1/* 2 * arch/alpha/boot/tools/objstrip.c 3 * 4 * Strip the object file headers/trailers from an executable (ELF or ECOFF). 5 * 6 * Copyright (C) 1996 David Mosberger-Tang. 7 */ 8/* 9 * Converts an ECOFF or ELF object file into a bootable file. The 10 * object file must be a OMAGIC file (i.e., data and bss follow immediately 11 * behind the text). See DEC "Assembly Language Programmer's Guide" 12 * documentation for details. The SRM boot process is documented in 13 * the Alpha AXP Architecture Reference Manual, Second Edition by 14 * Richard L. Sites and Richard T. Witek. 15 */ 16#include <stdio.h> 17#include <string.h> 18#include <stdlib.h> 19#include <unistd.h> 20 21#include <sys/fcntl.h> 22#include <sys/stat.h> 23#include <sys/types.h> 24 25#include <linux/a.out.h> 26#include <linux/coff.h> 27#include <linux/param.h> 28#ifdef __ELF__ 29# include <linux/elf.h> 30#endif 31 32/* bootfile size must be multiple of BLOCK_SIZE: */ 33#define BLOCK_SIZE 512 34 35const char * prog_name; 36 37 38static void 39usage (void) 40{ 41 fprintf(stderr, 42 "usage: %s [-v] -p file primary\n" 43 " %s [-vb] file [secondary]\n", prog_name, prog_name); 44 exit(1); 45} 46 47 48int 49main (int argc, char *argv[]) 50{ 51 size_t nwritten, tocopy, n, mem_size, fil_size, pad = 0; 52 int fd, ofd, i, j, verbose = 0, primary = 0; 53 char buf[8192], *inname; 54 struct exec * aout; /* includes file & aout header */ 55 long offset; 56#ifdef __ELF__ 57 struct elfhdr *elf; 58 struct elf_phdr *elf_phdr; /* program header */ 59 unsigned long long e_entry; 60#endif 61 62 prog_name = argv[0]; 63 64 for (i = 1; i < argc && argv[i][0] == '-'; ++i) { 65 for (j = 1; argv[i][j]; ++j) { 66 switch (argv[i][j]) { 67 case 'v': 68 verbose = ~verbose; 69 break; 70 71 case 'b': 72 pad = BLOCK_SIZE; 73 break; 74 75 case 'p': 76 primary = 1; /* make primary bootblock */ 77 break; 78 } 79 } 80 } 81 82 if (i >= argc) { 83 usage(); 84 } 85 inname = argv[i++]; 86 87 fd = open(inname, O_RDONLY); 88 if (fd == -1) { 89 perror("open"); 90 exit(1); 91 } 92 93 ofd = 1; 94 if (i < argc) { 95 ofd = open(argv[i++], O_WRONLY | O_CREAT | O_TRUNC, 0666); 96 if (ofd == -1) { 97 perror("open"); 98 exit(1); 99 } 100 } 101 102 if (primary) { 103 /* generate bootblock for primary loader */ 104 105 unsigned long bb[64], sum = 0; 106 struct stat st; 107 off_t size; 108 int i; 109 110 if (ofd == 1) { 111 usage(); 112 } 113 114 if (fstat(fd, &st) == -1) { 115 perror("fstat"); 116 exit(1); 117 } 118 119 size = (st.st_size + BLOCK_SIZE - 1) & ~(BLOCK_SIZE - 1); 120 memset(bb, 0, sizeof(bb)); 121 strcpy((char *) bb, "Linux SRM bootblock"); 122 bb[60] = size / BLOCK_SIZE; /* count */ 123 bb[61] = 1; /* starting sector # */ 124 bb[62] = 0; /* flags---must be 0 */ 125 for (i = 0; i < 63; ++i) { 126 sum += bb[i]; 127 } 128 bb[63] = sum; 129 if (write(ofd, bb, sizeof(bb)) != sizeof(bb)) { 130 perror("boot-block write"); 131 exit(1); 132 } 133 printf("%lu\n", size); 134 return 0; 135 } 136 137 /* read and inspect exec header: */ 138 139 if (read(fd, buf, sizeof(buf)) < 0) { 140 perror("read"); 141 exit(1); 142 } 143 144#ifdef __ELF__ 145 elf = (struct elfhdr *) buf; 146 147 if (elf->e_ident[0] == 0x7f && strncmp((char *)elf->e_ident + 1, "ELF", 3) == 0) { 148 if (elf->e_type != ET_EXEC) { 149 fprintf(stderr, "%s: %s is not an ELF executable\n", 150 prog_name, inname); 151 exit(1); 152 } 153 if (!elf_check_arch(elf)) { 154 fprintf(stderr, "%s: is not for this processor (e_machine=%d)\n", 155 prog_name, elf->e_machine); 156 exit(1); 157 } 158 if (elf->e_phnum != 1) { 159 fprintf(stderr, 160 "%s: %d program headers (forgot to link with -N?)