Add unvram, a nvram manipulation tool suitable for brcm-2.4 and bcm47xx platforms

SVN-Revision: 15426

7 files changed, 1051 insertions, 0 deletions

diff --git a/package/unvram/Makefile b/package/unvram/Makefile
new file mode 100644
index 0000000..5529bdf
--- /dev/null
+++ b/package/unvram/Makefile
@@ -0,0 +1,50 @@
+#
+# Copyright (C) 2009 Jo-Philipp Wich <xm@subsignal.org>
+#
+# This is free software, licensed under the GNU General Public License v2.
+# See /LICENSE for more information.
+#
+
+include $(TOPDIR)/rules.mk
+
+PKG_NAME:=unvram
+PKG_RELEASE:=1
+
+PKG_BUILD_DIR := $(BUILD_DIR)/$(PKG_NAME)
+
+include $(INCLUDE_DIR)/package.mk
+
+define Package/unvram
+  SECTION:=utils
+  CATEGORY:=Base system
+  TITLE:=Userspace port of the Broadcom NVRAM manipulation tool
+endef
+
+define Package/unvram/description
+ This package contains an utility to manipulate NVRAM on Broadcom based devices.
+ It works on both brcm-2.4 and bcm47xx (Linux 2.6) without using the kernel api.
+endef
+
+define Build/Prepare
+	mkdir -p $(PKG_BUILD_DIR)
+	$(CP) ./src/* $(PKG_BUILD_DIR)/
+endef
+
+define Build/Configure
+endef
+
+define Build/Compile
+	$(MAKE) -C $(PKG_BUILD_DIR) \
+		CC="$(TARGET_CC)" \
+		CFLAGS="$(TARGET_CFLAGS) -Wall" \
+		LDFLAGS="$(TARGET_LDFLAGS)"
+endef
+
+define Package/unvram/install
+	$(INSTALL_DIR) $(1)/sbin
+	$(INSTALL_BIN) $(PKG_BUILD_DIR)/unvram $(1)/sbin/
+	$(INSTALL_DIR) $(1)/usr/lib
+	$(INSTALL_BIN) $(PKG_BUILD_DIR)/libnvram.so.0.1 $(1)/usr/lib/
+endef
+
+$(eval $(call BuildPackage,unvram))
diff --git a/package/unvram/src/Makefile b/package/unvram/src/Makefile
new file mode 100644
index 0000000..7f92aa8
--- /dev/null
+++ b/package/unvram/src/Makefile
@@ -0,0 +1,33 @@
+CLI_FILENAME = unvram
+
+LIB_VERMAJOR = 0
+LIB_VERMINOR = 1
+LIB_FILENAME = libnvram.so
+
+LIB_CFLAGS  = $(CFLAGS) -shared -fPIC
+LIB_LDFLAGS = $(LDFLAGS) -Wl,-soname,$(LIB_FILENAME).$(LIB_VERMAJOR).$(LIB_VERMINOR)
+
+CLI_CFLAGS  = $(CFLAGS)
+CLI_LDFLAGS = $(LDFLAGS)
+
+CLI_OBJ = cli.o
+LIB_OBJ = crc.o nvram.o
+
+all: cli libnvram
+
+cli: libnvram
+	$(CC) $(CLI_CFLAGS) -c -o cli.o cli.c
+	$(CC) -o $(CLI_FILENAME) $(CLI_LDFLAGS) $(CLI_OBJ) \
+		$(LIB_FILENAME).$(LIB_VERMAJOR).$(LIB_VERMINOR)
+
+cli.o: cli.c
+	$(CC) $(CLI_CFLAGS) -c -o $@ $<
+
+libnvram:
+	$(CC) $(LIB_CFLAGS) -c -o crc.o crc.c
+	$(CC) $(LIB_CFLAGS) -c -o nvram.o nvram.c
+	$(CC) $(LIB_CFLAGS) $(LIB_LDFLAGS) \
+		-o $(LIB_FILENAME).$(LIB_VERMAJOR).$(LIB_VERMINOR) $(LIB_OBJ)
+
+clean:
+	rm -f nvram $(LIB_FILENAME)* *.o
diff --git a/package/unvram/src/cli.c b/package/unvram/src/cli.c
new file mode 100644
index 0000000..953910c
--- /dev/null
+++ b/package/unvram/src/cli.c
@@ -0,0 +1,233 @@
+/*
+ * Command line interface for libnvram
+ *
+ * Copyright 2009, Jo-Philipp Wich <xm@subsignal.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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ *
+ *
+ * The libnvram code is based on Broadcom code for Linux 2.4.x .
