added Dolphin's ELF reader to the project

This commit is contained in:
bunnei 2014-03-25 10:47:12 -04:00
parent e0cfd6b0b8
commit 872d9ae87f
3 changed files with 594 additions and 0 deletions

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// Copyright 2013 Dolphin Emulator Project
// Licensed under GPLv2
// Refer to the license.txt file included.
#include <string>
#include "common.h"
#include "mem_map.h"
#include "elf/elf_reader.h"
//#include "Core/Debugger/Debugger_SymbolMap.h"
//#include "Core/HW/Memmap.h"
//#include "Core/PowerPC/PPCSymbolDB.h"
//void bswap(Elf32_Word &w) {w = Common::swap32(w);}
//void bswap(Elf32_Half &w) {w = Common::swap16(w);}
#define bswap(w) w // Dirty bswap disable for now... 3DS is little endian, anyway
static void byteswapHeader(Elf32_Ehdr &ELF_H)
{
bswap(ELF_H.e_type);
bswap(ELF_H.e_machine);
bswap(ELF_H.e_ehsize);
bswap(ELF_H.e_phentsize);
bswap(ELF_H.e_phnum);
bswap(ELF_H.e_shentsize);
bswap(ELF_H.e_shnum);
bswap(ELF_H.e_shstrndx);
bswap(ELF_H.e_version);
bswap(ELF_H.e_entry);
bswap(ELF_H.e_phoff);
bswap(ELF_H.e_shoff);
bswap(ELF_H.e_flags);
}
static void byteswapSegment(Elf32_Phdr &sec)
{
bswap(sec.p_align);
bswap(sec.p_filesz);
bswap(sec.p_flags);
bswap(sec.p_memsz);
bswap(sec.p_offset);
bswap(sec.p_paddr);
bswap(sec.p_vaddr);
bswap(sec.p_type);
}
static void byteswapSection(Elf32_Shdr &sec)
{
bswap(sec.sh_addr);
bswap(sec.sh_addralign);
bswap(sec.sh_entsize);
bswap(sec.sh_flags);
bswap(sec.sh_info);
bswap(sec.sh_link);
bswap(sec.sh_name);
bswap(sec.sh_offset);
bswap(sec.sh_size);
bswap(sec.sh_type);
}
ElfReader::ElfReader(void *ptr)
{
base = (char*)ptr;
base32 = (u32 *)ptr;
header = (Elf32_Ehdr*)ptr;
byteswapHeader(*header);
segments = (Elf32_Phdr *)(base + header->e_phoff);
sections = (Elf32_Shdr *)(base + header->e_shoff);
for (int i = 0; i < GetNumSegments(); i++)
{
byteswapSegment(segments[i]);
}
for (int i = 0; i < GetNumSections(); i++)
{
byteswapSection(sections[i]);
}
entryPoint = header->e_entry;
}
const char *ElfReader::GetSectionName(int section) const
{
if (sections[section].sh_type == SHT_NULL)
return nullptr;
int nameOffset = sections[section].sh_name;
char *ptr = (char*)GetSectionDataPtr(header->e_shstrndx);
if (ptr)
return ptr + nameOffset;
else
return nullptr;
}
bool ElfReader::LoadInto(u32 vaddr)
{
DEBUG_LOG(MASTER_LOG,"String section: %i", header->e_shstrndx);
// sectionOffsets = new u32[GetNumSections()];
// sectionAddrs = new u32[GetNumSections()];
// Should we relocate?
