-
Notifications
You must be signed in to change notification settings - Fork 4
/
Copy pathcramfs_fs.h
165 lines (145 loc) · 5.17 KB
/
cramfs_fs.h
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
#ifndef __CRAMFS_FS_H
#define __CRAMFS_FS_H
#ifdef __KERNEL__
#include <asm/byteorder.h>
/* Uncompression interfaces to the underlying compression lib (none, zlib,
* other) */
int cramfs_uncompress_block(void *dst, int dstlen, void *src, int srclen,
int comp_method);
int cramfs_uncompress_init(int comp_method);
int cramfs_uncompress_exit(int comp_method);
#else /* not __KERNEL__ */
//#include <rg_config.h>
#include <byteswap.h>
#include <endian.h>
typedef unsigned char u8;
typedef unsigned short u16;
typedef unsigned int u32;
#endif /* not __KERNEL__ */
#define CRAMFS_MAGIC 0x28cd3d45 /* some random number */
#define CRAMFS_SIGNATURE "Compressed ROMFS"
/*
* Width of various bitfields in struct cramfs_inode.
* Primarily used to generate warnings in mkcramfs.
*/
#define CRAMFS_MODE_WIDTH 16
#define CRAMFS_UID_WIDTH 16
#define CRAMFS_GID_WIDTH 8
#define CRAMFS_NAMELEN_WIDTH 6
#define CRAMFS_OFFSET_WIDTH 26
/*
* Since inode.namelen is a unsigned 6-bit number, the maximum cramfs
* path length is 63 << 2 = 252.
*/
#define CRAMFS_MAXPATHLEN (((1 << CRAMFS_NAMELEN_WIDTH) - 1) << 2)
#define CRAMFS_SIZE_WIDTH 24
/*
* Reasonably terse representation of the inode data.
*/
struct cramfs_inode {
u32 mode:CRAMFS_MODE_WIDTH, uid:CRAMFS_UID_WIDTH;
/* SIZE for device files is i_rdev */
u32 size:CRAMFS_SIZE_WIDTH, gid:CRAMFS_GID_WIDTH;
/* NAMELEN is the length of the file name, divided by 4 and
rounded up. (cramfs doesn't support hard links.) */
/* OFFSET: For symlinks and non-empty regular files, this
contains the offset (divided by 4) of the file data in
compressed form (starting with an array of block pointers;
see README). For non-empty directories it is the offset
(divided by 4) of the inode of the first file in that
directory. For anything else, offset is zero. */
u32 namelen:CRAMFS_NAMELEN_WIDTH, offset:CRAMFS_OFFSET_WIDTH;
};
struct cramfs_info {
u32 crc;
u32 edition;
u32 blocks;
u32 files;
};
/*
* Superblock information at the beginning of the FS.
*/
struct cramfs_super {
u32 magic; /* 0x28cd3d45 - random number */
u32 size; /* length in bytes */
u32 flags; /* feature flags */
u32 future; /* reserved for future use */
u8 signature[16]; /* "Compressed ROMFS" */
struct cramfs_info fsid; /* unique filesystem info */
u8 name[16]; /* user-defined name */
struct cramfs_inode root; /* root inode data */
};
/*
* Feature flags
*
* 0x00000000 - 0x000000ff: features that work for all past kernels
* 0x00000100 - 0xffffffff: features that don't work for past kernels
*/
#define CRAMFS_FLAG_FSID_VERSION_2 0x00000001 /* fsid version #2 */
#define CRAMFS_FLAG_SORTED_DIRS 0x00000002 /* sorted dirs */
#define CRAMFS_FLAG_HOLES 0x00000100 /* support for holes */
#define CRAMFS_FLAG_WRONG_SIGNATURE 0x00000200 /* reserved */
#define CRAMFS_FLAG_SHIFTED_ROOT_OFFSET 0x00000400 /* shifted root fs */
#define CRAMFS_FLAG_BLKSZ_MASK 0x00003800 /* Block size mask */
#define CRAMFS_FLAG_COMP_METHOD_MASK 0x0000C000 /* Compression method
* mask */
#define CRAMFS_FLAG_BLKSZ_SHIFT 11
#define CRAMFS_FLAG_COMP_METHOD_SHIFT 14
#define CRAMFS_FLAG_COMP_METHOD_NONE 0
#define CRAMFS_FLAG_COMP_METHOD_GZIP 1
#define CRAMFS_FLAG_COMP_METHOD_LZMA 2
/*
* Valid values in super.flags. Currently we refuse to mount
* if (flags & ~CRAMFS_SUPPORTED_FLAGS). Maybe that should be
* changed to test super.future instead.
