diff options
Diffstat (limited to 'projects/bootloader/crc32.c')
-rw-r--r-- | projects/bootloader/crc32.c | 62 |
1 files changed, 0 insertions, 62 deletions
diff --git a/projects/bootloader/crc32.c b/projects/bootloader/crc32.c deleted file mode 100644 index 4d1a0bc..0000000 --- a/projects/bootloader/crc32.c +++ /dev/null @@ -1,62 +0,0 @@ -/* Reference code from RFC1952. Not meant to be used outside test code. */ - -#include "stm32f4xx_hal.h" - - -/* Table of CRCs of all 8-bit messages. */ -unsigned long crc_table[256]; - -/* Flag: has the table been computed? Initially false. */ -int crc_table_computed = 0; - -/* Make the table for a fast CRC. */ -void make_crc_table(void) -{ - unsigned long c; - - int n, k; - for (n = 0; n < 256; n++) { - c = (unsigned long) n; - for (k = 0; k < 8; k++) { - if (c & 1) { - c = 0xedb88320L ^ (c >> 1); - } else { - c = c >> 1; - } - } - crc_table[n] = c; - } - crc_table_computed = 1; -} - -/* - Update a running crc with the bytes buf[0..len-1] and return - the updated crc. The crc should be initialized to zero. Pre- and - post-conditioning (one's complement) is performed within this - function so it shouldn't be done by the caller. Usage example: - - unsigned long crc = 0L; - - while (read_buffer(buffer, length) != EOF) { - crc = update_crc(crc, buffer, length); - } - if (crc != original_crc) error(); -*/ -uint32_t update_crc(uint32_t crc, uint8_t *buf, int len) -{ - unsigned long c = crc ^ 0xffffffffL; - int n; - - if (!crc_table_computed) - make_crc_table(); - for (n = 0; n < len; n++) { - c = crc_table[(c ^ buf[n]) & 0xff] ^ (c >> 8); - } - return c ^ 0xffffffffL; -} - -/* Return the CRC of the bytes buf[0..len-1]. */ -unsigned long crc(unsigned char *buf, int len) -{ - return update_crc(0L, buf, len); -} |