xref: /openbmc/u-boot/include/fat.h (revision 40930316)
1 /*
2  * R/O (V)FAT 12/16/32 filesystem implementation by Marcus Sundberg
3  *
4  * 2002-07-28 - rjones@nexus-tech.net - ported to ppcboot v1.1.6
5  * 2003-03-10 - kharris@nexus-tech.net - ported to u-boot
6  *
7  * See file CREDITS for list of people who contributed to this
8  * project.
9  *
10  * This program is free software; you can redistribute it and/or
11  * modify it under the terms of the GNU General Public License as
12  * published by the Free Software Foundation; either version 2 of
13  * the License, or (at your option) any later version.
14  *
15  * This program is distributed in the hope that it will be useful,
16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18  * GNU General Public License for more details.
19  *
20  * You should have received a copy of the GNU General Public License
21  * along with this program; if not, write to the Free Software
22  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
23  * MA 02111-1307 USA
24  *
25  */
26 
27 #ifndef _FAT_H_
28 #define _FAT_H_
29 
30 #include <asm/byteorder.h>
31 
32 #define CONFIG_SUPPORT_VFAT
33 
34 #define SECTOR_SIZE FS_BLOCK_SIZE
35 
36 #define FS_BLOCK_SIZE	512
37 
38 #if FS_BLOCK_SIZE != SECTOR_SIZE
39 #error FS_BLOCK_SIZE != SECTOR_SIZE - This code needs to be fixed!
40 #endif
41 
42 #define MAX_CLUSTSIZE	65536
43 #define DIRENTSPERBLOCK	(FS_BLOCK_SIZE/sizeof(dir_entry))
44 #define DIRENTSPERCLUST	((mydata->clust_size*SECTOR_SIZE)/sizeof(dir_entry))
45 
46 #define FATBUFBLOCKS	6
47 #define FATBUFSIZE	(FS_BLOCK_SIZE*FATBUFBLOCKS)
48 #define FAT12BUFSIZE	((FATBUFSIZE*2)/3)
49 #define FAT16BUFSIZE	(FATBUFSIZE/2)
50 #define FAT32BUFSIZE	(FATBUFSIZE/4)
51 
52 
53 /* Filesystem identifiers */
54 #define FAT12_SIGN	"FAT12   "
55 #define FAT16_SIGN	"FAT16   "
56 #define FAT32_SIGN	"FAT32   "
57 #define SIGNLEN		8
58 
59 /* File attributes */
60 #define ATTR_RO	1
61 #define ATTR_HIDDEN	2
62 #define ATTR_SYS	4
63 #define ATTR_VOLUME	8
64 #define ATTR_DIR	16
65 #define ATTR_ARCH	32
66 
67 #define ATTR_VFAT	(ATTR_RO | ATTR_HIDDEN | ATTR_SYS | ATTR_VOLUME)
68 
69 #define DELETED_FLAG	((char)0xe5) /* Marks deleted files when in name[0] */
70 #define aRING		0x05	     /* Used as special character in name[0] */
71 
72 /*
73  * Indicates that the entry is the last long entry in a set of long
74  * dir entries
75  */
76 #define LAST_LONG_ENTRY_MASK	0x40
77 
78 /* Flags telling whether we should read a file or list a directory */
79 #define LS_NO		0
80 #define LS_YES		1
81 #define LS_DIR		1
82 #define LS_ROOT		2
83 
84 #define ISDIRDELIM(c)	((c) == '/' || (c) == '\\')
85 
86 #define FSTYPE_NONE	(-1)
87 
88 #if defined(__linux__) && defined(__KERNEL__)
89 #define FAT2CPU16	le16_to_cpu
90 #define FAT2CPU32	le32_to_cpu
91 #else
92 #if __LITTLE_ENDIAN
93 #define FAT2CPU16(x)	(x)
94 #define FAT2CPU32(x)	(x)
95 #else
96 #define FAT2CPU16(x)	((((x) & 0x00ff) << 8) | (((x) & 0xff00) >> 8))
97 #define FAT2CPU32(x)	((((x) & 0x000000ff) << 24)  |	\
98 			 (((x) & 0x0000ff00) << 8)  |	\
99 			 (((x) & 0x00ff0000) >> 8)  |	\
100 			 (((x) & 0xff000000) >> 24))
101 #endif
102 #endif
103 
104 #define TOLOWER(c)	if((c) >= 'A' && (c) <= 'Z'){(c)+=('a' - 'A');}
105 #define START(dent)	(FAT2CPU16((dent)->start) \
106 			+ (mydata->fatsize != 32 ? 0 : \
107 			  (FAT2CPU16((dent)->starthi) << 16)))
108 #define CHECK_CLUST(x, fatsize) ((x) <= 1 || \
109 				(x) >= ((fatsize) != 32 ? 0xfff0 : 0xffffff0))
110 
111 typedef struct boot_sector {
112 	__u8	ignored[3];	/* Bootstrap code */
113 	char	system_id[8];	/* Name of fs */
114 	__u8	sector_size[2];	/* Bytes/sector */
115 	__u8	cluster_size;	/* Sectors/cluster */
116 	__u16	reserved;	/* Number of reserved sectors */
117 	__u8	fats;		/* Number of FATs */
