diff options
Diffstat (limited to 'arch/mips/bcm47xx/nvram.c')
-rw-r--r-- | arch/mips/bcm47xx/nvram.c | 94 |
1 files changed, 94 insertions, 0 deletions
diff --git a/arch/mips/bcm47xx/nvram.c b/arch/mips/bcm47xx/nvram.c new file mode 100644 index 0000000..06e03b2 --- /dev/null +++ b/arch/mips/bcm47xx/nvram.c @@ -0,0 +1,94 @@ +/* + * 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 1; + + 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 1; +} +EXPORT_SYMBOL(nvram_getenv); |