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Diffstat (limited to 'arch/sparc/boot/piggyback.c')
| -rw-r--r-- | arch/sparc/boot/piggyback.c | 272 |
1 files changed, 272 insertions, 0 deletions
diff --git a/arch/sparc/boot/piggyback.c b/arch/sparc/boot/piggyback.c new file mode 100644 index 000000000000..c0a798fcf030 --- /dev/null +++ b/arch/sparc/boot/piggyback.c @@ -0,0 +1,272 @@ +/* + 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; +} |