174 lines
6.8 KiB
C
174 lines
6.8 KiB
C
|
/* packet.c - an elf and spin binary loader for the Parallax Propeller microcontroller
|
||
|
Copyright (c) 2011 David Michael Betz
|
||
|
See license at the end of the file
|
||
|
*/
|
||
|
|
||
|
#include <stdio.h>
|
||
|
#include <string.h>
|
||
|
#include "packet.h"
|
||
|
#include "osint.h"
|
||
|
|
||
|
/* packet format: SOH pkt# type length-lo length-hi hdrchk length*data crc1 crc2 */
|
||
|
#define HDR_SOH 0
|
||
|
#define HDR_TYPE 1
|
||
|
#define HDR_LEN_HI 2
|
||
|
#define HDR_LEN_LO 3
|
||
|
#define HDR_CHK 4
|
||
|
|
||
|
/* packet header and crc lengths */
|
||
|
#define PKTHDRLEN 5
|
||
|
#define PKTCRCLEN 2
|
||
|
|
||
|
/* maximum length of a frame */
|
||
|
#define FRAMELEN (PKTHDRLEN + PKTMAXLEN + PKTCRCLEN)
|
||
|
|
||
|
/* protocol characters */
|
||
|
#define SOH 0x01 /* start of a packet */
|
||
|
|
||
|
#define updcrc(crc, ch) (crctab[((crc) >> 8) & 0xff] ^ ((crc) << 8) ^ (ch))
|
||
|
|
||
|
static const uint16_t crctab[256] = {
|
||
|
0x0000, 0x1021, 0x2042, 0x3063, 0x4084, 0x50a5, 0x60c6, 0x70e7,
|
||
|
0x8108, 0x9129, 0xa14a, 0xb16b, 0xc18c, 0xd1ad, 0xe1ce, 0xf1ef,
|
||
|
0x1231, 0x0210, 0x3273, 0x2252, 0x52b5, 0x4294, 0x72f7, 0x62d6,
|
||
|
0x9339, 0x8318, 0xb37b, 0xa35a, 0xd3bd, 0xc39c, 0xf3ff, 0xe3de,
|
||
|
0x2462, 0x3443, 0x0420, 0x1401, 0x64e6, 0x74c7, 0x44a4, 0x5485,
|
||
|
0xa56a, 0xb54b, 0x8528, 0x9509, 0xe5ee, 0xf5cf, 0xc5ac, 0xd58d,
|
||
|
0x3653, 0x2672, 0x1611, 0x0630, 0x76d7, 0x66f6, 0x5695, 0x46b4,
|
||
|
0xb75b, 0xa77a, 0x9719, 0x8738, 0xf7df, 0xe7fe, 0xd79d, 0xc7bc,
|
||
|
0x48c4, 0x58e5, 0x6886, 0x78a7, 0x0840, 0x1861, 0x2802, 0x3823,
|
||
|
0xc9cc, 0xd9ed, 0xe98e, 0xf9af, 0x8948, 0x9969, 0xa90a, 0xb92b,
|
||
|
0x5af5, 0x4ad4, 0x7ab7, 0x6a96, 0x1a71, 0x0a50, 0x3a33, 0x2a12,
|
||
|
0xdbfd, 0xcbdc, 0xfbbf, 0xeb9e, 0x9b79, 0x8b58, 0xbb3b, 0xab1a,
|
||
|
0x6ca6, 0x7c87, 0x4ce4, 0x5cc5, 0x2c22, 0x3c03, 0x0c60, 0x1c41,
|
||
|
0xedae, 0xfd8f, 0xcdec, 0xddcd, 0xad2a, 0xbd0b, 0x8d68, 0x9d49,
|
||
|
0x7e97, 0x6eb6, 0x5ed5, 0x4ef4, 0x3e13, 0x2e32, 0x1e51, 0x0e70,
|
||
|
0xff9f, 0xefbe, 0xdfdd, 0xcffc, 0xbf1b, 0xaf3a, 0x9f59, 0x8f78,
|
||
|
0x9188, 0x81a9, 0xb1ca, 0xa1eb, 0xd10c, 0xc12d, 0xf14e, 0xe16f,
|
||
|
0x1080, 0x00a1, 0x30c2, 0x20e3, 0x5004, 0x4025, 0x7046, 0x6067,
|
||
|
0x83b9, 0x9398, 0xa3fb, 0xb3da, 0xc33d, 0xd31c, 0xe37f, 0xf35e,
