xref: /openbmc/u-boot/include/fat.h (revision 274bced8)
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 /* Maximum number of entry for long file name according to spec */
37 #define MAX_LFN_SLOT	20
38 
39 /* Filesystem identifiers */
40 #define FAT12_SIGN	"FAT12   "
41 #define FAT16_SIGN	"FAT16   "
42 #define FAT32_SIGN	"FAT32   "
43 #define SIGNLEN		8
44 
45 /* File attributes */
46 #define ATTR_RO	1
47 #define ATTR_HIDDEN	2
48 #define ATTR_SYS	4
49 #define ATTR_VOLUME	8
50 #define ATTR_DIR	16
51 #define ATTR_ARCH	32
52 
53 #define ATTR_VFAT	(ATTR_RO | ATTR_HIDDEN | ATTR_SYS | ATTR_VOLUME)
54 
55 #define DELETED_FLAG	((char)0xe5) /* Marks deleted files when in name[0] */
56 #define aRING		0x05	     /* Used as special character in name[0] */
57 
58 /*
59  * Indicates that the entry is the last long entry in a set of long
60  * dir entries
61  */
62 #define LAST_LONG_ENTRY_MASK	0x40
63 
64 /* Flags telling whether we should read a file or list a directory */
65 #define LS_NO		0
66 #define LS_YES		1
67 #define LS_DIR		1
68 #define LS_ROOT		2
69 
70 #define ISDIRDELIM(c)	((c) == '/' || (c) == '\\')
71 
72 #define FSTYPE_NONE	(-1)
73 
74 #if defined(__linux__) && defined(__KERNEL__)
75 #define FAT2CPU16	le16_to_cpu
76 #define FAT2CPU32	le32_to_cpu
77 #else
78 #if __LITTLE_ENDIAN
79 #define FAT2CPU16(x)	(x)
80 #define FAT2CPU32(x)	(x)
81 #else
82 #define FAT2CPU16(x)	((((x) & 0x00ff) << 8) | (((x) & 0xff00) >> 8))
83 #define FAT2CPU32(x)	((((x) & 0x000000ff) << 24)  |	\
84 			 (((x) & 0x0000ff00) << 8)  |	\
85 			 (((x) & 0x00ff0000) >> 8)  |	\
86 			 (((x) & 0xff000000) >> 24))
87 #endif
88 #endif
89 
90 #define START(dent)	(FAT2CPU16((dent)->start) \
91 			+ (mydata->fatsize != 32 ? 0 : \
92 			  (FAT2CPU16((dent)->starthi) << 16)))
93 #define IS_LAST_CLUST(x, fatsize) ((x) >= ((fatsize) != 32 ? \
94 					((fatsize) != 16 ? 0xff8 : 0xfff8) : \
95 					0xffffff8))
96 #define CHECK_CLUST(x, fatsize) ((x) <= 1 || \
97 				(x) >= ((fatsize) != 32 ? \
98 					((fatsize) != 16 ? 0xff0 : 0xfff0) : \
99 					0xffffff0))
100 
101 typedef struct boot_sector {
102 	__u8	ignored[3];	/* Bootstrap code */
103 	char	system_id[8];	/* Name of fs */
104 	__u8	sector_size[2];	/* Bytes/sector */
105 	__u8	cluster_size;	/* Sectors/cluster */
106 	__u16	reserved;	/* Number of reserved sectors */
107 	__u8	fats;		/* Number of FATs */
108 	__u8	dir_entries[2];	/* Number of root directory entries */
109 	__u8	sectors[2];	/* Number of sectors */
110 	__u8	media;		/* Media code */
111 	__u16	fat_length;	/* Sectors/FAT */
112 	__u16	secs_track;	/* Sectors/track */
113 	__u16	heads;		/* Number of heads */
114 	__u32	hidden;		/* Number of hidden sectors */
115 	__u32	total_sect;	/* Number of sectors (if sectors == 0) */
116 
117 	/* FAT32 only */
118 	__u32	fat32_length;	/* Sectors/FAT */
119 	__u16	flags;		/* Bit 8: fat mirroring, low 4: active fat */
120 	__u8	version[2];	/* Filesystem version */
121 	__u32	root_cluster;	/* First cluster in root directory */
122 	__u16	info_sector;	/* Filesystem info sector */
123 	__u16	backup_boot;	/* Backup boot sector */
124 	__u16	reserved2[6];	/* Unused */
125 } boot_sector;
126 
127 typedef struct volume_info
128 {
129 	__u8 drive_number;	/* BIOS drive number */
130 	__u8 reserved;		/* Unused */
131 	__u8 ext_boot_sign;	/* 0x29 if fields below exist (DOS 3.3+) */