bRelocate = (header->e_type != ET_EXEC);
if (bRelocate)
{
DEBUG_LOG(MASTER_LOG,"Relocatable module");
entryPoint += vaddr;
}
else
{
DEBUG_LOG(MASTER_LOG,"Prerelocated executable");
}
INFO_LOG(MASTER_LOG,"%i segments:", header->e_phnum);
// First pass : Get the 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;
INFO_LOG(MASTER_LOG, "Type: %i Vaddr: %08x Filesz: %i Memsz: %i ", p->p_type, p->p_vaddr, p->p_filesz, p->p_memsz);
if (p->p_type == PT_LOAD)
{
segmentVAddr[i] = baseAddress + p->p_vaddr;
u32 writeAddr = segmentVAddr[i];
const u8 *src = GetSegmentPtr(i);
u8 *dst = Memory::GetPointer(writeAddr);
u32 srcSize = p->p_filesz;
u32 dstSize = p->p_memsz;
u32 *s = (u32*)src;
u32 *d = (u32*)dst;
for (int j = 0; j < (int)(srcSize + 3) / 4; j++)
{
*d++ = /*_byteswap_ulong*/(*s++);
}
if (srcSize < dstSize)
{
//memset(dst + srcSize, 0, dstSize-srcSize); //zero out bss
}
INFO_LOG(MASTER_LOG,"Loadable Segment Copied to %08x, size %08x", writeAddr, p->p_memsz);
}
}
/*
LOG(MASTER_LOG,"%i sections:", header->e_shnum);
for (int i=0; i<GetNumSections(); i++)
{
Elf32_Shdr *s = &sections[i];
const char *name = GetSectionName(i);
u32 writeAddr = s->sh_addr + baseAddress;
sectionOffsets[i] = writeAddr - vaddr;
sectionAddrs[i] = writeAddr;
if (s->sh_flags & SHF_ALLOC)
{
LOG(MASTER_LOG,"Data Section found: %s Sitting at %08x, size %08x", name, writeAddr, s->sh_size);
}
else
{
LOG(MASTER_LOG,"NonData Section found: %s Ignoring (size=%08x) (flags=%08x)", name, s->sh_size, s->sh_flags);
}
}
*/
INFO_LOG(MASTER_LOG,"Done loading.");
return true;
}
SectionID ElfReader::GetSectionByName(const char *name, int firstSection) const
{
for (int i = firstSection; i < header->e_shnum; i++)
{
const char *secname = GetSectionName(i);
if (secname != nullptr && strcmp(name, secname) == 0)
return i;
}
return -1;
}
/* TODO(bunnei): The following is verbatim from Dolphin - needs to be updated for this project:
bool ElfReader::LoadSymbols()
{
bool hasSymbols = false;
SectionID sec = GetSectionByName(".symtab");
if (sec != -1)
{
int stringSection = sections[sec].sh_link;
const char *stringBase = (const char *)GetSectionDataPtr(stringSection);
//We have a symbol table!
Elf32_Sym *symtab = (Elf32_Sym *)(GetSectionDataPtr(sec));
int numSymbols = sections[sec].sh_size / sizeof(Elf32_Sym);
for (int sym = 0; sym < numSymbols; sym++)
{
int size = Common::swap32(symtab[sym].st_size);
if (size == 0)
continue;
// int bind = symtab[sym].st_info >> 4;
int type = symtab[sym].st_info & 0xF;
int sectionIndex = Common::swap16(symtab[sym].st_shndx);
int value = Common::swap32(symtab[sym].st_value);
const char *name = stringBase + Common::swap32(symtab[sym].st_name);
if (bRelocate)
value += sectionAddrs[sectionIndex];
int symtype = Symbol::SYMBOL_DATA;
switch (type)
{
case STT_OBJECT:
symtype = Symbol::SYMBOL_DATA; break;
case STT_FUNC:
symtype = Symbol::SYMBOL_FUNCTION; break;
default:
continue;
}
g_symbolDB.AddKnownSymbol(value, size, name, symtype);
hasSymbols = true;
}
}
g_symbolDB.Index();
return hasSymbols;
}
*/

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// Copyright 2013 Dolphin Emulator Project
// Licensed under GPLv2
// Refer to the license.txt file included.