+ *
+ */
+
+#include "nvram.h"
+
+
+static nvram_handle_t * nvram_open_rdonly(void)
+{
+	const char *file = nvram_find_staging();
+
+	if( file == NULL )
+		file = nvram_find_mtd();
+
+	if( file != NULL )
+		return nvram_open(file, NVRAM_RO);
+
+	return NULL;
+}
+
+static nvram_handle_t * nvram_open_staging(void)
+{
+	if( nvram_find_staging() != NULL || nvram_to_staging() == 0 )
+		return nvram_open(NVRAM_STAGING, NVRAM_RW);
+
+	return NULL;
+}
+
+static int do_show(nvram_handle_t *nvram)
+{
+	nvram_tuple_t *t;
+	int stat = 1;
+
+	if( (t = nvram_getall(nvram)) != NULL )
+	{
+		while( t )
+		{
+			printf("%s=%s\n", t->name, t->value);
+			t = t->next;
+		}
+
+		stat = 0;
+	}
+
+	return stat;
+}
+
+static int do_get(nvram_handle_t *nvram, const char *var)
+{
+	const char *val;
+	int stat = 1;
+
+	if( (val = nvram_get(nvram, var)) != NULL )
+	{
+		printf("%s\n", val);
+		stat = 0;
+	}
+
+	return stat;
+}
+
+static int do_unset(nvram_handle_t *nvram, const char *var)
+{
+	return nvram_unset(nvram, var);
+}
+
+static int do_set(nvram_handle_t *nvram, const char *pair)
+{
+	char *val = strstr(pair, "=");
+	char var[strlen(pair)];
+	int stat = 1;
+
+	if( val != NULL )
+	{
+		memset(var, 0, sizeof(var));
+		strncpy(var, pair, (int)(val-pair));
+		stat = nvram_set(nvram, var, (char *)(val + 1));
+	}
+
+	return stat;
+}
+
+static int do_info(nvram_handle_t *nvram)
+{
+	nvram_header_t *hdr = nvram_header(nvram);
+
+	/* CRC8 over the last 11 bytes of the header and data bytes */
+	uint8_t crc = hndcrc8((unsigned char *) &hdr[0] + NVRAM_CRC_START_POSITION,
+		hdr->len - NVRAM_CRC_START_POSITION, 0xff);
+
+	/* Show info */
+	printf("Magic:         0x%08X\n",   hdr->magic);
+	printf("Length:        0x%08X\n",   hdr->len);
+
+	printf("CRC8:          0x%02X (calculated: 0x%02X)\n",
+		hdr->crc_ver_init & 0xFF, crc);
+
+	printf("Version:       0x%02X\n",   (hdr->crc_ver_init >> 8) & 0xFF);
+	printf("SDRAM init:    0x%04X\n",   (hdr->crc_ver_init >> 16) & 0xFFFF);
+	printf("SDRAM config:  0x%04X\n",   hdr->config_refresh & 0xFFFF);
+	printf("SDRAM refresh: 0x%04X\n",   (hdr->config_refresh >> 16) & 0xFFFF);
+	printf("NCDL values:   0x%08X\n\n", hdr->config_ncdl);
+
+	printf("%i bytes used / %i bytes available (%.2f%%)\n",
+		hdr->len, NVRAM_SPACE - hdr->len,
+		(100.00 / (double)NVRAM_SPACE) * (double)hdr->len);
+
+	return 0;
+}
+
+
+int main( int argc, const char *argv[] )
+{
+	nvram_handle_t *nvram;
+	int commit = 0;
+	int write = 0;
+	int stat = 1;
+	int done = 0;
+	int i;
+
+	/* Ugly... iterate over arguments to see whether we can expect a write */
