1 files changed, 242 insertions, 0 deletions
diff --git a/roms/SLOF/lib/libnvram/envvar.c b/roms/SLOF/lib/libnvram/envvar.c
new file mode 100644
index 000000000..d413e9750
--- /dev/null
+++ b/roms/SLOF/lib/libnvram/envvar.c
@@ -0,0 +1,242 @@
+/******************************************************************************
+ * Copyright (c) 2004, 2008 IBM Corporation
+ * All rights reserved.
+ * This program and the accompanying materials
+ * are made available under the terms of the BSD License
+ * which accompanies this distribution, and is available at
+ * http://www.opensource.org/licenses/bsd-license.php
+ *
+ * Contributors:
+ *     IBM Corporation - initial implementation
+ *****************************************************************************/
+
+#include <stdint.h>
+#include "../libc/include/stdio.h"
+#include "../libc/include/string.h"
+#include "../libc/include/stdlib.h"
+#include "nvram.h"
+
+/* returns the offset of the first byte after the searched envvar */
+static int get_past_env_pos(partition_t part, char *envvar, int evlen)
+{
+	int offset, len;
+	static char temp[256];
+	uint8_t data;
+
+	offset=part.addr;
+
+	memset(temp, 0, 256);
+
+	do {
+		len=0;
+		while((data=nvram_read_byte(offset++)) && len < 256) {
+			temp[len++]=data;
+		}
+		if (!strncmp(envvar, temp, evlen)) {
+			return offset;
+		}
+	} while (len);
+
+	return -1;
+}
+
+/**
+ * @param partition name of the envvar partition
+ * @param envvar name of the environment variable
+ * @param evlen string length of the envvar parameter
+ * @return pointer to temporary string containing the value of envvar
+ */
+char *nvram_get_env(partition_t part, char *envvar, unsigned evlen)
+{
+	static char temp[256+1];
+	int len, offset;
+	uint8_t data;
+
+	DEBUG("nvram_get_env %p... ", envvar);
+	if(!part.addr) {
+		/* ERROR: No environment variable partition */
+		DEBUG("invalid partition.\n");
+		return NULL;
+	}
+
+	offset=part.addr;
+
+	do {
+		len=0;
+		while((data=nvram_read_byte(offset++)) && len < 256) {
+			temp[len++]=data;
+		}
+		temp[len]=0;
+
+		if (!strncmp(envvar, temp, evlen)) {
+			int pos=0;
+			while (temp[pos]!='=' && pos < len) pos++;
+			// DEBUG("value='%s'\n", temp+pos+1); 
+			return temp+pos+1;
+		}
+	} while (len);
+
+	DEBUG("not found\n");
+	return NULL;
+}
+
+static int find_last_envvar(partition_t part)
+{
+	uint8_t last, current;
+	int offset;
+
+	offset=part.addr;
+
+	last=nvram_read_byte(part.addr);
+
+	for (offset=part.addr; offset<(int)(part.addr+part.len); offset++) {
+		current=nvram_read_byte(offset);
+		if(!last && !current)
+			return offset;
+
+		last=current;
+	}
+
+	return -1;
+}
+
+int nvram_add_env(partition_t part, char *envvar, unsigned evlen, char *value, unsigned vallen)
+{
+	unsigned i, freespace, last, len, offset;
+
+	/* Find offset where we can write */
+	last = find_last_envvar(part);
+
+	/* How much space do we have left? */
+	freespace = part.addr+part.len-last;
+
+	/* how long is the entry we want to write? */
+	len = evlen + vallen + 2;
+
+	if(freespace<len) {
+		// TODO try to increase partition size
+		return -1;
+	}
+
+	offset=last;
+
+	for (i = 0; i < evlen; i++)
+		nvram_write_byte(offset++, envvar[i]);
+
+	nvram_write_byte(offset++, '=');
+
+	for (i = 0; i < vallen; i++)
+		nvram_write_byte(offset++, value[i]);
+
+	return 0;
+}
+
+int nvram_del_env(partition_t part, char *envvar, unsigned evlen)
+{
+	int last, current, pos, i;
+	char *buffer;
+
+	if(!part.addr)
+		return -1;
+
+	last=find_last_envvar(part);
+	current = pos = get_past_env_pos(part, envvar, evlen);
+	
+	// TODO is this really required?
+	/* go back to non-0 value */
+	current--;
+
+	while (nvram_read_byte(current))
+		current--;
+
+	// TODO is this required?
+	current++;
+
+	buffer=get_nvram_buffer(last-pos);
+
+	for (i=0; i<last-pos; i++)
+		buffer[i]=nvram_read_byte(i+pos);
+
+	for (i=0; i<last-pos; i++)
+		nvram_write_byte(i+current, buffer[i]);
+
+	free_nvram_buffer(buffer);
+
+	erase_nvram(last, current+last-pos);
+
+	return 0;
+}
+
+int nvram_set_env(partition_t part, char *envvar, unsigned evlen, char *value, unsigned vallen)
+{
+	char *oldvalue, *buffer;
+	unsigned last, current, buffersize, i;
+
+	DEBUG("nvram_set_env %lx[%lx]: %p=>%p\n", part.addr, part.len, envvar, value);
+
+	if(!part.addr)
+		return -1;
+
+	/* Check whether the environment variable exists already */
+	oldvalue = nvram_get_env(part, envvar, evlen);
+
+	if (oldvalue == NULL)
+		return nvram_add_env(part, envvar, evlen, value, vallen);
+
+
+	/* The value did not change. So we succeeded! */
+	if (strlen(oldvalue) == vallen && !strncmp(oldvalue, value, vallen))
+		return 0;
+
+	/* we need to overwrite environment variables, back them up first */
+
+	// DEBUG("overwriting existing environment variable\n");
+
+	/* allocate a buffer */
+	last=find_last_envvar(part);
+	current = get_past_env_pos(part, envvar, evlen);
+	buffersize = last - current;
+	buffer=get_nvram_buffer(buffersize);
+	if(!buffer)
+		return -1;
+
+	for (i=0; i<buffersize; i++) {
+		buffer[i] = nvram_read_byte(current+i);
+	}
+
+	/* walk back until the = */
+	while (nvram_read_byte(current)!='=') {
+		current--;
+	}
+
+	/* Start at envvar= */
+	current++;
+
+	/* Write the new value */
+	for(i = 0; i < vallen; i++) {
+		nvram_write_byte(current++, value[i]);
+	}
+	
+	/* Write end of string marker */
+	nvram_write_byte(current++, 0);
+
+	/* Copy back the buffer */
+	for (i=0; i<buffersize; i++) {
+		nvram_write_byte(current++, buffer[i]);
+	}
+
+	free_nvram_buffer(buffer);
+
+	/* If the new environment variable content is shorter than the old one,
+	 * we need to erase the rest of the bytes 
+	 */
+
+	if (current<last) {
+		for(i=current; i<last; i++) {
+			nvram_write_byte(i, 0);
+		}
+	}
+
+	return 0; /* success */
+}
+