123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125 |
- /*
- * abootconf.c
- *
- * This file is part of aboot, the SRM bootloader for Linux/Alpha
- * Copyright (C) 1996 Linus Torvalds, David Mosberger, and Michael Schwingen.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License as
- * published by the Free Software Foundation; either version 2 of the
- * License, or (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful, but
- * WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
- */
- #include <errno.h>
- #include <stdio.h>
- #include <stdlib.h>
- #include <unistd.h>
- #include <sys/fcntl.h>
- #include <config.h>
- const char * prog_name;
- int
- main (int argc, char ** argv)
- {
- unsigned long sector[512 / sizeof(unsigned long)];
- off_t aboot_pos;
- size_t nbytes;
- long part = -1;
- int disk, i;
- prog_name = argv[0];
- if (argc != 2 && argc != 3) {
- fprintf(stderr, "usage: %s device [partition]\n", prog_name);
- exit(1);
- }
- if (argc > 2) {
- errno = 0;
- part = strtol(argv[2], 0, 10);
- if (errno == ERANGE) {
- fprintf(stderr, "%s: bad partition number %s\n",
- prog_name, argv[2]);
- exit(1);
- }
- }
- disk = open(argv[1], part < 0 ? O_RDONLY : O_RDWR);
- if (disk < 0) {
- perror(argv[1]);
- exit(1);
- }
- nbytes = read(disk, sector, sizeof(sector));
- if (nbytes != sizeof(sector)) {
- if ((long) nbytes < 0) {
- perror("read");
- } else {
- fprintf(stderr, "%s: short read\n", prog_name);
- }
- exit(1);
- }
- aboot_pos = sector[61] * 512;
- if (lseek(disk, aboot_pos, SEEK_SET) != aboot_pos) {
- perror("lseek");
- exit(1);
- }
- nbytes = read(disk, sector, sizeof(sector));
- if (nbytes != sizeof(sector)) {
- if ((long) nbytes < 0) {
- perror("read");
- } else {
- fprintf(stderr, "%s: short read\n", prog_name);
- }
- exit(1);
- }
- for (i = 0; i < (int) (sizeof(sector)/sizeof(sector[0])); ++i) {
- if (sector[i] == ABOOT_MAGIC)
- break;
- }
- if (i >= (int) (sizeof(sector)/sizeof(sector[0]))) {
- fprintf(stderr, "%s: could not find aboot on disk %s\n",
- prog_name, argv[1]);
- exit(1);
- }
- if (part < 0) {
- printf("aboot.conf partition currently set to %ld\n",
- sector[i + 1]);
- exit(0);
- }
- if (lseek(disk, aboot_pos, SEEK_SET) != aboot_pos) {
- perror("lseek");
- exit(1);
- }
- sector[i + 1] = atoi(argv[2]);
- nbytes = write(disk, sector, sizeof(sector));
- if (nbytes != sizeof(sector)) {
- if ((long) nbytes < 0) {
- perror("write");
- } else {
- fprintf(stderr, "%s: short write\n", prog_name);
- }
- exit(1);
- }
- return 0;
- }
|