util/mkelfImage/main/mkelfImage.c

   1 #include <stdarg.h>
   2 #include <errno.h>
   3 #include <string.h>
   4 #include <stdint.h>
   5 #include <stdlib.h>
   6 #include <sys/types.h>
   7 #include <sys/stat.h>
   8 #include <fcntl.h>
   9 #include <unistd.h>
  10 #include <stdio.h>
  11 #include <getopt.h>
  12 #ifdef HAVE_ZLIB_H
  13 #include <zlib.h>
  14 #endif
  15 #include "elf.h"
  16 #include "elf_boot.h"
  17 #include "mkelfImage.h"
  18
  19 static struct file_type file_type[] = {
  20         { "linux-i386", linux_i386_probe, linux_i386_mkelf, linux_i386_usage },
  21         { "bzImage-i386", bzImage_i386_probe, linux_i386_mkelf, linux_i386_usage },
  22         { "vmlinux-i386", vmlinux_i386_probe, linux_i386_mkelf, linux_i386_usage },
  23         { "linux-ia64", linux_ia64_probe, linux_ia64_mkelf, linux_ia64_usage },
  24 };
  25 static const int file_types = sizeof(file_type)/sizeof(file_type[0]);
  26
  27 void die(char *fmt, ...)
  28 {
  29         va_list args;
  30         va_start(args, fmt);
  31         vfprintf(stderr, fmt, args);
  32         va_end(args);
  33         exit(1);
  34 }
  35
  36
  37
  38 /**************************************************************************
  39 IPCHKSUM - Checksum IP Header
  40 **************************************************************************/
  41 uint16_t ipchksum(const void *data, unsigned long length)
  42 {
  43         unsigned long sum;
  44         unsigned long i;
  45         const uint8_t *ptr;
  46
  47         /* In the most straight forward way possible,
  48          * compute an ip style checksum.
  49          */
  50         sum = 0;
  51         ptr = data;
  52         for(i = 0; i < length; i++) {
  53                 unsigned long value;
  54                 value = ptr[i];
  55                 if (i & 1) {
  56                         value <<= 8;
  57                 }
  58                 /* Add the new value */
  59                 sum += value;
  60                 /* Wrap around the carry */
  61                 if (sum > 0xFFFF) {
  62                         sum = (sum + (sum >> 16)) & 0xFFFF;
  63                 }
  64         }
  65         return (~cpu_to_le16(sum)) & 0xFFFF;
  66 }
  67
  68 uint16_t add_ipchksums(unsigned long offset, uint16_t sum, uint16_t new)
  69 {
  70         unsigned long checksum;
  71         sum = ~sum & 0xFFFF;
  72         new = ~new & 0xFFFF;
  73         if (offset & 1) {
  74                 /* byte swap the sum if it came from an odd offset
  75                  * since the computation is endian independant this
  76                  * works.
  77                  */
  78                 new = bswap_16(new);
  79         }
  80         checksum = sum + new;
  81         if (checksum > 0xFFFF) {
  82                 checksum -= 0xFFFF;
  83         }
  84         return (~checksum) & 0xFFFF;
  85 }
  86
  87 void *xmalloc(size_t size, const char *name)
  88 {
  89         void *buf;
  90         buf = malloc(size);
  91         if (!buf) {
  92                 die("Cannot malloc %ld bytes to hold %s: %s\n",
  93                         size + 0UL, name, strerror(errno));
  94         }
  95         return buf;
  96 }
  97
  98 void *xrealloc(void *ptr, size_t size, const char *name)
  99 {
 100         void *buf;
 101         buf = realloc(ptr, size);
 102         if (!buf) {
 103                 die("Cannot realloc %ld bytes to hold %s: %s\n",
 104                         size + 0UL, name, strerror(errno));
 105         }
 106         return buf;
 107 }
 108
 109
 110 char *slurp_file(const char *filename, off_t *r_size)
 111 {
 112         int fd;
 113         char *buf;
 114         off_t size, progress;
 115         ssize_t result;
 116         struct stat stats;
 117
