Took checksum function from uif430.
This commit is contained in:
Daniel Beer
parent
2a7a7189ae
commit
c96ce58a8f
4
AUTHORS
4
AUTHORS
|
|
@ -4,3 +4,7 @@ people who have made significant contributions are listed here.
|
|||
Doug Forman <doug.dougforman@gmail.com>:
|
||||
* Testing and analysis for TI Chronos devices.
|
||||
* Testing and analysis for FET430UIF firmware version 20404000.
|
||||
|
||||
Robert Kavaler <kavaler@diva.com>:
|
||||
* Author of uif430, from which much of the code in fet.c is
|
||||
derived (uif430 is available from www.relavak.com).
|
||||
|
|
|
|||
92
fet.c
92
fet.c
|
|
@ -40,9 +40,7 @@ struct fet_device {
|
|||
int version;
|
||||
int have_breakpoint;
|
||||
|
||||
uint16_t code_left[65536];
|
||||
|
||||
uint8_t fet_buf[65538];
|
||||
uint8_t fet_buf[65538];
|
||||
int fet_len;
|
||||
|
||||
/* Recieved packet is parsed into this struct */
|
||||
|
|
@ -121,53 +119,54 @@ struct fet_device {
|
|||
|
||||
/*********************************************************************
|
||||
* Checksum calculation
|
||||
*
|
||||
* This code table is also derived from uif430.
|
||||
*/
|
||||
|
||||
/* Initialise the code table. The code table is a function which takes
|
||||
* us from one checksum position code to the next.
|
||||
*/
|
||||
static const uint16_t fcstab[256] = {
|
||||
0x0000, 0x1189, 0x2312, 0x329b, 0x4624, 0x57ad, 0x6536, 0x74bf,
|
||||
0x8c48, 0x9dc1, 0xaf5a, 0xbed3, 0xca6c, 0xdbe5, 0xe97e, 0xf8f7,
|
||||
0x1081, 0x0108, 0x3393, 0x221a, 0x56a5, 0x472c, 0x75b7, 0x643e,
|
||||
0x9cc9, 0x8d40, 0xbfdb, 0xae52, 0xdaed, 0xcb64, 0xf9ff, 0xe876,
|
||||
0x2102, 0x308b, 0x0210, 0x1399, 0x6726, 0x76af, 0x4434, 0x55bd,
|
||||
0xad4a, 0xbcc3, 0x8e58, 0x9fd1, 0xeb6e, 0xfae7, 0xc87c, 0xd9f5,
|
||||
0x3183, 0x200a, 0x1291, 0x0318, 0x77a7, 0x662e, 0x54b5, 0x453c,
|
||||
0xbdcb, 0xac42, 0x9ed9, 0x8f50, 0xfbef, 0xea66, 0xd8fd, 0xc974,
|
||||
0x4204, 0x538d, 0x6116, 0x709f, 0x0420, 0x15a9, 0x2732, 0x36bb,
|
||||
0xce4c, 0xdfc5, 0xed5e, 0xfcd7, 0x8868, 0x99e1, 0xab7a, 0xbaf3,
|
||||
0x5285, 0x430c, 0x7197, 0x601e, 0x14a1, 0x0528, 0x37b3, 0x263a,
|
||||
0xdecd, 0xcf44, 0xfddf, 0xec56, 0x98e9, 0x8960, 0xbbfb, 0xaa72,
|
||||
0x6306, 0x728f, 0x4014, 0x519d, 0x2522, 0x34ab, 0x0630, 0x17b9,
|
||||
0xef4e, 0xfec7, 0xcc5c, 0xddd5, 0xa96a, 0xb8e3, 0x8a78, 0x9bf1,
|
||||
0x7387, 0x620e, 0x5095, 0x411c, 0x35a3, 0x242a, 0x16b1, 0x0738,
|
||||
0xffcf, 0xee46, 0xdcdd, 0xcd54, 0xb9eb, 0xa862, 0x9af9, 0x8b70,
|
||||
0x8408, 0x9581, 0xa71a, 0xb693, 0xc22c, 0xd3a5, 0xe13e, 0xf0b7,
|
||||
0x0840, 0x19c9, 0x2b52, 0x3adb, 0x4e64, 0x5fed, 0x6d76, 0x7cff,
|
||||
0x9489, 0x8500, 0xb79b, 0xa612, 0xd2ad, 0xc324, 0xf1bf, 0xe036,
|
||||
0x18c1, 0x0948, 0x3bd3, 0x2a5a, 0x5ee5, 0x4f6c, 0x7df7, 0x6c7e,
|
||||
0xa50a, 0xb483, 0x8618, 0x9791, 0xe32e, 0xf2a7, 0xc03c, 0xd1b5,
|
||||
0x2942, 0x38cb, 0x0a50, 0x1bd9, 0x6f66, 0x7eef, 0x4c74, 0x5dfd,
|
||||
0xb58b, 0xa402, 0x9699, 0x8710, 0xf3af, 0xe226, 0xd0bd, 0xc134,
|
||||
