static void
boot_sector_init( Bytes boot, Bytes info, Wide disk_size, const char* label )
{
int sectors_per_cluster = get_sectors_per_cluster(disk_size);
int sectors_per_fat = get_sectors_per_fat(disk_size, sectors_per_cluster);
int sectors_per_disk = (int)(disk_size / BYTES_PER_SECTOR);
int serial_id = get_serial_id();
int free_count;
if (label == NULL)
label = "SDCARD";
POKEB(boot, 0xeb);
POKEB(boot+1, 0x5a);
POKEB(boot+2, 0x90);
strcpy( (char*)boot + 3, "MSWIN4.1" );
POKES( boot + 0x0b, BYTES_PER_SECTOR ); /* sector size */
POKEB( boot + 0xd, sectors_per_cluster ); /* sectors per cluster */
POKES( boot + 0xe, RESERVED_SECTORS ); /* reserved sectors before first FAT */
POKEB( boot + 0x10, NUM_FATS ); /* number of FATs */
POKES( boot + 0x11, 0 ); /* max root directory entries for FAT12/FAT16, 0 for FAT32 */
POKES( boot + 0x13, 0 ); /* total sectors, 0 to use 32-bit value at offset 0x20 */
POKEB( boot + 0x15, 0xF8 ); /* media descriptor, 0xF8 == hard disk */
POKES( boot + 0x16, 0 ); /* Sectors per FAT for FAT12/16, 0 for FAT32 */
POKES( boot + 0x18, 9 ); /* Sectors per track (whatever) */
POKES( boot + 0x1a, 2 ); /* Number of heads (whatever) */
POKEW( boot + 0x1c, 0 ); /* Hidden sectors */
POKEW( boot + 0x20, sectors_per_disk ); /* Total sectors */
/* extension */
POKEW( boot + 0x24, sectors_per_fat ); /* Sectors per FAT */
POKES( boot + 0x28, 0 ); /* FAT flags */
POKES( boot + 0x2a, 0 ); /* version */
POKEW( boot + 0x2c, 2 ); /* cluster number of root directory start */
POKES( boot + 0x30, 1 ); /* sector number of FS information sector */
POKES( boot + 0x32, BACKUP_BOOT_SECTOR ); /* sector number of a copy of this boot sector */
POKEB( boot + 0x40, 0x80 ); /* physical drive number */
POKEB( boot + 0x42, 0x29 ); /* extended boot signature ?? */
POKEW( boot + 0x43, serial_id ); /* serial ID */
strncpy( (char*)boot + 0x47, label, 11 ); /* Volume Label */
memcpy( boot + 0x52, "FAT32 ", 8 ); /* FAT system type, padded with 0x20 */
POKEB( boot + BYTES_PER_SECTOR-2, 0x55 ); /* boot sector signature */
POKEB( boot + BYTES_PER_SECTOR-1, 0xAA );
/* FSInfo sector */
free_count = sectors_per_disk - 32 - 2*sectors_per_fat;
POKEW( info + 0, 0x41615252 );
POKEW( info + 484, 0x61417272 );
POKEW( info + 488, free_count ); /* number of free clusters */
POKEW( info + 492, 3 ); /* next free clusters, 0-1 reserved, 2 is used for the root dir */
POKEW( info + 508, 0xAA550000 );
}
bool SDCardCreate(u64 disk_size /*in MB*/, const std::string& filename)
{
u32 sectors_per_fat;
u32 sectors_per_disk;
// Convert MB to bytes
disk_size *= 1024 * 1024;
if (disk_size < 0x800000 || disk_size > 0x800000000ULL)
{
ERROR_LOG(COMMON, "Trying to create SD Card image of size %" PRIu64 "MB is out of range (8MB-32GB)", disk_size / (1024 * 1024));
return false;
}
// Pretty unlikely to overflow.