*/
#define CRAMFS_SUPPORTED_FLAGS ( 0x000000ff \
| CRAMFS_FLAG_HOLES \
| CRAMFS_FLAG_WRONG_SIGNATURE \
| CRAMFS_FLAG_SHIFTED_ROOT_OFFSET \
| CRAMFS_FLAG_BLKSZ_MASK \
| CRAMFS_FLAG_COMP_METHOD_MASK)
/*
* Since cramfs is little-endian, provide macros to swab the bitfields.
*/
#ifndef __BYTE_ORDER
#if defined(__LITTLE_ENDIAN) && !defined(__BIG_ENDIAN)
#define __BYTE_ORDER __LITTLE_ENDIAN
#elif defined(__BIG_ENDIAN) && !defined(__LITTLE_ENDIAN)
#define __BYTE_ORDER __BIG_ENDIAN
#else
#error "unable to define __BYTE_ORDER"
#endif
#endif /* not __BYTE_ORDER */
#if __BYTE_ORDER == __LITTLE_ENDIAN
#define CRAMFS_16(x) (x)
#define CRAMFS_24(x) (x)
#define CRAMFS_32(x) (x)
#define CRAMFS_GET_NAMELEN(x) ((x)->namelen)
#define CRAMFS_GET_SIZE(x) ((x)->size)
#define CRAMFS_GET_OFFSET(x) ((x)->offset)
#define CRAMFS_SET_OFFSET(x,y) ((x)->offset = (y))
#define CRAMFS_SET_NAMELEN(x,y) ((x)->namelen = (y))
#elif __BYTE_ORDER == __BIG_ENDIAN
#ifdef __KERNEL__
#define CRAMFS_16(x) swab16(x)
#define CRAMFS_24(x) ((swab32(x)) >> 8)
#define CRAMFS_32(x) swab32(x)
#else /* not __KERNEL__ */
#define CRAMFS_16(x) bswap_16(x)
#define CRAMFS_24(x) ((bswap_32(x)) >> 8)
#define CRAMFS_32(x) bswap_32(x)
#endif /* not __KERNEL__ */
#define CRAMFS_GET_NAMELEN(x) (((u8*)(x))[8] & 0x3f)
#define CRAMFS_GET_OFFSET(x) ((CRAMFS_24(((u32*)(x))[2] & 0xffffff) << 2) |\
((((u32*)(x))[2] & 0xc0000000) >> 30))
#define CRAMFS_GET_SIZE(x) ((CRAMFS_32(((u32*)(x))[1] & 0xffffff00)))
#define CRAMFS_SET_NAMELEN(x,y) (((u8*)(x))[8] = (((0x3f & (y))) | \
(0xc0 & ((u8*)(x))[8])))
#define CRAMFS_SET_OFFSET(x,y) (((u32*)(x))[2] = (((y) & 3) << 30) | \
CRAMFS_24((((y) & 0x03ffffff) >> 2)) | \
(((u32)(((u8*)(x))[8] & 0x3f)) << 24))
#else
#error "__BYTE_ORDER must be __LITTLE_ENDIAN or __BIG_ENDIAN"
#endif
#endif /* not __CRAMFS_FS_H */