Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* $Id: piggyback.c,v 1.2 2000/09/19 14:34:39 anton Exp $ |
| 2 | Simple utility to make a single-image install kernel with initial ramdisk |
| 3 | for Sparc64 tftpbooting without need to set up nfs. |
| 4 | |
| 5 | Copyright (C) 1997 Jakub Jelinek (jj@sunsite.mff.cuni.cz) |
| 6 | |
| 7 | This program is free software; you can redistribute it and/or modify |
| 8 | it under the terms of the GNU General Public License as published by |
| 9 | the Free Software Foundation; either version 2 of the License, or |
| 10 | (at your option) any later version. |
| 11 | |
| 12 | This program is distributed in the hope that it will be useful, |
| 13 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | GNU General Public License for more details. |
| 16 | |
| 17 | You should have received a copy of the GNU General Public License |
| 18 | along with this program; if not, write to the Free Software |
| 19 | Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ |
| 20 | |
| 21 | #include <stdio.h> |
| 22 | #include <string.h> |
| 23 | #include <ctype.h> |
| 24 | #include <errno.h> |
| 25 | #include <fcntl.h> |
| 26 | #include <dirent.h> |
| 27 | #include <unistd.h> |
| 28 | #include <stdlib.h> |
| 29 | #include <sys/types.h> |
| 30 | #include <sys/stat.h> |
| 31 | |
| 32 | /* Note: run this on an a.out kernel (use elftoaout for it), as PROM looks for a.out image onlly |
| 33 | usage: piggyback vmlinux System.map tail, where tail is gzipped fs of the initial ramdisk */ |
| 34 | |
| 35 | void die(char *str) |
| 36 | { |
| 37 | perror (str); |
| 38 | exit(1); |
| 39 | } |
| 40 | |
| 41 | int main(int argc,char **argv) |
| 42 | { |
| 43 | char buffer [1024], *q, *r; |
| 44 | unsigned int i, j, k, start, end, offset; |
| 45 | FILE *map; |
| 46 | struct stat s; |
| 47 | int image, tail; |
| 48 | |
| 49 | if (stat (argv[3], &s) < 0) die (argv[3]); |
| 50 | map = fopen (argv[2], "r"); |
| 51 | if (!map) die(argv[2]); |
| 52 | while (fgets (buffer, 1024, map)) { |
| 53 | if (!strcmp (buffer + 19, "_start\n")) |
| 54 | start = strtoul (buffer + 8, NULL, 16); |
| 55 | else if (!strcmp (buffer + 19, "_end\n")) |
| 56 | end = strtoul (buffer + 8, NULL, 16); |
| 57 | } |
| 58 | fclose (map); |
| 59 | if ((image = open(argv[1],O_RDWR)) < 0) die(argv[1]); |
| 60 | if (read(image,buffer,512) != 512) die(argv[1]); |
| 61 | if (!memcmp (buffer, "\177ELF", 4)) { |
| 62 | unsigned int *p = (unsigned int *)(buffer + *(unsigned int *)(buffer + 28)); |
| 63 | |
| 64 | i = p[1] + *(unsigned int *)(buffer + 24) - p[2]; |
| 65 | if (lseek(image,i,0) < 0) die("lseek"); |
| 66 | if (read(image,buffer,512) != 512) die(argv[1]); |
| 67 | j = 0; |
| 68 | } else if (*(unsigned int *)buffer == 0x01030107) { |
| 69 | i = j = 32; |
| 70 | } else { |
| 71 | fprintf (stderr, "Not ELF nor a.out. Don't blame me.\n"); |
| 72 | exit(1); |
| 73 | } |
| 74 | k = i; |
| 75 | if (j == 32 && buffer[40] == 'H' && buffer[41] == 'd' && buffer[42] == 'r' && buffer[43] == 'S') { |
| 76 | offset = 40 + 10; |
| 77 | } else { |
| 78 | i += ((*(unsigned short *)(buffer + j + 2))<<2) - 512; |
| 79 | if (lseek(image,i,0) < 0) die("lseek"); |
| 80 | if (read(image,buffer,1024) != 1024) die(argv[1]); |
| 81 | for (q = buffer, r = q + 512; q < r; q += 4) { |
| 82 | if (*q == 'H' && q[1] == 'd' && q[2] == 'r' && q[3] == 'S') |
| 83 | break; |
| 84 | } |
| 85 | if (q == r) { |
| 86 | fprintf (stderr, "Couldn't find headers signature in the kernel.\n"); |
| 87 | exit(1); |
| 88 | } |
| 89 | offset = i + (q - buffer) + 10; |
| 90 | } |
| 91 | if (lseek(image, offset, 0) < 0) die ("lseek"); |
| 92 | *(unsigned *)buffer = 0; |
| 93 | *(unsigned *)(buffer + 4) = 0x01000000; |
| 94 | *(unsigned *)(buffer + 8) = ((end + 32 + 8191) & ~8191); |
| 95 | *(unsigned *)(buffer + 12) = s.st_size; |
| 96 | if (write(image,buffer+2,14) != 14) die (argv[1]); |
| 97 | if (lseek(image, 4, 0) < 0) die ("lseek"); |
| 98 | *(unsigned *)buffer = ((end + 32 + 8191) & ~8191) - (start & ~0x3fffffUL) + s.st_size; |
| 99 | *(unsigned *)(buffer + 4) = 0; |
| 100 | *(unsigned *)(buffer + 8) = 0; |
| 101 | if (write(image,buffer,12) != 12) die (argv[1]); |
| 102 | if (lseek(image, k - start + ((end + 32 + 8191) & ~8191), 0) < 0) die ("lseek"); |
| 103 | if ((tail = open(argv[3],O_RDONLY)) < 0) die(argv[3]); |
| 104 | while ((i = read (tail,buffer,1024)) > 0) |
| 105 | if (write(image,buffer,i) != i) die (argv[1]); |
| 106 | if (close(image) < 0) die("close"); |
| 107 | if (close(tail) < 0) die("close"); |
| 108 | return 0; |
| 109 | } |