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authorUwe Hermann <uwe@hermann-uwe.de>2008-03-01 19:09:01 +0000
committerUwe Hermann <uwe@hermann-uwe.de>2008-03-01 19:09:01 +0000
commitcbb5ba8633c2ad143366c3bc367f8c4f6434c084 (patch)
tree5cd9812c1ca9ab13e3791221bdd8217627df860f /util/nvramtool/compute_ip_checksum.c
parent66d83cfa84f75ad3fba38d3b926da531d800b8a5 (diff)
downloadcoreboot-cbb5ba8633c2ad143366c3bc367f8c4f6434c084.tar.xz
Rename lxbios to nvramtool, step 3 (rename directory).
Signed-off-by: Uwe Hermann <uwe@hermann-uwe.de> Acked-by: Stefan Reinauer <stepan@coresystems.de> git-svn-id: svn://svn.coreboot.org/coreboot/trunk@3124 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1
Diffstat (limited to 'util/nvramtool/compute_ip_checksum.c')
-rw-r--r--util/nvramtool/compute_ip_checksum.c45
1 files changed, 45 insertions, 0 deletions
diff --git a/util/nvramtool/compute_ip_checksum.c b/util/nvramtool/compute_ip_checksum.c
new file mode 100644
index 0000000000..3d2c29feb8
--- /dev/null
+++ b/util/nvramtool/compute_ip_checksum.c
@@ -0,0 +1,45 @@
+/*****************************************************************************\
+ * compute_ip_checksum.c
+ * $Id$
+\*****************************************************************************/
+
+#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;
+}