client/hid-flasher/flash.c

   1 //-----------------------------------------------------------------------------
   2 // Copyright (C) 2010 Hector Martin "marcan" <marcan@marcansoft.com>
   3 //
   4 // This code is licensed to you under the terms of the GNU GPL, version 2 or,
   5 // at your option, any later version. See the LICENSE.txt file for the text of
   6 // the license.
   7 //-----------------------------------------------------------------------------
   8 // ELF file flasher
   9 //-----------------------------------------------------------------------------
  10
  11 #include <stdio.h>
  12 #include <string.h>
  13 #include <stdlib.h>
  14 #include "sleep.h"
  15 #include "proxusb.h"
  16 #include "flash.h"
  17 #include "elf.h"
  18 #include "proxendian.h"
  19
  20 // FIXME: what the fuckity fuck
  21 unsigned int current_command = CMD_UNKNOWN;
  22
  23 #define FLASH_START            0x100000
  24 #define FLASH_SIZE             (256*1024)
  25 #define FLASH_END              (FLASH_START + FLASH_SIZE)
  26 #define BOOTLOADER_SIZE        0x2000
  27 #define BOOTLOADER_END         (FLASH_START + BOOTLOADER_SIZE)
  28
  29 #define BLOCK_SIZE             0x100
  30
  31 static const uint8_t elf_ident[] = {
  32         0x7f, 'E', 'L', 'F',
  33         ELFCLASS32,
  34         ELFDATA2LSB,
  35         EV_CURRENT
  36 };
  37
  38 // Turn PHDRs into flasher segments, checking for PHDR sanity and merging adjacent
  39 // unaligned segments if needed
  40 static int build_segs_from_phdrs(flash_file_t *ctx, FILE *fd, Elf32_Phdr *phdrs, int num_phdrs)
  41 {
  42         Elf32_Phdr *phdr = phdrs;
  43         flash_seg_t *seg;
  44         uint32_t last_end = 0;
  45
  46         ctx->segments = malloc(sizeof(flash_seg_t) * num_phdrs);
  47         if (!ctx->segments) {
  48                 fprintf(stderr, "Out of memory\n");
  49                 return -1;
  50         }
  51         ctx->num_segs = 0;
  52         seg = ctx->segments;
  53
  54         fprintf(stderr, "Loading usable ELF segments:\n");
  55         for (int i = 0; i < num_phdrs; i++) {
  56                 if (le32(phdr->p_type) != PT_LOAD) {
  57                         phdr++;
  58                         continue;
  59                 }
  60                 uint32_t vaddr = le32(phdr->p_vaddr);
  61                 uint32_t paddr = le32(phdr->p_paddr);
  62                 uint32_t filesz = le32(phdr->p_filesz);
  63                 uint32_t memsz = le32(phdr->p_memsz);
  64                 uint32_t offset = le32(phdr->p_offset);
  65                 uint32_t flags = le32(phdr->p_flags);
  66                 if (!filesz) {
  67                         phdr++;
  68                         continue;
  69                 }
  70                 fprintf(stderr, "%d: V 0x%08x P 0x%08x (0x%08x->0x%08x) [%c%c%c] @0x%x\n",
  71                         i, vaddr, paddr, filesz, memsz,
  72                         flags & PF_R ? 'R' : ' ',
  73                         flags & PF_W ? 'W' : ' ',
  74                         flags & PF_X ? 'X' : ' ',
  75                         offset);
  76                 if (filesz != memsz) {
  77                         fprintf(stderr, "Error: PHDR file size does not equal memory size\n"
  78                                         "(DATA+BSS PHDRs do not make sense on ROM platforms!)\n");
  79                         return -1;
  80                 }
  81                 if (paddr < last_end) {
  82                         fprintf(stderr, "Error: PHDRs not sorted or overlap\n");
  83                         return -1;
  84                 }
  85                 if (paddr < FLASH_START || (paddr+filesz) > FLASH_END) {
  86                         fprintf(stderr, "Error: PHDR is not contained in Flash\n");
  87                         return -1;
  88                 }
  89                 if (vaddr >= FLASH_START && vaddr < FLASH_END && (flags & PF_W)) {
  90                         fprintf(stderr, "Error: Flash VMA segment is writable\n");
  91                         return -1;
