xref: /openbmc/u-boot/include/fat.h (revision 47c3e074)
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 /* Maximum Long File Name length supported here is 128 UTF-16 code units */
34 #define VFAT_MAXLEN_BYTES	256 /* Maximum LFN buffer in bytes */
35 #define VFAT_MAXSEQ		9   /* Up to 9 of 13 2-byte UTF-16 entries */
36 #define LINEAR_PREFETCH_SIZE	(SECTOR_SIZE*2) /* Prefetch buffer size */
37 
38 #define SECTOR_SIZE FS_BLOCK_SIZE
39 
40 #define FS_BLOCK_SIZE	512
41 
42 #if FS_BLOCK_SIZE != SECTOR_SIZE
43 #error FS_BLOCK_SIZE != SECTOR_SIZE - This code needs to be fixed!
44 #endif
45 
46 #define MAX_CLUSTSIZE	65536
47 #define DIRENTSPERBLOCK	(FS_BLOCK_SIZE/sizeof(dir_entry))
48 #define DIRENTSPERCLUST	((mydata->clust_size*SECTOR_SIZE)/sizeof(dir_entry))
49 
50 #define FATBUFBLOCKS	6
51 #define FATBUFSIZE	(FS_BLOCK_SIZE*FATBUFBLOCKS)
52 #define FAT12BUFSIZE	((FATBUFSIZE*2)/3)
53 #define FAT16BUFSIZE	(FATBUFSIZE/2)
54 #define FAT32BUFSIZE	(FATBUFSIZE/4)
55 
56 
57 /* Filesystem identifiers */
58 #define FAT12_SIGN	"FAT12   "
59 #define FAT16_SIGN	"FAT16   "
60 #define FAT32_SIGN	"FAT32   "
61 #define SIGNLEN		8
62 
63 /* File attributes */
64 #define ATTR_RO	1
65 #define ATTR_HIDDEN	2
66 #define ATTR_SYS	4
67 #define ATTR_VOLUME	8
68 #define ATTR_DIR	16
69 #define ATTR_ARCH	32
70 
71 #define ATTR_VFAT	(ATTR_RO | ATTR_HIDDEN | ATTR_SYS | ATTR_VOLUME)
72 
73 #define DELETED_FLAG	((char)0xe5) /* Marks deleted files when in name[0] */
74 #define aRING		0x05	     /* Used as special character in name[0] */
75 
76 /*
77  * Indicates that the entry is the last long entry in a set of long
78  * dir entries
79  */
80 #define LAST_LONG_ENTRY_MASK	0x40
81 
82 /* Flags telling whether we should read a file or list a directory */
83 #define LS_NO		0
84 #define LS_YES		1
85 #define LS_DIR		1
86 #define LS_ROOT		2
87 
88 #define ISDIRDELIM(c)	((c) == '/' || (c) == '\\')
89 
90 #define FSTYPE_NONE	(-1)
91 
92 #if defined(__linux__) && defined(__KERNEL__)
93 #define FAT2CPU16	le16_to_cpu
94 #define FAT2CPU32	le32_to_cpu
95 #else
96 #if __LITTLE_ENDIAN
97 #define FAT2CPU16(x)	(x)
98 #define FAT2CPU32(x)	(x)
99 #else
100 #define FAT2CPU16(x)	((((x) & 0x00ff) << 8) | (((x) & 0xff00) >> 8))
101 #define FAT2CPU32(x)	((((x) & 0x000000ff) << 24)  |	\
102 			 (((x) & 0x0000ff00) << 8)  |	\
103 			 (((x) & 0x00ff0000) >> 8)  |	\
104 			 (((x) & 0xff000000) >> 24))
105 #endif
106 #endif
107 
108 #define TOLOWER(c)	if((c) >= 'A' && (c) <= 'Z'){(c)+=('a' - 'A');}
109 #define START(dent)	(FAT2CPU16((dent)->start) \
110 			+ (mydata->fatsize != 32 ? 0 : \
111 			  (FAT2CPU16((dent)->starthi) << 16)))
112 #define CHECK_CLUST(x, fatsize) ((x) <= 1 || \
113 				(x) >= ((fatsize) != 32 ? 0xfff0 : 0xffffff0))
114 
115 typedef struct boot_sector {
116 	__u8	ignored[3];	/* Bootstrap code */
117 	char	system_id[8];	/* Name of fs */
118 	__u8	sector_size[2];	/* Bytes/sector */
119 	__u8	cluster_size;	/* Sectors/cluster */
120 	__u16	reserved;	/* Number of reserved sectors */
121 	__u8	fats;		/* Number of FATs */
122 	__u8	dir_entries[2];	/* Number of root directory entries */
123 	__u8	sectors[2];	/* Number of sectors */
124 	__u8	media;		/* Media code */
125 	__u16	fat_length;	/* Sectors/FAT */
126 	__u16	secs_track;	/* Sectors/track */
127 	__u16	heads;		/* Number of heads */
128 	__u32	hidden;		/* Number of hidden sectors */
129 	__u32	total_sect;	/* Number of sectors (if sectors == 0) */