#pragma once
#include "elf/elf_types.h"
enum KnownElfTypes
{
KNOWNELF_PSP = 0,
KNOWNELF_DS = 1,
KNOWNELF_GBA = 2,
KNOWNELF_GC = 3,
};
typedef int SectionID;
class ElfReader
{
private:
char *base;
u32 *base32;
Elf32_Ehdr *header;
Elf32_Phdr *segments;
Elf32_Shdr *sections;
u32 *sectionAddrs;
bool bRelocate;
u32 entryPoint;
public:
ElfReader(void *ptr);
~ElfReader() { }
u32 Read32(int off) const { return base32[off>>2]; }
// Quick accessors
ElfType GetType() const { return (ElfType)(header->e_type); }
ElfMachine GetMachine() const { return (ElfMachine)(header->e_machine); }
u32 GetEntryPoint() const { return entryPoint; }
u32 GetFlags() const { return (u32)(header->e_flags); }
bool LoadInto(u32 vaddr);
bool LoadSymbols();
int GetNumSegments() const { return (int)(header->e_phnum); }
int GetNumSections() const { return (int)(header->e_shnum); }
const u8 *GetPtr(int offset) const { return (u8*)base + offset; }
const char *GetSectionName(int section) const;
const u8 *GetSectionDataPtr(int section) const
{
if (section < 0 || section >= header->e_shnum)
return nullptr;
if (sections[section].sh_type != SHT_NOBITS)
return GetPtr(sections[section].sh_offset);
else
return nullptr;
}
bool IsCodeSection(int section) const
{
return sections[section].sh_type == SHT_PROGBITS;
}
const u8 *GetSegmentPtr(int segment)
{
return GetPtr(segments[segment].p_offset);
}
u32 GetSectionAddr(SectionID section) const { return sectionAddrs[section]; }
int GetSectionSize(SectionID section) const { return sections[section].sh_size; }
SectionID GetSectionByName(const char *name, int firstSection = 0) const; //-1 for not found
bool DidRelocate() {
return bRelocate;
}
};

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// Copyright 2013 Dolphin Emulator Project
// Licensed under GPLv2
// Refer to the license.txt file included.
#pragma once
// ELF Header Constants
// File type
enum ElfType
{
ET_NONE = 0,
ET_REL = 1,
ET_EXEC = 2,
ET_DYN = 3,
ET_CORE = 4,
ET_LOPROC = 0xFF00,
ET_HIPROC = 0xFFFF,
};
// Machine/Architecture
enum ElfMachine
{
EM_NONE = 0,
EM_M32 = 1,
EM_SPARC = 2,
EM_386 = 3,
EM_68K = 4,
EM_88K = 5,
EM_860 = 7,
EM_MIPS = 8
};
// File version
#define EV_NONE 0
#define EV_CURRENT 1
// Identification index
#define EI_MAG0 0
#define EI_MAG1 1
#define EI_MAG2 2
#define EI_MAG3 3
#define EI_CLASS 4
#define EI_DATA 5
#define EI_VERSION 6
#define EI_PAD 7
#define EI_NIDENT 16
// Magic number
#define ELFMAG0 0x7F
#define ELFMAG1 'E'
#define ELFMAG2 'L'
#define ELFMAG3 'F'
// File class
#define ELFCLASSNONE 0
#define ELFCLASS32 1
#define ELFCLASS64 2
// Encoding
#define ELFDATANONE 0
#define ELFDATA2LSB 1
#define ELFDATA2MSB 2
// Sections constants
// Section indexes
#define SHN_UNDEF 0
#define SHN_LORESERVE 0xFF00
#define SHN_LOPROC 0xFF00
#define SHN_HIPROC 0xFF1F
#define SHN_ABS 0xFFF1
#define SHN_COMMON 0xFFF2
#define SHN_HIRESERVE 0xFFFF
// Section types
#define SHT_NULL 0
#define SHT_PROGBITS 1
#define SHT_SYMTAB 2
#define SHT_STRTAB 3
#define SHT_RELA 4
#define SHT_HASH 5
#define SHT_DYNAMIC 6
#define SHT_NOTE 7
#define SHT_NOBITS 8
#define SHT_REL 9
#define SHT_SHLIB 10
#define SHT_DYNSYM 11
#define SHT_LOPROC 0x70000000
#define SHT_HIPROC 0x7FFFFFFF
#define SHT_LOUSER 0x80000000
#define SHT_HIUSER 0xFFFFFFFF