 118
 119         if (!filename) {
 120                 *r_size = 0;
 121                 return 0;
 122         }
 123         fd = open(filename, O_RDONLY);
 124         if (fd < 0) {
 125                 die("Cannot open `%s': %s\n",
 126                         filename, strerror(errno));
 127         }
 128         result = fstat(fd, &stats);
 129         if (result < 0) {
 130                 die("Cannot stat: %s: %s\n",
 131                         filename, strerror(errno));
 132         }
 133         size = stats.st_size;
 134         *r_size = size;
 135         buf = xmalloc(size, filename);
 136         progress = 0;
 137         while(progress < size) {
 138                 result = read(fd, buf + progress, size - progress);
 139                 if (result < 0) {
 140                         if ((errno == EINTR) || (errno == EAGAIN))
 141                                 continue;
 142                         die("read on %s of %ld bytes failed: %s\n",
 143                                 filename, (size - progress)+ 0UL, strerror(errno));
 144                 }
 145                 progress += result;
 146         }
 147         result = close(fd);
 148         if (result < 0) {
 149                 die("Close of %s failed: %s\n",
 150                         filename, strerror(errno));
 151         }
 152         return buf;
 153 }
 154
 155 #if HAVE_ZLIB_H
 156 char *slurp_decompress_file(const char *filename, off_t *r_size)
 157 {
 158         gzFile fp;
 159         int errnum;
 160         const char *msg;
 161         char *buf;
 162         off_t size, allocated;
 163         ssize_t result;
 164
 165         if (!filename) {
 166                 *r_size = 0;
 167                 return 0;
 168         }
 169         fp = gzopen(filename, "rb");
 170         if (fp == 0) {
 171                 msg = gzerror(fp, &errnum);
 172                 if (errnum == Z_ERRNO) {
 173                         msg = strerror(errno);
 174                 }
 175                 die("Cannot open `%s': %s\n", filename, msg);
 176         }
 177         size = 0;
 178         allocated = 65536;
 179         buf = xmalloc(allocated, filename);
 180         do {
 181                 if (size == allocated) {
 182                         allocated <<= 1;
 183                         buf = xrealloc(buf, allocated, filename);
 184                 }
 185                 result = gzread(fp, buf + size, allocated - size);
 186                 if (result < 0) {
 187                         if ((errno == EINTR) || (errno == EAGAIN))
 188                                 continue;
 189
 190                         msg = gzerror(fp, &errnum);
 191                         if (errnum == Z_ERRNO) {
 192                                 msg = strerror(errno);
 193                         }
 194                         die ("read on %s of %ld bytes failed: %s\n",
 195                                 filename, (allocated - size) + 0UL, msg);
 196                 }
 197                 size += result;
 198         } while(result > 0);
 199         result = gzclose(fp);
 200         if (result != Z_OK) {
 201                 msg = gzerror(fp, &errnum);
 202                 if (errnum == Z_ERRNO) {
 203                         msg = strerror(errno);
 204                 }
 205                 die ("Close of %s failed: %s\n", filename, msg);
 206         }
 207         *r_size =  size;
 208         return buf;
 209 }
 210 #else
 211 char *slurp_decompress_file(const char *filename, off_t *r_size)
 212 {
 213         return slurp_file(filename, r_size);
 214 }
 215 #endif
 216
 217 struct memelfphdr *add_program_headers(struct memelfheader *ehdr, int count)
 218 {
 219         struct memelfphdr *phdr;
 220         int i;
 221         ehdr->e_phnum = count;