  92                 }
  93
  94                 uint8_t *data;
  95                 // make extra space if we need to move the data forward
  96                 data = malloc(filesz + BLOCK_SIZE);
  97                 if (!data) {
  98                         fprintf(stderr, "Out of memory\n");
  99                         return -1;
 100                 }
 101                 if (fseek(fd, offset, SEEK_SET) < 0 || fread(data, 1, filesz, fd) != filesz) {
 102                         fprintf(stderr, "Error while reading PHDR payload\n");
 103                         free(data);
 104                         return -1;
 105                 }
 106
 107                 uint32_t block_offset = paddr & (BLOCK_SIZE-1);
 108                 if (block_offset) {
 109                         if (ctx->num_segs) {
 110                                 flash_seg_t *prev_seg = seg - 1;
 111                                 uint32_t this_end = paddr + filesz;
 112                                 uint32_t this_firstblock = paddr & ~(BLOCK_SIZE-1);
 113                                 uint32_t prev_lastblock = (last_end - 1) & ~(BLOCK_SIZE-1);
 114
 115                                 if (this_firstblock == prev_lastblock) {
 116                                         uint32_t new_length = this_end - prev_seg->start;
 117                                         uint32_t this_offset = paddr - prev_seg->start;
 118                                         uint32_t hole = this_offset - prev_seg->length;
 119                                         uint8_t *new_data = malloc(new_length);
 120                                         if (!new_data) {
 121                                                 fprintf(stderr, "Out of memory\n");
 122                                                 free(data);
 123                                                 return -1;
 124                                         }
 125                                         memset(new_data, 0xff, new_length);
 126                                         memcpy(new_data, prev_seg->data, prev_seg->length);
 127                                         memcpy(new_data + this_offset, data, filesz);
 128                                         fprintf(stderr, "Note: Extending previous segment from 0x%x to 0x%x bytes\n",
 129                                                 prev_seg->length, new_length);
 130                                         if (hole)
 131                                                 fprintf(stderr, "Note: 0x%x-byte hole created\n", hole);
 132                                         free(data);
 133                                         free(prev_seg->data);
 134                                         prev_seg->data = new_data;
 135                                         prev_seg->length = new_length;
 136                                         last_end = this_end;
 137                                         phdr++;
 138                                         continue;
 139                                 }
 140                         }
 141                         fprintf(stderr, "Warning: segment does not begin on a block boundary, will pad\n");
 142                         memmove(data + block_offset, data, filesz);
 143                         memset(data, 0xFF, block_offset);
 144                         filesz += block_offset;
 145                         paddr -= block_offset;
 146                 }
 147
 148                 seg->data = data;
 149                 seg->start = paddr;
 150                 seg->length = filesz;
 151                 seg++;
 152                 ctx->num_segs++;
 153
 154                 last_end = paddr + filesz;
 155                 phdr++;
 156         }
 157         return 0;
 158 }
 159
 160 // Sanity check segments and check for bootloader writes
 161 static int check_segs(flash_file_t *ctx, int can_write_bl) {
 162         for (int i = 0; i < ctx->num_segs; i++) {
 163                 flash_seg_t *seg = &ctx->segments[i];
 164
 165                 if (seg->start & (BLOCK_SIZE-1)) {
