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Fix XModem CRC

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This commit is contained in:
Aaron Cook 2022-02-09 19:05:29 -06:00
commit 9150f7ae6f
1 changed files with 25 additions and 27 deletions
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54
src/xmodem.c
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@ -10,8 +10,8 @@
int _xmodem_wait(int fd, uint8_t *ret, int timeout_ms); int _xmodem_wait(int fd, uint8_t *ret, int timeout_ms);
uint16_t _xmodem_crc(void *buf, size_t len); uint16_t _xmodem_crc(const uint8_t *buf, size_t len);
uint8_t _xmodem_csum(void *buf, size_t len); uint8_t _xmodem_csum(const uint8_t *buf, size_t len);
void _xmodem_status_print(size_t sent, size_t total); void _xmodem_status_print(size_t sent, size_t total);
int int
@ -167,37 +167,35 @@ _xmodem_wait(int fd, uint8_t *ret, int timeout_ms)
return 0; return 0;
} }
uint16_t uint8_t
_xmodem_crc(void *buf, size_t len) _xmodem_csum(const uint8_t *data, size_t sz)
{ {
uint16_t crc; uint16_t sum = 0;
char i; int i;
for (i = 0; i < sz; i++) {
sum += data[i];
}
return (uint8_t)(sum & 0xff);
}
crc = 0; uint16_t
while (--len >= 0) _xmodem_crc(const uint8_t *data, size_t len)
{ {
crc = crc ^ (uint16_t) (*(uint8_t *)buf++) << 8; uint16_t crc = 0;
i = 8;
do while ((len--) > 0) {
{ uint8_t i = 8;
if (crc & 0x8000)
crc = crc ^ (uint16_t) *data++ << 8;
do {
if (crc & 0x8000) {
crc = crc << 1 ^ 0x1021; crc = crc << 1 ^ 0x1021;
else } else {
crc = crc << 1; crc = crc << 1;
} while(--i); }
} while (--i);
} }
return (crc); return (crc);
} }
uint8_t
_xmodem_csum(void *buf, size_t len)
{
uint8_t ret = 0;
for (size_t i = 0; i < len; i++) {
ret += ((uint8_t *)buf)[i];
}
return ret;
}