+++ /dev/null
-/*
- * CFE environment variable access
- *
- * Copyright 2001-2003, Broadcom Corporation
- * Copyright 2006, Felix Fietkau <nbd@openwrt.org>
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License as published by the
- * Free Software Foundation; either version 2 of the License, or (at your
- * option) any later version.
- */
-
-#include <linux/init.h>
-#include <linux/module.h>
-#include <linux/kernel.h>
-#include <linux/string.h>
-#include <asm/io.h>
-#include <asm/uaccess.h>
-
-#define NVRAM_SIZE (0x1ff0)
-static char _nvdata[NVRAM_SIZE];
-static char _valuestr[256];
-
-/*
- * TLV types. These codes are used in the "type-length-value"
- * encoding of the items stored in the NVRAM device (flash or EEPROM)
- *
- * The layout of the flash/nvram is as follows:
- *
- * <type> <length> <data ...> <type> <length> <data ...> <type_end>
- *
- * The type code of "ENV_TLV_TYPE_END" marks the end of the list.
- * The "length" field marks the length of the data section, not
- * including the type and length fields.
- *
- * Environment variables are stored as follows:
- *
- * <type_env> <length> <flags> <name> = <value>
- *
- * If bit 0 (low bit) is set, the length is an 8-bit value.
- * If bit 0 (low bit) is clear, the length is a 16-bit value
- *
- * Bit 7 set indicates "user" TLVs. In this case, bit 0 still
- * indicates the size of the length field.
- *
- * Flags are from the constants below:
- *
- */
-#define ENV_LENGTH_16BITS 0x00 /* for low bit */
-#define ENV_LENGTH_8BITS 0x01
-
-#define ENV_TYPE_USER 0x80
-
-#define ENV_CODE_SYS(n,l) (((n)<<1)|(l))
-#define ENV_CODE_USER(n,l) ((((n)<<1)|(l)) | ENV_TYPE_USER)
-
-/*
- * The actual TLV types we support
- */
-
-#define ENV_TLV_TYPE_END 0x00
-#define ENV_TLV_TYPE_ENV ENV_CODE_SYS(0,ENV_LENGTH_8BITS)
-
-/*
- * Environment variable flags
- */
-
-#define ENV_FLG_NORMAL 0x00 /* normal read/write */
-#define ENV_FLG_BUILTIN 0x01 /* builtin - not stored in flash */
-#define ENV_FLG_READONLY 0x02 /* read-only - cannot be changed */
-
-#define ENV_FLG_MASK 0xFF /* mask of attributes we keep */
-#define ENV_FLG_ADMIN 0x100 /* lets us internally override permissions */
-
-
-/* *********************************************************************
- * _nvram_read(buffer,offset,length)
- *
- * Read data from the NVRAM device
- *
- * Input parameters:
- * buffer - destination buffer
- * offset - offset of data to read
- * length - number of bytes to read
- *
- * Return value:
- * number of bytes read, or <0 if error occured
- ********************************************************************* */
-static int
-_nvram_read(unsigned char *nv_buf, unsigned char *buffer, int offset, int length)
-{
- int i;
- if (offset > NVRAM_SIZE)
- return -1;
-
- for ( i = 0; i < length; i++) {
- buffer[i] = ((volatile unsigned char*)nv_buf)[offset + i];
- }
- return length;
-}
-
-
-static char*
-_strnchr(const char *dest,int c,size_t cnt)
-{
- while (*dest && (cnt > 0)) {
- if (*dest == c) return (char *) dest;
- dest++;
- cnt--;
- }
- return NULL;
-}
-
-
-
-/*
- * Core support API: Externally visible.
- */
-
-/*
- * Get the value of an NVRAM variable
- * @param name name of variable to get
- * @return value of variable or NULL if undefined
- */
-
-char*
-cfe_env_get(unsigned char *nv_buf, char* name)
-{
- int size;
- unsigned char *buffer;
- unsigned char *ptr;
- unsigned char *envval;
- unsigned int reclen;
- unsigned int rectype;
- int offset;
- int flg;
-
- if (!strcmp(name, "nvram_type"))
- return "cfe";
-
- size = NVRAM_SIZE;
- buffer = &_nvdata[0];
-
- ptr = buffer;
- offset = 0;
-
- /* Read the record type and length */
- if (_nvram_read(nv_buf, ptr,offset,1) != 1) {
- goto error;
- }
-
- while ((*ptr != ENV_TLV_TYPE_END) && (size > 1)) {
-
- /* Adjust pointer for TLV type */
- rectype = *(ptr);
- offset++;
- size--;
-
- /*
- * Read the length. It can be either 1 or 2 bytes
- * depending on the code
- */
- if (rectype & ENV_LENGTH_8BITS) {
- /* Read the record type and length - 8 bits */
- if (_nvram_read(nv_buf, ptr,offset,1) != 1) {
- goto error;
- }
- reclen = *(ptr);
- size--;
- offset++;
- }
- else {
- /* Read the record type and length - 16 bits, MSB first */
- if (_nvram_read(nv_buf, ptr,offset,2) != 2) {
- goto error;
- }
- reclen = (((unsigned int) *(ptr)) << 8) + (unsigned int) *(ptr+1);
- size -= 2;
- offset += 2;
- }
-
- if (reclen > size)
- break; /* should not happen, bad NVRAM */
-
- switch (rectype) {
- case ENV_TLV_TYPE_ENV:
- /* Read the TLV data */
- if (_nvram_read(nv_buf, ptr,offset,reclen) != reclen)
- goto error;
- flg = *ptr++;
- envval = (unsigned char *) _strnchr(ptr,'=',(reclen-1));
- if (envval) {
- *envval++ = '\0';
- memcpy(_valuestr,envval,(reclen-1)-(envval-ptr));
- _valuestr[(reclen-1)-(envval-ptr)] = '\0';
-#if 0
- printk(KERN_INFO "NVRAM:%s=%s\n", ptr, _valuestr);
-#endif
- if(!strcmp(ptr, name)){
- return _valuestr;
- }
- if((strlen(ptr) > 1) && !strcmp(&ptr[1], name))
- return _valuestr;
- }
- break;
-
- default:
- /* Unknown TLV type, skip it. */
- break;
- }
-
- /*
- * Advance to next TLV
- */
-
- size -= (int)reclen;
- offset += reclen;
-
- /* Read the next record type */
- ptr = buffer;
- if (_nvram_read(nv_buf, ptr,offset,1) != 1)
- goto error;
- }
-
-error:
- return NULL;
-
-}
-
projects / openwrt / svn-archive / archive.git / blobdiff