+	for( i = 1; i < argc; i++ )
+		if( ( !strcmp(argv[i], "set")   && ++i < argc ) ||
+			( !strcmp(argv[i], "unset") && ++i < argc ) ||
+			!strcmp(argv[i], "commit") )
+		{
+			write = 1;
+			break;
+		}
+
+
+	nvram = write ? nvram_open_staging() : nvram_open_rdonly();
+
+	if( nvram != NULL && argc > 1 )
+	{
+		for( i = 1; i < argc; i++ )
+		{
+			if( !strcmp(argv[i], "show") )
+			{
+				stat = do_show(nvram);
+				done++;
+			}
+			else if( !strcmp(argv[i], "info") )
+			{
+				stat = do_info(nvram);
+				done++;
+			}
+			else if( !strcmp(argv[i], "get") && ++i < argc )
+			{
+				stat = do_get(nvram, argv[i]);
+				done++;
+			}
+			else if( !strcmp(argv[i], "unset") && ++i < argc )
+			{
+				stat = do_unset(nvram, argv[i]);
+				done++;
+			}
+			else if( !strcmp(argv[i], "set") && ++i < argc )
+			{
+				stat = do_set(nvram, argv[i]);
+				done++;
+			}
+			else if( !strcmp(argv[i], "commit") )
+			{
+				commit = 1;
+				done++;
+			}
+			else
+			{
+				fprintf(stderr, "Unknown option '%s' !\n", argv[i]);
+				done = 0;
+				break;
+			}
+		}
+
+		if( write )
+			stat = nvram_commit(nvram);
+
+		nvram_close(nvram);
+
+		if( commit )
+			stat = staging_to_nvram();
+	}
+
+	if( !nvram )
+	{
+		fprintf(stderr,
+			"Could not open nvram! Possible reasons are:\n"
+			"	- No device found (/proc not mounted or no nvram present)\n"
+			"	- Insufficient permissions to open mtd device\n"
+			"	- Insufficient memory to complete operation\n"
+			"	- Memory mapping failed or not supported\n"
+		);
+
+		stat = 1;
+	}
+	else if( !done )
+	{
+		fprintf(stderr,
+			"Usage:\n"
+			"	nvram show\n"
+			"	nvram info\n"
+			"	nvram get variable\n"
+			"	nvram set variable=value [set ...]\n"
+			"	nvram unset variable [unset ...]\n"
+			"	nvram commit\n"
+		);
+
+		stat = 1;
+	}
+
+	return stat;
+}
diff --git a/package/unvram/src/crc.c b/package/unvram/src/crc.c
new file mode 100644
index 0000000..22a3665
--- /dev/null
+++ b/package/unvram/src/crc.c
@@ -0,0 +1,69 @@
+#include "nvram.h"
+
+/*******************************************************************************
+ * crc8
+ *
+ * Computes a crc8 over the input data using the polynomial:
+ *
+ *       x^8 + x^7 +x^6 + x^4 + x^2 + 1
+ *
+ * The caller provides the initial value (either CRC8_INIT_VALUE
+ * or the previous returned value) to allow for processing of
+ * discontiguous blocks of data.  When generating the CRC the
+ * caller is responsible for complementing the final return value
+ * and inserting it into the byte stream.  When checking, a final
+ * return value of CRC8_GOOD_VALUE indicates a valid CRC.
