mirror of
https://github.com/oliverschmidt/contiki.git
synced 2024-10-08 13:54:52 +00:00
uIP checksum calculation for MSP430
This commit is contained in:
parent
c1df2e6df8
commit
36c17d22d0
28
cpu/msp430/uip-ipchksum.c
Normal file
28
cpu/msp430/uip-ipchksum.c
Normal file
@ -0,0 +1,28 @@
|
||||
/*---------------------------------------------------------------------------*/
|
||||
#ifdef UIP_ARCH_IPCHKSUM
|
||||
u16_t
|
||||
uip_ipchksum(void)
|
||||
{
|
||||
/* Assumes proper alignement of uip_buf. */
|
||||
u16_t *p = (u16_t *)&uip_buf[UIP_LLH_LEN];
|
||||
register u16_t sum;
|
||||
|
||||
sum = p[0];
|
||||
asmv("add %[p], %[sum]": [sum] "+r" (sum): [p] "m" (p[1]));
|
||||
asmv("addc %[p], %[sum]": [sum] "+r" (sum): [p] "m" (p[2]));
|
||||
asmv("addc %[p], %[sum]": [sum] "+r" (sum): [p] "m" (p[3]));
|
||||
asmv("addc %[p], %[sum]": [sum] "+r" (sum): [p] "m" (p[4]));
|
||||
asmv("addc %[p], %[sum]": [sum] "+r" (sum): [p] "m" (p[5]));
|
||||
asmv("addc %[p], %[sum]": [sum] "+r" (sum): [p] "m" (p[6]));
|
||||
asmv("addc %[p], %[sum]": [sum] "+r" (sum): [p] "m" (p[7]));
|
||||
asmv("addc %[p], %[sum]": [sum] "+r" (sum): [p] "m" (p[8]));
|
||||
asmv("addc %[p], %[sum]": [sum] "+r" (sum): [p] "m" (p[9]));
|
||||
|
||||
/* Finally, add the remaining carry bit. */
|
||||
asmv("addc #0, %[sum]": [sum] "+r" (sum));
|
||||
|
||||
/* Return sum in network byte order. */
|
||||
return (sum == 0) ? 0xffff : sum;
|
||||
}
|
||||
#endif
|
||||
/*---------------------------------------------------------------------------*/
|
Loading…
Reference in New Issue
Block a user