132 	__u8 volume_id[4];	/* Volume ID number */
133 	char volume_label[11];	/* Volume label */
134 	char fs_type[8];	/* Typically FAT12, FAT16, or FAT32 */
135 	/* Boot code comes next, all but 2 bytes to fill up sector */
136 	/* Boot sign comes last, 2 bytes */
137 } volume_info;
138 
139 typedef struct dir_entry {
140 	char	name[8],ext[3];	/* Name and extension */
141 	__u8	attr;		/* Attribute bits */
142 	__u8	lcase;		/* Case for base and extension */
143 	__u8	ctime_ms;	/* Creation time, milliseconds */
144 	__u16	ctime;		/* Creation time */
145 	__u16	cdate;		/* Creation date */
146 	__u16	adate;		/* Last access date */
147 	__u16	starthi;	/* High 16 bits of cluster in FAT32 */
148 	__u16	time,date,start;/* Time, date and first cluster */
149 	__u32	size;		/* File size in bytes */
150 } dir_entry;
151 
152 typedef struct dir_slot {
153 	__u8	id;		/* Sequence number for slot */
154 	__u8	name0_4[10];	/* First 5 characters in name */
155 	__u8	attr;		/* Attribute byte */
156 	__u8	reserved;	/* Unused */
157 	__u8	alias_checksum;/* Checksum for 8.3 alias */
158 	__u8	name5_10[12];	/* 6 more characters in name */
159 	__u16	start;		/* Unused */
160 	__u8	name11_12[4];	/* Last 2 characters in name */
161 } dir_slot;
162 
163 /*
164  * Private filesystem parameters
165  *
166  * Note: FAT buffer has to be 32 bit aligned
167  * (see FAT32 accesses)
168  */
169 typedef struct {
170 	__u8	*fatbuf;	/* Current FAT buffer */
171 	int	fatsize;	/* Size of FAT in bits */
172 	__u32	fatlength;	/* Length of FAT in sectors */
173 	__u16	fat_sect;	/* Starting sector of the FAT */
174 	__u8	fat_dirty;      /* Set if fatbuf has been modified */
175 	__u32	rootdir_sect;	/* Start sector of root directory */
176 	__u16	sect_size;	/* Size of sectors in bytes */
177 	__u16	clust_size;	/* Size of clusters in sectors */
178 	int	data_begin;	/* The sector of the first cluster, can be negative */
179 	int	fatbufnum;	/* Used by get_fatent, init to -1 */
180 } fsdata;
181 
182 typedef int	(file_detectfs_func)(void);
183 typedef int	(file_ls_func)(const char *dir);
184 typedef int	(file_read_func)(const char *filename, void *buffer,
185 				 int maxsize);
186 
187 struct filesystem {
188 	file_detectfs_func	*detect;
189 	file_ls_func		*ls;
190 	file_read_func		*read;
191 	const char		name[12];
192 };
193 
194 /* FAT tables */
195 file_detectfs_func	file_fat_detectfs;
196 file_ls_func		file_fat_ls;
197 file_read_func		file_fat_read;
198 
199 /* Currently this doesn't check if the dir exists or is valid... */
200 int file_cd(const char *path);
201 int file_fat_detectfs(void);
202 int file_fat_ls(const char *dir);
203 int fat_exists(const char *filename);
204 int fat_size(const char *filename, loff_t *size);
205 int file_fat_read_at(const char *filename, loff_t pos, void *buffer,
206 		     loff_t maxsize, loff_t *actread);
207 int file_fat_read(const char *filename, void *buffer, int maxsize);
208 const char *file_getfsname(int idx);
209 int fat_set_blk_dev(struct blk_desc *rbdd, disk_partition_t *info);
210 int fat_register_device(struct blk_desc *dev_desc, int part_no);
211 
212 int file_fat_write(const char *filename, void *buf, loff_t offset, loff_t len,
213 		   loff_t *actwrite);
214 int fat_read_file(const char *filename, void *buf, loff_t offset, loff_t len,
215 		  loff_t *actread);
216 void fat_close(void);
217 #endif /* _FAT_H_ */
218