 222         ehdr->e_phdr = phdr = xmalloc(count *sizeof(*phdr), "Program headers");
 223         /* Set the default values */
 224         for(i = 0; i < count; i++) {
 225                 phdr[i].p_type   = PT_LOAD;
 226                 phdr[i].p_flags  = PF_R | PF_W | PF_X;
 227                 phdr[i].p_vaddr  = 0;
 228                 phdr[i].p_paddr  = 0;
 229                 phdr[i].p_filesz = 0;
 230                 phdr[i].p_memsz  = 0;
 231                 phdr[i].p_data   = 0;
 232         }
 233         return phdr;
 234 }
 235
 236 struct memelfnote *add_notes(struct memelfheader *ehdr, int count)
 237 {
 238         struct memelfnote *notes;
 239         ehdr->e_notenum = count;
 240         ehdr->e_notes = notes = xmalloc(count *sizeof(*notes), "Notes");
 241         memset(notes, 0, count *sizeof(*notes));
 242         return notes;
 243 }
 244
 245 static int sizeof_notes(struct memelfnote *note, int notes)
 246 {
 247         int size;
 248         int i;
 249
 250         size = 0;
 251         for(i = 0; i < notes; i++) {
 252                 size += sizeof(Elf_Nhdr);
 253                 size += roundup(strlen(note[i].n_name)+1, 4);
 254                 size += roundup(note[i].n_descsz, 4);
 255         }
 256         return size;
 257 }
 258
 259 static uint16_t cpu_to_elf16(struct memelfheader *ehdr, uint16_t val)
 260 {
 261         if (ehdr->ei_data == ELFDATA2LSB) {
 262                 return cpu_to_le16(val);
 263         }
 264         else if (ehdr->ei_data == ELFDATA2MSB) {
 265                 return cpu_to_be16(val);
 266         }
 267         die("Uknown elf layout in cpu_to_elf16");
 268         return 0;
 269 }
 270
 271 static uint32_t cpu_to_elf32(struct memelfheader *ehdr, uint32_t val)
 272 {
 273         if (ehdr->ei_data == ELFDATA2LSB) {
 274                 return cpu_to_le32(val);
 275         }
 276         else if (ehdr->ei_data == ELFDATA2MSB) {
 277                 return cpu_to_be32(val);
 278         }
 279         die("Uknown elf layout in cpu_to_elf32");
 280         return 0;
 281 }
 282
 283 static uint64_t cpu_to_elf64(struct memelfheader *ehdr, uint64_t val)
 284 {
 285         if (ehdr->ei_data == ELFDATA2LSB) {
 286                 return cpu_to_le64(val);
 287         }
 288         else if (ehdr->ei_data == ELFDATA2MSB) {
 289                 return cpu_to_be64(val);
 290         }
 291         die("Uknown elf layout in cpu_to_elf64");
 292         return 0;
 293 }
 294
 295 static void serialize_notes(char *buf, struct memelfheader *ehdr)
 296 {
 297         struct Elf_Nhdr hdr;
 298         struct memelfnote *note;
 299         int notes;
 300         size_t size, offset;
 301         int i;
 302
 303         /* Clear the buffer */
 304         note = ehdr->e_notes;
 305         notes = ehdr->e_notenum;
 306         size = sizeof_notes(note, notes);
 307         memset(buf, 0, size);
 308
 309         /* Write the Elf Notes */
 310         offset = 0;
 311         for(i = 0; i < notes; i++) {
 312                 /* Compute the note header */
 313                 size_t n_namesz;
 314                 n_namesz = strlen(note[i].n_name) +1;
 315                 hdr.n_namesz = cpu_to_elf32(ehdr, n_namesz);
 316                 hdr.n_descsz = cpu_to_elf32(ehdr, note[i].n_descsz);
 317                 hdr.n_type   = cpu_to_elf32(ehdr, note[i].n_type);
 318
 319                 /* Copy the note into the buffer */
 320                 memcpy(buf + offset, &hdr,       sizeof(hdr));
 321                 offset += sizeof(hdr);
 322                 memcpy(buf + offset, note[i].n_name, n_namesz);
 323                 offset += roundup(n_namesz, 4);
 324                 memcpy(buf + offset, note[i].n_desc, note[i].n_descsz);