130 
131 	/* FAT32 only */
132 	__u32	fat32_length;	/* Sectors/FAT */
133 	__u16	flags;		/* Bit 8: fat mirroring, low 4: active fat */
134 	__u8	version[2];	/* Filesystem version */
135 	__u32	root_cluster;	/* First cluster in root directory */
136 	__u16	info_sector;	/* Filesystem info sector */
137 	__u16	backup_boot;	/* Backup boot sector */
138 	__u16	reserved2[6];	/* Unused */
139 } boot_sector;
140 
141 typedef struct volume_info
142 {
143 	__u8 drive_number;	/* BIOS drive number */
144 	__u8 reserved;		/* Unused */
145 	__u8 ext_boot_sign;	/* 0x29 if fields below exist (DOS 3.3+) */
146 	__u8 volume_id[4];	/* Volume ID number */
147 	char volume_label[11];	/* Volume label */
148 	char fs_type[8];	/* Typically FAT12, FAT16, or FAT32 */
149 	/* Boot code comes next, all but 2 bytes to fill up sector */
150 	/* Boot sign comes last, 2 bytes */
151 } volume_info;
152 
153 typedef struct dir_entry {
154 	char	name[8],ext[3];	/* Name and extension */
155 	__u8	attr;		/* Attribute bits */
156 	__u8	lcase;		/* Case for base and extension */
157 	__u8	ctime_ms;	/* Creation time, milliseconds */
158 	__u16	ctime;		/* Creation time */
159 	__u16	cdate;		/* Creation date */
160 	__u16	adate;		/* Last access date */
161 	__u16	starthi;	/* High 16 bits of cluster in FAT32 */
162 	__u16	time,date,start;/* Time, date and first cluster */
163 	__u32	size;		/* File size in bytes */
164 } dir_entry;
165 
166 typedef struct dir_slot {
167 	__u8	id;		/* Sequence number for slot */
168 	__u8	name0_4[10];	/* First 5 characters in name */
169 	__u8	attr;		/* Attribute byte */
170 	__u8	reserved;	/* Unused */
171 	__u8	alias_checksum;/* Checksum for 8.3 alias */
172 	__u8	name5_10[12];	/* 6 more characters in name */
173 	__u16	start;		/* Unused */
174 	__u8	name11_12[4];	/* Last 2 characters in name */
175 } dir_slot;
176 
177 /*
178  * Private filesystem parameters
179  *
180  * Note: FAT buffer has to be 32 bit aligned
181  * (see FAT32 accesses)
182  */
183 typedef struct {
184 	__u8	fatbuf[FATBUFSIZE]; /* Current FAT buffer */
185 	int	fatsize;	/* Size of FAT in bits */
186 	__u16	fatlength;	/* Length of FAT in sectors */
187 	__u16	fat_sect;	/* Starting sector of the FAT */
188 	__u16	rootdir_sect;	/* Start sector of root directory */
189 	__u16	clust_size;	/* Size of clusters in sectors */
190 	short	data_begin;	/* The sector of the first cluster, can be negative */
191 	int	fatbufnum;	/* Used by get_fatent, init to -1 */
192 } fsdata;
193 
194 typedef int	(file_detectfs_func)(void);
195 typedef int	(file_ls_func)(const char *dir);
196 typedef long	(file_read_func)(const char *filename, void *buffer,
197 				 unsigned long maxsize);
198 
199 struct filesystem {
200 	file_detectfs_func	*detect;
201 	file_ls_func		*ls;
202 	file_read_func		*read;
203 	const char		name[12];
204 };
205 
206 /* FAT tables */
207 file_detectfs_func	file_fat_detectfs;
208 file_ls_func		file_fat_ls;
209 file_read_func		file_fat_read;
210 
211 /* Currently this doesn't check if the dir exists or is valid... */
212 int file_cd(const char *path);
213 int file_fat_detectfs(void);
214 int file_fat_ls(const char *dir);
215 long file_fat_read(const char *filename, void *buffer, unsigned long maxsize);
216 const char *file_getfsname(int idx);
217 int fat_register_device(block_dev_desc_t *dev_desc, int part_no);
218 
219 #endif /* _FAT_H_ */
220