118 	__u8	dir_entries[2];	/* Number of root directory entries */
119 	__u8	sectors[2];	/* Number of sectors */
120 	__u8	media;		/* Media code */
121 	__u16	fat_length;	/* Sectors/FAT */
122 	__u16	secs_track;	/* Sectors/track */
123 	__u16	heads;		/* Number of heads */
124 	__u32	hidden;		/* Number of hidden sectors */
125 	__u32	total_sect;	/* Number of sectors (if sectors == 0) */
126 
127 	/* FAT32 only */
128 	__u32	fat32_length;	/* Sectors/FAT */
129 	__u16	flags;		/* Bit 8: fat mirroring, low 4: active fat */
130 	__u8	version[2];	/* Filesystem version */
131 	__u32	root_cluster;	/* First cluster in root directory */
132 	__u16	info_sector;	/* Filesystem info sector */
133 	__u16	backup_boot;	/* Backup boot sector */
134 	__u16	reserved2[6];	/* Unused */
135 } boot_sector;
136 
137 typedef struct volume_info
138 {
139 	__u8 drive_number;	/* BIOS drive number */
140 	__u8 reserved;		/* Unused */
141 	__u8 ext_boot_sign;	/* 0x29 if fields below exist (DOS 3.3+) */
142 	__u8 volume_id[4];	/* Volume ID number */
143 	char volume_label[11];	/* Volume label */
144 	char fs_type[8];	/* Typically FAT12, FAT16, or FAT32 */
145 	/* Boot code comes next, all but 2 bytes to fill up sector */
146 	/* Boot sign comes last, 2 bytes */
147 } volume_info;
148 
149 typedef struct dir_entry {
150 	char	name[8],ext[3];	/* Name and extension */
151 	__u8	attr;		/* Attribute bits */
152 	__u8	lcase;		/* Case for base and extension */
153 	__u8	ctime_ms;	/* Creation time, milliseconds */
154 	__u16	ctime;		/* Creation time */
155 	__u16	cdate;		/* Creation date */
156 	__u16	adate;		/* Last access date */
157 	__u16	starthi;	/* High 16 bits of cluster in FAT32 */
158 	__u16	time,date,start;/* Time, date and first cluster */
159 	__u32	size;		/* File size in bytes */
160 } dir_entry;
161 
162 typedef struct dir_slot {
163 	__u8	id;		/* Sequence number for slot */
164 	__u8	name0_4[10];	/* First 5 characters in name */
165 	__u8	attr;		/* Attribute byte */
166 	__u8	reserved;	/* Unused */
167 	__u8	alias_checksum;/* Checksum for 8.3 alias */
168 	__u8	name5_10[12];	/* 6 more characters in name */
169 	__u16	start;		/* Unused */
170 	__u8	name11_12[4];	/* Last 2 characters in name */
171 } dir_slot;
172 
173 /*
174  * Private filesystem parameters
175  *
176  * Note: FAT buffer has to be 32 bit aligned
177  * (see FAT32 accesses)
178  */
179 typedef struct {
180 	__u8	fatbuf[FATBUFSIZE]; /* Current FAT buffer */
181 	int	fatsize;	/* Size of FAT in bits */
182 	__u16	fatlength;	/* Length of FAT in sectors */
183 	__u16	fat_sect;	/* Starting sector of the FAT */
184 	__u16	rootdir_sect;	/* Start sector of root directory */
185 	__u16	clust_size;	/* Size of clusters in sectors */
186 	short	data_begin;	/* The sector of the first cluster, can be negative */
187 	int	fatbufnum;	/* Used by get_fatent, init to -1 */
188 } fsdata;
189 
190 typedef int	(file_detectfs_func)(void);
191 typedef int	(file_ls_func)(const char *dir);
192 typedef long	(file_read_func)(const char *filename, void *buffer,
193 				 unsigned long maxsize);
194 
195 struct filesystem {
196 	file_detectfs_func	*detect;
197 	file_ls_func		*ls;
198 	file_read_func		*read;
199 	const char		name[12];
200 };
201 
202 /* FAT tables */
203 file_detectfs_func	file_fat_detectfs;
204 file_ls_func		file_fat_ls;
205 file_read_func		file_fat_read;
206 
207 /* Currently this doesn't check if the dir exists or is valid... */
208 int file_cd(const char *path);
209 int file_fat_detectfs(void);
210 int file_fat_ls(const char *dir);
211 long file_fat_read(const char *filename, void *buffer, unsigned long maxsize);
212 const char *file_getfsname(int idx);
213 int fat_register_device(block_dev_desc_t *dev_desc, int part_no);
214 
215 #endif /* _FAT_H_ */
216