|  | /* | 
|  | 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; | 
|  | } |