// SPDX-License-Identifier: GPL-2.0-or-later /* * hack-coff.c - hack the header of an xcoff file to fill in * a few fields needed by the Open Firmware xcoff loader on * Power Macs but not initialized by objcopy. * * Copyright (C) Paul Mackerras 1997. */ #include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <fcntl.h> #include <string.h> #include "rs6000.h" #define AOUT_MAGIC 0x010b #define get_16be(x) ((((unsigned char *)(x))[0] << 8) \ + ((unsigned char *)(x))[1]) #define put_16be(x, v) (((unsigned char *)(x))[0] = (v) >> 8, \ ((unsigned char *)(x))[1] = (v) & 0xff) #define get_32be(x) ((((unsigned char *)(x))[0] << 24) \ + (((unsigned char *)(x))[1] << 16) \ + (((unsigned char *)(x))[2] << 8) \ + ((unsigned char *)(x))[3]) int main(int ac, char **av) { int fd; int i, nsect; int aoutsz; struct external_filehdr fhdr; AOUTHDR aout; struct external_scnhdr shdr; if (ac != 2) { fprintf(stderr, "Usage: hack-coff coff-file\n"); exit(1); } if ((fd = open(av[1], 2)) == -1) { perror(av[2]); exit(1); } if (read(fd, &fhdr, sizeof(fhdr)) != sizeof(fhdr)) goto readerr; i = get_16be(fhdr.f_magic); if (i != U802TOCMAGIC && i != U802WRMAGIC && i != U802ROMAGIC) { fprintf(stderr, "%s: not an xcoff file\n", av[1]); exit(1); } aoutsz = get_16be(fhdr.f_opthdr); if (read(fd, &aout, aoutsz) != aoutsz) goto readerr; nsect = get_16be(fhdr.f_nscns); for (i = 0; i < nsect; ++i) { if (read(fd, &shdr, sizeof(shdr)) != sizeof(shdr)) goto readerr; if (strcmp(shdr.s_name, ".text") == 0) { put_16be(aout.o_snentry, i+1); put_16be(aout.o_sntext, i+1); } else if (strcmp(shdr.s_name, ".data") == 0) { put_16be(aout.o_sndata, i+1); } else if (strcmp(shdr.s_name, ".bss") == 0) { put_16be(aout.o_snbss, i+1); } } put_16be(aout.magic, AOUT_MAGIC); if (lseek(fd, (long) sizeof(struct external_filehdr), 0) == -1 || write(fd, &aout, aoutsz) != aoutsz) { fprintf(stderr, "%s: write error\n", av[1]); exit(1); } close(fd); exit(0); readerr: fprintf(stderr, "%s: read error or file too short\n", av[1]); exit(1); }