dd if=/dev/mmcblk1p1 bs=1M iflag=count_bytes count=424673280 | md5sum

2a65d7d4cd692e4ca18a883da496ac49  -

404+1 records in

404+1 records out

424672768 bytes (425 MB, 405 MiB) copied, 20.9962 s, 20.2 MB/s