|
||
|
0x02b1, 0x1290, 0x22f3, 0x32d2, 0x4235, 0x5214, 0x6277, 0x7256,
|
||
|
0xb5ea, 0xa5cb, 0x95a8, 0x8589, 0xf56e, 0xe54f, 0xd52c, 0xc50d,
|
||
|
0x34e2, 0x24c3, 0x14a0, 0x0481, 0x7466, 0x6447, 0x5424, 0x4405,
|
||
|
0xa7db, 0xb7fa, 0x8799, 0x97b8, 0xe75f, 0xf77e, 0xc71d, 0xd73c,
|
||
|
0x26d3, 0x36f2, 0x0691, 0x16b0, 0x6657, 0x7676, 0x4615, 0x5634,
|
||
|
0xd94c, 0xc96d, 0xf90e, 0xe92f, 0x99c8, 0x89e9, 0xb98a, 0xa9ab,
|
||
|
0x5844, 0x4865, 0x7806, 0x6827, 0x18c0, 0x08e1, 0x3882, 0x28a3,
|
||
|
0xcb7d, 0xdb5c, 0xeb3f, 0xfb1e, 0x8bf9, 0x9bd8, 0xabbb, 0xbb9a,
|
||
|
0x4a75, 0x5a54, 0x6a37, 0x7a16, 0x0af1, 0x1ad0, 0x2ab3, 0x3a92,
|
||
|
0xfd2e, 0xed0f, 0xdd6c, 0xcd4d, 0xbdaa, 0xad8b, 0x9de8, 0x8dc9,
|
||
|
0x7c26, 0x6c07, 0x5c64, 0x4c45, 0x3ca2, 0x2c83, 0x1ce0, 0x0cc1,
|
||
|
0xef1f, 0xff3e, 0xcf5d, 0xdf7c, 0xaf9b, 0xbfba, 0x8fd9, 0x9ff8,
|
||
|
0x6e17, 0x7e36, 0x4e55, 0x5e74, 0x2e93, 0x3eb2, 0x0ed1, 0x1ef0
|
||
|
};
|
||
|
|
||
|
int SendPacket(int type, uint8_t *buf, int len)
|
||
|
{
|
||
|
uint8_t hdr[PKTHDRLEN], crc[PKTCRCLEN], *p;
|
||
|
uint16_t crc16 = 0;
|
||
|
int cnt;
|
||
|
|
||
|
/* setup the frame header */
|
||
|
hdr[HDR_SOH] = SOH; /* SOH */
|
||
|
hdr[HDR_TYPE] = type; /* type type */
|
||
|
hdr[HDR_LEN_HI] = (uint8_t)(len >> 8); /* data length - high byte */
|
||
|
hdr[HDR_LEN_LO] = (uint8_t)len; /* data length - low byte */
|
||
|
hdr[HDR_CHK] = hdr[1] + hdr[2] + hdr[3]; /* header checksum */
|
||
|
printf("tx length %d\n", len);
|
||
|
printf("%02x %02x %02x\n", hdr[1], hdr[2], hdr[3]);
|
||
|
|
||
|
/* compute the crc */
|
||
|
for (p = buf, cnt = len; --cnt >= 0; ++p)
|
||
|
crc16 = updcrc(crc16, *p);
|
||
|
crc16 = updcrc(crc16, '\0');
|
||
|
crc16 = updcrc(crc16, '\0');
|
||
|
|
||
|
/* add the crc to the frame */
|
||
|
crc[0] = (uint8_t)(crc16 >> 8);
|
||
|
crc[1] = (uint8_t)crc16;
|
||
|
|
||
|
/* send the packet */
|
||
|
tx(hdr, PKTHDRLEN);
|
||
|
if (len > 0)
|
||
|
tx(buf, len);
|
||
|
tx(crc, PKTCRCLEN);
|
||
|
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
int ReceivePacket(int *pType, uint8_t *buf, int len)
|
||
|
{
|
||
|
uint8_t hdr[PKTHDRLEN], crc[PKTCRCLEN];
|
||
|
int actual_len, chk;
|
||
|
uint16_t crc16 = 0;
|
||
|
int retries = 10;
|
||
|
printf("Looking for SOH\n");
|
||
|
|
||
|
/* look for start of packet */
|
||
|
do {
|
||
|
