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 immediatly 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#include <linux/string.h> 29#ifdef __ELF__ 30# include <asm/elf.h> 31# include <linux/elf.h> 32#endif 33 34/* bootfile size must be multiple of BLOCK_SIZE: */ 35#define BLOCK_SIZE 512 36 37const char * prog_name; 38 39 40void 41usage (void) 42{ 43 fprintf(stderr, 44 "usage: %s [-v] -p file primary\n" 45 " %s [-vb] file [secondary]\n", prog_name, prog_name); 46 exit(1); 47} 48 49 50int 51main (int argc, char *argv[]) 52{ 53 size_t nwritten, tocopy, n, mem_size, fil_size, pad = 0; 54 int fd, ofd, i, j, verbose = 0, primary = 0; 55 char buf[8192], *inname; 56 struct exec * aout; /* includes file & aout header */ 57 long offset; 58#ifdef __ELF__ 59 struct elfhdr *elf; 60 struct elf_phdr *elf_phdr; /* program header */ 61 unsigned long long e_entry; 62#endif 63 64 prog_name = argv[0]; 65 66 for (i = 1; i < argc && argv[i][0] == '-'; ++i) { 67 for (j = 1; argv[i][j]; ++j) { 68 switch (argv[i][j]) { 69 case 'v': 70 verbose = ~verbose; 71 break; 72 73 case 'b': 74 pad = BLOCK_SIZE; 75 break; 76 77 case 'p': 78 primary = 1; /* make primary bootblock */ 79 break; 80 } 81 } 82 } 83 84 if (i >= argc) { 85 usage(); 86 } 87 inname = argv[i++]; 88 89 fd = open(inname, O_RDONLY); 90 if (fd == -1) { 91 perror("open"); 92 exit(1); 93 } 94 95 ofd = 1; 96 if (i < argc) { 97 ofd = open(argv[i++], O_WRONLY | O_CREAT | O_TRUNC, 0666); 98 if (fd == -1) { 99 perror("open"); 100 exit(1); 101 } 102 } 103 104 if (primary) { 105 /* generate bootblock for primary loader */ 106 107 unsigned long bb[64], sum = 0; 108 struct stat st; 109 off_t size; 110 int i; 111 112 if (ofd == 1) { 113 usage(); 114 } 115 116 if (fstat(fd, &st) == -1) { 117 perror("fstat"); 118 exit(1); 119 } 120 121 size = (st.st_size + BLOCK_SIZE - 1) & ~(BLOCK_SIZE - 1); 122 memset(bb, 0, sizeof(bb)); 123 strcpy((char *) bb, "Linux SRM bootblock"); 124 bb[60] = size / BLOCK_SIZE; /* count */ 125 bb[61] = 1; /* starting sector # */ 126 bb[62] = 0; /* flags---must be 0 */ 127 for (i = 0; i < 63; ++i) { 128 sum += bb[i]; 129 } 130 bb[63] = sum; 131 if (write(ofd, bb, sizeof(bb)) != sizeof(bb)) { 132 perror("boot-block write"); 133 exit(1); 134 } 135 printf("%lu\n", size); 136 return 0; 137 } 138 139 /* read and inspect exec header: */ 140 141 if (read(fd, buf, sizeof(buf)) < 0) { 142 perror("read"); 143 exit(1); 144 } 145 146#ifdef __ELF__ 147 elf = (struct elfhdr *) buf; 148 149 if (elf->e_ident[0] == 0x7f && strncmp(elf->e_ident + 1, "ELF", 3) == 0) { 150 if (elf->e_type != ET_EXEC) { 151 fprintf(stderr, "%s: %s is not an ELF executable\n", 152 prog_name, inname); 153 exit(1); 154 } 155 if (!elf_check_arch(elf)) { 156 fprintf(stderr, "%s: is not for this processor (e_machine=%d)\n", 157 prog_name, elf->e_machine); 158 exit(1); 159 } 160 if (elf->e_phnum != 1) { 161 fprintf(stderr, 162 "%s: %d program headers (forgot to link with -N?)