;
return ERROR_PSMF_NOT_INITIALIZED;
}
DEBUG_LOG(ME, "scePsmfGetEPWithTimestamp(%08x, %i, %08x)", psmfStruct, ts, entryAddr);
if (ts < psmf->presentationStartTime) {
ERROR_LOG(ME, "scePsmfGetEPWithTimestamp(%08x, %i): invalid timestamp", psmfStruct, ts);
return ERROR_PSMF_INVALID_TIMESTAMP;
return ERROR_PSMF_NOT_FOUND;
}
int epid = psmf->FindEPWithTimestamp(ts);
if (epid < 0 || epid >= (int)psmf->EPMap.size()) {
ERROR_LOG(ME, "scePsmfGetEPWithTimestamp(%08x, %i): invalid id", psmfStruct, epid);
return ERROR_PSMF_INVALID_ID;
return ERROR_PSMF_NOT_FOUND;
}
if (Memory::IsValidAddress(entryAddr)) {