Make CRC on stm32 match with software implementation

Upd. See the end of post for working code

I'm already mad with this. How can I make checksum from CRC unit on stm32f103 match with software implementation? Stm has polynom 0x04C11DB7 and reset value 0xFFFFFFFF. So I've tried to calculate it in python.

Code for stm:

uint32_t crc32_hard_block(uint32_t *buf, uint32_t len){    CRC_ResetDR();    uint32_t crc = CRC_CalcBlockCRC(buf, len);    return crc;}uint32_t buf[4] = {50, 10, 243, 147};uint32_t crc_hard_block = crc32_hard_block(buf, 4);

Code for python:

custom_crc_table = {}def int_to_bytes(i):    return [(i >> 24) & 0xFF, (i >> 16) & 0xFF, (i >> 8) & 0xFF, i & 0xFF]def reverse_int(i, w):    b = '{:0{width}b}'.format(i, width=w)    return int(b[::-1], 2)def generate_crc32_table(_poly):    global custom_crc_table    for i in range(256):        c = i << 24        for j in range(8):            c = (c << 1) ^ _poly if (c & 0x80000000) else c << 1        custom_crc_table[i] = cdef custom_crc32(buf, _poly):    global custom_crc_table    crc = 0xFFFFFFFF    for integer in buf:        b = int_to_bytes(integer)        for byte in b:            top = (crc >> 24) & 0xFF            crc = (crc << 8) | byte            crc = crc ^ custom_crc_table[top]    return crc, reverse_int(crc, 32)poly = 0x04C11DB7buf = [50, 10, 243, 147]generate_crc32_table(poly)custom_crc, rev = custom_crc32(buf, poly)print("Custom rev src      "+ hex(rev))print("Custom crc          "+ hex(custom_crc))

Testing on array [50, 10, 243, 147] gives me output:

In python:

Custom rev src      0x344a9514f010200020100010100020301000203Custom crc          0x3010002030100020200020100010203ca2a548b #reversed

It's definetly something wrong with my crc.

In stm:

0x491b3bf3

UPDATE

Here is working code for software crc as on stm32f103 and code for stm32f103.

Python:

def generate_crc32_table(_poly):    global custom_crc_table    for i in range(256):        c = i << 24        for j in range(8):            c = (c << 1) ^ _poly if (c & 0x80000000) else c << 1        custom_crc_table[i] = c & 0xffffffffdef crc32_stm(bytes_arr):    length = len(bytes_arr)    crc = 0xffffffff    k = 0    while length >= 4:        v = ((bytes_arr[k] << 24) & 0xFF000000) | ((bytes_arr[k+1] << 16) & 0xFF0000) | \        ((bytes_arr[k+2] << 8) & 0xFF00) | (bytes_arr[k+3] & 0xFF)        crc = ((crc << 8) & 0xffffffff) ^ custom_crc_table[0xFF & ((crc >> 24) ^ v)]        crc = ((crc << 8) & 0xffffffff) ^ custom_crc_table[0xFF & ((crc >> 24) ^ (v >> 8))]        crc = ((crc << 8) & 0xffffffff) ^ custom_crc_table[0xFF & ((crc >> 24) ^ (v >> 16))]        crc = ((crc << 8) & 0xffffffff) ^ custom_crc_table[0xFF & ((crc >> 24) ^ (v >> 24))]        k += 4        length -= 4    if length > 0:        v = 0        for i in range(length):            v |= (bytes_arr[k+i] << 24-i*8)        if length == 1:            v &= 0xFF000000        elif length == 2:            v &= 0xFFFF0000        elif length == 3:            v &= 0xFFFFFF00        crc = (( crc << 8 ) & 0xffffffff) ^ custom_crc_table[0xFF & ( (crc >> 24) ^ (v ) )];        crc = (( crc << 8 ) & 0xffffffff) ^ custom_crc_table[0xFF & ( (crc >> 24) ^ (v >> 8) )];        crc = (( crc << 8 ) & 0xffffffff) ^ custom_crc_table[0xFF & ( (crc >> 24) ^ (v >> 16) )];        crc = (( crc << 8 ) & 0xffffffff) ^ custom_crc_table[0xFF & ( (crc >> 24) ^ (v >> 24) )];    return crcpoly = 0x04C11DB7buf = [50, 10, 243, 147]generate_crc32_table(poly)crc_stm = crc32_stm(bytearray(buf))

Stm32f103:

#include <stm32f10x_crc.h>    uint32_t crc32_native(char *bfr, int len, int clear) {    uint32_t crc;    int l = len / 4;    uint32_t *p = (uint32_t*)bfr;    uint32_t x = p[l];    if(clear)    {        CRC_ResetDR();    }    while(l--)    {        crc = CRC_CalcCRC(*p++);    }    switch(len & 3)    {        case 1: crc = CRC_CalcCRC(x & 0x000000FF); break;        case 2: crc = CRC_CalcCRC(x & 0x0000FFFF); break;        case 3: crc = CRC_CalcCRC(x & 0x00FFFFFF); break;    }    return crc;}