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/*
Simple utility to make a single-image install kernel with initial ramdisk
for Sparc tftpbooting without need to set up nfs.
Copyright (C) 1996 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
Pete Zaitcev <zaitcev@yahoo.com> endian fixes for cross-compiles, 2000.
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 <dirent.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
/*
* Note: run this on an a.out kernel (use elftoaout for it),
* as PROM looks for a.out image only.
*/
/* read two bytes as big endian */
static unsigned short ld2(char *p)
{
return (p[0] << 8) | p[1];
}
/* read 4 bytes as big endian */
static unsigned int ld4(char *p)
{
return (p[0] << 24) | (p[1] << 16) | (p[2] << 8) | p[3];
}
/* save 4 bytes as big endian */
static void st4(char *p, unsigned int x)
{
p[0] = x >> 24;
p[1] = x >> 16;
p[2] = x >> 8;
p[3] = x;
}
static void die(const char *str)
{
perror(str);
exit(1);
}
static void usage(void)
{
/* fs_img.gz is an image of initial ramdisk. */
fprintf(stderr, "Usage: piggyback vmlinux.aout System.map fs_img.gz\n");
fprintf(stderr, "\tKernel image will be modified in place.\n");
exit(1);
}
static int start_line(const char *line)
{
if (strcmp(line + 8, " T _start\n") == 0)
return 1;
else if (strcmp(line + 16, " T _start\n") == 0)
return 1;
return 0;
}
static int end_line(const char *line)
{
if (strcmp(line + 8, " A _end\n") == 0)
return 1;
else if (strcmp (line + 16, " A _end\n") == 0)
return 1;
return 0;
}
/*
* Find address for start and end in System.map.
* The file looks like this:
* f0004000 T _start
* f0379f79 A _end
* 1234567890123456
* ^coloumn 1
* There is support for 64 bit addresses too.
*
* Return 0 if either start or end is not found
*/
static int get_start_end(const char *filename, unsigned int *start, unsigned int *end)
{
FILE *map;
char buffer[1024];
*start = 0;
*end = 0;
map = fopen(filename, "r");
if (!map)
die(filename);
while (fgets(buffer, 1024, map)) {
if (start_line(buffer))
*start = strtoul(buffer, NULL, 16);
else if (end_line(buffer))
*end = strtoul(buffer, NULL, 16);
}
fclose (map);
if (*start == 0 || *end == 0)
return 0;
return 1;
}
int main(int argc,char **argv)
{
static char aout_magic[] = { 0x01, 0x03, 0x01, 0x07 };
char buffer[1024], *q, *r;
unsigned int i, j, k, start, end, offset;
struct stat s;
int image, tail;
if (argc != 4)
usage();
if (stat (argv[3], &s) < 0)
die(argv[3]);
if (!get_start_end(argv[2], &start, &end)) {
fprintf (stderr, "Could not determine start and end from %s\n", argv[2]);
exit(1);
}
if ((image = open(argv[1], O_RDWR)) < 0)
die(argv[1]);
if (read(image, buffer, 512) != 512)
die(argv[1]);
if (memcmp (buffer, "\177ELF", 4) == 0) {
q = buffer + ld4(buffer + 28);
i = ld4(q + 4) + ld4(buffer + 24) - ld4(q + 8);
if (lseek(image, i, 0) < 0)
die("lseek");
if (read(image, buffer, 512) != 512)
die(argv[1]);
j = 0;
} else if (memcmp(buffer, aout_magic, 4) == 0) {
i = j = 32;
} else {
fprintf (stderr, "Not ELF nor a.out. Don't blame me.\n");
exit(1);
}
k = i;
i += (ld2(buffer + j + 2) << 2) - 512;
if (lseek(image, i, 0) < 0)
die("lseek");
if (read(image, buffer, 1024) != 1024)
die(argv[1]);
for (q = buffer, r = q + 512; q < r; q += 4) {
if (*q == 'H' && q[1] == 'd' && q[2] == 'r' && q[3] == 'S')
break;
}
if (q == r) {
fprintf (stderr, "Couldn't find headers signature in the kernel.\n");
exit(1);
}
offset = i + (q - buffer) + 10;
if (lseek(image, offset, 0) < 0)
die("lseek");
st4(buffer, 0);
st4(buffer + 4, 0x01000000);
st4(buffer + 8, (end + 32 + 4095) & ~4095);
st4(buffer + 12, s.st_size);
if (write(image, buffer + 2, 14) != 14)
die(argv[1]);
if (lseek(image, k - start + ((end + 32 + 4095) & ~4095), 0) < 0)
die("lseek");
if ((tail = open(argv[3],O_RDONLY)) < 0)
die(argv[3]);
while ((i = read (tail, buffer, 1024)) > 0)
if (write(image, buffer, i) != i)
die(argv[1]);
if (close(image) < 0)
die("close");
if (close(tail) < 0)
die("close");
return 0;
}
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