+ *
+ * Reference: Dallas Semiconductor Application Note 27
+ *   Williams, Ross N., "A Painless Guide to CRC Error Detection Algorithms",
+ *     ver 3, Aug 1993, ross@guest.adelaide.edu.au, Rocksoft Pty Ltd.,
+ *     ftp://ftp.rocksoft.com/clients/rocksoft/papers/crc_v3.txt
+ *
+ * ****************************************************************************
+ */
+
+static const uint8_t crc8_table[256] = {
+	0x00, 0xF7, 0xB9, 0x4E, 0x25, 0xD2, 0x9C, 0x6B,
+	0x4A, 0xBD, 0xF3, 0x04, 0x6F, 0x98, 0xD6, 0x21,
+	0x94, 0x63, 0x2D, 0xDA, 0xB1, 0x46, 0x08, 0xFF,
+	0xDE, 0x29, 0x67, 0x90, 0xFB, 0x0C, 0x42, 0xB5,
+	0x7F, 0x88, 0xC6, 0x31, 0x5A, 0xAD, 0xE3, 0x14,
+	0x35, 0xC2, 0x8C, 0x7B, 0x10, 0xE7, 0xA9, 0x5E,
+	0xEB, 0x1C, 0x52, 0xA5, 0xCE, 0x39, 0x77, 0x80,
+	0xA1, 0x56, 0x18, 0xEF, 0x84, 0x73, 0x3D, 0xCA,
+	0xFE, 0x09, 0x47, 0xB0, 0xDB, 0x2C, 0x62, 0x95,
+	0xB4, 0x43, 0x0D, 0xFA, 0x91, 0x66, 0x28, 0xDF,
+	0x6A, 0x9D, 0xD3, 0x24, 0x4F, 0xB8, 0xF6, 0x01,
+	0x20, 0xD7, 0x99, 0x6E, 0x05, 0xF2, 0xBC, 0x4B,
+	0x81, 0x76, 0x38, 0xCF, 0xA4, 0x53, 0x1D, 0xEA,
+	0xCB, 0x3C, 0x72, 0x85, 0xEE, 0x19, 0x57, 0xA0,
+	0x15, 0xE2, 0xAC, 0x5B, 0x30, 0xC7, 0x89, 0x7E,
+	0x5F, 0xA8, 0xE6, 0x11, 0x7A, 0x8D, 0xC3, 0x34,
+	0xAB, 0x5C, 0x12, 0xE5, 0x8E, 0x79, 0x37, 0xC0,
+	0xE1, 0x16, 0x58, 0xAF, 0xC4, 0x33, 0x7D, 0x8A,
+	0x3F, 0xC8, 0x86, 0x71, 0x1A, 0xED, 0xA3, 0x54,
+	0x75, 0x82, 0xCC, 0x3B, 0x50, 0xA7, 0xE9, 0x1E,
+	0xD4, 0x23, 0x6D, 0x9A, 0xF1, 0x06, 0x48, 0xBF,
+	0x9E, 0x69, 0x27, 0xD0, 0xBB, 0x4C, 0x02, 0xF5,
+	0x40, 0xB7, 0xF9, 0x0E, 0x65, 0x92, 0xDC, 0x2B,
+	0x0A, 0xFD, 0xB3, 0x44, 0x2F, 0xD8, 0x96, 0x61,
+	0x55, 0xA2, 0xEC, 0x1B, 0x70, 0x87, 0xC9, 0x3E,
+	0x1F, 0xE8, 0xA6, 0x51, 0x3A, 0xCD, 0x83, 0x74,
+	0xC1, 0x36, 0x78, 0x8F, 0xE4, 0x13, 0x5D, 0xAA,
+	0x8B, 0x7C, 0x32, 0xC5, 0xAE, 0x59, 0x17, 0xE0,
+	0x2A, 0xDD, 0x93, 0x64, 0x0F, 0xF8, 0xB6, 0x41,
+	0x60, 0x97, 0xD9, 0x2E, 0x45, 0xB2, 0xFC, 0x0B,
+	0xBE, 0x49, 0x07, 0xF0, 0x9B, 0x6C, 0x22, 0xD5,
+	0xF4, 0x03, 0x4D, 0xBA, 0xD1, 0x26, 0x68, 0x9F
+};
+
+uint8_t hndcrc8 (
+	uint8_t * pdata,  /* pointer to array of data to process */
+	uint32_t nbytes,  /* number of input data bytes to process */
+	uint8_t crc       /* either CRC8_INIT_VALUE or previous return value */
+) {
+	while (nbytes-- > 0)
+		crc = crc8_table[(crc ^ *pdata++) & 0xff];
+
+	return crc;
+}
diff --git a/package/unvram/src/nvram.c b/package/unvram/src/nvram.c
new file mode 100644
index 0000000..4dfe0a9
--- /dev/null
+++ b/package/unvram/src/nvram.c
@@ -0,0 +1,511 @@
+/*
+ * NVRAM variable manipulation (common)
+ *
+ * Copyright 2004, 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.
+ *
+ */
+
+#include "nvram.h"
+
+#define TRACE(msg) \
+	printf("%s(%i) in %s(): %s\n", \
+		__FILE__, __LINE__, __FUNCTION__, msg ? msg : "?")