rx_timeout(&hdr[HDR_SOH], 1, 100);
|
||
|
} while (hdr[HDR_SOH] != SOH && --retries >= 0);
|
||
|
printf(" retries %d\n", retries);
|
||
|
|
||
|
/* check for a timeout waiting for the packet */
|
||
|
if (retries < 0)
|
||
|
return -1;
|
||
|
|
||
|
/* receive the rest of the header */
|
||
|
rx(&hdr[HDR_TYPE], PKTHDRLEN - 1);
|
||
|
printf("%02x %02x %02x %02x %02x\n", hdr[0], hdr[1], hdr[2], hdr[3], hdr[4]);
|
||
|
|
||
|
/* check the header checksum */
|
||
|
chk = (hdr[1] + hdr[2] + hdr[3]) & 0xff;
|
||
|
if (hdr[HDR_CHK] != chk)
|
||
|
return -1;
|
||
|
printf("checksum okay\n");
|
||
|
|
||
|
/* make sure the buffer is big enough for the payload */
|
||
|
actual_len = (hdr[HDR_LEN_HI] << 8) | hdr[HDR_LEN_LO];
|
||
|
printf("rx length %d\n", actual_len);
|
||
|
if (actual_len > len)
|
||
|
return -1;
|
||
|
printf("length okay\n");
|
||
|
|
||
|
/* receive the packet payload */
|
||
|
rx(buf, actual_len);
|
||
|
|
||
|
/* compute the crc */
|
||
|
for (len = actual_len; --len >= 0; )
|
||
|
crc16 = updcrc(crc16, *buf++);
|
||
|
|
||
|
/* receive the crc */
|
||
|
rx(crc, PKTCRCLEN);
|
||
|
|
||
|
/* check the crc */
|
||
|
crc16 = updcrc(crc16, crc[0]);
|
||
|
crc16 = updcrc(crc16, crc[1]);
|
||
|
if (crc16 != 0)
|
||
|
return -1;
|
||
|
printf("crc okay\n");
|
||
|
|
||
|
/* return packet type and the length of the payload */
|
||
|
*pType = hdr[HDR_TYPE];
|
||
|
return actual_len;
|
||
|
}
|
||
|
|
||
|
/*
|
||
|
|
||
|
Permission is hereby granted, free of charge, to any person obtaining a copy of this software
|
||
|
and associated documentation files (the "Software"), to deal in the Software without restriction,
|
||
|
including without limitation the rights to use, copy, modify, merge, publish, distribute,
|
||
|
sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
|
||
|
furnished to do so, subject to the following conditions:
|
||
|
|
||
|
The above copyright notice and this permission notice shall be included in all copies or
|
||
|
substantial portions of the Software.
|
||
|
|
||
|
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING
|
||
|
BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
|
||
|
NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
|
||
|
DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
|
||
|
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
|
||
|
|
||
|
*/
|