arch/sparc64/boot/piggyback.c

   1 /*
   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 }