gpread Posted July 2, 2021 Posted July 2, 2021 U-boot defaults to "In: serial" and also listens for packets (its assumed that its a keyboard/terminal) so that a keypress can stop autoboot. I am successfully using /dev/ttyS2 after modifying /boot/armbianEnv.txt (Console=Display) and masking the gettyS2 service. The device/system I have connected to UART2 (/dev/ttyS2) periodically sends bytes. Thus, if a remote restart or a cold boot is performed (power glitch or power reset) while that system is connected to UART2, it triggers the abort of Autoboot. Requiring the other system/device to be disconnected from UART2, a cold boot of the RockPi4 and then reconnection of the system/device to UART2. I don't see any standard way to reconfigure things to avoid use of UART2 during U-boot and of course its useful for dealing with real issues to be able to interrupt autoboot and then interactively control what happens. Hence the best solution I can see would be for there to be a change to the armbian u-boot to look for a specific key or key sequence rather than just any old key/byte that hits the UART2 RX. Perhaps there could even be a parameter added for use in armbianEnv.txt that allows the abort Autoboot key or key sequence to be defined/redefined ? Thanks for any/all assistance
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