 166                         fprintf(stderr, "Error: Segment is not aligned\n");
 167                         return -1;
 168                 }
 169                 if (seg->start < FLASH_START) {
 170                         fprintf(stderr, "Error: Segment is outside of flash bounds\n");
 171                         return -1;
 172                 }
 173                 if (seg->start + seg->length > FLASH_END) {
 174                         fprintf(stderr, "Error: Segment is outside of flash bounds\n");
 175                         return -1;
 176                 }
 177                 if (!can_write_bl && seg->start < BOOTLOADER_END) {
 178                         fprintf(stderr, "Attempted to write bootloader but bootloader writes are not enabled\n");
 179                         return -1;
 180                 }
 181         }
 182         return 0;
 183 }
 184
 185 // Load an ELF file and prepare it for flashing
 186 int flash_load(flash_file_t *ctx, const char *name, int can_write_bl)
 187 {
 188         FILE *fd = NULL;
 189         Elf32_Ehdr ehdr;
 190         Elf32_Phdr *phdrs = NULL;
 191         int num_phdrs;
 192         int res;
 193
 194         fd = fopen(name, "rb");
 195         if (!fd) {
 196                 fprintf(stderr, "Could not open file '%s': ", name);
 197                 perror(NULL);
 198                 goto fail;
 199         }
 200
 201         fprintf(stderr, "Loading ELF file '%s'...\n", name);
 202
 203         if (fread(&ehdr, sizeof(ehdr), 1, fd) != 1) {
 204                 fprintf(stderr, "Error while reading ELF file header\n");
 205                 goto fail;
 206         }
 207         if (memcmp(ehdr.e_ident, elf_ident, sizeof(elf_ident))
 208                 || le32(ehdr.e_version) != 1)
 209         {
 210                 fprintf(stderr, "Not an ELF file or wrong ELF type\n");
 211                 goto fail;
 212         }
 213         if (le16(ehdr.e_type) != ET_EXEC) {
 214                 fprintf(stderr, "ELF is not executable\n");
 215                 goto fail;
 216         }
 217         if (le16(ehdr.e_machine) != EM_ARM) {
 218                 fprintf(stderr, "Wrong ELF architecture\n");
 219                 goto fail;
 220         }
 221         if (!ehdr.e_phnum || !ehdr.e_phoff) {
 222                 fprintf(stderr, "ELF has no PHDRs\n");
 223                 goto fail;
 224         }
 225         if (le16(ehdr.e_phentsize) != sizeof(Elf32_Phdr)) {
 226                 // could be a structure padding issue...
 227                 fprintf(stderr, "Either the ELF file or this code is made of fail\n");
 228                 goto fail;
 229         }
 230         num_phdrs = le16(ehdr.e_phnum);
 231
 232         phdrs = malloc(le16(ehdr.e_phnum) * sizeof(Elf32_Phdr));
 233         if (!phdrs) {
 234                 fprintf(stderr, "Out of memory\n");
 235                 goto fail;
 236         }
 237         if (fseek(fd, le32(ehdr.e_phoff), SEEK_SET) < 0) {
 238                 fprintf(stderr, "Error while reading ELF PHDRs\n");
 239                 goto fail;
 240         }
 241         if (fread(phdrs, sizeof(Elf32_Phdr), num_phdrs, fd) != num_phdrs) {
 242                 fprintf(stderr, "Error while reading ELF PHDRs\n");
 243                 goto fail;
 244         }
 245
 246         res = build_segs_from_phdrs(ctx, fd, phdrs, num_phdrs);
 247         if (res < 0)
 248                 goto fail;
 249         res = check_segs(ctx, can_write_bl);
 250         if (res < 0)
 251                 goto fail;
 252
 253         free(phdrs);
 254         fclose(fd);
 255         ctx->filename = name;
 256         return 0;
 257
 258 fail:
 259         if (phdrs)
 260                 free(phdrs);
 261         if (fd)
 262                 fclose(fd);
 263         flash_free(ctx);
 264         return -1;
 265 }
 266
 267 // Get the state of the proxmark, backwards compatible
 268 static int get_proxmark_state(uint32_t *state)
 269 {
 270         UsbCommand c;
 271         c.cmd = CMD_DEVICE_INFO;
 272         SendCommand(&c);
