xref: /openbmc/u-boot/include/fat.h (revision 699c4e59)
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  * SPDX-License-Identifier:	GPL-2.0+
8  */
9 
10 #ifndef _FAT_H_
11 #define _FAT_H_
12 
13 #include <asm/byteorder.h>
14 
15 #define CONFIG_SUPPORT_VFAT
16 /* Maximum Long File Name length supported here is 128 UTF-16 code units */
17 #define VFAT_MAXLEN_BYTES	256 /* Maximum LFN buffer in bytes */
18 #define VFAT_MAXSEQ		9   /* Up to 9 of 13 2-byte UTF-16 entries */
19 #define PREFETCH_BLOCKS		2
20 
21 #ifndef CONFIG_FS_FAT_MAX_CLUSTSIZE
22 #define CONFIG_FS_FAT_MAX_CLUSTSIZE 65536
23 #endif
24 #define MAX_CLUSTSIZE	CONFIG_FS_FAT_MAX_CLUSTSIZE
25 
26 #define DIRENTSPERBLOCK	(mydata->sect_size / sizeof(dir_entry))
27 #define DIRENTSPERCLUST	((mydata->clust_size * mydata->sect_size) / \
28 			 sizeof(dir_entry))
29 
30 #define FATBUFBLOCKS	6
31 #define FATBUFSIZE	(mydata->sect_size * FATBUFBLOCKS)
32 #define FAT12BUFSIZE	((FATBUFSIZE*2)/3)
33 #define FAT16BUFSIZE	(FATBUFSIZE/2)
34 #define FAT32BUFSIZE	(FATBUFSIZE/4)
35 
36 
37 /* Filesystem identifiers */
38 #define FAT12_SIGN	"FAT12   "
39 #define FAT16_SIGN	"FAT16   "
40 #define FAT32_SIGN	"FAT32   "
41 #define SIGNLEN		8
42 
43 /* File attributes */
44 #define ATTR_RO	1
45 #define ATTR_HIDDEN	2
46 #define ATTR_SYS	4
47 #define ATTR_VOLUME	8
48 #define ATTR_DIR	16
49 #define ATTR_ARCH	32
50 
51 #define ATTR_VFAT	(ATTR_RO | ATTR_HIDDEN | ATTR_SYS | ATTR_VOLUME)
52 
53 #define DELETED_FLAG	((char)0xe5) /* Marks deleted files when in name[0] */
54 #define aRING		0x05	     /* Used as special character in name[0] */
55 
56 /*
57  * Indicates that the entry is the last long entry in a set of long
58  * dir entries
59  */
60 #define LAST_LONG_ENTRY_MASK	0x40
61 
62 /* Flags telling whether we should read a file or list a directory */
63 #define LS_NO		0
64 #define LS_YES		1
65 #define LS_DIR		1
66 #define LS_ROOT		2
67 
68 #define ISDIRDELIM(c)	((c) == '/' || (c) == '\\')
69 
70 #define FSTYPE_NONE	(-1)
71 
72 #if defined(__linux__) && defined(__KERNEL__)
73 #define FAT2CPU16	le16_to_cpu
74 #define FAT2CPU32	le32_to_cpu
75 #else
76 #if __LITTLE_ENDIAN
77 #define FAT2CPU16(x)	(x)
78 #define FAT2CPU32(x)	(x)
79 #else
80 #define FAT2CPU16(x)	((((x) & 0x00ff) << 8) | (((x) & 0xff00) >> 8))
81 #define FAT2CPU32(x)	((((x) & 0x000000ff) << 24)  |	\
82 			 (((x) & 0x0000ff00) << 8)  |	\
83 			 (((x) & 0x00ff0000) >> 8)  |	\
84 			 (((x) & 0xff000000) >> 24))
85 #endif
86 #endif
87 
88 #define START(dent)	(FAT2CPU16((dent)->start) \
89 			+ (mydata->fatsize != 32 ? 0 : \
90 			  (FAT2CPU16((dent)->starthi) << 16)))
91 #define IS_LAST_CLUST(x, fatsize) ((x) >= ((fatsize) != 32 ? \
92 					((fatsize) != 16 ? 0xff8 : 0xfff8) : \
93 					0xffffff8))
94 #define CHECK_CLUST(x, fatsize) ((x) <= 1 || \
95 				(x) >= ((fatsize) != 32 ? \
96 					((fatsize) != 16 ? 0xff0 : 0xfff0) : \
97 					0xffffff0))
98 
99 typedef struct boot_sector {
100 	__u8	ignored[3];	/* Bootstrap code */
101 	char	system_id[8];	/* Name of fs */
102 	__u8	sector_size[2];	/* Bytes/sector */
103 	__u8	cluster_size;	/* Sectors/cluster */
104 	__u16	reserved;	/* Number of reserved sectors */
105 	__u8	fats;		/* Number of FATs */
106 	__u8	dir_entries[2];	/* Number of root directory entries */
107 	__u8	sectors[2];	/* Number of sectors */
108 	__u8	media;		/* Media code */
109 	__u16	fat_length;	/* Sectors/FAT */
110 	__u16	secs_track;	/* Sectors/track */
111 	__u16	heads;		/* Number of heads */
112 	__u32	hidden;		/* Number of hidden sectors */
113 	__u32	total_sect;	/* Number of sectors (if sectors == 0) */
114 
115 	/* FAT32 only */
116 	__u32	fat32_length;	/* Sectors/FAT */
117 	__u16	flags;		/* Bit 8: fat mirroring, low 4: active fat */
118 	__u8	version[2];	/* Filesystem version */
