Using ymodem on the M0 kernel will cause hardfault problems

[su5176]

Because M0 kernel MCU does not support non aligned access, when receiving data to write to on-chip memory, if using 32-bit pointer to access buffer, it will cause failure.

Solution: when the buffer pointer is passed, copy the data to the aligned buffer and pass it again.

[qz721]

And also lowers the efficiency...:-(

If the starting address of the buffer passed is not aligned, use the nearest aligned one as the starting address, and print a warning message.

Or simply report an error and terminate the procedure.