 325                 offset += roundup(note[i].n_descsz, 4);
 326
 327         }
 328 }
 329 static void serialize_ehdr(char *buf, struct memelfheader *ehdr)
 330 {
 331         if (ehdr->ei_class == ELFCLASS32) {
 332                 Elf32_Ehdr *hdr = (Elf32_Ehdr *)buf;
 333                 hdr->e_ident[EI_MAG0]    = ELFMAG0;
 334                 hdr->e_ident[EI_MAG1]    = ELFMAG1;
 335                 hdr->e_ident[EI_MAG2]    = ELFMAG2;
 336                 hdr->e_ident[EI_MAG3]    = ELFMAG3;
 337                 hdr->e_ident[EI_CLASS]   = ehdr->ei_class;
 338                 hdr->e_ident[EI_DATA]    = ehdr->ei_data;
 339                 hdr->e_ident[EI_VERSION] = EV_CURRENT;
 340                 hdr->e_type      = cpu_to_elf16(ehdr, ehdr->e_type);
 341                 hdr->e_machine   = cpu_to_elf16(ehdr, ehdr->e_machine);
 342                 hdr->e_version   = cpu_to_elf32(ehdr, EV_CURRENT);
 343                 hdr->e_entry     = cpu_to_elf32(ehdr, ehdr->e_entry);
 344                 hdr->e_phoff     = cpu_to_elf32(ehdr, sizeof(*hdr));
 345                 hdr->e_shoff     = cpu_to_elf32(ehdr, 0);
 346                 hdr->e_flags     = cpu_to_elf32(ehdr, ehdr->e_flags);
 347                 hdr->e_ehsize    = cpu_to_elf16(ehdr, sizeof(*hdr));
 348                 hdr->e_phentsize = cpu_to_elf16(ehdr, sizeof(Elf32_Phdr));
 349                 hdr->e_phnum     = cpu_to_elf16(ehdr, ehdr->e_phnum);
 350                 hdr->e_shentsize = cpu_to_elf16(ehdr, 0);
 351                 hdr->e_shnum     = cpu_to_elf16(ehdr, 0);
 352                 hdr->e_shstrndx  = cpu_to_elf16(ehdr, 0);
 353         }
 354         else if (ehdr->ei_class == ELFCLASS64) {
 355                 Elf64_Ehdr *hdr = (Elf64_Ehdr *)buf;
 356                 hdr->e_ident[EI_MAG0]    = ELFMAG0;
 357                 hdr->e_ident[EI_MAG1]    = ELFMAG1;
 358                 hdr->e_ident[EI_MAG2]    = ELFMAG2;
 359                 hdr->e_ident[EI_MAG3]    = ELFMAG3;
 360                 hdr->e_ident[EI_CLASS]   = ehdr->ei_class;
 361                 hdr->e_ident[EI_DATA]    = ehdr->ei_data;
 362                 hdr->e_ident[EI_VERSION] = EV_CURRENT;
 363                 hdr->e_type      = cpu_to_elf16(ehdr, ehdr->e_type);
 364                 hdr->e_machine   = cpu_to_elf16(ehdr, ehdr->e_machine);
 365                 hdr->e_version   = cpu_to_elf32(ehdr, EV_CURRENT);
 366                 hdr->e_entry     = cpu_to_elf64(ehdr, ehdr->e_entry);
 367                 hdr->e_phoff     = cpu_to_elf64(ehdr, sizeof(*hdr));
 368                 hdr->e_shoff     = cpu_to_elf64(ehdr, 0);
 369                 hdr->e_flags     = cpu_to_elf32(ehdr, ehdr->e_flags);
 370                 hdr->e_ehsize    = cpu_to_elf16(ehdr, sizeof(*hdr));
 371                 hdr->e_phentsize = cpu_to_elf16(ehdr, sizeof(Elf64_Phdr));
 372                 hdr->e_phnum     = cpu_to_elf16(ehdr, ehdr->e_phnum);
 373                 hdr->e_shentsize = cpu_to_elf16(ehdr, 0);
 374                 hdr->e_shnum     = cpu_to_elf16(ehdr, 0);
 375                 hdr->e_shstrndx  = cpu_to_elf16(ehdr, 0);
 376         }
 377         else die("Uknown elf class: %x\n", ehdr->ei_class);
 378 }
 379 static void serialize_phdrs(char *buf, struct memelfheader *ehdr, size_t note_size)
 380 {
 381         int i;
 382         size_t offset, note_offset;
 383         if (ehdr->ei_class == ELFCLASS32) {
 384                 Elf32_Phdr *phdr = (Elf32_Phdr *)buf;
 385                 note_offset =
 386                         sizeof(Elf32_Ehdr) + (sizeof(Elf32_Phdr)*ehdr->e_phnum);
 387                 offset = note_offset + note_size;
 388                 for(i = 0; i < ehdr->e_phnum; i++) {
 389                         struct memelfphdr *hdr = ehdr->e_phdr + i;
 390                         phdr[i].p_type   = cpu_to_elf32(ehdr, hdr->p_type);