 273
 274         UsbCommand resp;
 275         ReceiveCommand(&resp);
 276
 277         // Three outcomes:
 278         // 1. The old bootrom code will ignore CMD_DEVICE_INFO, but respond with an ACK
 279         // 2. The old os code will respond with CMD_DEBUG_PRINT_STRING and "unknown command"
 280         // 3. The new bootrom and os codes will respond with CMD_DEVICE_INFO and flags
 281
 282         switch (resp.cmd) {
 283                 case CMD_ACK:
 284                         *state = DEVICE_INFO_FLAG_CURRENT_MODE_BOOTROM;
 285                         break;
 286                 case CMD_DEBUG_PRINT_STRING:
 287                         *state = DEVICE_INFO_FLAG_CURRENT_MODE_OS;
 288                         break;
 289                 case CMD_DEVICE_INFO:
 290                         *state = resp.arg[0];
 291                         break;
 292                 default:
 293                         fprintf(stderr, "Error: Couldn't get proxmark state, bad response type: 0x%04x\n", resp.cmd);
 294                         return -1;
 295                         break;
 296         }
 297
 298         return 0;
 299 }
 300
 301 // Enter the bootloader to be able to start flashing
 302 static int enter_bootloader(void)
 303 {
 304         uint32_t state;
 305
 306         if (get_proxmark_state(&state) < 0)
 307                 return -1;
 308
 309         if (state & DEVICE_INFO_FLAG_CURRENT_MODE_BOOTROM) {
 310                 /* Already in flash state, we're done. */
 311                 return 0;
 312         }
 313
 314         if (state & DEVICE_INFO_FLAG_CURRENT_MODE_OS) {
 315                 fprintf(stderr,"Entering bootloader...\n");
 316                 UsbCommand c;
 317                 memset(&c, 0, sizeof (c));
 318
 319                 if ((state & DEVICE_INFO_FLAG_BOOTROM_PRESENT)
 320                         && (state & DEVICE_INFO_FLAG_OSIMAGE_PRESENT))
 321                 {
 322                         // New style handover: Send CMD_START_FLASH, which will reset the board
 323                         // and enter the bootrom on the next boot.
 324                         c.cmd = CMD_START_FLASH;
 325                         SendCommand(&c);
 326                         fprintf(stderr,"(Press and release the button only to abort)\n");
 327                 } else {
 328                         // Old style handover: Ask the user to press the button, then reset the board
 329                         c.cmd = CMD_HARDWARE_RESET;
 330                         SendCommand(&c);
 331                         fprintf(stderr,"Press and hold down button NOW if your bootloader requires it.\n");
 332                 }
 333                 fprintf(stderr,"Waiting for Proxmark to reappear on USB...");
 334
 335                 CloseProxmark();
 336                 sleep(1);
 337                 while (!OpenProxmark(0)) {
 338                         sleep(1);
 339                         fprintf(stderr, ".");
 340                 }
 341                 fprintf(stderr," Found.\n");
 342
 343                 return 0;
 344         }
 345
 346         fprintf(stderr, "Error: Unknown Proxmark mode\n");
 347         return -1;
 348 }
 349
 350 static int wait_for_ack(void)
 351 {
 352         UsbCommand ack;
 353         ReceiveCommand(&ack);
 354         if (ack.cmd != CMD_ACK) {
 355                 printf("Error: Unexpected reply 0x%04x (expected ACK)\n", ack.cmd);
 356                 return -1;
 357         }
 358         return 0;
 359 }
 360
 361 // Go into flashing mode
 362 int flash_start_flashing(int enable_bl_writes)
 363 {
 364         uint32_t state;
 365
 366         if (enter_bootloader() < 0)
 367                 return -1;
 368
 369         if (get_proxmark_state(&state) < 0)
 370                 return -1;
 371
 372         if (state & DEVICE_INFO_FLAG_UNDERSTANDS_START_FLASH) {
 373                 // This command is stupid. Why the heck does it care which area we're
 374                 // flashing, as long as it's not the bootloader area? The mind boggles.