\n", 163 prog_name, elf->e_phnum); 164 } 165 166 e_entry = elf->e_entry; 167 168 lseek(fd, elf->e_phoff, SEEK_SET); 169 if (read(fd, buf, sizeof(*elf_phdr)) != sizeof(*elf_phdr)) { 170 perror("read"); 171 exit(1); 172 } 173 174 elf_phdr = (struct elf_phdr *) buf; 175 offset = elf_phdr->p_offset; 176 mem_size = elf_phdr->p_memsz; 177 fil_size = elf_phdr->p_filesz; 178 179 /* work around ELF bug: */ 180 if (elf_phdr->p_vaddr < e_entry) { 181 unsigned long delta = e_entry - elf_phdr->p_vaddr; 182 offset += delta; 183 mem_size -= delta; 184 fil_size -= delta; 185 elf_phdr->p_vaddr += delta; 186 } 187 188 if (verbose) { 189 fprintf(stderr, "%s: extracting %#016lx-%#016lx (at %lx)\n", 190 prog_name, (long) elf_phdr->p_vaddr, 191 elf_phdr->p_vaddr + fil_size, offset); 192 } 193 } else 194#endif 195 { 196 aout = (struct exec *) buf; 197 198 if (!(aout->fh.f_flags & COFF_F_EXEC)) { 199 fprintf(stderr, "%s: %s is not in executable format\n", 200 prog_name, inname); 201 exit(1); 202 } 203 204 if (aout->fh.f_opthdr != sizeof(aout->ah)) { 205 fprintf(stderr, "%s: %s has unexpected optional header size\n", 206 prog_name, inname); 207 exit(1); 208 } 209 210 if (N_MAGIC(*aout) != OMAGIC) { 211 fprintf(stderr, "%s: %s is not an OMAGIC file\n", 212 prog_name, inname); 213 exit(1); 214 } 215 offset = N_TXTOFF(*aout); 216 fil_size = aout->ah.tsize + aout->ah.dsize; 217 mem_size = fil_size + aout->ah.bsize; 218 219 if (verbose) { 220 fprintf(stderr, "%s: extracting %#016lx-%#016lx (at %lx)\n", 221 prog_name, aout->ah.text_start, 222 aout->ah.text_start + fil_size, offset); 223 } 224 } 225 226 if (lseek(fd, offset, SEEK_SET) != offset) { 227 perror("lseek"); 228 exit(1); 229 } 230 231 if (verbose) { 232 fprintf(stderr, "%s: copying %lu byte from %s\n", 233 prog_name, (unsigned long) fil_size, inname); 234 } 235 236 tocopy = fil_size; 237 while (tocopy > 0) { 238 n = tocopy; 239 if (n > sizeof(buf)) { 240 n = sizeof(buf); 241 } 242 tocopy -= n; 243 if ((size_t) read(fd, buf, n) != n) { 244 perror("read"); 245 exit(1); 246 } 247 do { 248 nwritten = write(ofd, buf, n); 249 if ((ssize_t) nwritten == -1) { 250 perror("write"); 251 exit(1); 252 } 253 n -= nwritten; 254 } while (n > 0); 255 } 256 257 if (pad) { 258 mem_size = ((mem_size + pad - 1) / pad) * pad; 259 } 260 261 tocopy = mem_size - fil_size; 262 if (tocopy > 0) { 263 fprintf(stderr, 264 "%s: zero-filling bss and aligning to %lu with %lu bytes\n", 265 prog_name, pad, (unsigned long) tocopy); 266 267 memset(buf, 0x00, sizeof(buf)); 268 do { 269 n = tocopy; 270 if (n > sizeof(buf)) { 271 n = sizeof(buf); 272 } 273 nwritten = write(ofd, buf, n); 274 if ((ssize_t) nwritten == -1) { 275 perror("write"); 276 exit(1); 277 } 278 tocopy -= nwritten; 279 } while (tocopy > 0); 280 } 281 return 0; 282} 283