qemu/disas.c

82 lines
2.1 KiB
C

/* General "disassemble this chunk" code. Used for debugging. */
#include "dis-asm.h"
#include "disas.h"
#include "elf.h"
/* Filled in by elfload.c. Simplistic, but will do for now. */
unsigned int disas_num_syms;
void *disas_symtab;
const char *disas_strtab;
/* Disassemble this for me please... (debugging). */
void disas(FILE *out, void *code, unsigned long size, enum disas_type type)
{
uint8_t *pc;
int count;
struct disassemble_info disasm_info;
int (*print_insn)(bfd_vma pc, disassemble_info *info);
INIT_DISASSEMBLE_INFO(disasm_info, out, fprintf);
disasm_info.buffer = code;
disasm_info.buffer_vma = (unsigned long)code;
disasm_info.buffer_length = size;
if (type == DISAS_TARGET) {
#ifdef WORDS_BIGENDIAN
disasm_info.endian = BFD_ENDIAN_BIG;
#else
disasm_info.endian = BFD_ENDIAN_LITTLE;
#endif
#ifdef __i386__
disasm_info.mach = bfd_mach_i386_i386;
print_insn = print_insn_i386;
#elif defined(__powerpc__)
print_insn = print_insn_ppc;
#elif defined(__alpha__)
print_insn = print_insn_alpha;
#else
fprintf(out, "Asm output not supported on this arch\n");
return;
#endif
} else {
/* Currently only source supported in x86. */
disasm_info.endian = BFD_ENDIAN_LITTLE;
if (type == DISAS_I386_I386)
disasm_info.mach = bfd_mach_i386_i386;
else
disasm_info.mach = bfd_mach_i386_i8086;
print_insn = print_insn_i386;
}
for (pc = code; pc < (uint8_t *)code + size; pc += count) {
fprintf(out, "0x%08lx: ", (long)pc);
count = print_insn((long)pc, &disasm_info);
fprintf(out, "\n");
if (count < 0)
break;
}
}
/* Look up symbol for debugging purpose. Returns "" if unknown. */
const char *lookup_symbol(void *orig_addr)
{
unsigned int i;
/* Hack, because we know this is x86. */
Elf32_Sym *sym = disas_symtab;
for (i = 0; i < disas_num_syms; i++) {
if (sym[i].st_shndx == SHN_UNDEF
|| sym[i].st_shndx >= SHN_LORESERVE)
continue;
if (ELF_ST_TYPE(sym[i].st_info) != STT_FUNC)
continue;
if ((long)orig_addr >= sym[i].st_value
&& (long)orig_addr < sym[i].st_value + sym[i].st_size)
return disas_strtab + sym[i].st_name;
}
return "";
}