1 /* 2 Simple utility to make a single-image install kernel with initial ramdisk 3 for Sparc tftpbooting without need to set up nfs. 4 5 Copyright (C) 1996 Jakub Jelinek (jj@sunsite.mff.cuni.cz) 6 Pete Zaitcev <zaitcev@yahoo.com> endian fixes for cross-compiles, 2000. 7 8 This program is free software; you can redistribute it and/or modify 9 it under the terms of the GNU General Public License as published by 10 the Free Software Foundation; either version 2 of the License, or 11 (at your option) any later version. 12 13 This program is distributed in the hope that it will be useful, 14 but WITHOUT ANY WARRANTY; without even the implied warranty of 15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 GNU General Public License for more details. 17 18 You should have received a copy of the GNU General Public License 19 along with this program; if not, write to the Free Software 20 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ 21 22 #include <stdio.h> 23 #include <string.h> 24 #include <ctype.h> 25 #include <errno.h> 26 #include <fcntl.h> 27 #include <dirent.h> 28 #include <unistd.h> 29 #include <stdlib.h> 30 #include <sys/types.h> 31 #include <sys/stat.h> 32 33 /* 34 * Note: run this on an a.out kernel (use elftoaout for it), 35 * as PROM looks for a.out image only. 36 */ 37 38 unsigned short ld2(char *p) 39 { 40 return (p[0] << 8) | p[1]; 41 } 42 43 unsigned int ld4(char *p) 44 { 45 return (p[0] << 24) | (p[1] << 16) | (p[2] << 8) | p[3]; 46 } 47 48 void st4(char *p, unsigned int x) 49 { 50 p[0] = x >> 24; 51 p[1] = x >> 16; 52 p[2] = x >> 8; 53 p[3] = x; 54 } 55 56 void usage(void) 57 { 58 /* fs_img.gz is an image of initial ramdisk. */ 59 fprintf(stderr, "Usage: piggyback vmlinux.aout System.map fs_img.gz\n"); 60 fprintf(stderr, "\tKernel image will be modified in place.\n"); 61 exit(1); 62 } 63 64 void die(char *str) 65 { 66 perror (str); 67 exit(1); 68 } 69 70 int main(int argc,char **argv) 71 { 72 static char aout_magic[] = { 0x01, 0x03, 0x01, 0x07 }; 73 unsigned char buffer[1024], *q, *r; 74 unsigned int i, j, k, start, end, offset; 75 FILE *map; 76 struct stat s; 77 int image, tail; 78 79 if (argc != 4) usage(); 80 start = end = 0; 81 if (stat (argv[3], &s) < 0) die (argv[3]); 82 map = fopen (argv[2], "r"); 83 if (!map) die(argv[2]); 84 while (fgets (buffer, 1024, map)) { 85 if (!strcmp (buffer + 8, " T start\n") || !strcmp (buffer + 16, " T start\n")) 86 start = strtoul (buffer, NULL, 16); 87 else if (!strcmp (buffer + 8, " A end\n") || !strcmp (buffer + 16, " A end\n")) 88 end = strtoul (buffer, NULL, 16); 89 } 90 fclose (map); 91 if (!start || !end) { 92 fprintf (stderr, "Could not determine start and end from System.map\n"); 93 exit(1); 94 } 95 if ((image = open(argv[1],O_RDWR)) < 0) die(argv[1]); 96 if (read(image,buffer,512) != 512) die(argv[1]); 97 if (memcmp (buffer, "\177ELF", 4) == 0) { 98 q = buffer + ld4(buffer + 28); 99 i = ld4(q + 4) + ld4(buffer + 24) - ld4(q + 8); 100 if (lseek(image,i,0) < 0) die("lseek"); 101 if (read(image,buffer,512) != 512) die(argv[1]); 102 j = 0; 103 } else if (memcmp(buffer, aout_magic, 4) == 0) { 104 i = j = 32; 105 } else { 106 fprintf (stderr, "Not ELF nor a.out. Don't blame me.\n"); 107 exit(1); 108 } 109 k = i; 110 i += (ld2(buffer + j + 2)<<2) - 512; 111 if (lseek(image,i,0) < 0) die("lseek"); 112 if (read(image,buffer,1024) != 1024) die(argv[1]); 113 for (q = buffer, r = q + 512; q < r; q += 4) { 114 if (*q == 'H' && q[1] == 'd' && q[2] == 'r' && q[3] == 'S') 115 break; 116 } 117 if (q == r) { 118 fprintf (stderr, "Couldn't find headers signature in the kernel.\n"); 119 exit(1); 120 } 121 offset = i + (q - buffer) + 10; 122 if (lseek(image, offset, 0) < 0) die ("lseek"); 123 124 st4(buffer, 0); 125 st4(buffer + 4, 0x01000000); 126 st4(buffer + 8, (end + 32 + 4095) & ~4095); 127 st4(buffer + 12, s.st_size); 128 129 if (write(image,buffer+2,14) != 14) die (argv[1]); 130 if (lseek(image, k - start + ((end + 32 + 4095) & ~4095), 0) < 0) die ("lseek"); 131 if ((tail = open(argv[3],O_RDONLY)) < 0) die(argv[3]); 132 while ((i = read (tail,buffer,1024)) > 0) 133 if (write(image,buffer,i) != i) die (argv[1]); 134 if (close(image) < 0) die("close"); 135 if (close(tail) < 0) die("close"); 136 return 0; 137 } 138