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 } 85