diff --git a/fs/fat/ff.c b/fs/fat/ff.c index 66db1d6b5..33f8b6195 100644 --- a/fs/fat/ff.c +++ b/fs/fat/ff.c @@ -93,6 +93,7 @@ #include #include #include +#include #include "ff.h" /* FatFs configurations and declarations */ #include "diskio.h" /* Declarations of low level disk I/O functions */ @@ -1531,29 +1532,20 @@ int follow_path ( /* 0(0): successful, !=0: error code */ /* * Load boot record and check if it is an FAT boot record */ -static int check_fs ( /* 0:The FAT BR, 1:Valid BR but not an FAT, 2:Not a BR, 3:Disk error */ +static enum filetype check_fs ( /* 0:The FAT BR, 1:Valid BR but not an FAT, 2:Not a BR, 3:Disk error */ FATFS *fs, /* File system object */ - DWORD sect /* Sector# (lba) to check if it is an FAT boot record or not */ + DWORD sect, /* Sector# (lba) to check if it is an FAT boot record or not */ + DWORD *bootsec ) { - int ret; + enum filetype ret; /* Load boot record */ ret = disk_read(fs, fs->win, sect, 1); if (ret) - return ret; - /* Check record signature (always placed at offset 510 even if the sector size is>512) */ - if (LD_WORD(&fs->win[BS_55AA]) != 0xAA55) - return -ENODEV; + return filetype_unknown; - /* Check "FAT" string */ - if ((LD_DWORD(&fs->win[BS_FilSysType]) & 0xFFFFFF) == 0x544146) - return 0; - - if ((LD_DWORD(&fs->win[BS_FilSysType32]) & 0xFFFFFF) == 0x544146) - return 0; - - return -ENODEV; + return is_fat_or_mbr(fs->win, bootsec); } /* @@ -1565,8 +1557,10 @@ static int chk_mounted ( /* 0(0): successful, !=0: any error occurred */ ) { BYTE fmt, b; + DWORD first_boot_sect; DWORD bsect, fasize, tsect, sysect, nclst, szbfat; WORD nrsv; + enum filetype type; INIT_LIST_HEAD(&fs->dirtylist); @@ -1579,9 +1573,16 @@ static int chk_mounted ( /* 0(0): successful, !=0: any error occurred */ return -EIO; #endif /* Search FAT partition on the drive. Supports only generic partitionings, FDISK and SFD. */ - fmt = check_fs(fs, bsect = 0); /* Check sector 0 if it is a VBR */ - if (fmt) - return fmt; /* No FAT volume is found */ + type = check_fs(fs, bsect = 0, &first_boot_sect); /* Check sector 0 if it is a VBR */ + if (type == filetype_mbr) { + /* Sector 0 is an MBR, now check for FAT in the first partition */ + type = check_fs(fs, bsect = first_boot_sect, NULL); + if (type != filetype_fat) + return -ENODEV; + } + + if (type == filetype_unknown) + return -ENODEV; /* Following code initializes the file system object */