ext.h

/*
 * Copyright (C) 1992, 1993, 1994, 1995
 * Remy Card (card@masi.ibp.fr)
 * Laboratoire MASI - Institut Blaise Pascal
 * Universite Pierre et Marie Curie (Paris VI)
 *
 *  from
 *
 *  linux/include/linux/minix_fs.h
 *
 *  Copyright (C) 1991, 1992  Linus Torvalds
 */

uint32_t fillBuffer(uint16_t songIndex, uint8_t buffer[256], uint32_t callCount);
/*
 * Special inode numbers
 */
#define EXT2_ROOT_INO        2  /* Root inode */

/* First non-reserved inode for old ext2 filesystems */
#define EXT2_GOOD_OLD_FIRST_INO 11

/*
 * Structure of a blocks group descriptor
 */
struct ext2_group_desc
{
   uint32_t bg_block_bitmap;    /* Blocks bitmap block */
   uint32_t bg_inode_bitmap;    /* Inodes bitmap block */
   uint32_t bg_inode_table;     /* Inodes table block */
   uint16_t bg_free_blocks_count;   /* Free blocks count */
   uint16_t bg_free_inodes_count;   /* Free inodes count */
   uint16_t bg_used_dirs_count; /* Directories count */
   uint16_t bg_pad;
   uint32_t bg_reserved[3];
};

/*
 * Constants relative to the data blocks
 */
#define EXT2_NDIR_BLOCKS        12
#define EXT2_IND_BLOCK          EXT2_NDIR_BLOCKS
#define EXT2_DIND_BLOCK         (EXT2_IND_BLOCK + 1)
#define EXT2_TIND_BLOCK         (EXT2_DIND_BLOCK + 1)
#define EXT2_N_BLOCKS           (EXT2_TIND_BLOCK + 1)

/*
 * Structure of an inode on the disk
 */
struct ext2_inode {
   uint16_t i_mode;     /* File mode */
   uint16_t i_uid;      /* Low 16 bits of Owner Uid */
   uint32_t i_size;     /* Size in bytes */
   uint32_t i_atime;    /* Access time */
   uint32_t i_ctime;    /* Creation time */
   uint32_t i_mtime;    /* Modification time */
   uint32_t i_dtime;    /* Deletion Time */
   uint16_t i_gid;      /* Low 16 bits of Group Id */
   uint16_t i_links_count;  /* Links count */
   uint32_t i_blocks;   /* Blocks count */
   uint32_t i_flags;    /* File flags */
   union {
      struct {
         uint32_t  l_i_reserved1;
      } linux1;
      struct {
         uint32_t  h_i_translator;
      } hurd1;
      struct {
         uint32_t  m_i_reserved1;
      } masix1;
   } osd1;              /* OS dependent 1 */
   uint32_t i_block[EXT2_N_BLOCKS];/* Pointers to blocks */
   uint32_t i_generation;   /* File version (for NFS) */
   uint32_t i_file_acl; /* File ACL */
   uint32_t i_dir_acl;  /* Directory ACL */
   uint32_t i_faddr;    /* Fragment address */
   union {
      struct {
         uint8_t    l_i_frag;   /* Fragment number */
         uint8_t    l_i_fsize;  /* Fragment size */
         uint16_t   i_pad1;
         uint16_t   l_i_uid_high;   /* these 2 fields    */
         uint16_t   l_i_gid_high;   /* were reserved2[0] */
         uint32_t   l_i_reserved2;
      } linux2;
      struct {
         uint8_t    h_i_frag;   /* Fragment number */
         uint8_t    h_i_fsize;  /* Fragment size */
         uint16_t   h_i_mode_high;
         uint16_t   h_i_uid_high;
         uint16_t   h_i_gid_high;
         uint32_t   h_i_author;
      } hurd2;
      struct {
         uint8_t    m_i_frag;   /* Fragment number */
         uint8_t    m_i_fsize;  /* Fragment size */
         uint16_t   m_pad1;
         uint32_t   m_i_reserved2[2];
      } masix2;
   } osd2;              /* OS dependent 2 */
};

/*
 * Structure of the super block
 */
struct ext2_super_block {
   uint32_t s_inodes_count;     /* Inodes count */
   uint32_t s_blocks_count;     /* Blocks count */
   uint32_t s_r_blocks_count;   /* Reserved blocks count */
   uint32_t s_free_blocks_count;    /* Free blocks count */
   uint32_t s_free_inodes_count;    /* Free inodes count */
   uint32_t s_first_data_block; /* First Data Block */
   uint32_t s_log_block_size;   /* Block size */
   uint32_t s_log_frag_size;    /* Fragment size */
   uint32_t s_blocks_per_group; /* # Blocks per group */
   uint32_t s_frags_per_group;  /* # Fragments per group */
   uint32_t s_inodes_per_group; /* # Inodes per group */
   uint32_t s_mtime;        /* Mount time */
   uint32_t s_wtime;        /* Write time */
   uint16_t s_mnt_count;        /* Mount count */
   uint16_t s_max_mnt_count;    /* Maximal mount count */
   uint16_t s_magic;        /* Magic signature */
   uint16_t s_state;        /* File system state */
   uint16_t s_errors;       /* Behavior when detecting errors */
   uint16_t s_minor_rev_level;  /* minor revision level */
   uint32_t s_lastcheck;        /* time of last check */
   uint32_t s_checkinterval;    /* max. time between checks */
   uint32_t s_creator_os;       /* OS */
   uint32_t s_rev_level;        /* Revision level */
   uint16_t s_def_resuid;       /* Default uid for reserved blocks */
   uint16_t s_def_resgid;       /* Default gid for reserved blocks */
};

/*
 * Revision levels
 */
#define EXT2_GOOD_OLD_REV   0   /* The good old (original) format */
#define EXT2_CURRENT_REV    EXT2_GOOD_OLD_REV
#define EXT2_GOOD_OLD_INODE_SIZE 128

/*
 * Structure of a directory entry
 */

struct ext2_dir_entry {
   uint32_t inode;          /* Inode number */
   uint16_t rec_len;        /* Directory entry length */
   uint16_t name_len;       /* Name length */
   char name[];                 /* File name, up to EXT2_NAME_LEN */
};

/*
 * Ext2 directory file types.  Only the low 3 bits are used.  The
 * other bits are reserved for now.
 */
enum {
   EXT2_FT_UNKNOWN  = 0,
   EXT2_FT_REG_FILE = 1,
   EXT2_FT_DIR      = 2,
   EXT2_FT_CHRDEV   = 3,
   EXT2_FT_BLKDEV   = 4,
   EXT2_FT_FIFO     = 5,
   EXT2_FT_SOCK     = 6,
   EXT2_FT_SYMLINK  = 7,
   EXT2_FT_MAX
};