0x39c3, 0x284a, 0x1ad1, 0x0b58, 0x7fe7, 0x6e6e, 0x5cf5, 0x4d7c,
|
||||
0xc60c, 0xd785, 0xe51e, 0xf497, 0x8028, 0x91a1, 0xa33a, 0xb2b3,
|
||||
0x4a44, 0x5bcd, 0x6956, 0x78df, 0x0c60, 0x1de9, 0x2f72, 0x3efb,
|
||||
0xd68d, 0xc704, 0xf59f, 0xe416, 0x90a9, 0x8120, 0xb3bb, 0xa232,
|
||||
0x5ac5, 0x4b4c, 0x79d7, 0x685e, 0x1ce1, 0x0d68, 0x3ff3, 0x2e7a,
|
||||
0xe70e, 0xf687, 0xc41c, 0xd595, 0xa12a, 0xb0a3, 0x8238, 0x93b1,
|
||||
0x6b46, 0x7acf, 0x4854, 0x59dd, 0x2d62, 0x3ceb, 0x0e70, 0x1ff9,
|
||||
0xf78f, 0xe606, 0xd49d, 0xc514, 0xb1ab, 0xa022, 0x92b9, 0x8330,
|
||||
0x7bc7, 0x6a4e, 0x58d5, 0x495c, 0x3de3, 0x2c6a, 0x1ef1, 0x0f78
|
||||
};
|
||||
|
||||
static void init_codes(struct fet_device *dev)
|
||||
static uint16_t calc_checksum(uint8_t *cp, int len)
|
||||
{
|
||||
int i;
|
||||
uint16_t fcs = 0xffff;
|
||||
|
||||
for (i = 0; i < 65536; i++) {
|
||||
uint16_t right = i << 1;
|
||||
while (len--) {
|
||||
fcs = (fcs >> 8) ^ fcstab[(fcs ^ *cp++) & 0xff];
|
||||
}
|
||||
|
||||
if (i & 0x8000)
|
||||
right ^= 0x0811;
|
||||
|
||||
dev->code_left[right] = i;
|
||||
}
|
||||
}
|
||||
|
||||
/* Calculate the checksum over the given payload and return it. This checksum
|
||||
* needs to be stored in little-endian format at the end of the payload.
|
||||
*/
|
||||
|
||||
static uint16_t calc_checksum(struct fet_device *dev,
|
||||
const uint8_t *data, int len)
|
||||
{
|
||||
int i;
|
||||
uint16_t cksum = 0xffff;
|
||||
uint16_t code = 0x8408;
|
||||
|
||||
for (i = len * 8; i; i--)
|
||||
cksum = dev->code_left[cksum];
|
||||
|
||||
for (i = len - 1; i >= 0; i--) {
|
||||
int j;
|
||||
uint8_t c = data[i];
|
||||
|
||||
for (j = 0; j < 8; j++) {
|
||||
if (c & 0x80)
|
||||
cksum ^= code;
|
||||
code = dev->code_left[code];
|
||||
c <<= 1;
|
||||
}
|
||||
}
|
||||
|
||||
return cksum ^ 0xffff;
|
||||
return fcs ^ 0xffff;
|
||||
}
|
||||
|
||||
/*********************************************************************
|
||||
|
|
@ -284,7 +283,7 @@ static const char *error_strings[] =
|
|||
|
||||
static int parse_packet(struct fet_device *dev, int plen)
|
||||
{
|
||||
uint16_t c = calc_checksum(dev, dev->fet_buf + 2, plen - 2);
|
||||
uint16_t c = calc_checksum(dev->fet_buf + 2, plen - 2);
|
||||
uint16_t r = BUFFER_WORD(dev->fet_buf, plen);
|
||||
int i = 2;
|
||||
int type;
|
||||
|
|
@ -453,7 +452,7 @@ static int send_command(struct fet_device *dev, int command_code,
|
|||
}
|
||||
|
||||
/* Checksum */
|
||||
cksum = calc_checksum(dev, datapkt, len);
|
||||
cksum = calc_checksum(datapkt, len);
|
||||
datapkt[len++] = cksum & 0xff;
|
||||
datapkt[len++] = cksum >> 8;
|
||||
|
||||
|
|
@ -940,7 +939,6 @@ device_t fet_open(transport_t transport, int proto_flags, int vcc_mv)
|
|||
dev->is_rf2500 = proto_flags & FET_PROTO_RF2500;
|
||||
dev->have_breakpoint = 0;
|
||||
|
||||
init_codes(dev);
|
||||
dev->fet_len = 0;
|
||||
|
||||
if (xfer(dev, C_INITIALIZE, NULL, 0, 0) < 0) {
|
||||
|
|
|
|||
Loading…
Reference in New Issue