1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0-or-later
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun * hack-coff.c - hack the header of an xcoff file to fill in
4*4882a593Smuzhiyun * a few fields needed by the Open Firmware xcoff loader on
5*4882a593Smuzhiyun * Power Macs but not initialized by objcopy.
6*4882a593Smuzhiyun *
7*4882a593Smuzhiyun * Copyright (C) Paul Mackerras 1997.
8*4882a593Smuzhiyun */
9*4882a593Smuzhiyun #include <stdio.h>
10*4882a593Smuzhiyun #include <stdlib.h>
11*4882a593Smuzhiyun #include <unistd.h>
12*4882a593Smuzhiyun #include <fcntl.h>
13*4882a593Smuzhiyun #include <string.h>
14*4882a593Smuzhiyun #include "rs6000.h"
15*4882a593Smuzhiyun
16*4882a593Smuzhiyun #define AOUT_MAGIC 0x010b
17*4882a593Smuzhiyun
18*4882a593Smuzhiyun #define get_16be(x) ((((unsigned char *)(x))[0] << 8) \
19*4882a593Smuzhiyun + ((unsigned char *)(x))[1])
20*4882a593Smuzhiyun #define put_16be(x, v) (((unsigned char *)(x))[0] = (v) >> 8, \
21*4882a593Smuzhiyun ((unsigned char *)(x))[1] = (v) & 0xff)
22*4882a593Smuzhiyun #define get_32be(x) ((((unsigned char *)(x))[0] << 24) \
23*4882a593Smuzhiyun + (((unsigned char *)(x))[1] << 16) \
24*4882a593Smuzhiyun + (((unsigned char *)(x))[2] << 8) \
25*4882a593Smuzhiyun + ((unsigned char *)(x))[3])
26*4882a593Smuzhiyun
27*4882a593Smuzhiyun int
main(int ac,char ** av)28*4882a593Smuzhiyun main(int ac, char **av)
29*4882a593Smuzhiyun {
30*4882a593Smuzhiyun int fd;
31*4882a593Smuzhiyun int i, nsect;
32*4882a593Smuzhiyun int aoutsz;
33*4882a593Smuzhiyun struct external_filehdr fhdr;
34*4882a593Smuzhiyun AOUTHDR aout;
35*4882a593Smuzhiyun struct external_scnhdr shdr;
36*4882a593Smuzhiyun
37*4882a593Smuzhiyun if (ac != 2) {
38*4882a593Smuzhiyun fprintf(stderr, "Usage: hack-coff coff-file\n");
39*4882a593Smuzhiyun exit(1);
40*4882a593Smuzhiyun }
41*4882a593Smuzhiyun if ((fd = open(av[1], 2)) == -1) {
42*4882a593Smuzhiyun perror(av[2]);
43*4882a593Smuzhiyun exit(1);
44*4882a593Smuzhiyun }
45*4882a593Smuzhiyun if (read(fd, &fhdr, sizeof(fhdr)) != sizeof(fhdr))
46*4882a593Smuzhiyun goto readerr;
47*4882a593Smuzhiyun i = get_16be(fhdr.f_magic);
48*4882a593Smuzhiyun if (i != U802TOCMAGIC && i != U802WRMAGIC && i != U802ROMAGIC) {
49*4882a593Smuzhiyun fprintf(stderr, "%s: not an xcoff file\n", av[1]);
50*4882a593Smuzhiyun exit(1);
51*4882a593Smuzhiyun }
52*4882a593Smuzhiyun aoutsz = get_16be(fhdr.f_opthdr);
53*4882a593Smuzhiyun if (read(fd, &aout, aoutsz) != aoutsz)
54*4882a593Smuzhiyun goto readerr;
55*4882a593Smuzhiyun nsect = get_16be(fhdr.f_nscns);
56*4882a593Smuzhiyun for (i = 0; i < nsect; ++i) {
57*4882a593Smuzhiyun if (read(fd, &shdr, sizeof(shdr)) != sizeof(shdr))
58*4882a593Smuzhiyun goto readerr;
59*4882a593Smuzhiyun if (strcmp(shdr.s_name, ".text") == 0) {
60*4882a593Smuzhiyun put_16be(aout.o_snentry, i+1);
61*4882a593Smuzhiyun put_16be(aout.o_sntext, i+1);
62*4882a593Smuzhiyun } else if (strcmp(shdr.s_name, ".data") == 0) {
63*4882a593Smuzhiyun put_16be(aout.o_sndata, i+1);
64*4882a593Smuzhiyun } else if (strcmp(shdr.s_name, ".bss") == 0) {
65*4882a593Smuzhiyun put_16be(aout.o_snbss, i+1);
66*4882a593Smuzhiyun }
67*4882a593Smuzhiyun }
68*4882a593Smuzhiyun put_16be(aout.magic, AOUT_MAGIC);
69*4882a593Smuzhiyun if (lseek(fd, (long) sizeof(struct external_filehdr), 0) == -1
70*4882a593Smuzhiyun || write(fd, &aout, aoutsz) != aoutsz) {
71*4882a593Smuzhiyun fprintf(stderr, "%s: write error\n", av[1]);
72*4882a593Smuzhiyun exit(1);
73*4882a593Smuzhiyun }
74*4882a593Smuzhiyun close(fd);
75*4882a593Smuzhiyun exit(0);
76*4882a593Smuzhiyun
77*4882a593Smuzhiyun readerr:
78*4882a593Smuzhiyun fprintf(stderr, "%s: read error or file too short\n", av[1]);
79*4882a593Smuzhiyun exit(1);
80*4882a593Smuzhiyun }
81