mirror of
https://github.com/oliverschmidt/contiki.git
synced 2024-10-11 08:23:42 +00:00
69 lines
2.8 KiB
C
69 lines
2.8 KiB
C
/*
|
|
* Copyright (c) 2007, Swedish Institute of Computer Science.
|
|
* All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
|
|
* 3. Neither the name of the Institute nor the names of its contributors
|
|
* may be used to endorse or promote products derived from this software
|
|
* without specific prior written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
|
|
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
|
|
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
* SUCH DAMAGE.
|
|
*
|
|
* This file is part of the Contiki operating system.
|
|
*
|
|
* $Id: uip-ipchksum.c,v 1.2 2007/03/15 21:39:23 adamdunkels Exp $
|
|
*/
|
|
|
|
/**
|
|
* \file
|
|
* uIP checksum calculation for MSP430
|
|
* \author
|
|
* Björn Grönvall <bg@sics.se>
|
|
*/
|
|
|
|
/*---------------------------------------------------------------------------*/
|
|
#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
|
|
/*---------------------------------------------------------------------------*/
|