/* mksdcard.c ** ** Copyright 2007, The Android Open Source Project ** ** Redistribution and use in source and binary forms, with or without ** modification, are permitted provided that the following conditions are met: ** * Redistributions of source code must retain the above copyright ** notice, this list of conditions and the following disclaimer. ** * Redistributions in binary form must reproduce the above copyright ** notice, this list of conditions and the following disclaimer in the ** documentation and/or other materials provided with the distribution. ** * Neither the name of Google Inc. nor the names of its contributors may ** be used to endorse or promote products derived from this software ** without specific prior written permission. ** ** THIS SOFTWARE IS PROVIDED BY Google Inc. ``AS IS'' AND ANY EXPRESS OR ** IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF ** MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO ** EVENT SHALL Google Inc. BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, ** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, ** PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; ** OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, ** WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR ** OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ** ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ // A simple and portable piece of code used to generate a blank FAT32 image file. // Modified for Dolphin. #include "SDCardUtil.h" #include #include #include #include #include /* believe me, you *don't* want to change these constants !! */ #define BYTES_PER_SECTOR 512 #define RESERVED_SECTORS 32 #define BACKUP_BOOT_SECTOR 6 #define NUM_FATS 2 #define BYTE_(p,i) (((u8*)(p))[(i)]) #define POKEB(p,v) BYTE_(p,0) = (u8)(v) #define POKES(p,v) ( BYTE_(p,0) = (u8)(v), BYTE_(p,1) = (u8)((v) >> 8) ) #define POKEW(p,v) ( BYTE_(p,0) = (u8)(v), BYTE_(p,1) = (u8)((v) >> 8), BYTE_(p,2) = (u8)((v) >> 16), BYTE_(p,3) = (u8)((v) >> 24) ) static u8 s_boot_sector [ BYTES_PER_SECTOR ]; /* boot sector */ static u8 s_fsinfo_sector [ BYTES_PER_SECTOR ]; /* FS Info sector */ static u8 s_fat_head [ BYTES_PER_SECTOR ]; /* first FAT sector */ static u8 s_zero_sector [ BYTES_PER_SECTOR ]; /* empty sector */ /* this is the date and time when creating the disk */ static int get_serial_id() { u16 lo, hi; time_t now = time(NULL); struct tm tm = gmtime( &now )[0]; lo = (u16)(tm.tm_mday + ((tm.tm_mon+1) << 8) + (tm.tm_sec << 8)); hi = (u16)(tm.tm_min + (tm.tm_hour << 8) + (tm.tm_year + 1900)); return lo + (hi << 16); } static int get_sectors_per_cluster(u64 disk_size) { u64 disk_MB = disk_size/(1024*1024); if (disk_MB < 260) return 1; if (disk_MB < 8192) return 4; if (disk_MB < 16384) return 8; if (disk_MB < 32768) return 16; return 32; } static int get_sectors_per_fat(u64 disk_size, int sectors_per_cluster) { u64 divider; /* weird computation from MS - see fatgen103.doc for details */ disk_size -= RESERVED_SECTORS * BYTES_PER_SECTOR; /* don't count 32 reserved sectors */ disk_size /= BYTES_PER_SECTOR; /* disk size in sectors */ divider = ((256 * sectors_per_cluster) + NUM_FATS) / 2; return (int)( (disk_size + (divider-1)) / divider ); } static void boot_sector_init(u8* boot, u8* info, u64 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 = "DOLPHINSD"; 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 ); } static void fat_init(u8* fat) { POKEW( fat, 0x0ffffff8 ); /* reserve cluster 1, media id in low byte */ POKEW( fat + 4, 0x0fffffff ); /* reserve cluster 2 */ POKEW( fat + 8, 0x0fffffff ); /* end of clust chain for root dir */ } static int write_sector(FILE* file, u8* sector) { return fwrite(sector, 1, 512, file) != 512; } static int write_empty(FILE* file, u64 count) { static u8 empty[64*1024]; count *= 512; while (count > 0) { u64 len = sizeof(empty); if (len > count) len = count; if ( fwrite(empty, 1, (size_t)len, file) != (size_t)len ) return 1; count -= len; } return 0; } bool SDCardCreate(u32 disk_size /*in MB*/, char* filename) { int sectors_per_fat; int sectors_per_disk; FILE* f; // 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 %iMB is out of range (8MB-32GB)", disk_size/(1024*1024)); sectors_per_disk = 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, NULL ); fat_init(s_fat_head); f = fopen(filename, "wb"); if (!f) ERROR_LOG(COMMON, "could not create file '%s', aborting...\n", filename); /* 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 true; FailWrite: ERROR_LOG(COMMON, "could not write to '%s', aborting...\n", filename); unlink(filename); fclose(f); return false; }