coreboot-kgpe-d16/util/nvramtool/compute_ip_checksum.c
Stefan Reinauer a67aab7083 Add string support to nvramtool.
To add a string to your cmos.layout, you need to specify type 's':

#start     len       type    unused   name
416        512       s       0        boot_devices

With this patch you can do

$ nvramtool -w boot_devices="(hd0,0);(hd2,1);(hd3)"

And FILO will attempt to load a menu.lst from any of these devices in that
order.

The patch is not exactly pretty, but a cleaner solution might have resulted in
a complete rewrite of the tool, which I did not want.

Signed-off-by: Stefan Reinauer <stepan@coresystems.de>
Acked-by: Joseph Smith <joe@settoplinux.org>



git-svn-id: svn://svn.coreboot.org/coreboot/trunk@3613 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1
2008-09-27 10:08:28 +00:00

44 lines
1.4 KiB
C

/*****************************************************************************\
* compute_ip_checksum.c
\*****************************************************************************/
#include <stdint.h>
#include "ip_checksum.h"
/* Note: The contents of this file were borrowed from the coreboot source
* code which may be obtained from http://www.coreboot.org.
* Specifically, this code was obtained from coreboot (LinuxBIOS)
* version 1.0.0.8.
*/
unsigned long compute_ip_checksum(void *addr, unsigned long length)
{
uint8_t *ptr;
volatile union {
uint8_t byte[2];
uint16_t word;
} value;
unsigned long sum;
unsigned long i;
/* In the most straight forward way possible,
* compute an ip style checksum.
*/
sum = 0;
ptr = addr;
for(i = 0; i < length; i++) {
unsigned long value;
value = ptr[i];
if (i & 1) {
value <<= 8;
}
/* Add the new value */
sum += value;
/* Wrap around the carry */
if (sum > 0xFFFF) {
sum = (sum + (sum >> 16)) & 0xFFFF;
}
}
value.byte[0] = sum & 0xff;
value.byte[1] = (sum >> 8) & 0xff;
return (~value.word) & 0xFFFF;
}