xref: /openbmc/u-boot/include/fat.h (revision 365475e6)
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 #define MAX_CLUSTSIZE	65536
22 #define DIRENTSPERBLOCK	(mydata->sect_size / sizeof(dir_entry))
23 #define DIRENTSPERCLUST	((mydata->clust_size * mydata->sect_size) / \
24 			 sizeof(dir_entry))
25 
26 #define FATBUFBLOCKS	6
27 #define FATBUFSIZE	(mydata->sect_size * FATBUFBLOCKS)
28 #define FAT12BUFSIZE	((FATBUFSIZE*2)/3)
29 #define FAT16BUFSIZE	(FATBUFSIZE/2)
30 #define FAT32BUFSIZE	(FATBUFSIZE/4)
31 
32 
33 /* Filesystem identifiers */
34 #define FAT12_SIGN	"FAT12   "
35 #define FAT16_SIGN	"FAT16   "
36 #define FAT32_SIGN	"FAT32   "
37 #define SIGNLEN		8
38 
39 /* File attributes */
40 #define ATTR_RO	1
41 #define ATTR_HIDDEN	2
42 #define ATTR_SYS	4
43 #define ATTR_VOLUME	8
44 #define ATTR_DIR	16
45 #define ATTR_ARCH	32
46 
47 #define ATTR_VFAT	(ATTR_RO | ATTR_HIDDEN | ATTR_SYS | ATTR_VOLUME)
48 
49 #define DELETED_FLAG	((char)0xe5) /* Marks deleted files when in name[0] */
50 #define aRING		0x05	     /* Used as special character in name[0] */
51 
52 /*
53  * Indicates that the entry is the last long entry in a set of long
54  * dir entries
55  */
56 #define LAST_LONG_ENTRY_MASK	0x40
57 
58 /* Flags telling whether we should read a file or list a directory */
59 #define LS_NO		0
60 #define LS_YES		1
61 #define LS_DIR		1
62 #define LS_ROOT		2
63 
64 #define ISDIRDELIM(c)	((c) == '/' || (c) == '\\')
65 
66 #define FSTYPE_NONE	(-1)
67 
68 #if defined(__linux__) && defined(__KERNEL__)
69 #define FAT2CPU16	le16_to_cpu
70 #define FAT2CPU32	le32_to_cpu
71 #else
72 #if __LITTLE_ENDIAN
73 #define FAT2CPU16(x)	(x)
74 #define FAT2CPU32(x)	(x)
75 #else
76 #define FAT2CPU16(x)	((((x) & 0x00ff) << 8) | (((x) & 0xff00) >> 8))
77 #define FAT2CPU32(x)	((((x) & 0x000000ff) << 24)  |	\
78 			 (((x) & 0x0000ff00) << 8)  |	\
79 			 (((x) & 0x00ff0000) >> 8)  |	\
80 			 (((x) & 0xff000000) >> 24))
81 #endif
82 #endif
83 
84 #define START(dent)	(FAT2CPU16((dent)->start) \
85 			+ (mydata->fatsize != 32 ? 0 : \
86 			  (FAT2CPU16((dent)->starthi) << 16)))
87 #define CHECK_CLUST(x, fatsize) ((x) <= 1 || \
88 				(x) >= ((fatsize) != 32 ? 0xfff0 : 0xffffff0))
89 
90 typedef struct boot_sector {
91 	__u8	ignored[3];	/* Bootstrap code */
92 	char	system_id[8];	/* Name of fs */
93 	__u8	sector_size[2];	/* Bytes/sector */
94 	__u8	cluster_size;	/* Sectors/cluster */
95 	__u16	reserved;	/* Number of reserved sectors */
96 	__u8	fats;		/* Number of FATs */
97 	__u8	dir_entries[2];	/* Number of root directory entries */
98 	__u8	sectors[2];	/* Number of sectors */
99 	__u8	media;		/* Media code */
100 	__u16	fat_length;	/* Sectors/FAT */
101 	__u16	secs_track;	/* Sectors/track */
102 	__u16	heads;		/* Number of heads */
103 	__u32	hidden;		/* Number of hidden sectors */
104 	__u32	total_sect;	/* Number of sectors (if sectors == 0) */
105 
106 	/* FAT32 only */
107 	__u32	fat32_length;	/* Sectors/FAT */
108 	__u16	flags;		/* Bit 8: fat mirroring, low 4: active fat */
109 	__u8	version[2];	/* Filesystem version */
110 	__u32	root_cluster;	/* First cluster in root directory */
111 	__u16	info_sector;	/* Filesystem info sector */
112 	__u16	backup_boot;	/* Backup boot sector */
113 	__u16	reserved2[6];	/* Unused */
114 } boot_sector;
115 
116 typedef struct volume_info
117 {
118 	__u8 drive_number;	/* BIOS drive number */
