static inline uint32_t stream2int(const uint8_t *stream) {

    return (((uint32_t) stream[0]) << 24 |
            ((uint32_t) stream[1]) << 16 |
            ((uint32_t) stream[2]) <<  8 |
            ((uint32_t) stream[3]) <<  0);
}

[...]
    uint8_t  request[];
    uint16_t crc;

    request[crc2_idx] = (crc >> 0) & 0xff;
    request[crc1_idx] = (crc >> 8) & 0xff;

[...]

    uint8_t  request[]
    uint32_t field;

    memcpy(data, (const char *) &(field));

    uint8_t   data[]
    uint32_t *data32 = (uint32_t *) data;

    register_write(R_ETH_TX, data32);