Update superblock format definition.

diff --git a/libexfat/exfatfs.h b/libexfat/exfatfs.h
index 4a5c7dd..5bc1f7a 100644 (file)
--- a/libexfat/exfatfs.h
+++ b/libexfat/exfatfs.h
@@ -35,7 +35,7 @@ struct exfat_super_block
 {
        uint8_t jump[3];                                /* 0x00 jmp and nop instructions */
        uint8_t oem_name[8];                    /* 0x03 "EXFAT   " */
-       uint8_t __unknown1[53];                 /* 0x0B ? always 0 */
+       uint8_t __unused1[53];                  /* 0x0B always 0 */
        le64_t block_start;                             /* 0x40 partition first block */
        le64_t block_count;                             /* 0x48 partition blocks count */
        le32_t fat_block_start;                 /* 0x50 FAT first block */
@@ -43,15 +43,15 @@ struct exfat_super_block
        le32_t cluster_block_start;             /* 0x58 first cluster block */
        le32_t cluster_count;                   /* 0x5C total clusters count */
        le32_t rootdir_cluster;                 /* 0x60 first cluster of the root dir */
-       le32_t volume_serial;                   /* 0x64 */
-       le16_t __unknown2;                              /* 0x68 version? always 0x00 0x01 */
-       le16_t volume_state;                    /* 0x6A */
+       le32_t volume_serial;                   /* 0x64 volume serial number */
+       le16_t version;                                 /* 0x68 FS version */
+       le16_t volume_state;                    /* 0x6A volume state flags */
        uint8_t block_bits;                             /* 0x6C block size as (1 << n) */
        uint8_t bpc_bits;                               /* 0x6D blocks per cluster as (1 << n) */
-       uint8_t __unknown3;                             /* 0x6E ? always 1 */
-       uint8_t __unknown4;                             /* 0x6F drive number? always 0x80 */
+       uint8_t fat_count;                              /* 0x6E always 1 */
+       uint8_t drive_no;                               /* 0x6F always 0x80 */
        uint8_t allocated_percent;              /* 0x70 percentage of allocated space */
-       uint8_t __unknown5[397];                /* 0x71 padding? all zero */
+       uint8_t __unused2[397];                 /* 0x71 always 0 */
        le16_t boot_signature;                  /* the value of 0xAA55 */
 };