LXR linux/arch/sparc/boot/piggyback

   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
  35static void die(char *str)
  36{
  37        perror (str);
  38        exit(1);
  39}
  40
  41int 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        start = end = 0;
  50        if (stat (argv[3], &s) < 0) die (argv[3]);
  51        map = fopen (argv[2], "r");
  52        if (!map) die(argv[2]);
  53        while (fgets (buffer, 1024, map)) {
  54                if (!strcmp (buffer + 19, "_start\n"))
  55                start = strtoul (buffer + 8, NULL, 16);
  56                else if (!strcmp (buffer + 19, "_end\n"))
  57                end = strtoul (buffer + 8, NULL, 16);
  58        }
  59        fclose (map);
  60        if ((image = open(argv[1],O_RDWR)) < 0) die(argv[1]);
  61        if (read(image,buffer,512) != 512) die(argv[1]);
  62        if (!memcmp (buffer, "\177ELF", 4)) {
  63                unsigned int *p = (unsigned int *)(buffer + *(unsigned int *)(buffer + 28));
  64                
  65                i = p[1] + *(unsigned int *)(buffer + 24) - p[2];
  66                if (lseek(image,i,0) < 0) die("lseek");
  67                if (read(image,buffer,512) != 512) die(argv[1]);
  68                j = 0;
  69        } else if (*(unsigned int *)buffer == 0x01030107) {
  70                i = j = 32;
  71        } else {
  72                fprintf (stderr, "Not ELF nor a.out. Don't blame me.\n");
  73                exit(1);
  74        }
  75        k = i;
  76        if (j == 32 && buffer[40] == 'H' && buffer[41] == 'd' && buffer[42] == 'r' && buffer[43] == 'S') {
  77                offset = 40 + 10;
  78        } else {
  79                i += ((*(unsigned short *)(buffer + j + 2))<<2) - 512;
  80                if (lseek(image,i,0) < 0) die("lseek");
  81                if (read(image,buffer,1024) != 1024) die(argv[1]);
  82                for (q = buffer, r = q + 512; q < r; q += 4) {
  83                        if (*q == 'H' && q[1] == 'd' && q[2] == 'r' && q[3] == 'S')
  84                                break;
  85                }
  86                if (q == r) {
  87                        fprintf (stderr, "Couldn't find headers signature in the kernel.\n");
  88                        exit(1);
  89                }
  90                offset = i + (q - buffer) + 10;
  91        }
  92        if (lseek(image, offset, 0) < 0) die ("lseek");
  93        *(unsigned *)buffer = 0;
  94        *(unsigned *)(buffer + 4) = 0x01000000;
  95        *(unsigned *)(buffer + 8) = ((end + 32 + 8191) & ~8191);
  96        *(unsigned *)(buffer + 12) = s.st_size;
  97        if (write(image,buffer+2,14) != 14) die (argv[1]);
  98        if (lseek(image, 4, 0) < 0) die ("lseek");
  99        *(unsigned *)buffer = ((end + 32 + 8191) & ~8191) - (start & ~0x3fffffUL) + s.st_size;
 100        *(unsigned *)(buffer + 4) = 0;
 101        *(unsigned *)(buffer + 8) = 0;
 102        if (write(image,buffer,12) != 12) die (argv[1]);
 103        if (lseek(image, k - start + ((end + 32 + 8191) & ~8191), 0) < 0) die ("lseek");
 104        if ((tail = open(argv[3],O_RDONLY)) < 0) die(argv[3]);
 105        while ((i = read (tail,buffer,1024)) > 0)
 106                if (write(image,buffer,i) != i) die (argv[1]);
 107        if (close(image) < 0) die("close");
 108        if (close(tail) < 0) die("close");
 109        return 0;
 110}
 111