private void ProcessRelaSection(Elf elf, Elf.ElfSection relocs, Elf.ElfSection section, Elf.ElfSection symtab)
{
if (relocs.sh_entsize != 12)
{
throw new InvalidDataException("Invalid relocs format (sh_entsize != 12)");
}
if (symtab.sh_type != Elf.ElfSection.Type.SHT_SYMTAB)
{
throw new InvalidDataException("Symbol table does not have type SHT_SYMTAB");
}
var reader = new BinaryReader(new MemoryStream(relocs.data));
int count = relocs.data.Length / 12;
for (int i = 0; i < count; i++)
{
uint r_offset = reader.ReadBigUInt32();
uint r_info = reader.ReadBigUInt32();
int r_addend = reader.ReadBigInt32();
Elf.Reloc reloc = (Elf.Reloc)(r_info & 0xFF);
int symIndex = (int)(r_info >> 8);
if (symIndex == 0)
{
throw new InvalidDataException("linking to undefined symbol");
}
if (!_sectionBases.ContainsKey(section))
{
continue; // we don't care about this
}
string symName = _symbolTableContents[symtab][symIndex];
//Console.WriteLine("{0,-30} {1}", symName, reloc);
Word source = _sectionBases[section] + r_offset;
Word dest = ResolveSymbol(elf, symName).address + r_addend;
//Console.WriteLine("Linking from {0} to {1}", source, dest);
if (!KamekUseReloc(reloc, source, dest))
{
_fixups.Add(new Fixup {
type = reloc, source = source, dest = dest
});
}
}
}
private string[] ParseSymbolTable(Elf elf, Elf.ElfSection symtab, Elf.ElfSection strtab, Dictionary <string, Symbol> locals)
{
if (symtab.sh_entsize != 16)
{
throw new InvalidDataException("Invalid symbol table format (sh_entsize != 16)");
}
if (strtab.sh_type != Elf.ElfSection.Type.SHT_STRTAB)
{
throw new InvalidDataException("String table does not have type SHT_STRTAB");
}
var symbolNames = new List <string>();
var reader = new BinaryReader(new MemoryStream(symtab.data));
int count = symtab.data.Length / 16;
// always ignore the first symbol
symbolNames.Add(null);
reader.BaseStream.Seek(16, SeekOrigin.Begin);
for (int i = 1; i < count; i++)
{
// Read info from the ELF
uint st_name = reader.ReadBigUInt32();
uint st_value = reader.ReadBigUInt32();
uint st_size = reader.ReadBigUInt32();
byte st_info = reader.ReadByte();
byte st_other = reader.ReadByte();
ushort st_shndx = reader.ReadBigUInt16();
Elf.SymBind bind = (Elf.SymBind)(st_info >> 4);
Elf.SymType type = (Elf.SymType)(st_info & 0xF);
string name = Util.ExtractNullTerminatedString(strtab.data, (int)st_name);
symbolNames.Add(name);
if (name.Length == 0 || st_shndx == 0)
{
continue;
}
// What location is this referencing?
Elf.ElfSection refSection;
if (st_shndx < 0xFF00)
{
refSection = elf.Sections[st_shndx];
}
else if (st_shndx == 0xFFF1) // absolute symbol
{
refSection = null;
}
else
{
throw new InvalidDataException("unknown section index found in symbol table");
}
Word addr;
if (st_shndx == 0xFFF1)
{
// Absolute symbol
addr = new Word(WordType.AbsoluteAddr, st_value);
}
else if (st_shndx < 0xFF00)
{
// Part of a section
var section = elf.Sections[st_shndx];
if (!_sectionBases.ContainsKey(section))
{
continue; // skips past symbols we don't care about, like DWARF junk
}
addr = _sectionBases[section] + st_value;
}
else
{
throw new NotImplementedException("unknown section index found in symbol table");
}
switch (bind)
{
case Elf.SymBind.STB_LOCAL:
if (locals.ContainsKey(name))
{
throw new InvalidDataException("redefinition of local symbol " + name);
}
locals[name] = new Symbol {
address = addr, size = st_size
};
_symbolSizes[addr] = st_size;
break;
case Elf.SymBind.STB_GLOBAL:
if (_globalSymbols.ContainsKey(name) && !_globalSymbols[name].isWeak)
{
throw new InvalidDataException("redefinition of global symbol " + name);
}
_globalSymbols[name] = new Symbol {
address = addr, size = st_size
};
_symbolSizes[addr] = st_size;
break;
case Elf.SymBind.STB_WEAK:
if (!_globalSymbols.ContainsKey(name))
{
_globalSymbols[name] = new Symbol {
address = addr, size = st_size, isWeak = true
};
_symbolSizes[addr] = st_size;
}
break;
}
}
return(symbolNames.ToArray());
}