 391                         phdr[i].p_offset = cpu_to_elf32(ehdr, offset);
 392                         phdr[i].p_vaddr  = cpu_to_elf32(ehdr, hdr->p_vaddr);
 393                         phdr[i].p_paddr  = cpu_to_elf32(ehdr, hdr->p_paddr);
 394                         phdr[i].p_filesz = cpu_to_elf32(ehdr, hdr->p_filesz);
 395                         phdr[i].p_memsz  = cpu_to_elf32(ehdr, hdr->p_memsz);
 396                         phdr[i].p_flags  = cpu_to_elf32(ehdr, hdr->p_flags);
 397                         phdr[i].p_align  = cpu_to_elf32(ehdr, 0);
 398                         if (phdr[i].p_type == PT_NOTE) {
 399                                 phdr[i].p_filesz = cpu_to_elf32(ehdr, note_size);
 400                                 phdr[i].p_memsz  = cpu_to_elf32(ehdr, note_size);
 401                                 phdr[i].p_offset = cpu_to_elf32(ehdr, note_offset);
 402                         } else {
 403                                 offset += hdr->p_filesz;
 404                         }
 405                 }
 406         }
 407         else if (ehdr->ei_class == ELFCLASS64) {
 408                 Elf64_Phdr *phdr = (Elf64_Phdr *)buf;
 409                 note_offset =
 410                         sizeof(Elf64_Ehdr) + (sizeof(Elf64_Phdr)*ehdr->e_phnum);
 411                 offset = note_offset + note_size;
 412                 for(i = 0; i < ehdr->e_phnum; i++) {
 413                         struct memelfphdr *hdr = ehdr->e_phdr + i;
 414                         phdr[i].p_type   = cpu_to_elf32(ehdr, hdr->p_type);
 415                         phdr[i].p_flags  = cpu_to_elf32(ehdr, hdr->p_flags);
 416                         phdr[i].p_offset = cpu_to_elf64(ehdr, offset);
 417                         phdr[i].p_vaddr  = cpu_to_elf64(ehdr, hdr->p_vaddr);
 418                         phdr[i].p_paddr  = cpu_to_elf64(ehdr, hdr->p_paddr);
 419                         phdr[i].p_filesz = cpu_to_elf64(ehdr, hdr->p_filesz);
 420                         phdr[i].p_memsz  = cpu_to_elf64(ehdr, hdr->p_memsz);
 421                         phdr[i].p_align  = cpu_to_elf64(ehdr, 0);
 422                         if (phdr[i].p_type == PT_NOTE) {
 423                                 phdr[i].p_filesz = cpu_to_elf64(ehdr, note_size);
 424                                 phdr[i].p_memsz  = cpu_to_elf64(ehdr, note_size);
 425                                 phdr[i].p_offset = cpu_to_elf64(ehdr, note_offset);
 426                         } else {
 427                                 offset += hdr->p_filesz;
 428                         }
 429                 }
 430         }
 431         else {
 432                 die("Unknwon elf class: %x\n", ehdr->ei_class);
 433         }
 434 }
 435
 436 static void write_buf(int fd, char *buf, size_t size)
 437 {
 438         size_t progress = 0;
 439         ssize_t result;
 440         while(progress < size) {
 441                 result = write(fd, buf + progress, size - progress);
 442                 if (result < 0) {
 443                         if ((errno == EAGAIN) || (errno == EINTR)) {
 444                                 continue;
 445                         }
 446                         die ("write of %ld bytes failed: %s\n",
 447                                 size - progress, strerror(errno));
 448                 }
 449                 progress += result;
 450         }
 451 }
 452 static void write_elf(struct memelfheader *ehdr, char *output)
 453 {
 454         size_t ehdr_size;
 455         size_t phdr_size;
 456         size_t note_size;
 457         size_t size;
 458         uint16_t checksum;
 459         size_t bytes;
 460         char *buf;
 461         int result, fd;
 462         int i;
 463         /* Prep for adding the checksum */
