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Implemented classic segment relocations

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This commit is contained in:
Arthur Blot 2012-12-27 21:32:12 +01:00
parent 70045f2b38
commit a7af13b523
2 changed files with 131 additions and 114 deletions
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243
Core/ELF/ElfReader.cpp
View File

@ -50,6 +50,118 @@ void addrToHiLo(u32 addr, u16 &hi, s16 &lo)
}
}
void ElfReader::LoadRelocations(Elf32_Rel *rels, int numRelocs)
{
for (int r = 0; r < numRelocs; r++)
{
u32 info = rels[r].r_info;
u32 addr = rels[r].r_offset;
int type = info & 0xf;
int readwrite = (info>>8) & 0xff;
int relative = (info>>16) & 0xff;
//0 = code
//1 = data
addr += segmentVAddr[readwrite];
u32 op = Memory::ReadUnchecked_U32(addr);
const bool log = false;
//log=true;
if (log)
{
DEBUG_LOG(LOADER,"rel at: %08x type: %08x",addr,info);
}
u32 relocateTo = segmentVAddr[relative];
#define R_MIPS32 2
#define R_MIPS26 4
#define R_MIPS16_HI 5
#define R_MIPS16_LO 6
switch (type)
{
case R_MIPS32:
if (log)
DEBUG_LOG(LOADER,"Full address reloc %08x", addr);
//full address, no problemo
op += relocateTo;
break;
case R_MIPS26: //j, jal
//add on to put in correct address space
if (log)
DEBUG_LOG(LOADER,"j/jal reloc %08x", addr);
op = (op & 0xFC000000) | (((op&0x03FFFFFF)+(relocateTo>>2))&0x03FFFFFFF);
break;
case R_MIPS16_HI: //lui part of lui-addiu pairs
{
if (log)
DEBUG_LOG(LOADER,"HI reloc %08x", addr);
u32 cur = (op & 0xFFFF) << 16;
u16 hi = 0;
bool found = false;
for (int t = r + 1; t<numRelocs; t++)
{
if ((rels[t].r_info & 0xF) == R_MIPS16_LO)
{
u32 corrLoAddr = rels[t].r_offset + segmentVAddr[readwrite];
if (log)
{
DEBUG_LOG(LOADER,"Corresponding lo found at %08x", corrLoAddr);
}
s16 lo = (s32)(s16)(u16)(Memory::ReadUnchecked_U32(corrLoAddr) & 0xFFFF); //signed??
cur += lo;
cur += relocateTo;
addrToHiLo(cur, hi, lo);
found = true;
break;
}
}
if (!found)
ERROR_LOG(LOADER, "R_MIPS16: not found");
op = (op & 0xFFFF0000) | (hi);
}
break;
case R_MIPS16_LO: //addiu part of lui-addiu pairs
{
if (log)
DEBUG_LOG(LOADER,"LO reloc %08x", addr);
u32 cur = op & 0xFFFF;
cur += relocateTo;
cur &= 0xFFFF;
op = (op & 0xFFFF0000) | cur;
}
break;
case 7: //gp
if (log)
ERROR_LOG(LOADER,"ARGH IT'S A GP!!!!!!!! %08x", addr);
break;
case 0: // another GP reloc!
{
char temp[256];
MIPSDisAsm(op, 0, temp);
ERROR_LOG(LOADER,"WARNING: GP reloc? @ %08x : 0 : %s", addr, temp );
}
break;
default:
ERROR_LOG(LOADER,"ARGH IT'S A UNKNOWN RELOCATION!!!!!!!! %08x", addr);
break;
}
Memory::Write_U32(op, addr);
}
}
bool ElfReader::LoadInto(u32 loadAddress)
{
@ -109,9 +221,8 @@ bool ElfReader::LoadInto(u32 loadAddress)
DEBUG_LOG(LOADER,"%i segments:", header->e_phnum);
// First pass : Get the damn bits into RAM
u32 segmentVAddr[32];
u32 baseAddress = bRelocate?vaddr:0;
for (int i=0; i<header->e_phnum; i++)
{
Elf32_Phdr *p = segments + i;
@ -170,7 +281,6 @@ bool ElfReader::LoadInto(u32 loadAddress)
if (s->sh_type == SHT_PSPREL)
{
//We have a relocation table!
int symbolSection = s->sh_link;
int sectionToModify = s->sh_info;
if (!(sections[sectionToModify].sh_flags & SHF_ALLOC))
@ -184,116 +294,7 @@ bool ElfReader::LoadInto(u32 loadAddress)
Elf32_Rel *rels = (Elf32_Rel *)GetSectionDataPtr(i);
