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https://github.com/fail0verflow/switch-coreboot.git
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b41e38e4a2
Comitting IP checksum code, and its usage in linuxbios table creation. Mods to the dts, so that the device ops for the domain are set to the proper structure. This change is important. It gets rid of the obscure, confusing use of the enable_dev function to pick the right ops for a device. It makes the ops initilization very clear at the top level, in the dts. This has been tested and works, linux boots on Bochs under this version. Signed-off-by: Ronald G. Minnich <rminnich@gmail.com> Acked-by: Stefan Reinauer <stepan@coresystems.de> git-svn-id: svn://coreboot.org/repository/LinuxBIOSv3@191 f3766cd6-281f-0410-b1cd-43a5c92072e9
53 lines
1.1 KiB
C
53 lines
1.1 KiB
C
#include <stdint.h>
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#include <ip_checksum.h>
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unsigned long compute_ip_checksum(void *addr, unsigned long length)
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{
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uint8_t *ptr;
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volatile union {
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uint8_t byte[2];
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uint16_t word;
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} value;
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unsigned long sum;
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unsigned long i;
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/* In the most straight forward way possible,
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* compute an ip style checksum.
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*/
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sum = 0;
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ptr = addr;
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for(i = 0; i < length; i++) {
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unsigned long value;
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value = ptr[i];
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if (i & 1) {
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value <<= 8;
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}
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/* Add the new value */
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sum += value;
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/* Wrap around the carry */
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if (sum > 0xFFFF) {
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sum = (sum + (sum >> 16)) & 0xFFFF;
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}
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}
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value.byte[0] = sum & 0xff;
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value.byte[1] = (sum >> 8) & 0xff;
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return (~value.word) & 0xFFFF;
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}
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unsigned long add_ip_checksums(unsigned long offset, unsigned long sum, unsigned long new)
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{
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unsigned long checksum;
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sum = ~sum & 0xFFFF;
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new = ~new & 0xFFFF;
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if (offset & 1) {
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/* byte swap the sum if it came from an odd offset
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* since the computation is endian independant this
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* works.
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*/
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new = ((new >> 8) & 0xff) | ((new << 8) & 0xff00);
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}
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checksum = sum + new;
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if (checksum > 0xFFFF) {
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checksum -= 0xFFFF;
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}
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return (~checksum) & 0xFFFF;
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}
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