+
+size_t nvram_erase_size = 0;
+
+
+/*
+ * -- Helper functions --
+ */
+
+/* String hash */
+static uint32_t hash(const char *s)
+{
+	uint32_t hash = 0;
+
+	while (*s)
+		hash = 31 * hash + *s++;
+
+	return hash;
+}
+
+/* Free all tuples. */
+static void _nvram_free(nvram_handle_t *h)
+{
+	uint32_t i;
+	nvram_tuple_t *t, *next;
+
+	/* Free hash table */
+	for (i = 0; i < NVRAM_ARRAYSIZE(h->nvram_hash); i++) {
+		for (t = h->nvram_hash[i]; t; t = next) {
+			next = t->next;
+			free(t);
+		}
+		h->nvram_hash[i] = NULL;
+	}
+
+	/* Free dead table */
+	for (t = h->nvram_dead; t; t = next) {
+		next = t->next;
+		free(t);
+	}
+
+	h->nvram_dead = NULL;
+}
+
+/* (Re)allocate NVRAM tuples. */
+static nvram_tuple_t * _nvram_realloc( nvram_handle_t *h, nvram_tuple_t *t,
+	const char *name, const char *value )
+{
+	if ((strlen(value) + 1) > NVRAM_SPACE)
+		return NULL;
+
+	if (!t) {
+		if (!(t = malloc(sizeof(nvram_tuple_t) + strlen(name) + 1)))
+			return NULL;
+
+		/* Copy name */
+		t->name = (char *) &t[1];
+		strcpy(t->name, name);
+
+		t->value = NULL;
+	}
+
+	/* Copy value */
+	if (!t->value || strcmp(t->value, value))
+	{
+		if(!(t->value = (char *) realloc(t->value, strlen(value)+1)))
+			return NULL;
+
+		strcpy(t->value, value);
+		t->value[strlen(value)] = '\0';
+	}
+
+	return t;
+}
+
+/* (Re)initialize the hash table. */
+static int _nvram_rehash(nvram_handle_t *h)
+{
+	nvram_header_t *header = nvram_header(h);
+	char buf[] = "0xXXXXXXXX", *name, *value, *eq;
+
+	/* (Re)initialize hash table */
+	_nvram_free(h);
+
+	/* Parse and set "name=value\0 ... \0\0" */
+	name = (char *) &header[1];
+
+	for (; *name; name = value + strlen(value) + 1) {
+		if (!(eq = strchr(name, '=')))
+			break;
+		*eq = '\0';
+		value = eq + 1;
+		nvram_set(h, name, value);
+		*eq = '=';
+	}
+
+	/* Set special SDRAM parameters */
+	if (!nvram_get(h, "sdram_init")) {
+		sprintf(buf, "0x%04X", (uint16_t)(header->crc_ver_init >> 16));
+		nvram_set(h, "sdram_init", buf);
+	}
+	if (!nvram_get(h, "sdram_config")) {
+		sprintf(buf, "0x%04X", (uint16_t)(header->config_refresh & 0xffff));
+		nvram_set(h, "sdram_config", buf);
+	}
+	if (!nvram_get(h, "sdram_refresh")) {
+		sprintf(buf, "0x%04X",
+			(uint16_t)((header->config_refresh >> 16) & 0xffff));
+		nvram_set(h, "sdram_refresh", buf);
+	}
+	if (!nvram_get(h, "sdram_ncdl")) {
+		sprintf(buf, "0x%08X", header->config_ncdl);
+		nvram_set(h, "sdram_ncdl", buf);
+	}
+
+	return 0;
+}
+
+
+/*
+ * -- Public functions --
+ */
+
+/* Get nvram header. */
+nvram_header_t * nvram_header(nvram_handle_t *h)
+{
+	return (nvram_header_t *) &h->mmap[NVRAM_START(nvram_erase_size)];
+}
+
+/* Get the value of an NVRAM variable. */
+char * nvram_get(nvram_handle_t *h, const char *name)
+{
+	uint32_t i;
+	nvram_tuple_t *t;
+	char *value;
+
+	if (!name)
+		return NULL;
+
+	/* Hash the name */
+	i = hash(name) % NVRAM_ARRAYSIZE(h->nvram_hash);
+
+	/* Find the associated tuple in the hash table */
+	for (t = h->nvram_hash[i]; t && strcmp(t->name, name); t = t->next);
