Hello JerryChang,
I think I’ve found the cause of “timeout in USB write” issue. In one of the fantazillion tests I’ve done, I removed the -u pkc.pem -v sbk.key command line options during rootfs image generation, and that’s the image I was using during the failed flash attempts on the PKC + SBK protected machine.
Rebuilt the rootfs image, flashing problem gone. So, the message “ERROR: might be timeout in USB write” does appear not only for real USB data transfer issues, but also in case of a misunderstanding (or better, a squabble?) between the flashing script and the target device. Am I right? I was not able to find (neither Gemini, too) any explicit reference to this kind of behavior on the forum.
Thanks