DEBUG_LOG(LOADER,"%s: Performing %i relocations on %s",name,numRelocs,GetSectionName(sectionToModify));
for (int r = 0; r < numRelocs; r++)
{
u32 info = rels[r].r_info;
u32 addr = rels[r].r_offset;
int type = info & 0xf;
int readwrite = (info>>8) & 0xff;
int relative = (info>>16) & 0xff;
//0 = code
//1 = data
addr += segmentVAddr[readwrite];
u32 op = Memory::ReadUnchecked_U32(addr);
const bool log = false;
//log=true;
if (log)
{
DEBUG_LOG(LOADER,"rel at: %08x type: %08x",addr,info);
}
u32 relocateTo = segmentVAddr[relative];
#define R_MIPS32 2
#define R_MIPS26 4
#define R_MIPS16_HI 5
#define R_MIPS16_LO 6
switch (type)
{
case R_MIPS32:
if (log)
DEBUG_LOG(LOADER,"Full address reloc %08x", addr);
//full address, no problemo
op += relocateTo;
break;
case R_MIPS26: //j, jal
//add on to put in correct address space
if (log)
DEBUG_LOG(LOADER,"j/jal reloc %08x", addr);
op = (op & 0xFC000000) | (((op&0x03FFFFFF)+(relocateTo>>2))&0x03FFFFFFF);
break;
case R_MIPS16_HI: //lui part of lui-addiu pairs
{
if (log)
DEBUG_LOG(LOADER,"HI reloc %08x", addr);
u32 cur = (op & 0xFFFF) << 16;
u16 hi = 0;
bool found = false;
for (int t = r + 1; t<numRelocs; t++)
{
if ((rels[t].r_info & 0xF) == R_MIPS16_LO)
{
u32 corrLoAddr = rels[t].r_offset + segmentVAddr[readwrite];
if (log)
{
DEBUG_LOG(LOADER,"Corresponding lo found at %08x", corrLoAddr);
}
s16 lo = (s32)(s16)(u16)(Memory::ReadUnchecked_U32(corrLoAddr) & 0xFFFF); //signed??
cur += lo;
cur += relocateTo;
addrToHiLo(cur, hi, lo);
found = true;
break;
}
}
if (!found)
ERROR_LOG(LOADER, "R_MIPS16: not found");
op = (op & 0xFFFF0000) | (hi);
}
break;
case R_MIPS16_LO: //addiu part of lui-addiu pairs
{
if (log)
DEBUG_LOG(LOADER,"LO reloc %08x", addr);
u32 cur = op & 0xFFFF;
cur += relocateTo;
cur &= 0xFFFF;
op = (op & 0xFFFF0000) | cur;
}
break;
case 7: //gp
if (log)
ERROR_LOG(LOADER,"ARGH IT'S A GP!!!!!!!! %08x", addr);
break;
case 0: // another GP reloc!
{
char temp[256];
MIPSDisAsm(op, 0, temp);
ERROR_LOG(LOADER,"WARNING: GP reloc? @ %08x : 0 : %s", addr, temp );
}
break;
default:
ERROR_LOG(LOADER,"ARGH IT'S A UNKNOWN RELOCATION!!!!!!!! %08x", addr);
break;
}
Memory::Write_U32(op, addr);
}
LoadRelocations(rels, numRelocs);
}
else if (s->sh_type == SHT_REL)
{
@ -305,7 +306,6 @@ bool ElfReader::LoadInto(u32 loadAddress)
else
{
//We have a relocation table!
int symbolSection = s->sh_link;
int sectionToModify = s->sh_info;
if (!(sections[sectionToModify].sh_flags & SHF_ALLOC))
{
@ -317,6 +317,21 @@ bool ElfReader::LoadInto(u32 loadAddress)
}
}
// Segment relocations (a few games use them)
for (int i=0; i<header->e_phnum; i++)
{
Elf32_Phdr *p = &segments[i];
if (p->p_type == 0x700000A0)
{
INFO_LOG(LOADER,"Loading segment relocations");
int numRelocs = p->p_filesz / sizeof(Elf32_Rel);
Elf32_Rel *rels = (Elf32_Rel *)GetSegmentPtr(i);
LoadRelocations(rels, numRelocs);
}
}
NOTICE_LOG(LOADER,"ELF loading completed successfully.");
return true;
}

2
Core/ELF/ElfReader.h
View File

@ -42,6 +42,7 @@ class ElfReader
bool bRelocate;
u32 entryPoint;
u32 vaddr;
u32 segmentVAddr[32];
public:
ElfReader(void *ptr)
{
@ -117,4 +118,5 @@ public:
// More indepth stuff:)
bool LoadInto(u32 vaddr);
bool LoadSymbols();
void LoadRelocations(Elf32_Rel *rels, int numRelocs);
};