| /* |
| Simple utility to make a single-image install kernel with initial ramdisk |
| for Sparc tftpbooting without need to set up nfs. |
| |
| Copyright (C) 1996,1997 Jakub Jelinek (jj@sunsite.mff.cuni.cz) |
| Pete Zaitcev <zaitcev@yahoo.com> endian fixes for cross-compiles, 2000. |
| Copyright (C) 2011 Sam Ravnborg <sam@ravnborg.org> |
| |
| 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. |
| */ |
| |
| #define AOUT_TEXT_OFFSET 32 |
| |
| static int is64bit = 0; |
| |
| /* align to power-of-two size */ |
| static int align(int n) |
| { |
| if (is64bit) |
| return (n + 0x1fff) & ~0x1fff; |
| else |
| return (n + 0xfff) & ~0xfff; |
| } |
| |
| /* read two bytes as big endian */ |
| static unsigned short ld2(char *p) |
| { |
| return (p[0] << 8) | p[1]; |
| } |
| |
| /* 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 bits 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; |
| } |
| |
| #define LOOKBACK (128 * 4) |
| #define BUFSIZE 1024 |
| /* |
| * Find the HdrS entry from head_32/head_64. |
| * We check if it is at the beginning of the file (sparc64 case) |
| * and if not we search for it. |
| * When we search do so in steps of 4 as HdrS is on a 4-byte aligned |
| * address (it is on same alignment as sparc instructions) |
| * Return the offset to the HdrS entry (as off_t) |
| */ |
| static off_t get_hdrs_offset(int kernelfd, const char *filename) |
| { |
| char buffer[BUFSIZE]; |
| off_t offset; |
| int i; |
| |
| if (lseek(kernelfd, 0, SEEK_SET) < 0) |
| die("lseek"); |
| if (read(kernelfd, buffer, BUFSIZE) != BUFSIZE) |
| die(filename); |
| |
| if (buffer[40] == 'H' && buffer[41] == 'd' && |
| buffer[42] == 'r' && buffer[43] == 'S') { |
| return 40; |
| } else { |
| /* Find the gokernel label */ |
| /* Decode offset from branch instruction */ |
| offset = ld2(buffer + AOUT_TEXT_OFFSET + 2) << 2; |
| /* Go back 512 bytes so we do not miss HdrS */ |
| offset -= LOOKBACK; |
| /* skip a.out header */ |
| offset += AOUT_TEXT_OFFSET; |
| if (lseek(kernelfd, offset, SEEK_SET) < 0) |
| die("lseek"); |
| if (read(kernelfd, buffer, BUFSIZE) != BUFSIZE) |
| die(filename); |
| |
| for (i = 0; i < LOOKBACK; i += 4) { |
| if (buffer[i + 0] == 'H' && buffer[i + 1] == 'd' && |
| buffer[i + 2] == 'r' && buffer[i + 3] == 'S') { |
| return offset + i; |
| } |
| } |
| } |
| fprintf (stderr, "Couldn't find headers signature in %s\n", filename); |
| exit(1); |
| } |
| |
| int main(int argc,char **argv) |
| { |
| static char aout_magic[] = { 0x01, 0x03, 0x01, 0x07 }; |
| char buffer[1024]; |
| unsigned int i, start, end; |
| off_t offset; |
| struct stat s; |
| int image, tail; |
| |
| if (argc != 5) |
| usage(); |
| if (strcmp(argv[1], "64") == 0) |
| is64bit = 1; |
| if (stat (argv[4], &s) < 0) |
| die(argv[4]); |
| |
| if (!get_start_end(argv[3], &start, &end)) { |
| fprintf(stderr, "Could not determine start and end from %s\n", |
| argv[3]); |
| exit(1); |
| } |
| if ((image = open(argv[2], O_RDWR)) < 0) |
| die(argv[2]); |
| if (read(image, buffer, 512) != 512) |
| die(argv[2]); |
| if (memcmp(buffer, aout_magic, 4) != 0) { |
| fprintf (stderr, "Not a.out. Don't blame me.\n"); |
| exit(1); |
| } |
| /* |
| * We need to fill in values for |
| * sparc_ramdisk_image + sparc_ramdisk_size |
| * To locate these symbols search for the "HdrS" text which appear |
| * in the image a little before the gokernel symbol. |
| * See definition of these in init_32.S |
| */ |
| |
| offset = get_hdrs_offset(image, argv[2]); |
| /* skip HdrS + LINUX_VERSION_CODE + HdrS version */ |
| offset += 10; |
| |
| if (lseek(image, offset, 0) < 0) |
| die("lseek"); |
| |
| /* |
| * root_flags = 0 |
| * root_dev = 1 (RAMDISK_MAJOR) |
| * ram_flags = 0 |
| * sparc_ramdisk_image = "PAGE aligned address after _end") |
| * sparc_ramdisk_size = size of image |
| */ |
| st4(buffer, 0); |
| st4(buffer + 4, 0x01000000); |
| st4(buffer + 8, align(end + 32)); |
| st4(buffer + 12, s.st_size); |
| |
| if (write(image, buffer + 2, 14) != 14) |
| die(argv[2]); |
| |
| /* For sparc64 update a_text and clear a_data + a_bss */ |
| if (is64bit) |
| { |
| if (lseek(image, 4, 0) < 0) |
| die("lseek"); |
| /* a_text */ |
| st4(buffer, align(end + 32 + 8191) - (start & ~0x3fffffUL) + |
| s.st_size); |
| /* a_data */ |
| st4(buffer + 4, 0); |
| /* a_bss */ |
| st4(buffer + 8, 0); |
| if (write(image, buffer, 12) != 12) |
| die(argv[2]); |
| } |
| |
| /* seek page aligned boundary in the image file and add boot image */ |
| if (lseek(image, AOUT_TEXT_OFFSET - start + align(end + 32), 0) < 0) |
| die("lseek"); |
| if ((tail = open(argv[4], O_RDONLY)) < 0) |
| die(argv[4]); |
| while ((i = read(tail, buffer, 1024)) > 0) |
| if (write(image, buffer, i) != i) |
| die(argv[2]); |
| if (close(image) < 0) |
| die("close"); |
| if (close(tail) < 0) |
| die("close"); |
| return 0; |
| } |