arch/powerpc/boot/hack-coff.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * hack-coff.c - hack the header of an xcoff file to fill in
   4  * a few fields needed by the Open Firmware xcoff loader on
   5  * Power Macs but not initialized by objcopy.
   6  *
   7  * Copyright (C) Paul Mackerras 1997.
   8  */
   9 #include <stdio.h>
  10 #include <stdlib.h>
  11 #include <unistd.h>
  12 #include <fcntl.h>
  13 #include <string.h>
  14 #include "rs6000.h"
  15
  16 #define AOUT_MAGIC      0x010b
  17
  18 #define get_16be(x)     ((((unsigned char *)(x))[0] << 8) \
  19                          + ((unsigned char *)(x))[1])
  20 #define put_16be(x, v)  (((unsigned char *)(x))[0] = (v) >> 8, \
  21                          ((unsigned char *)(x))[1] = (v) & 0xff)
  22 #define get_32be(x)     ((((unsigned char *)(x))[0] << 24) \
  23                          + (((unsigned char *)(x))[1] << 16) \
  24                          + (((unsigned char *)(x))[2] << 8) \
  25                          + ((unsigned char *)(x))[3])
  26
  27 int
  28 main(int ac, char **av)
  29 {
  30     int fd;
  31     int i, nsect;
  32     int aoutsz;
  33     struct external_filehdr fhdr;
  34     AOUTHDR aout;
  35     struct external_scnhdr shdr;
  36
  37     if (ac != 2) {
  38         fprintf(stderr, "Usage: hack-coff coff-file\n");
  39         exit(1);
  40     }
  41     if ((fd = open(av[1], 2)) == -1) {
  42         perror(av[2]);
  43         exit(1);
  44     }
  45     if (read(fd, &fhdr, sizeof(fhdr)) != sizeof(fhdr))
  46         goto readerr;
  47     i = get_16be(fhdr.f_magic);
  48     if (i != U802TOCMAGIC && i != U802WRMAGIC && i != U802ROMAGIC) {
  49         fprintf(stderr, "%s: not an xcoff file\n", av[1]);
  50         exit(1);
  51     }
  52     aoutsz = get_16be(fhdr.f_opthdr);
  53     if (read(fd, &aout, aoutsz) != aoutsz)
  54         goto readerr;
  55     nsect = get_16be(fhdr.f_nscns);
  56     for (i = 0; i < nsect; ++i) {
  57         if (read(fd, &shdr, sizeof(shdr)) != sizeof(shdr))
  58             goto readerr;
  59         if (strcmp(shdr.s_name, ".text") == 0) {
  60             put_16be(aout.o_snentry, i+1);
  61             put_16be(aout.o_sntext, i+1);
  62         } else if (strcmp(shdr.s_name, ".data") == 0) {
  63             put_16be(aout.o_sndata, i+1);
  64         } else if (strcmp(shdr.s_name, ".bss") == 0) {
  65             put_16be(aout.o_snbss, i+1);
  66         }
  67     }
  68     put_16be(aout.magic, AOUT_MAGIC);
  69     if (lseek(fd, (long) sizeof(struct external_filehdr), 0) == -1
  70         || write(fd, &aout, aoutsz) != aoutsz) {
  71         fprintf(stderr, "%s: write error\n", av[1]);
  72         exit(1);
  73     }
  74     close(fd);
  75     exit(0);
  76
  77 readerr:
  78     fprintf(stderr, "%s: read error or file too short\n", av[1]);
  79     exit(1);
  80 }