diff options
Diffstat (limited to 'common/filetype.c')
| -rw-r--r-- | common/filetype.c | 68 |
1 files changed, 56 insertions, 12 deletions
diff --git a/common/filetype.c b/common/filetype.c index e736d43efe..6a0dcfb760 100644 --- a/common/filetype.c +++ b/common/filetype.c @@ -26,6 +26,7 @@ #include <fcntl.h> #include <fs.h> #include <malloc.h> +#include <errno.h> 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; + + /* + * 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; + + /* Check "FAT" string */ + if ((get_unaligned_le32(§or[BS_FilSysType]) & 0xFFFFFF) == 0x544146) + return filetype_fat; - /* FAT */ - if ((get_unaligned_le32(&buf[54]) & 0xFFFFFF) == 0x544146) - return 1; + if ((get_unaligned_le32(§or[BS_FilSysType32]) & 0xFFFFFF) == 0x544146) + return filetype_fat; - /* FAT32 */ - if ((get_unaligned_le32(&buf[82]) & 0xFFFFFF) == 0x544146) - return 1; + 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 0; + 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); |