Archipelago » qemu

/* General "disassemble this chunk" code.  Used for debugging. */

#include "config.h"

#include "dis-asm.h"

#include "disas.h"

#include "elf.h"

#include <errno.h>

#include "cpu.h"

#include "exec-all.h"

/* Filled in by elfload.c.  Simplistic, but will do for now. */

unsigned int disas_num_syms;

void *disas_symtab;

const char *disas_strtab;

/* Get LENGTH bytes from info's buffer, at target address memaddr.

   Transfer them to myaddr.  */

int

buffer_read_memory (memaddr, myaddr, length, info)

     bfd_vma memaddr;

     bfd_byte *myaddr;

     int length;

     struct disassemble_info *info;

{

    if (memaddr < info->buffer_vma

        || memaddr + length > info->buffer_vma + info->buffer_length)

        /* Out of bounds.  Use EIO because GDB uses it.  */

        return EIO;

    memcpy (myaddr, info->buffer + (memaddr - info->buffer_vma), length);

    return 0;

}

#if !defined(CONFIG_USER_ONLY)

/* Get LENGTH bytes from info's buffer, at target address memaddr.

   Transfer them to myaddr.  */

static int

target_read_memory (memaddr, myaddr, length, info)

     bfd_vma memaddr;

     bfd_byte *myaddr;

     int length;

     struct disassemble_info *info;

{

    int i;

    for(i = 0; i < length; i++) {

        myaddr[i] = ldub_code((void *)((long)memaddr + i));

    }

    return 0;

}

#endif

/* Print an error message.  We can assume that this is in response to

   an error return from buffer_read_memory.  */

void

perror_memory (status, memaddr, info)

     int status;

     bfd_vma memaddr;

     struct disassemble_info *info;

{

  if (status != EIO)

    /* Can't happen.  */

    (*info->fprintf_func) (info->stream, "Unknown error %d\n", status);

  else

    /* Actually, address between memaddr and memaddr + len was

       out of bounds.  */

    (*info->fprintf_func) (info->stream,

                           "Address 0x%llx is out of bounds.\n", memaddr);

}

/* This could be in a separate file, to save miniscule amounts of space

   in statically linked executables.  */

/* Just print the address is hex.  This is included for completeness even

   though both GDB and objdump provide their own (to print symbolic

   addresses).  */

void

generic_print_address (addr, info)

     bfd_vma addr;

     struct disassemble_info *info;

{

  (*info->fprintf_func) (info->stream, "0x%llx", addr);

}

/* Just return the given address.  */

int

generic_symbol_at_address (addr, info)

     bfd_vma addr;

     struct disassemble_info * info;

{

  return 1;

}

bfd_vma bfd_getl32 (const bfd_byte *addr)

{

  unsigned long v;

  v = (unsigned long) addr[0];

  v |= (unsigned long) addr[1] << 8;

  v |= (unsigned long) addr[2] << 16;

  v |= (unsigned long) addr[3] << 24;

  return (bfd_vma) v;

}

bfd_vma bfd_getb32 (const bfd_byte *addr)

{

  unsigned long v;

  v = (unsigned long) addr[0] << 24;

  v |= (unsigned long) addr[1] << 16;

  v |= (unsigned long) addr[2] << 8;

  v |= (unsigned long) addr[3];

  return (bfd_vma) v;

}

/* Disassemble this for me please... (debugging). 'flags' is only used

   for i386: non zero means 16 bit code */

void disas(FILE *out, void *code, unsigned long size, int is_host, int flags)

{

    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);

#if !defined(CONFIG_USER_ONLY)

    if (!is_host) {

        disasm_info.read_memory_func = target_read_memory;

    }

#endif

    disasm_info.buffer = code;

    disasm_info.buffer_vma = (unsigned long)code;

    disasm_info.buffer_length = size;

    if (is_host) {

#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;

#elif defined(__sparc__)

        print_insn = print_insn_sparc;

#elif defined(__arm__) 

        print_insn = print_insn_arm;

#else

        fprintf(out, "Asm output not supported on this arch\n");

        return;

#endif

    } else {

#ifdef TARGET_WORDS_BIGENDIAN

        disasm_info.endian = BFD_ENDIAN_BIG;

#else

        disasm_info.endian = BFD_ENDIAN_LITTLE;

#endif

#if defined(TARGET_I386)

        if (!flags)

            disasm_info.mach = bfd_mach_i386_i386;

        else

            disasm_info.mach = bfd_mach_i386_i8086;

        print_insn = print_insn_i386;

#elif defined(TARGET_ARM)

        print_insn = print_insn_arm;

#elif defined(TARGET_SPARC)

        print_insn = print_insn_sparc;

#elif defined(TARGET_PPC)

        print_insn = print_insn_ppc;

#else

        fprintf(out, "Asm output not supported on this arch\n");

        return;

#endif

    }

    for (pc = code; pc < (uint8_t *)code + size; pc += count) {

        fprintf(out, "0x%08lx:  ", (long)pc);

#ifdef __arm__

        /* since data are included in the code, it is better to

           display code data too */

        if (is_host) {

            fprintf(out, "%08x  ", (int)bfd_getl32((const bfd_byte *)pc));

        }

#endif

        count = print_insn((unsigned 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 "";

}