 464         for(i = 0; i < ehdr->e_notenum; i++) {
 465                 if ((memcmp(ehdr->e_notes[i].n_name, "ELFBoot", 8) == 0) &&
 466                         (ehdr->e_notes[i].n_type == EIN_PROGRAM_CHECKSUM)) {
 467                         ehdr->e_notes[i].n_desc = &checksum;
 468                         ehdr->e_notes[i].n_descsz = 2;
 469                 }
 470         }
 471         /* Compute the sizes */
 472         ehdr_size = 0;
 473         phdr_size = 0;
 474         note_size = 0;
 475         if (ehdr->e_notenum) {
 476                 note_size = sizeof_notes(ehdr->e_notes, ehdr->e_notenum);
 477         }
 478         if (ehdr->ei_class == ELFCLASS32) {
 479                 ehdr_size = sizeof(Elf32_Ehdr);
 480                 phdr_size = sizeof(Elf32_Phdr) * ehdr->e_phnum;
 481         }
 482         else if (ehdr->ei_class == ELFCLASS64) {
 483                 ehdr_size = sizeof(Elf64_Ehdr);
 484                 phdr_size = sizeof(Elf64_Phdr) * ehdr->e_phnum;
 485         }
 486         else {
 487                 die("Unknown elf class: %x\n", ehdr->ei_class);
 488         }
 489
 490         /* Allocate a buffer to temporarily hold the serialized forms */
 491         size = ehdr_size + phdr_size + note_size;
 492         buf = xmalloc(size, "Elf Headers");
 493         memset(buf, 0, size);
 494         serialize_ehdr(buf, ehdr);
 495         serialize_phdrs(buf + ehdr_size, ehdr, note_size);
 496
 497         /* Compute the checksum... */
 498         checksum = ipchksum(buf, ehdr_size + phdr_size);
 499         bytes = ehdr_size + phdr_size;
 500         for(i = 0; i < ehdr->e_phnum; i++) {
 501                 checksum = add_ipchksums(bytes, checksum,
 502                         ipchksum(ehdr->e_phdr[i].p_data, ehdr->e_phdr[i].p_filesz));
 503                 bytes += ehdr->e_phdr[i].p_memsz;
 504         }
 505
 506         /* Compute the final form of the notes */
 507         serialize_notes(buf + ehdr_size + phdr_size, ehdr);
 508
 509         /* Now write the elf image */
 510         fd = open(output, O_WRONLY | O_CREAT | O_EXCL, S_IRUSR | S_IRGRP | S_IROTH);
 511         if (fd < 0) {
 512                 die("Cannot open ``%s'':%s\n",
 513                         output, strerror(errno));
 514         }
 515         write_buf(fd, buf, size);
 516         for(i = 0; i < ehdr->e_phnum; i++) {
 517                 write_buf(fd, ehdr->e_phdr[i].p_data, ehdr->e_phdr[i].p_filesz);
 518         }
 519         result = close(fd);
 520         if (result < 0) {
 521                 die("Close on %s failed: %s\n",
 522                         output, strerror(errno));
 523         }
 524 }
 525
 526 static void version(void)
 527 {
 528         printf("mkelfImage " VERSION " released " RELEASE_DATE "\n");
 529 }
 530 void usage(void)
 531 {
 532         int i;
 533         version();
 534         printf(
 535                 "Usage: mkelfImage [OPTION]... <kernel> <elf_kernel>\n"
 536                 "Build an ELF bootable kernel image from a normal kernel image\n"
 537                 "\n"
 538                 " -h, --help                  Print this help.\n"
 539                 " -v, --version               Print the version of kexec.\n"
 540                 "     --kernel=<filename>     Set the kernel to <filename>\n"
 541                 "     --output=<filename>     Output to <filename>\n"
 542                 " -t, --type=TYPE             Specify the new kernel is of <type>.\n"
 543                 "\n"
 544                 "Supported kernel types: \n"
 545                 );
 546         for(i = 0; i < file_types; i++) {
 547                 printf("%s\n", file_type[i].name);
 548                 file_type[i].usage();
 549         }
 550         printf("\n");
 551 }
 552
 553 void error(char *fmt, ...)
