I can see how frustrating it would be when the msh CLI behaves differently depending on whether commands are typed or pasted. The scrambled text from whd_res_download whd_firmware makes me wonder whether terminal settings, baud rate, or paste handling could be affecting the input. I would also compare the behavior with a shorter command to determine whether the issue is related to command length or specific characters. Slope Rider is far removed from RT-Thread firmware work, but I always find these kinds of debugging problems interesting. I hope you can identify the cause and get the WHD firmware update working properly.