sectors_per_disk = (u32)(disk_size / 512);
sectors_per_fat = get_sectors_per_fat(disk_size, get_sectors_per_cluster(disk_size));
boot_sector_init(s_boot_sector, s_fsinfo_sector, disk_size, nullptr);
fat_init(s_fat_head);
File::IOFile file(filename, "wb");
FILE* const f = file.GetHandle();
if (!f)
{
ERROR_LOG(COMMON, "Could not create file '%s', aborting...", filename.c_str());
return false;
}
/* Here's the layout:
*
* boot_sector
* fsinfo_sector
* empty
* backup boot sector
* backup fsinfo sector
* RESERVED_SECTORS - 4 empty sectors (if backup sectors), or RESERVED_SECTORS - 2 (if no backup)
* first fat
* second fat
* zero sectors
*/
if (write_sector(f, s_boot_sector))
goto FailWrite;
if (write_sector(f, s_fsinfo_sector))
goto FailWrite;
if (BACKUP_BOOT_SECTOR > 0)
{
if (write_empty(f, BACKUP_BOOT_SECTOR - 2))
goto FailWrite;
if (write_sector(f, s_boot_sector))
goto FailWrite;
if (write_sector(f, s_fsinfo_sector))
goto FailWrite;
if (write_empty(f, RESERVED_SECTORS - 2 - BACKUP_BOOT_SECTOR))
goto FailWrite;
}
else
{
if (write_empty(f, RESERVED_SECTORS - 2)) goto FailWrite;
}
if (write_sector(f, s_fat_head))
goto FailWrite;
if (write_empty(f, sectors_per_fat - 1))
goto FailWrite;
if (write_sector(f, s_fat_head))
goto FailWrite;
if (write_empty(f, sectors_per_fat - 1))
goto FailWrite;
if (write_empty(f, sectors_per_disk - RESERVED_SECTORS - 2 * sectors_per_fat))
goto FailWrite;
return true;
FailWrite:
ERROR_LOG(COMMON, "Could not write to '%s', aborting...", filename.c_str());
if (unlink(filename.c_str()) < 0)
ERROR_LOG(COMMON, "unlink(%s) failed: %s", filename.c_str(), GetLastErrorMsg().c_str());
return false;
}
int main( int argc, char** argv )
{
Wide disk_size;
int sectors_per_fat;
int sectors_per_disk;
char* end;
const char* label = NULL;
FILE* f = NULL;
for ( ; argc > 1 && argv[1][0] == '-'; argc--, argv++ )
{
char* arg = argv[1] + 1;
switch (arg[0]) {
case 'l':
if (arg[1] != 0)
arg += 2;
else {
argc--;
argv++;
if (argc <= 1)
usage();
arg = argv[1];
}
label = arg;
break;
default:
usage();
}
}
if (argc != 3)
usage();
disk_size = strtoll( argv[1], &end, 10 );
if (disk_size < 0 || (disk_size == 0 && (errno == EINVAL || errno == ERANGE))) {
fprintf(stderr, "Invalid argument size '%s'\n\n", argv[1]);
usage();
}
if (*end == 'K')
disk_size *= 1024;
else if (*end == 'M')
disk_size *= 1024*1024;
else if (*end == 'G')
disk_size *= 1024*1024*1024;
if (disk_size < 9*1024*1024) {
fprintf(stderr, "Invalid argument: size '%s' is too small.\n\n", argv[1]);
usage();
} else if (disk_size > MAX_DISK_SIZE) {
fprintf(stderr, "Invalid argument: size '%s' is too large.\n\n", argv[1]);
usage();
}
sectors_per_disk = disk_size / BYTES_PER_SECTOR;
sectors_per_fat = get_sectors_per_fat( disk_size, get_sectors_per_cluster( disk_size ) );
boot_sector_init( s_boot_sector, s_fsinfo_sector, disk_size, NULL );
fat_init( s_fat_head );
f = fopen( argv[2], "wb" );
if ( !f ) {
fprintf(stderr, "Could not create file '%s': %s\n", argv[2], strerror(errno));
goto FailWrite;
}
/* here's the layout:
*
* boot_sector
* fsinfo_sector
* empty
* backup boot sector
* backup fsinfo sector
* RESERVED_SECTORS - 4 empty sectors (if backup sectors), or RESERVED_SECTORS - 2 (if no backup)
* first fat
* second fat
* zero sectors
*/
if ( write_sector( f, s_boot_sector ) ) goto FailWrite;
if ( write_sector( f, s_fsinfo_sector ) ) goto FailWrite;
if ( BACKUP_BOOT_SECTOR > 0 ) {
if ( write_empty( f, BACKUP_BOOT_SECTOR - 2 ) ) goto FailWrite;
if ( write_sector( f, s_boot_sector ) ) goto FailWrite;
if ( write_sector( f, s_fsinfo_sector ) ) goto FailWrite;
if ( write_empty( f, RESERVED_SECTORS - 2 - BACKUP_BOOT_SECTOR ) ) goto FailWrite;
}
else if ( write_empty( f, RESERVED_SECTORS - 2 ) ) goto FailWrite;
if ( write_sector( f, s_fat_head ) ) goto FailWrite;
if ( write_empty( f, sectors_per_fat-1 ) ) goto FailWrite;
if ( write_sector( f, s_fat_head ) ) goto FailWrite;
if ( write_empty( f, sectors_per_fat-1 ) ) goto FailWrite;
if ( write_empty( f, sectors_per_disk - RESERVED_SECTORS - 2*sectors_per_fat ) ) goto FailWrite;
fclose(f);
return 0;
FailWrite:
if (f != NULL) {
fclose(f);
unlink( argv[2] );
fprintf(stderr, "File '%s' was not created.\n", argv[2]);
}
return 1;
}
