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
main(int ac,char ** av)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 }
85