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
main(int ac,char ** av)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 }
81