119 	__u8 reserved;		/* Unused */
120 	__u8 ext_boot_sign;	/* 0x29 if fields below exist (DOS 3.3+) */
121 	__u8 volume_id[4];	/* Volume ID number */
122 	char volume_label[11];	/* Volume label */
123 	char fs_type[8];	/* Typically FAT12, FAT16, or FAT32 */
124 	/* Boot code comes next, all but 2 bytes to fill up sector */
125 	/* Boot sign comes last, 2 bytes */
126 } volume_info;
127 
128 typedef struct dir_entry {
129 	char	name[8],ext[3];	/* Name and extension */
130 	__u8	attr;		/* Attribute bits */
131 	__u8	lcase;		/* Case for base and extension */
132 	__u8	ctime_ms;	/* Creation time, milliseconds */
133 	__u16	ctime;		/* Creation time */
134 	__u16	cdate;		/* Creation date */
135 	__u16	adate;		/* Last access date */
136 	__u16	starthi;	/* High 16 bits of cluster in FAT32 */
137 	__u16	time,date,start;/* Time, date and first cluster */
138 	__u32	size;		/* File size in bytes */
139 } dir_entry;
140 
141 typedef struct dir_slot {
142 	__u8	id;		/* Sequence number for slot */
143 	__u8	name0_4[10];	/* First 5 characters in name */
144 	__u8	attr;		/* Attribute byte */
145 	__u8	reserved;	/* Unused */
146 	__u8	alias_checksum;/* Checksum for 8.3 alias */
147 	__u8	name5_10[12];	/* 6 more characters in name */
148 	__u16	start;		/* Unused */
149 	__u8	name11_12[4];	/* Last 2 characters in name */
150 } dir_slot;
151 
152 /*
153  * Private filesystem parameters
154  *
155  * Note: FAT buffer has to be 32 bit aligned
156  * (see FAT32 accesses)
157  */
158 typedef struct {
159 	__u8	*fatbuf;	/* Current FAT buffer */
160 	int	fatsize;	/* Size of FAT in bits */
161 	__u32	fatlength;	/* Length of FAT in sectors */
162 	__u16	fat_sect;	/* Starting sector of the FAT */
163 	__u32	rootdir_sect;	/* Start sector of root directory */
164 	__u16	sect_size;	/* Size of sectors in bytes */
165 	__u16	clust_size;	/* Size of clusters in sectors */
166 	int	data_begin;	/* The sector of the first cluster, can be negative */
167 	int	fatbufnum;	/* Used by get_fatent, init to -1 */
168 } fsdata;
169 
170 typedef int	(file_detectfs_func)(void);
171 typedef int	(file_ls_func)(const char *dir);
172 typedef long	(file_read_func)(const char *filename, void *buffer,
173 				 unsigned long maxsize);
174 
175 struct filesystem {
176 	file_detectfs_func	*detect;
177 	file_ls_func		*ls;
178 	file_read_func		*read;
179 	const char		name[12];
180 };
181 
182 /* FAT tables */
183 file_detectfs_func	file_fat_detectfs;
184 file_ls_func		file_fat_ls;
185 file_read_func		file_fat_read;
186 
187 /* Currently this doesn't check if the dir exists or is valid... */
188 int file_cd(const char *path);
189 int file_fat_detectfs(void);
190 int file_fat_ls(const char *dir);
191 int fat_exists(const char *filename);
192 long file_fat_read_at(const char *filename, unsigned long pos, void *buffer,
193 		      unsigned long maxsize);
194 long file_fat_read(const char *filename, void *buffer, unsigned long maxsize);
195 const char *file_getfsname(int idx);
196 int fat_set_blk_dev(block_dev_desc_t *rbdd, disk_partition_t *info);
197 int fat_register_device(block_dev_desc_t *dev_desc, int part_no);
198 
199 int file_fat_write(const char *filename, void *buffer, unsigned long maxsize);
200 int fat_read_file(const char *filename, void *buf, int offset, int len);
201 void fat_close(void);
202 #endif /* _FAT_H_ */
203