arch/powerpc/boot/hack-coff.c

   1 /*
   2  * hack-coff.c - hack the header of an xcoff file to fill in
   3  * a few fields needed by the Open Firmware xcoff loader on
   4  * Power Macs but not initialized by objcopy.
   5  *
   6  * Copyright (C) Paul Mackerras 1997.
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public License
  10  * as published by the Free Software Foundation; either version
  11  * 2 of the License, or (at your option) any later version.
  12  */
  13 #include <stdio.h>
  14 #include <stdlib.h>
  15 #include <unistd.h>
  16 #include <fcntl.h>
  17 #include <string.h>
  18 #include "rs6000.h"
  19
  20 #define AOUT_MAGIC      0x010b
  21
  22 #define get_16be(x)     ((((unsigned char *)(x))[0] << 8) \
  23                          + ((unsigned char *)(x))[1])
  24 #define put_16be(x, v)  (((unsigned char *)(x))[0] = (v) >> 8, \
  25                          ((unsigned char *)(x))[1] = (v) & 0xff)
  26 #define get_32be(x)     ((((unsigned char *)(x))[0] << 24) \
  27                          + (((unsigned char *)(x))[1] << 16) \
  28                          + (((unsigned char *)(x))[2] << 8) \
  29                          + ((unsigned char *)(x))[3])
  30
  31 int
  32 main(int ac, char **av)
  33 {
  34     int fd;
  35     int i, nsect;
  36     int aoutsz;
  37     struct external_filehdr fhdr;
  38     AOUTHDR aout;
  39     struct external_scnhdr shdr;
  40
  41     if (ac != 2) {
  42         fprintf(stderr, "Usage: hack-coff coff-file\n");
  43         exit(1);
  44     }
  45     if ((fd = open(av[1], 2)) == -1) {
  46         perror(av[2]);
  47         exit(1);
  48     }
  49     if (read(fd, &fhdr, sizeof(fhdr)) != sizeof(fhdr))
  50         goto readerr;
  51     i = get_16be(fhdr.f_magic);
  52     if (i != U802TOCMAGIC && i != U802WRMAGIC && i != U802ROMAGIC) {
  53         fprintf(stderr, "%s: not an xcoff file\n", av[1]);
  54         exit(1);
  55     }
  56     aoutsz = get_16be(fhdr.f_opthdr);
  57     if (read(fd, &aout, aoutsz) != aoutsz)
  58         goto readerr;
  59     nsect = get_16be(fhdr.f_nscns);
  60     for (i = 0; i < nsect; ++i) {
  61         if (read(fd, &shdr, sizeof(shdr)) != sizeof(shdr))
  62             goto readerr;
  63         if (strcmp(shdr.s_name, ".text") == 0) {
  64             put_16be(aout.o_snentry, i+1);
  65             put_16be(aout.o_sntext, i+1);
  66         } else if (strcmp(shdr.s_name, ".data") == 0) {
  67             put_16be(aout.o_sndata, i+1);
  68         } else if (strcmp(shdr.s_name, ".bss") == 0) {
  69             put_16be(aout.o_snbss, i+1);
  70         }
  71     }
  72     put_16be(aout.magic, AOUT_MAGIC);
  73     if (lseek(fd, (long) sizeof(struct external_filehdr), 0) == -1
  74         || write(fd, &aout, aoutsz) != aoutsz) {
  75         fprintf(stderr, "%s: write error\n", av[1]);
  76         exit(1);
  77     }
  78     close(fd);
  79     exit(0);
  80
  81 readerr:
  82     fprintf(stderr, "%s: read error or file too short\n", av[1]);
  83     exit(1);
  84 }