// Custom section types
#define SHT_PSPREL 0x700000a0
// Section flags
enum ElfSectionFlags
{
SHF_WRITE = 0x1,
SHF_ALLOC = 0x2,
SHF_EXECINSTR = 0x4,
SHF_MASKPROC = 0xF0000000,
};
// Symbol binding
#define STB_LOCAL 0
#define STB_GLOBAL 1
#define STB_WEAK 2
#define STB_LOPROC 13
#define STB_HIPROC 15
// Symbol types
#define STT_NOTYPE 0
#define STT_OBJECT 1
#define STT_FUNC 2
#define STT_SECTION 3
#define STT_FILE 4
#define STT_LOPROC 13
#define STT_HIPROC 15
// Undefined name
#define STN_UNDEF 0
// Relocation types
#define R_386_NONE 0
#define R_386_32 1
#define R_386_PC32 2
#define R_386_GOT32 3
#define R_386_PLT32 4
#define R_386_COPY 5
#define R_386_GLOB_DAT 6
#define R_386_JMP_SLOT 7
#define R_386_RELATIVE 8
#define R_386_GOTOFF 9
#define R_386_GOTPC 10
// Segment types
#define PT_NULL 0
#define PT_LOAD 1
#define PT_DYNAMIC 2
#define PT_INTERP 3
#define PT_NOTE 4
#define PT_SHLIB 5
#define PT_PHDR 6
#define PT_LOPROC 0x70000000
#define PT_HIPROC 0x7FFFFFFF
// Segment flags
#define PF_X 1
#define PF_W 2
#define PF_R 4
// Dynamic Array Tags
#define DT_NULL 0
#define DT_NEEDED 1
#define DT_PLTRELSZ 2
#define DT_PLTGOT 3
#define DT_HASH 4
#define DT_STRTAB 5
#define DT_SYMTAB 6
#define DT_RELA 7
#define DT_RELASZ 8
#define DT_RELAENT 9
#define DT_STRSZ 10
#define DT_SYMENT 11
#define DT_INIT 12
#define DT_FINI 13
#define DT_SONAME 14
#define DT_RPATH 15
#define DT_SYMBOLIC 16
#define DT_REL 17
#define DT_RELSZ 18
#define DT_RELENT 19
#define DT_PLTREL 20
#define DT_DEBUG 21
#define DT_TEXTREL 22
#define DT_JMPREL 23
#define DT_LOPROC 0x70000000
#define DT_HIPROC 0x7FFFFFFF
typedef unsigned int Elf32_Addr;
typedef unsigned short Elf32_Half;
typedef unsigned int Elf32_Off;
typedef signed int Elf32_Sword;
typedef unsigned int Elf32_Word;
// ELF file header
struct Elf32_Ehdr
{
unsigned char e_ident[EI_NIDENT];
Elf32_Half e_type;
Elf32_Half e_machine;
Elf32_Word e_version;
Elf32_Addr e_entry;
Elf32_Off e_phoff;
Elf32_Off e_shoff;
Elf32_Word e_flags;
Elf32_Half e_ehsize;
Elf32_Half e_phentsize;
Elf32_Half e_phnum;
Elf32_Half e_shentsize;
Elf32_Half e_shnum;
Elf32_Half e_shstrndx;
};
// Section header
struct Elf32_Shdr
{
Elf32_Word sh_name;
Elf32_Word sh_type;
Elf32_Word sh_flags;
Elf32_Addr sh_addr;
Elf32_Off sh_offset;
Elf32_Word sh_size;
Elf32_Word sh_link;
Elf32_Word sh_info;
Elf32_Word sh_addralign;
Elf32_Word sh_entsize;
};
// Segment header
struct Elf32_Phdr
{
Elf32_Word p_type;
Elf32_Off p_offset;
Elf32_Addr p_vaddr;
Elf32_Addr p_paddr;
Elf32_Word p_filesz;
Elf32_Word p_memsz;
Elf32_Word p_flags;
Elf32_Word p_align;
};
// Symbol table entry
struct Elf32_Sym
{
Elf32_Word st_name;
Elf32_Addr st_value;
Elf32_Word st_size;
unsigned char st_info;
unsigned char st_other;
Elf32_Half st_shndx;
};
#define ELF32_ST_BIND(i) ((i)>>4)
#define ELF32_ST_TYPE(i) ((i)&0xf)
#define ELF32_ST_INFO(b,t) (((b)<<4)+((t)&0xf))
// Relocation entries
struct Elf32_Rel
{
Elf32_Addr r_offset;
Elf32_Word r_info;
};
struct Elf32_Rela
{
Elf32_Addr r_offset;
Elf32_Word r_info;
Elf32_Sword r_addend;
};
#define ELF32_R_SYM(i) ((i)>>8)
#define ELF32_R_TYPE(i) ((unsigned char)(i))
#define ELF32_R_INFO(s,t) (((s)<<8 )+(unsigned char)(t))
struct Elf32_Dyn
{
Elf32_Sword d_tag;
union
{
Elf32_Word d_val;
Elf32_Addr d_ptr;
} d_un;
};