\n", 161 prog_name, elf->e_phnum); 162 } 163 164 e_entry = elf->e_entry; 165 166 lseek(fd, elf->e_phoff, SEEK_SET); 167 if (read(fd, buf, sizeof(*elf_phdr)) != sizeof(*elf_phdr)) { 168 perror("read"); 169 exit(1); 170 } 171 172 elf_phdr = (struct elf_phdr *) buf; 173 offset = elf_phdr->p_offset; 174 mem_size = elf_phdr->p_memsz; 175 fil_size = elf_phdr->p_filesz; 176 177 if (elf_phdr->p_vaddr < e_entry) { 178 unsigned long delta = e_entry - elf_phdr->p_vaddr; 179 offset += delta; 180 mem_size -= delta; 181 fil_size -= delta; 182 elf_phdr->p_vaddr += delta; 183 } 184 185 if (verbose) { 186 fprintf(stderr, "%s: extracting %#016lx-%#016lx (at %lx)\n", 187 prog_name, (long) elf_phdr->p_vaddr, 188 elf_phdr->p_vaddr + fil_size, offset); 189 } 190 } else 191#endif 192 { 193 aout = (struct exec *) buf; 194 195 if (!(aout->fh.f_flags & COFF_F_EXEC)) { 196 fprintf(stderr, "%s: %s is not in executable format\n", 197 prog_name, inname); 198 exit(1); 199 } 200 201 if (aout->fh.f_opthdr != sizeof(aout->ah)) { 202 fprintf(stderr, "%s: %s has unexpected optional header size\n", 203 prog_name, inname); 204 exit(1); 205 } 206 207 if (N_MAGIC(*aout) != OMAGIC) { 208 fprintf(stderr, "%s: %s is not an OMAGIC file\n", 209 prog_name, inname); 210 exit(1); 211 } 212 offset = N_TXTOFF(*aout); 213 fil_size = aout->ah.tsize + aout->ah.dsize; 214 mem_size = fil_size + aout->ah.bsize; 215 216 if (verbose) { 217 fprintf(stderr, "%s: extracting %#016lx-%#016lx (at %lx)\n", 218 prog_name, aout->ah.text_start, 219 aout->ah.text_start + fil_size, offset); 220 } 221 } 222 223 if (lseek(fd, offset, SEEK_SET) != offset) { 224 perror("lseek"); 225 exit(1); 226 } 227 228 if (verbose) { 229 fprintf(stderr, "%s: copying %lu byte from %s\n", 230 prog_name, (unsigned long) fil_size, inname); 231 } 232 233 tocopy = fil_size; 234 while (tocopy > 0) { 235 n = tocopy; 236 if (n > sizeof(buf)) { 237 n = sizeof(buf); 238 } 239 tocopy -= n; 240 if ((size_t) read(fd, buf, n) != n) { 241 perror("read"); 242 exit(1); 243 } 244 do { 245 nwritten = write(ofd, buf, n); 246 if ((ssize_t) nwritten == -1) { 247 perror("write"); 248 exit(1); 249 } 250 n -= nwritten; 251 } while (n > 0); 252 } 253 254 if (pad) { 255 mem_size = ((mem_size + pad - 1) / pad) * pad; 256 } 257 258 tocopy = mem_size - fil_size; 259 if (tocopy > 0) { 260 fprintf(stderr, 261 "%s: zero-filling bss and aligning to %lu with %lu bytes\n", 262 prog_name, pad, (unsigned long) tocopy); 263 264 memset(buf, 0x00, sizeof(buf)); 265 do { 266 n = tocopy; 267 if (n > sizeof(buf)) { 268 n = sizeof(buf); 269 } 270 nwritten = write(ofd, buf, n); 271 if ((ssize_t) nwritten == -1) { 272 perror("write"); 273 exit(1); 274 } 275 tocopy -= nwritten; 276 } while (tocopy > 0); 277 } 278 return 0; 279} 280