Archipelago » qemu

/* 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 "";

}