diff --git a/common/filetype.c b/common/filetype.c index e736d43ef..6a0dcfb76 100644 --- a/common/filetype.c +++ b/common/filetype.c @@ -26,6 +26,7 @@ #include #include #include +#include static const char *filetype_str[] = { [filetype_unknown] = "unknown", @@ -42,6 +43,7 @@ static const char *filetype_str[] = { [filetype_sh] = "Bourne Shell", [filetype_mips_barebox] = "MIPS barebox image", [filetype_fat] = "FAT filesytem", + [filetype_mbr] = "MBR sector", }; const char *file_type_to_string(enum filetype f) @@ -52,26 +54,51 @@ const char *file_type_to_string(enum filetype f) return NULL; } -static int is_fat(u8 *buf) +#define MBR_StartSector 8 /* MBR: Offset of Starting Sector in Partition Table Entry */ +#define BS_55AA 510 /* Boot sector signature (2) */ +#define MBR_Table 446 /* MBR: Partition table offset (2) */ +#define BS_FilSysType32 82 /* File system type (1) */ +#define BS_FilSysType 54 /* File system type (1) */ + +enum filetype is_fat_or_mbr(const unsigned char *sector, unsigned long *bootsec) { - if (get_unaligned_le16(&buf[510]) != 0xAA55) - return 0; + /* + * bootsec can be used to return index of the first sector in the + * first partition + */ + if (bootsec) + *bootsec = 0; - /* FAT */ - if ((get_unaligned_le32(&buf[54]) & 0xFFFFFF) == 0x544146) - return 1; + /* + * Check record signature (always placed at offset 510 even if the + * sector size is > 512) + */ + if (get_unaligned_le16(§or[BS_55AA]) != 0xAA55) + return filetype_unknown; - /* FAT32 */ - if ((get_unaligned_le32(&buf[82]) & 0xFFFFFF) == 0x544146) - return 1; + /* Check "FAT" string */ + if ((get_unaligned_le32(§or[BS_FilSysType]) & 0xFFFFFF) == 0x544146) + return filetype_fat; - return 0; + if ((get_unaligned_le32(§or[BS_FilSysType32]) & 0xFFFFFF) == 0x544146) + return filetype_fat; + + if (bootsec) + /* + * This must be an MBR, so return the starting sector of the + * first partition so we could check if there is a FAT boot + * sector there + */ + *bootsec = get_unaligned_le16(§or[MBR_Table + MBR_StartSector]); + + return filetype_mbr; } enum filetype file_detect_type(void *_buf) { u32 *buf = _buf; u8 *buf8 = _buf; + enum filetype type; if (strncmp(buf8, "#!/bin/sh", 9) == 0) return filetype_sh; @@ -99,8 +126,9 @@ enum filetype file_detect_type(void *_buf) return filetype_aimage; if (strncmp(buf8 + 0x10, "barebox", 7) == 0) return filetype_mips_barebox; - if (is_fat(buf8)) - return filetype_fat; + type = is_fat_or_mbr(buf8, NULL); + if (type != filetype_unknown) + return type; return filetype_unknown; } @@ -110,6 +138,7 @@ enum filetype file_name_detect_type(const char *filename) int fd, ret; void *buf; enum filetype type = filetype_unknown; + unsigned long bootsec; fd = open(filename, O_RDONLY); if (fd < 0) @@ -123,6 +152,21 @@ enum filetype file_name_detect_type(const char *filename) type = file_detect_type(buf); + if (type == filetype_mbr) { + /* + * Get the first partition start sector + * and check for FAT in it + */ + is_fat_or_mbr(buf, &bootsec); + ret = lseek(fd, (bootsec) * 512, SEEK_SET); + if (ret < 0) + goto err_out; + ret = read(fd, buf, 512); + if (ret < 0) + goto err_out; + type = is_fat_or_mbr((u8 *)buf, NULL); + } + err_out: close(fd); free(buf); 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 */ diff --git a/include/filetype.h b/include/filetype.h index 179ec0f5e..37eb62020 100644 --- a/include/filetype.h +++ b/include/filetype.h @@ -19,10 +19,12 @@ enum filetype { filetype_sh, filetype_mips_barebox, filetype_fat, + filetype_mbr, }; const char *file_type_to_string(enum filetype f); enum filetype file_detect_type(void *_buf); enum filetype file_name_detect_type(const char *filename); +enum filetype is_fat_or_mbr(const unsigned char *sector, unsigned long *bootsec); #endif /* __FILE_TYPE_H */