| 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 long length; |
| 50 | struct nvram_tuple *nvram_hash[257]; |
| 51 | struct nvram_tuple *nvram_dead; |
| 52 | }; |
| 53 | |
| 54 | typedef struct nvram_handle nvram_handle_t; |
| 55 | typedef struct nvram_header nvram_header_t; |
| 56 | typedef struct nvram_tuple nvram_tuple_t; |
| 57 | |
| 58 | |
| 59 | /* Get nvram header. */ |
| 60 | nvram_header_t * nvram_header(nvram_handle_t *h); |
| 61 | |
| 62 | /* Set the value of an NVRAM variable */ |
| 63 | int nvram_set(nvram_handle_t *h, const char *name, const char *value); |
| 64 | |
| 65 | /* Get the value of an NVRAM variable. */ |
| 66 | char * nvram_get(nvram_handle_t *h, const char *name); |
| 67 | |
| 68 | /* Unset the value of an NVRAM variable. */ |
| 69 | int nvram_unset(nvram_handle_t *h, const char *name); |
| 70 | |
| 71 | /* Get all NVRAM variables. */ |
| 72 | nvram_tuple_t * nvram_getall(nvram_handle_t *h); |
| 73 | |
| 74 | /* Regenerate NVRAM. */ |
| 75 | int nvram_commit(nvram_handle_t *h); |
| 76 | |
| 77 | /* Open NVRAM and obtain a handle. */ |
| 78 | nvram_handle_t * nvram_open(const char *file, int rdonly); |
| 79 | |
| 80 | /* Close NVRAM and free memory. */ |
| 81 | int nvram_close(nvram_handle_t *h); |
| 82 | |
| 83 | /* Get the value of an NVRAM variable in a safe way, use "" instead of NULL. */ |
| 84 | #define nvram_safe_get(h, name) (nvram_get(h, name) ? : "") |
| 85 | |
| 86 | /* Computes a crc8 over the input data. */ |
| 87 | uint8_t hndcrc8 (uint8_t * pdata, uint32_t nbytes, uint8_t crc); |
| 88 | |
| 89 | /* Returns the crc value of the nvram. */ |
| 90 | uint8_t nvram_calc_crc(nvram_header_t * nvh); |
| 91 | |
| 92 | /* Determine NVRAM device node. */ |
| 93 | char * nvram_find_mtd(void); |
| 94 | |
| 95 | /* Copy NVRAM contents to staging file. */ |
| 96 | int nvram_to_staging(void); |
| 97 | |
| 98 | /* Copy staging file to NVRAM device. */ |
| 99 | int staging_to_nvram(void); |
| 100 | |
| 101 | /* Check NVRAM staging file. */ |
| 102 | char * nvram_find_staging(void); |
| 103 | |
| 104 | |
| 105 | /* Staging file for NVRAM */ |
| 106 | #define NVRAM_STAGING "/tmp/.nvram" |
| 107 | #define NVRAM_RO 1 |
| 108 | #define NVRAM_RW 0 |
| 109 | |
| 110 | /* Helper macros */ |
| 111 | #define NVRAM_ARRAYSIZE(a) sizeof(a)/sizeof(a[0]) |
| 112 | #define NVRAM_ROUNDUP(x, y) ((((x)+((y)-1))/(y))*(y)) |
| 113 | |
| 114 | /* NVRAM constants */ |
| 115 | #define NVRAM_SPACE 0x8000 |
| 116 | #define NVRAM_START(x) x - NVRAM_SPACE |
| 117 | #define NVRAM_MAGIC 0x48534C46 /* 'FLSH' */ |
| 118 | #define NVRAM_VERSION 1 |
| 119 | |
| 120 | #define NVRAM_CRC_START_POSITION 9 /* magic, len, crc8 to be skipped */ |
| 121 | |
| 122 | |
| 123 | #endif /* _nvram_h_ */ |
| 124 | |
