linux/arch/mips/bcm47xx/nvram.c

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/*
* BCM947xx nvram variable access
*
* Copyright (C) 2005 Broadcom Corporation
* Copyright (C) 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/types.h>
#include <linux/module.h>
#include <linux/ssb/ssb.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <asm/addrspace.h>
#include <asm/mach-bcm47xx/nvram.h>
#include <asm/mach-bcm47xx/bcm47xx.h>
static char nvram_buf[NVRAM_SPACE];
/* Probe for NVRAM header */
static void __init early_nvram_init(void)
{
struct ssb_mipscore *mcore = &ssb_bcm47xx.mipscore;
struct nvram_header *header;
int i;
u32 base, lim, off;
u32 *src, *dst;
base = mcore->flash_window;
lim = mcore->flash_window_size;
off = FLASH_MIN;
while (off <= lim) {
/* Windowed flash access */
header = (struct nvram_header *)
KSEG1ADDR(base + off - NVRAM_SPACE);
if (header->magic == NVRAM_HEADER)
goto found;
off <<= 1;
}
/* Try embedded NVRAM at 4 KB and 1 KB as last resorts */
header = (struct nvram_header *) KSEG1ADDR(base + 4096);
if (header->magic == NVRAM_HEADER)
goto found;
header = (struct nvram_header *) KSEG1ADDR(base + 1024);
if (header->magic == NVRAM_HEADER)
goto found;
return;
found:
src = (u32 *) header;
dst = (u32 *) nvram_buf;
for (i = 0; i < sizeof(struct nvram_header); i += 4)
*dst++ = *src++;
for (; i < header->len && i < NVRAM_SPACE; i += 4)
*dst++ = le32_to_cpu(*src++);
}
int nvram_getenv(char *name, char *val, size_t val_len)
{
char *var, *value, *end, *eq;
if (!name)
return NVRAM_ERR_INV_PARAM;
if (!nvram_buf[0])
early_nvram_init();
/* Look for name=value and return value */
var = &nvram_buf[sizeof(struct nvram_header)];
end = nvram_buf + sizeof(nvram_buf) - 2;
end[0] = end[1] = '\0';
for (; *var; var = value + strlen(value) + 1) {
eq = strchr(var, '=');
if (!eq)
break;
value = eq + 1;
if ((eq - var) == strlen(name) &&
strncmp(var, name, (eq - var)) == 0) {
snprintf(val, val_len, "%s", value);
return 0;
}
}
return NVRAM_ERR_ENVNOTFOUND;
}
EXPORT_SYMBOL(nvram_getenv);