+
+	value = t ? t->value : NULL;
+
+	return value;
+}
+
+/* Set the value of an NVRAM variable. */
+int nvram_set(nvram_handle_t *h, const char *name, const char *value)
+{
+	uint32_t i;
+	nvram_tuple_t *t, *u, **prev;
+
+	/* Hash the name */
+	i = hash(name) % NVRAM_ARRAYSIZE(h->nvram_hash);
+
+	/* Find the associated tuple in the hash table */
+	for (prev = &h->nvram_hash[i], t = *prev;
+		 t && strcmp(t->name, name); prev = &t->next, t = *prev);
+
+	/* (Re)allocate tuple */
+	if (!(u = _nvram_realloc(h, t, name, value)))
+		return -12; /* -ENOMEM */
+
+	/* Value reallocated */
+	if (t && t == u)
+		return 0;
+
+	/* Move old tuple to the dead table */
+	if (t) {
+		*prev = t->next;
+		t->next = h->nvram_dead;
+		h->nvram_dead = t;
+	}
+
+	/* Add new tuple to the hash table */
+	u->next = h->nvram_hash[i];
+	h->nvram_hash[i] = u;
+
+	return 0;
+}
+
+/* Unset the value of an NVRAM variable. */
+int nvram_unset(nvram_handle_t *h, const char *name)
+{
+	uint32_t i;
+	nvram_tuple_t *t, **prev;
+
+	if (!name)
+		return 0;
+
+	/* Hash the name */
+	i = hash(name) % NVRAM_ARRAYSIZE(h->nvram_hash);
+
+	/* Find the associated tuple in the hash table */
+	for (prev = &h->nvram_hash[i], t = *prev;
+		 t && strcmp(t->name, name); prev = &t->next, t = *prev);
+
+	/* Move it to the dead table */
+	if (t) {
+		*prev = t->next;
+		t->next = h->nvram_dead;
+		h->nvram_dead = t;
+	}
+
+	return 0;
+}
+
+/* Get all NVRAM variables. */
+nvram_tuple_t * nvram_getall(nvram_handle_t *h)
+{
+	int i;
+	nvram_tuple_t *t, *l, *x;
+
+	l = NULL;
+
+	for (i = 0; i < NVRAM_ARRAYSIZE(h->nvram_hash); i++) {
+		for (t = h->nvram_hash[i]; t; t = t->next) {
+			if( (x = (nvram_tuple_t *) malloc(sizeof(nvram_tuple_t))) != NULL )
+			{
+				x->name  = t->name;
+				x->value = t->value;
+				x->next  = l;
+				l = x;
+			}
+			else
+			{
+				break;
+			}
+		}
+	}
+
+	return l;
+}
+
+/* Regenerate NVRAM. */
+int nvram_commit(nvram_handle_t *h)
+{
+	nvram_header_t *header = nvram_header(h);
+	char *init, *config, *refresh, *ncdl;
+	char *ptr, *end;
+	int i;
+	nvram_tuple_t *t;
+	nvram_header_t tmp;
+	uint8_t crc;
+
+	/* Regenerate header */
+	header->magic = NVRAM_MAGIC;
+	header->crc_ver_init = (NVRAM_VERSION << 8);
+	if (!(init = nvram_get(h, "sdram_init")) ||
+		!(config = nvram_get(h, "sdram_config")) ||
+		!(refresh = nvram_get(h, "sdram_refresh")) ||
+		!(ncdl = nvram_get(h, "sdram_ncdl"))) {
+		header->crc_ver_init |= SDRAM_INIT << 16;
+		header->config_refresh = SDRAM_CONFIG;
+		header->config_refresh |= SDRAM_REFRESH << 16;
+		header->config_ncdl = 0;
+	} else {
+		header->crc_ver_init |= (strtoul(init, NULL, 0) & 0xffff) << 16;
+		header->config_refresh = strtoul(config, NULL, 0) & 0xffff;
+		header->config_refresh |= (strtoul(refresh, NULL, 0) & 0xffff) << 16;
+		header->config_ncdl = strtoul(ncdl, NULL, 0);
+	}
+
+	/* Clear data area */
+	ptr = (char *) header + sizeof(nvram_header_t);
+	memset(ptr, 0xFF, NVRAM_SPACE - sizeof(nvram_header_t));
+	memset(&tmp, 0, sizeof(nvram_header_t));
