xref: /openbmc/u-boot/include/fat.h (revision 15855700)
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 /* Indicates that the entry is the last long entry in a set of long
73  * dir entries
74  */
75 #define LAST_LONG_ENTRY_MASK	0x40
76 
77 /* Flags telling whether we should read a file or list a directory */
78 #define LS_NO	0
79 #define LS_YES	1
80 #define LS_DIR	1
81 #define LS_ROOT	2
82 
83 #ifdef DEBUG
84 #define FAT_DPRINT(args...)	printf(args)
85 #else
86 #define FAT_DPRINT(args...)
87 #endif
88 #define FAT_ERROR(arg)		printf(arg)
89 
90 #define ISDIRDELIM(c)   ((c) == '/' || (c) == '\\')
91 
92 #define FSTYPE_NONE	(-1)
93 
94 #if defined(__linux__) && defined(__KERNEL__)
95 #define FAT2CPU16	le16_to_cpu
96 #define FAT2CPU32	le32_to_cpu
97 #else
98 #if __LITTLE_ENDIAN
99 #define FAT2CPU16(x)	(x)
100 #define FAT2CPU32(x)	(x)
101 #else
102 #define FAT2CPU16(x)	((((x) & 0x00ff) << 8) | (((x) & 0xff00) >> 8))
103 #define FAT2CPU32(x)	((((x) & 0x000000ff) << 24)  |	\
104 			 (((x) & 0x0000ff00) << 8)  |	\
105 			 (((x) & 0x00ff0000) >> 8)  |	\
106 			 (((x) & 0xff000000) >> 24))
107 #endif
108 #endif
109 
110 #define TOLOWER(c)	if((c) >= 'A' && (c) <= 'Z'){(c)+=('a' - 'A');}
111 #define START(dent)	(FAT2CPU16((dent)->start) \
112 			+ (mydata->fatsize != 32 ? 0 : \
113 			  (FAT2CPU16((dent)->starthi) << 16)))
114 #define CHECK_CLUST(x, fatsize) ((x) <= 1 || \
115 				(x) >= ((fatsize) != 32 ? 0xfff0 : 0xffffff0))
116 
117 typedef struct boot_sector {
118 	__u8	ignored[3];	/* Bootstrap code */
119 	char	system_id[8];	/* Name of fs */
120 	__u8	sector_size[2];	/* Bytes/sector */
121 	__u8	cluster_size;	/* Sectors/cluster */
122 	__u16	reserved;	/* Number of reserved sectors */
123 	__u8	fats;		/* Number of FATs */
124 	__u8	dir_entries[2];	/* Number of root directory entries */
125 	__u8	sectors[2];	/* Number of sectors */
126 	__u8	media;		/* Media code */
127 	__u16	fat_length;	/* Sectors/FAT */
128 	__u16	secs_track;	/* Sectors/track */
129 	__u16	heads;		/* Number of heads */
130 	__u32	hidden;		/* Number of hidden sectors */
131 	__u32	total_sect;	/* Number of sectors (if sectors == 0) */
132 
133 	/* FAT32 only */
134 	__u32	fat32_length;	/* Sectors/FAT */
135 	__u16	flags;		/* Bit 8: fat mirroring, low 4: active fat */
136 	__u8	version[2];	/* Filesystem version */
137 	__u32	root_cluster;	/* First cluster in root directory */
138 	__u16	info_sector;	/* Filesystem info sector */
139 	__u16	backup_boot;	/* Backup boot sector */
140 	__u16	reserved2[6];	/* Unused */
141 } boot_sector;
142 
143 typedef struct volume_info
144 {
145 	__u8 drive_number;	/* BIOS drive number */
146 	__u8 reserved;		/* Unused */
147 	__u8 ext_boot_sign;	/* 0x29 if fields below exist (DOS 3.3+) */
148 	__u8 volume_id[4];	/* Volume ID number */
149 	char volume_label[11];	/* Volume label */
150 	char fs_type[8];	/* Typically FAT12, FAT16, or FAT32 */
151 	/* Boot code comes next, all but 2 bytes to fill up sector */
152 	/* Boot sign comes last, 2 bytes */
153 } volume_info;
154 
155 typedef struct dir_entry {
156 	char	name[8],ext[3];	/* Name and extension */
157 	__u8	attr;		/* Attribute bits */
158 	__u8	lcase;		/* Case for base and extension */
159 	__u8	ctime_ms;	/* Creation time, milliseconds */
160 	__u16	ctime;		/* Creation time */
161 	__u16	cdate;		/* Creation date */
162 	__u16	adate;		/* Last access date */
163 	__u16	starthi;	/* High 16 bits of cluster in FAT32 */
164 	__u16	time,date,start;/* Time, date and first cluster */
165 	__u32	size;		/* File size in bytes */
166 } dir_entry;
167 
168 typedef struct dir_slot {
169 	__u8    id;		/* Sequence number for slot */
170 	__u8    name0_4[10];	/* First 5 characters in name */
171 	__u8    attr;		/* Attribute byte */
172 	__u8    reserved;	/* Unused */
173 	__u8    alias_checksum;/* Checksum for 8.3 alias */
174 	__u8    name5_10[12];	/* 6 more characters in name */
175 	__u16   start;		/* Unused */
176 	__u8    name11_12[4];	/* Last 2 characters in name */
177 } dir_slot;
178 
179 /* Private filesystem parameters
180  *
181  * Note: FAT buffer has to be 32 bit aligned
182  * (see FAT32 accesses)
183  */
184 typedef struct {
185 	__u8	fatbuf[FATBUFSIZE]; /* Current FAT buffer */
186 	int	fatsize;	/* Size of FAT in bits */
187 	__u16	fatlength;	/* Length of FAT in sectors */
188 	__u16	fat_sect;	/* Starting sector of the FAT */
189 	__u16	rootdir_sect;	/* Start sector of root directory */
190 	__u16	clust_size;	/* Size of clusters in sectors */
191 	short	data_begin;	/* The sector of the first cluster, can be negative */
192 	int	fatbufnum;	/* Used by get_fatent, init to -1 */
193 } fsdata;
194 
195 typedef int	(file_detectfs_func)(void);
196 typedef int	(file_ls_func)(const char *dir);
197 typedef long	(file_read_func)(const char *filename, void *buffer,
198 				 unsigned long maxsize);
199 
200 struct filesystem {
201 	file_detectfs_func *detect;
202 	file_ls_func	   *ls;
203 	file_read_func	   *read;
204 	const char	    name[12];
205 };
206 
207 /* FAT tables */
208 file_detectfs_func	file_fat_detectfs;
209 file_ls_func		file_fat_ls;
210 file_read_func		file_fat_read;
211 
212 /* Currently this doesn't check if the dir exists or is valid... */
213 int file_cd(const char *path);
214 int file_fat_detectfs(void);
215 int file_fat_ls(const char *dir);
216 long file_fat_read(const char *filename, void *buffer, unsigned long maxsize);
217 const char *file_getfsname(int idx);
218 int fat_register_device(block_dev_desc_t *dev_desc, int part_no);
219 
220 #endif /* _FAT_H_ */
221