 554 {
 555         va_list args;
 556         va_start(args, fmt);
 557         vfprintf(stderr, fmt, args);
 558         va_end(args);
 559         usage();
 560         exit(1);
 561 }
 562
 563 int main(int argc, char **argv)
 564 {
 565         int opt;
 566         int fileind;
 567         char *type, *kernel, *output;
 568         off_t kernel_size;
 569         char *kernel_buf;
 570         int result;
 571         int i;
 572         struct memelfheader hdr;
 573
 574         static const struct option options[] = {
 575                 MKELF_OPTIONS
 576                 { 0, 0, 0, 0 },
 577         };
 578         static const char short_options[] = MKELF_OPT_STR;
 579
 580         memset(&hdr, 0, sizeof(hdr));
 581         kernel = 0;
 582         output = 0;
 583
 584         /* Get the default type from the program name */
 585         type = strrchr(argv[0], '/');
 586         if (!type) type = argv[0];
 587         if (memcmp(type, "mkelf-", 6) == 0) {
 588                 type = type + 6;
 589         } else {
 590                 type = 0;
 591         }
 592         opterr = 0; /* Don't complain about unrecognized options here */
 593         while ((opt = getopt_long(argc, argv, short_options, options, 0)) != -1) {
 594                 switch(opt) {
 595                 case OPT_HELP:
 596                         usage();
 597                         return 0;
 598                 case OPT_VERSION:
 599                         version();
 600                         return 0;
 601                 case OPT_KERNEL:
 602                         kernel = optarg;
 603                         break;
 604                 case OPT_OUTPUT:
 605                         output = optarg;
 606                         break;
 607                 case OPT_TYPE:
 608                         type = optarg;
 609                         break;
 610                 default:
 611                         break;
 612                 }
 613         }
 614         fileind = optind;
 615
 616         /* Reset getopt for the next pass */
 617         opterr = 1;
 618         optind = 1;
 619
 620         if (argc - fileind > 0) {
 621                 kernel = argv[fileind++];
 622         }
 623         if (argc - fileind > 0) {
 624                 output = argv[fileind++];
 625         }
 626         if (!kernel) {
 627                 error("No kernel specified!\n");
 628         }
 629         if (!output) {
 630                 error("No output file specified!\n");
 631         }
 632         if (argc - fileind > 0) {
 633                 error("%d extra options specified!\n", argc - fileind);
 634         }
 635
 636         /* slurp in the input kernel */
 637         kernel_buf = slurp_decompress_file(kernel, &kernel_size);
 638
 639         /* Find/verify the kernel type */
 640         for(i = 0; i < file_types; i++) {
 641                 char *reason;
 642                 if (type && (strcmp(type, file_type[i].name) != 0)) {
 643                         continue;
 644                 }
 645                 reason = file_type[i].probe(kernel_buf, kernel_size);
 646                 if (reason == 0) {
 647                         break;
 648                 }
 649                 if (type) {
 650                         die("Not %s: %s\n", type, reason);
 651                 }
 652         }
 653         if (i == file_types) {
 654                 die("Can not determine the file type of %s\n", kernel);
 655         }
 656         result = file_type[i].mkelf(argc, argv, &hdr, kernel_buf, kernel_size);
 657         if (result < 0) {
 658                 die("Cannot create %s result: %d\n", output, result);
 659         }
 660         /* open the output file */
 661         write_elf(&hdr, output);
 662         return 0;
 663 }