openwrt/package/nvram/src/nvram.h

124 lines
3.1 KiB
C

/*
* NVRAM variable manipulation
*
* Copyright 2007, Broadcom Corporation
* Copyright 2009, OpenWrt.org
* All Rights Reserved.
*
* THIS SOFTWARE IS OFFERED "AS IS", AND BROADCOM GRANTS NO WARRANTIES OF ANY
* KIND, EXPRESS OR IMPLIED, BY STATUTE, COMMUNICATION OR OTHERWISE. BROADCOM
* SPECIFICALLY DISCLAIMS ANY IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS
* FOR A SPECIFIC PURPOSE OR NONINFRINGEMENT CONCERNING THIS SOFTWARE.
*
*/
#ifndef _nvram_h_
#define _nvram_h_
#include <stdint.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <linux/limits.h>
#include "sdinitvals.h"
struct nvram_header {
uint32_t magic;
uint32_t len;
uint32_t crc_ver_init; /* 0:7 crc, 8:15 ver, 16:31 sdram_init */
uint32_t config_refresh; /* 0:15 sdram_config, 16:31 sdram_refresh */
uint32_t config_ncdl; /* ncdl values for memc */
} __attribute__((__packed__));
struct nvram_tuple {
char *name;
char *value;
struct nvram_tuple *next;
};
struct nvram_handle {
int fd;
char *mmap;
unsigned long length;
struct nvram_tuple *nvram_hash[257];
struct nvram_tuple *nvram_dead;
};
typedef struct nvram_handle nvram_handle_t;
typedef struct nvram_header nvram_header_t;
typedef struct nvram_tuple nvram_tuple_t;
/* Get nvram header. */
nvram_header_t * nvram_header(nvram_handle_t *h);
/* Set the value of an NVRAM variable */
int nvram_set(nvram_handle_t *h, const char *name, const char *value);
/* Get the value of an NVRAM variable. */
char * nvram_get(nvram_handle_t *h, const char *name);
/* Unset the value of an NVRAM variable. */
int nvram_unset(nvram_handle_t *h, const char *name);
/* Get all NVRAM variables. */
nvram_tuple_t * nvram_getall(nvram_handle_t *h);
/* Regenerate NVRAM. */
int nvram_commit(nvram_handle_t *h);
/* Open NVRAM and obtain a handle. */
nvram_handle_t * nvram_open(const char *file, int rdonly);
/* Close NVRAM and free memory. */
int nvram_close(nvram_handle_t *h);
/* Get the value of an NVRAM variable in a safe way, use "" instead of NULL. */
#define nvram_safe_get(h, name) (nvram_get(h, name) ? : "")
/* Computes a crc8 over the input data. */
uint8_t hndcrc8 (uint8_t * pdata, uint32_t nbytes, uint8_t crc);
/* Returns the crc value of the nvram. */
uint8_t nvram_calc_crc(nvram_header_t * nvh);
/* Determine NVRAM device node. */
char * nvram_find_mtd(void);
/* Copy NVRAM contents to staging file. */
int nvram_to_staging(void);
/* Copy staging file to NVRAM device. */
int staging_to_nvram(void);
/* Check NVRAM staging file. */
char * nvram_find_staging(void);
/* Staging file for NVRAM */
#define NVRAM_STAGING "/tmp/.nvram"
#define NVRAM_RO 1
#define NVRAM_RW 0
/* Helper macros */
#define NVRAM_ARRAYSIZE(a) sizeof(a)/sizeof(a[0])
#define NVRAM_ROUNDUP(x, y) ((((x)+((y)-1))/(y))*(y))
/* NVRAM constants */
#define NVRAM_SPACE 0x8000
#define NVRAM_START(x) x - NVRAM_SPACE
#define NVRAM_MAGIC 0x48534C46 /* 'FLSH' */
#define NVRAM_VERSION 1
#define NVRAM_CRC_START_POSITION 9 /* magic, len, crc8 to be skipped */
#endif /* _nvram_h_ */