OrgZephyr/zephyr
OrgZephyr
/
zephyr
mirror of https://github.com/zephyrproject-rtos/zephyr.git
1
0
Fork 0
Code Issues Releases Wiki Activity
zephyr/lib/crc/crc7_sw.c

20 lines
320 B
C
Raw Normal View History

lib: add crc7. Used as a checksum on command messages when talking with MMC cards. Implemented using the unwound bytewise implementation from https://en.wikipedia.org/wiki/Computation_of_cyclic_redundancy_checks which is a good mix of size and speed. The API and naming matches lib/crc7.c in Linux. Signed-off-by: Michael Hope <mlhx@google.com>
2018-02-12 01:07:39 +08:00
/*
* Copyright (c) 2018 Google LLC.
*
* SPDX-License-Identifier: Apache-2.0
*/
lib: migrate includes to <zephyr/...> In order to bring consistency in-tree, migrate all lib code to the new prefix <zephyr/...>. Note that the conversion has been scripted, refer to zephyrproject-rtos#45388 for more details. Signed-off-by: Gerard Marull-Paretas <gerard.marull@nordicsemi.no>
2022-05-06 17:23:05 +08:00
#include <zephyr/sys/crc.h>
lib: add crc7. Used as a checksum on command messages when talking with MMC cards. Implemented using the unwound bytewise implementation from https://en.wikipedia.org/wiki/Computation_of_cyclic_redundancy_checks which is a good mix of size and speed. The API and naming matches lib/crc7.c in Linux. Signed-off-by: Michael Hope <mlhx@google.com>
2018-02-12 01:07:39 +08:00
zephyr: replace zephyr integer types with C99 types git grep -l 'u\(8\|16\|32\|64\)_t' | \ xargs sed -i "s/u\(8\|16\|32\|64\)_t/uint\1_t/g" git grep -l 's\(8\|16\|32\|64\)_t' | \ xargs sed -i "s/s\(8\|16\|32\|64\)_t/int\1_t/g" Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
2020-05-28 00:26:57 +08:00
uint8_t crc7_be(uint8_t seed, const uint8_t *src, size_t len)
lib: add crc7. Used as a checksum on command messages when talking with MMC cards. Implemented using the unwound bytewise implementation from https://en.wikipedia.org/wiki/Computation_of_cyclic_redundancy_checks which is a good mix of size and speed. The API and naming matches lib/crc7.c in Linux. Signed-off-by: Michael Hope <mlhx@google.com>
2018-02-12 01:07:39 +08:00
{
lib: change controlling expressions in if/while to Boolean Use `do { ... } while (false)' instead of `do { ... } while (0)'. Use comparisons with zero instead of implicitly testing integers. Use comparisons with NULL instead of implicitly testing pointers. Use comparisons with NUL instead of implicitly testing plain chars. Use `bool' instead of `int' to represent Boolean values. Use `while (true)' instead of `while (1)' to express infinite loops. Signed-off-by: frei tycho <tfrei@baumer.com>
2024-06-07 22:51:44 +08:00
while (len-- != 0UL) {
zephyr: replace zephyr integer types with C99 types git grep -l 'u\(8\|16\|32\|64\)_t' | \ xargs sed -i "s/u\(8\|16\|32\|64\)_t/uint\1_t/g" git grep -l 's\(8\|16\|32\|64\)_t' | \ xargs sed -i "s/s\(8\|16\|32\|64\)_t/int\1_t/g" Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
2020-05-28 00:26:57 +08:00
uint8_t e = seed ^ *src++;
uint8_t f = e ^ (e >> 4) ^ (e >> 7);
lib: add crc7. Used as a checksum on command messages when talking with MMC cards. Implemented using the unwound bytewise implementation from https://en.wikipedia.org/wiki/Computation_of_cyclic_redundancy_checks which is a good mix of size and speed. The API and naming matches lib/crc7.c in Linux. Signed-off-by: Michael Hope <mlhx@google.com>
2018-02-12 01:07:39 +08:00
seed = (f << 1) ^ (f << 4);
}
return seed;
}