119 	__u32	root_cluster;	/* First cluster in root directory */
120 	__u16	info_sector;	/* Filesystem info sector */
121 	__u16	backup_boot;	/* Backup boot sector */
122 	__u16	reserved2[6];	/* Unused */
123 } boot_sector;
124 
125 typedef struct volume_info
126 {
127 	__u8 drive_number;	/* BIOS drive number */
128 	__u8 reserved;		/* Unused */
129 	__u8 ext_boot_sign;	/* 0x29 if fields below exist (DOS 3.3+) */
130 	__u8 volume_id[4];	/* Volume ID number */
131 	char volume_label[11];	/* Volume label */
132 	char fs_type[8];	/* Typically FAT12, FAT16, or FAT32 */
133 	/* Boot code comes next, all but 2 bytes to fill up sector */
134 	/* Boot sign comes last, 2 bytes */
135 } volume_info;
136 
137 typedef struct dir_entry {
138 	char	name[8],ext[3];	/* Name and extension */
139 	__u8	attr;		/* Attribute bits */
140 	__u8	lcase;		/* Case for base and extension */
141 	__u8	ctime_ms;	/* Creation time, milliseconds */
142 	__u16	ctime;		/* Creation time */
143 	__u16	cdate;		/* Creation date */
144 	__u16	adate;		/* Last access date */
145 	__u16	starthi;	/* High 16 bits of cluster in FAT32 */
146 	__u16	time,date,start;/* Time, date and first cluster */
147 	__u32	size;		/* File size in bytes */
148 } dir_entry;
149 
150 typedef struct dir_slot {
151 	__u8	id;		/* Sequence number for slot */
152 	__u8	name0_4[10];	/* First 5 characters in name */
153 	__u8	attr;		/* Attribute byte */
154 	__u8	reserved;	/* Unused */
155 	__u8	alias_checksum;/* Checksum for 8.3 alias */
156 	__u8	name5_10[12];	/* 6 more characters in name */
157 	__u16	start;		/* Unused */
158 	__u8	name11_12[4];	/* Last 2 characters in name */
159 } dir_slot;
160 
161 /*
162  * Private filesystem parameters
163  *
164  * Note: FAT buffer has to be 32 bit aligned
165  * (see FAT32 accesses)
166  */
167 typedef struct {
168 	__u8	*fatbuf;	/* Current FAT buffer */
169 	int	fatsize;	/* Size of FAT in bits */
170 	__u32	fatlength;	/* Length of FAT in sectors */
171 	__u16	fat_sect;	/* Starting sector of the FAT */
172 	__u32	rootdir_sect;	/* Start sector of root directory */
173 	__u16	sect_size;	/* Size of sectors in bytes */
174 	__u16	clust_size;	/* Size of clusters in sectors */
175 	int	data_begin;	/* The sector of the first cluster, can be negative */
176 	int	fatbufnum;	/* Used by get_fatent, init to -1 */
177 } fsdata;
178 
179 typedef int	(file_detectfs_func)(void);
180 typedef int	(file_ls_func)(const char *dir);
181 typedef int	(file_read_func)(const char *filename, void *buffer,
182 				 int maxsize);
183 
184 struct filesystem {
185 	file_detectfs_func	*detect;
186 	file_ls_func		*ls;
187 	file_read_func		*read;
188 	const char		name[12];
189 };
190 
191 /* FAT tables */
192 file_detectfs_func	file_fat_detectfs;
193 file_ls_func		file_fat_ls;
194 file_read_func		file_fat_read;
195 
196 /* Currently this doesn't check if the dir exists or is valid... */
197 int file_cd(const char *path);
198 int file_fat_detectfs(void);
199 int file_fat_ls(const char *dir);
200 int fat_exists(const char *filename);
201 int fat_size(const char *filename, loff_t *size);
202 int file_fat_read_at(const char *filename, loff_t pos, void *buffer,
203 		     loff_t maxsize, loff_t *actread);
204 int file_fat_read(const char *filename, void *buffer, int maxsize);
205 const char *file_getfsname(int idx);
206 int fat_set_blk_dev(struct blk_desc *rbdd, disk_partition_t *info);
207 int fat_register_device(struct blk_desc *dev_desc, int part_no);
208 
209 int file_fat_write(const char *filename, void *buf, loff_t offset, loff_t len,
210 		   loff_t *actwrite);
211 int fat_read_file(const char *filename, void *buf, loff_t offset, loff_t len,
212 		  loff_t *actread);
213 void fat_close(void);
214 #endif /* _FAT_H_ */
215