215d816327c7e35adaff83f75bd253bf8d47fec8
[openwrt/openwrt.git] / package / utils / nvram / src / nvram.h
1 /*
2 * NVRAM variable manipulation
3 *
4 * Copyright 2007, Broadcom Corporation
5 * Copyright 2009, OpenWrt.org
6 * All Rights Reserved.
7 *
8 * THIS SOFTWARE IS OFFERED "AS IS", AND BROADCOM GRANTS NO WARRANTIES OF ANY
9 * KIND, EXPRESS OR IMPLIED, BY STATUTE, COMMUNICATION OR OTHERWISE. BROADCOM
10 * SPECIFICALLY DISCLAIMS ANY IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS
11 * FOR A SPECIFIC PURPOSE OR NONINFRINGEMENT CONCERNING THIS SOFTWARE.
12 *
13 */
14
15 #ifndef _nvram_h_
16 #define _nvram_h_
17
18 #include <stdint.h>
19 #include <string.h>
20 #include <stdio.h>
21 #include <stdlib.h>
22 #include <fcntl.h>
23 #include <unistd.h>
24 #include <errno.h>
25 #include <sys/mman.h>
26 #include <sys/stat.h>
27 #include <linux/limits.h>
28
29 #include "sdinitvals.h"
30
31
32 struct nvram_header {
33 uint32_t magic;
34 uint32_t len;
35 uint32_t crc_ver_init; /* 0:7 crc, 8:15 ver, 16:31 sdram_init */
36 uint32_t config_refresh; /* 0:15 sdram_config, 16:31 sdram_refresh */
37 uint32_t config_ncdl; /* ncdl values for memc */
38 } __attribute__((__packed__));
39
40 struct nvram_tuple {
41 char *name;
42 char *value;
43 struct nvram_tuple *next;
44 };
45
46 struct nvram_handle {
47 int fd;
48 char *mmap;
49 unsigned int length;
50 unsigned int offset;
51 struct nvram_tuple *nvram_hash[257];
52 struct nvram_tuple *nvram_dead;
53 };
54
55 typedef struct nvram_handle nvram_handle_t;
56 typedef struct nvram_header nvram_header_t;
57 typedef struct nvram_tuple nvram_tuple_t;
58
59
60 /* Get nvram header. */
61 nvram_header_t * nvram_header(nvram_handle_t *h);
62
63 /* Set the value of an NVRAM variable */
64 int nvram_set(nvram_handle_t *h, const char *name, const char *value);
65
66 /* Get the value of an NVRAM variable. */
67 char * nvram_get(nvram_handle_t *h, const char *name);
68
69 /* Unset the value of an NVRAM variable. */
70 int nvram_unset(nvram_handle_t *h, const char *name);
71
72 /* Get all NVRAM variables. */
73 nvram_tuple_t * nvram_getall(nvram_handle_t *h);
74
75 /* Regenerate NVRAM. */
76 int nvram_commit(nvram_handle_t *h);
77
78 /* Open NVRAM and obtain a handle. */
79 nvram_handle_t * nvram_open(const char *file, int rdonly);
80
81 /* Close NVRAM and free memory. */
82 int nvram_close(nvram_handle_t *h);
83
84 /* Get the value of an NVRAM variable in a safe way, use "" instead of NULL. */
85 #define nvram_safe_get(h, name) (nvram_get(h, name) ? : "")
86
87 /* Computes a crc8 over the input data. */
88 uint8_t hndcrc8 (uint8_t * pdata, uint32_t nbytes, uint8_t crc);
89
90 /* Returns the crc value of the nvram. */
91 uint8_t nvram_calc_crc(nvram_header_t * nvh);
92
93 /* Determine NVRAM device node. */
94 char * nvram_find_mtd(void);
95
96 /* Copy NVRAM contents to staging file. */
97 int nvram_to_staging(void);
98
99 /* Copy staging file to NVRAM device. */
100 int staging_to_nvram(void);
101
102 /* Check NVRAM staging file. */
103 char * nvram_find_staging(void);
104
105
106 /* Staging file for NVRAM */
107 #define NVRAM_STAGING "/tmp/.nvram"
108 #define NVRAM_RO 1
109 #define NVRAM_RW 0
110
111 /* Helper macros */
112 #define NVRAM_ARRAYSIZE(a) sizeof(a)/sizeof(a[0])
113 #define NVRAM_ROUNDUP(x, y) ((((x)+((y)-1))/(y))*(y))
114
115 /* NVRAM constants */
116 #define NVRAM_MIN_SPACE 0x8000
117 #define NVRAM_SPACE 0x10000
118 #define NVRAM_MAGIC 0x48534C46 /* 'FLSH' */
119 #define NVRAM_VERSION 1
120
121 #define NVRAM_CRC_START_POSITION 9 /* magic, len, crc8 to be skipped */
122
123
124 #endif /* _nvram_h_ */