+
+	/* Leave space for a double NUL at the end */
+	end = (char *) header + NVRAM_SPACE - 2;
+
+	/* Write out all tuples */
+	for (i = 0; i < NVRAM_ARRAYSIZE(h->nvram_hash); i++) {
+		for (t = h->nvram_hash[i]; t; t = t->next) {
+			if ((ptr + strlen(t->name) + 1 + strlen(t->value) + 1) > end)
+				break;
+			ptr += sprintf(ptr, "%s=%s", t->name, t->value) + 1;
+		}
+	}
+
+	/* End with a double NULL and pad to 4 bytes */
+	*ptr = '\0';
+	ptr++;
+
+	if( (int)ptr % 4 )
+		memset(ptr, 0, 4 - ((int)ptr % 4));
+
+	ptr++;
+
+	/* Set new length */
+	header->len = NVRAM_ROUNDUP(ptr - (char *) header, 4);
+
+	/* Little-endian CRC8 over the last 11 bytes of the header */
+	tmp.crc_ver_init   = header->crc_ver_init;
+	tmp.config_refresh = header->config_refresh;
+	tmp.config_ncdl    = header->config_ncdl;
+	crc = hndcrc8((unsigned char *) &tmp + NVRAM_CRC_START_POSITION,
+		sizeof(nvram_header_t) - NVRAM_CRC_START_POSITION, 0xff);
+
+	/* Continue CRC8 over data bytes */
+	crc = hndcrc8((unsigned char *) &header[0] + sizeof(nvram_header_t),
+		header->len - sizeof(nvram_header_t), crc);
+
+	/* Set new CRC8 */
+	header->crc_ver_init |= crc;
+
+	/* Write out */
+	msync(h->mmap, h->length, MS_SYNC);
+	fsync(h->fd);
+
+	/* Reinitialize hash table */
+	return _nvram_rehash(h);
+}
+
+/* Open NVRAM and obtain a handle. */
+nvram_handle_t * nvram_open(const char *file, int rdonly)
+{
+	int fd;
+	nvram_handle_t *h;
+	nvram_header_t *header;
+
+	/* If erase size or file are undefined then try to define them */
+	if( (nvram_erase_size == 0) || (file == NULL) )
+	{
+		/* Finding the mtd will set the appropriate erase size */
+		if( file == NULL )
+			file = nvram_find_mtd();
+		else
+			(void) nvram_find_mtd();
+
+		if( nvram_erase_size == 0 )
+			return NULL;
+	}
+
+	if( (fd = open(file, O_RDWR)) > -1 )
+	{
+		char *mmap_area = (char *) mmap(
+			NULL, nvram_erase_size, PROT_READ | PROT_WRITE,
+			( rdonly == NVRAM_RO ) ? MAP_PRIVATE : MAP_SHARED, fd, 0);
+
+		if( mmap_area != MAP_FAILED )
+		{
+			memset(mmap_area, 0xFF, NVRAM_START(nvram_erase_size));
+
+			if((h = (nvram_handle_t *) malloc(sizeof(nvram_handle_t))) != NULL)
+			{
+				memset(h, 0, sizeof(nvram_handle_t));
+
+				h->fd     = fd;
+				h->mmap   = mmap_area;
+				h->length = nvram_erase_size;
+
+				header = nvram_header(h);
+
+				if( header->magic == NVRAM_MAGIC )
+				{
+					_nvram_rehash(h);
+					return h;
+				}
+				else
+				{
+					munmap(h->mmap, h->length);
+					free(h);
+				}
+			}
+		}
+	}
+
+	return NULL;
+}
+
+/* Close NVRAM and free memory. */
+int nvram_close(nvram_handle_t *h)
+{
+	_nvram_free(h);
+	munmap(h->mmap, h->length);
+	close(h->fd);
+	free(h);
+
+	return 0;
+}
+
+/* Determine NVRAM device node. */
+const char * nvram_find_mtd(void)
+{
+	FILE *fp;
+	int i, esz;
+	char dev[PATH_MAX];
+	char *path = NULL;
+
+	// "/dev/mtdblock/" + ( 0 < x < 99 ) + \0 = 19
+	if( (path = (char *) malloc(19)) == NULL )
+		return NULL;
+
+	if ((fp = fopen("/proc/mtd", "r"))) {
+		while (fgets(dev, sizeof(dev), fp)) {
