int nvram_add_env(partition_t part, char *envvar, int evlen, char *value, int vallen)
{
int freespace, last, len, offset;
unsigned int i;
/* 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, int 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;
}
void test (void *data)
{
int i;
unsigned char c;
for (;;) {
printf (&uart, "\n\nTesting NVRAM, total %d bytes.", E2END+1);
puts (&uart, "\nWriting: ");
for (i=0; i<=E2END; ++i) {
nvram_write_byte (i, ~i);
if ((i & 63) == 63)
putchar (&uart, '.');
}
puts (&uart, "\nReading: ");
for (i=0; i<=E2END; ++i) {
c = nvram_read_byte (i);
if (c != (unsigned char) ~i) {
printf (&uart, "error on byte 0x%x: written 0x%x, read 0x%x\n",
i, (unsigned char) ~i, c);
continue;
}
if ((i & 63) == 63)
putchar (&uart, '.');
}
puts (&uart, "\nPress <Enter> to continue: ");
getchar (&uart);
}
}
static ssize_t write_nvram(struct file *file, const char *buf,
size_t count, loff_t *ppos)
{
unsigned int i;
const char *p = buf;
char c;
if (verify_area(VERIFY_READ, buf, count))
return -EFAULT;
if (*ppos >= NVRAM_SIZE)
return 0;
for (i = *ppos; count > 0 && i < NVRAM_SIZE; ++i, ++p, --count) {
if (__get_user(c, p))
return -EFAULT;
nvram_write_byte(c, i);
}
*ppos = i;
return p - buf;
}
static ssize_t write_nvram(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
unsigned int i;
const char __user *p = buf;
char c;
if (!access_ok(VERIFY_READ, buf, count))
return -EFAULT;
if (*ppos >= nvram_len)
return 0;
for (i = *ppos; count > 0 && i < nvram_len; ++i, ++p, --count) {
if (__get_user(c, p))
return -EFAULT;
nvram_write_byte(c, i);
}
*ppos = i;
return p - buf;
}
int nvram_set_env(partition_t part, char *envvar, int evlen, char *value, int vallen)
{
char *oldvalue, *buffer;
int 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 */
}
