bool storage_read_block(uint8_t *dest, uint32_t block) {
//printf("RD %u\n", block);
if (block == 0) {
// fake the MBR so we can decide on our own partition table
for (int i = 0; i < 446; i++) {
dest[i] = 0;
}
build_partition(dest + 446, 0, 0x01 /* FAT12 */, FLASH_PART1_START_BLOCK, FLASH_PART1_NUM_BLOCKS);
build_partition(dest + 462, 0, 0, 0, 0);
build_partition(dest + 478, 0, 0, 0, 0);
build_partition(dest + 494, 0, 0, 0, 0);
dest[510] = 0x55;
dest[511] = 0xaa;
return true;
} else {
// non-MBR block, get data from flash memory, possibly via cache
uint32_t flash_addr = convert_block_to_flash_addr(block);
if (flash_addr == -1) {
// bad block number
return false;
}
uint8_t *src = flash_cache_get_addr_for_read(flash_addr);
memcpy(dest, src, FLASH_BLOCK_SIZE);
return true;
}
}
bool storage_read_block(uint8_t *dest, uint32_t block) {
//printf("RD %u\n", block);
if (block == 0) {
// fake the MBR so we can decide on our own partition table
for (int i = 0; i < 446; i++) {
dest[i] = 0;
}
build_partition(dest + 446, 0, 0x01 /* FAT12 */, FLASH_PART1_START_BLOCK, FLASH_PART1_NUM_BLOCKS);
build_partition(dest + 462, 0, 0, 0, 0);
build_partition(dest + 478, 0, 0, 0, 0);
build_partition(dest + 494, 0, 0, 0, 0);
dest[510] = 0x55;
dest[511] = 0xaa;
return true;
} else {
#if USE_INTERNAL
// non-MBR block, get data from flash memory, possibly via cache
uint32_t flash_addr = convert_block_to_flash_addr(block);
if (flash_addr == -1) {
// bad block number
return false;
}
uint8_t *src = flash_cache_get_addr_for_read(flash_addr);
memcpy(dest, src, FLASH_BLOCK_SIZE);
return true;
#else
// non-MBR block, get data from SPI flash
if (block < FLASH_PART1_START_BLOCK || block >= FLASH_PART1_START_BLOCK + FLASH_PART1_NUM_BLOCKS) {
// bad block number
return false;
}
// we must disable USB irqs to prevent MSC contention with SPI flash
uint32_t basepri = raise_irq_pri(IRQ_PRI_OTG_FS);
mp_spiflash_read((mp_spiflash_t*)&spiflash,
(block - FLASH_PART1_START_BLOCK) * FLASH_BLOCK_SIZE, FLASH_BLOCK_SIZE, dest);
restore_irq_pri(basepri);
return true;
#endif
}
}
unsigned long fetch_partition_offset(int part, FILE* diskImage, bool verbose) {
unsigned long offset;
partition partitionTable[4];
/* Special value for uninitialized. */
if (part == -1) {
return 0;
}
/* Check bounds. */
if (part < 0 || part > 3) {
fprintf(stderr,
"There are only 4 primary partitions on a disk (0-indexed)\n");
exit(1);
}
build_partition(partitionTable, diskImage, offset, verbose);
if (partitionTable[part].type != MINIX_FILESYSTEM_TYPE) {
fprintf(stderr, "Bad partition type. (%#x)\n",
partitionTable[part].type);
fprintf(stderr, "This doesn't appear to be a Minix partition.\n");
exit(1);
}
offset = partitionTable[part].lFirst * SECTOR_SIZE;
if (verbose) {
fprintf(stderr, "Calculated offset for the partition is %lu bytes.\n",
offset);
}
return offset;
}