+			if (strstr(dev, "nvram") && sscanf(dev, "mtd%d: %08x", &i, &esz)) {
+				if( (path = (char *) malloc(19)) != NULL )
+				{
+					nvram_erase_size = esz;
+					snprintf(path, 19, "/dev/mtdblock/%d", i);
+					break;
+				}
+			}
+		}
+		fclose(fp);
+	}
+
+	return path;
+}
+
+/* Check NVRAM staging file. */
+const char * nvram_find_staging(void)
+{
+	struct stat s;
+
+	if( (stat(NVRAM_STAGING, &s) > -1) && (s.st_mode & S_IFREG) )
+	{
+		return NVRAM_STAGING;
+	}
+
+	return NULL;
+}
+
+/* Copy NVRAM contents to staging file. */
+int nvram_to_staging(void)
+{
+	int fdmtd, fdstg, stat;
+	const char *mtd = nvram_find_mtd();
+	char buf[nvram_erase_size];
+
+	stat = -1;
+
+	if( (mtd != NULL) && (nvram_erase_size > 0) )
+	{
+		if( (fdmtd = open(mtd, O_RDONLY)) > -1 )
+		{
+			if( read(fdmtd, buf, sizeof(buf)) == sizeof(buf) )
+			{
+				if((fdstg = open(NVRAM_STAGING, O_WRONLY | O_CREAT, 0600)) > -1)
+				{
+					write(fdstg, buf, sizeof(buf));
+					fsync(fdstg);
+					close(fdstg);
+
+					stat = 0;
+				}
+			}
+
+			close(fdmtd);
+		}
+	}
+
+	return stat;
+}
+
+/* Copy staging file to NVRAM device. */
+int staging_to_nvram(void)
+{
+	int fdmtd, fdstg, stat;
+	const char *mtd = nvram_find_mtd();
+	char buf[nvram_erase_size];
+
+	stat = -1;
+
+	if( (mtd != NULL) && (nvram_erase_size > 0) )
+	{
+		if( (fdstg = open(NVRAM_STAGING, O_RDONLY)) > -1 )
+		{
+			if( read(fdstg, buf, sizeof(buf)) == sizeof(buf) )
+			{
+				if( (fdmtd = open(mtd, O_WRONLY | O_SYNC)) > -1 )
+				{
+					write(fdmtd, buf, sizeof(buf));
+					fsync(fdmtd);
+					close(fdmtd);
+					stat = 0;
+				}
+			}
+
+			close(fdstg);
+
+			if( !stat )
+				stat = unlink(NVRAM_STAGING) ? 1 : 0;
+		}
+	}
+
+	return stat;
+}
diff --git a/package/unvram/src/nvram.h b/package/unvram/src/nvram.h
new file mode 100644
index 0000000..0965023
--- /dev/null
+++ b/package/unvram/src/nvram.h
@@ -0,0 +1,125 @@
+/*
+ * 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 <sys/ioctl.h>
+#include <arpa/inet.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. */
+const 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. */
+const 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_ */
diff --git a/package/unvram/src/sdinitvals.h b/package/unvram/src/sdinitvals.h
new file mode 100644
index 0000000..5a289ad
--- /dev/null
+++ b/package/unvram/src/sdinitvals.h
@@ -0,0 +1,30 @@
+/*
+ * SDRAM init values
+ *
+ * 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 _sdinitvals_h_
+#define _sdinitvals_h_
+
+/* SDRAM refresh control (refresh) register bits */
+#define SDRAM_REF(p)    (((p)&0xff) | SDRAM_REF_EN)     /* Refresh period */
+#define SDRAM_REF_EN    0x8000          /* Writing 1 enables periodic refresh */
+
+/* SDRAM Core default Init values (OCP ID 0x803) */
+#define MEM4MX16X2      0x419   /* 16 MB */
+
+#define SDRAM_INIT	MEM4MX16X2
+#define SDRAM_BURSTFULL 0x0000  /* Use full page bursts */
+#define SDRAM_CONFIG    SDRAM_BURSTFULL
+#define SDRAM_REFRESH   SDRAM_REF(0x40)
+
+#endif /* _sdinitvals_h_ */