fs_ext2.h

pocket pc hx4700 bootloader

/*
 *  GRUB  --  GRand Unified Bootloader
 *  Copyright (C) 2003, 2004, 2005  Free Software Foundation, Inc.
 *  Copyright 2006 Pawel Kolodziejski - adopted to linux native bootloader
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#ifndef __GRUB_EXT2_H__
#define __GRUB_EXT2_H__

/* Magic value used to identify an ext2 filesystem.  */
#define	EXT2_MAGIC		0xEF53
/* Amount of indirect blocks in an inode.  */
#define INDIRECT_BLOCKS		12
/* Maximum lenght of a pathname.  */
#define EXT2_PATH_MAX		4096
/* Maximum nesting of symlinks, used to prevent a loop.  */
#define	EXT2_MAX_SYMLINKCNT	8

/* Filetype used in directory entry.  */
#define	FILETYPE_UNKNOWN	0
#define	FILETYPE_REG		1
#define	FILETYPE_DIRECTORY	2
#define	FILETYPE_SYMLINK	7

/* Filetype information as used in inodes.  */
#define FILETYPE_INO_MASK	0170000
#define FILETYPE_INO_REG	0100000
#define FILETYPE_INO_DIRECTORY	0040000
#define FILETYPE_INO_SYMLINK	0120000

/* Log2 size of ext2 block in 512 blocks.  */
#define LOG2_EXT2_BLOCK_SIZE(data)			\
	(grub_le_to_cpu32 (data->sblock.log2_block_size) + 1)
     
/* Log2 size of ext2 block in bytes.  */
#define LOG2_BLOCK_SIZE(data)					\
	(grub_le_to_cpu32 (data->sblock.log2_block_size) + 10)

/* The size of an ext2 block in bytes.  */
#define EXT2_BLOCK_SIZE(data)		(1 << LOG2_BLOCK_SIZE(data))

/* The ext2 superblock.  */
struct grub_ext2_sblock {
	grub_uint32_t total_inodes;
	grub_uint32_t total_blocks;
	grub_uint32_t reserved_blocks;
	grub_uint32_t free_blocks;
	grub_uint32_t free_inodes;
	grub_uint32_t first_data_block;
	grub_uint32_t log2_block_size;
	grub_uint32_t log2_fragment_size;
	grub_uint32_t blocks_per_group;
	grub_uint32_t fragments_per_group;
	grub_uint32_t inodes_per_group;
	grub_uint32_t mtime;
	grub_uint32_t utime;
	grub_uint16_t mnt_count;
	grub_uint16_t max_mnt_count;
	grub_uint16_t magic;
	grub_uint16_t fs_state;
	grub_uint16_t error_handling;
	grub_uint16_t minor_revision_level;
	grub_uint32_t lastcheck;
	grub_uint32_t checkinterval;
	grub_uint32_t creator_os;
	grub_uint32_t revision_level;
	grub_uint16_t uid_reserved;
	grub_uint16_t gid_reserved;
	grub_uint32_t first_inode;
	grub_uint16_t inode_size;
	grub_uint16_t block_group_number;
	grub_uint32_t feature_compatibility;
	grub_uint32_t feature_incompat;
	grub_uint32_t feature_ro_compat;
	grub_uint32_t unique_id[4];
	char volume_name[16];
	char last_mounted_on[64];
	grub_uint32_t compression_info;
};

/* The ext2 blockgroup.  */
struct grub_ext2_block_group {
	grub_uint32_t block_id;
	grub_uint32_t inode_id;
	grub_uint32_t inode_table_id;
	grub_uint16_t free_blocks;
	grub_uint16_t free_inodes;
	grub_uint16_t pad;
	grub_uint32_t reserved[3];
};

/* The ext2 inode.  */
struct grub_ext2_inode {
	grub_uint16_t mode;
	grub_uint16_t uid;
	grub_uint32_t size;
	grub_uint32_t atime;
	grub_uint32_t ctime;
	grub_uint32_t mtime;
	grub_uint32_t dtime;
	grub_uint16_t gid;
	grub_uint16_t nlinks;
	grub_uint32_t blockcnt;  /* Blocks of 512 bytes!! */
	grub_uint32_t flags;
	grub_uint32_t osd1;
	union {
		struct datablocks {
			grub_uint32_t dir_blocks[INDIRECT_BLOCKS];
			grub_uint32_t indir_block;
			grub_uint32_t double_indir_block;
			grub_uint32_t tripple_indir_block;
		} blocks;
		char symlink[60];
	};
	grub_uint32_t version;
	grub_uint32_t acl;
	grub_uint32_t dir_acl;
	grub_uint32_t fragment_addr;
	grub_uint32_t osd2[3];
};

/* The header of an ext2 directory entry.  */
struct ext2_dirent {
	grub_uint32_t inode;
	grub_uint16_t direntlen;
	grub_uint8_t namelen;
	grub_uint8_t filetype;
};

struct grub_fshelp_node {
	struct grub_ext2_data *data;
	struct grub_ext2_inode inode;
	int ino;
	int inode_read;
};
typedef struct grub_fshelp_node *grub_fshelp_node_t;

/* Information about a "mounted" ext2 filesystem.  */
struct grub_ext2_data {
	struct grub_ext2_sblock sblock;
	grub_disk_t disk;
	struct grub_ext2_inode *inode;
	struct grub_fshelp_node diropen;
};

grub_ssize_t grub_fshelp_read_file(grub_disk_t disk, grub_fshelp_node_t node,
    				void (*read_hook)(grub_disk_addr_t sector, unsigned offset, unsigned length),
				int pos, grub_size_t len, char *buf,
				int (*get_block)(grub_fshelp_node_t node, int block),
				grub_off_t filesize, int log2blocksize);

#endif