 375                 UsbCommand c = {CMD_START_FLASH};
 376
 377                 if (enable_bl_writes) {
 378                         c.arg[0] = FLASH_START;
 379                         c.arg[1] = FLASH_END;
 380                         c.arg[2] = START_FLASH_MAGIC;
 381                 } else {
 382                         c.arg[0] = BOOTLOADER_END;
 383                         c.arg[1] = FLASH_END;
 384                         c.arg[2] = 0;
 385                 }
 386                 SendCommand(&c);
 387                 return wait_for_ack();
 388         } else {
 389                 fprintf(stderr, "Note: Your bootloader does not understand the new START_FLASH command\n");
 390                 fprintf(stderr, "      It is recommended that you update your bootloader\n\n");
 391         }
 392
 393         return 0;
 394 }
 395
 396 static int write_block(uint32_t address, uint8_t *data, uint32_t length)
 397 {
 398         uint8_t block_buf[BLOCK_SIZE];
 399
 400         memset(block_buf, 0xFF, BLOCK_SIZE);
 401         memcpy(block_buf, data, length);
 402
 403         UsbCommand c = {CMD_SETUP_WRITE};
 404         for (int i = 0; i < 240; i += 48) {
 405                 memcpy(c.d.asBytes, block_buf + i, 48);
 406                 c.arg[0] = i / 4;
 407                 SendCommand(&c);
 408                 if (wait_for_ack() < 0)
 409                         return -1;
 410         }
 411
 412         c.cmd = CMD_FINISH_WRITE;
 413         c.arg[0] = address;
 414         memcpy(c.d.asBytes, block_buf+240, 16);
 415         SendCommand(&c);
 416         return wait_for_ack();
 417 }
 418
 419 // Write a file's segments to Flash
 420 int flash_write(flash_file_t *ctx)
 421 {
 422         fprintf(stderr, "Writing segments for file: %s\n", ctx->filename);
 423         for (int i = 0; i < ctx->num_segs; i++) {
 424                 flash_seg_t *seg = &ctx->segments[i];
 425
 426                 uint32_t length = seg->length;
 427                 uint32_t blocks = (length + BLOCK_SIZE - 1) / BLOCK_SIZE;
 428                 uint32_t end = seg->start + length;
 429
 430                 fprintf(stderr, " 0x%08x..0x%08x [0x%x / %d blocks]",
 431                         seg->start, end - 1, length, blocks);
 432
 433                 int block = 0;
 434                 uint8_t *data = seg->data;
 435                 uint32_t baddr = seg->start;
 436
 437                 while (length) {
 438                         uint32_t block_size = length;
 439                         if (block_size > BLOCK_SIZE)
 440                                 block_size = BLOCK_SIZE;
 441
 442                         if (write_block(baddr, data, block_size) < 0) {
 443                                 fprintf(stderr, " ERROR\n");
 444                                 fprintf(stderr, "Error writing block %d of %d\n", block, blocks);
 445                                 return -1;
 446                         }
 447
 448                         data += block_size;
 449                         baddr += block_size;
 450                         length -= block_size;
 451                         block++;
 452                         fprintf(stderr, ".");
 453                 }
 454                 fprintf(stderr, " OK\n");
 455         }
 456         return 0;
 457 }
 458
 459 // free a file context
 460 void flash_free(flash_file_t *ctx)
 461 {
 462         if (!ctx)
 463                 return;
 464         if (ctx->segments) {
 465                 for (int i = 0; i < ctx->num_segs; i++)
 466                         free(ctx->segments[i].data);
 467                 free(ctx->segments);
 468                 ctx->segments = NULL;
 469                 ctx->num_segs = 0;
 470         }
 471 }
 472
 473 // just reset the unit
 474 int flash_stop_flashing(void) {
 475         UsbCommand c = {CMD_HARDWARE_RESET};
 476         SendCommand(&c);
 477         return 0;
 478 }