RPi 3B+ blank screen and no serial console

M95DM95D
edited May 2019 in Supported devices

Hi.
I'm trying to boot latest version on Raspberry Pi 3B+. It appears to boot, but after kernel loading, the display goes blank.
There are no messages on serial port because the kernel boot parameter "console=serial2,115200" is wrong. There are only two serial ports on RPi and the second one is used by bluetooth. It should be "console=serial0,115200". With this setting, kernel boot messages can be seen, but still no console/prompt is available on the serial port after booting, so there must be some other wrong setting in the OS configuration.

I'm attaching two boot logs. First is captured with TV connected. Second is captured with DSI touchscreen connected.
Thanks.
M95D

marius95.go.ro/posted/rpi-emteria-boot.txt

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Comments

  • kalkovkalkov

    There are no messages on serial port because the kernel boot parameter "console=serial2,115200" is wrong.

    It is done on purpose, so everybody knows the format, but the default setting doesn't interfere with user's own UART applications. If you want to use it, make sure to add enable_uart=1 to the config.txt. On my device, I can press "enter" just after the kernel is loaded and access Android logs with "logcat". It will be useful for you to debug the resolutions issue (which it seems to be).

    First is captured with TV connected. Second is captured with DSI touchscreen connected.

    The OS performs several checks during the very first boot for detecting the screen and supported resolutions. If you want to switch the screen, try a fresh installation.

  • M95DM95D

    @kalkov said:
    It is done on purpose, so everybody knows the format, but the default setting doesn't interfere with user's own UART applications. If you want to use it, make sure to add enable_uart=1 to the config.txt. On my device, I can press "enter" just after the kernel is loaded and access Android logs with "logcat". It will be useful for you to debug the resolutions issue (which it seems to be).

    OK. I already enabled serial port and changed console parameter. I can see the kernel logs, but no console prompt after OS booted. (I assume it's finished booting after 10 min since last serial message.) Pressing Enter at this point does nothing.

    The OS performs several checks during the very first boot for detecting the screen and supported resolutions. If you want to switch the screen, try a fresh installation.

    OK. Will try.
    Is this documented?

    Thanks!

  • kalkovkalkov

    (I assume it's finished booting after 10 min since last serial message.) Pressing Enter at this point does nothing.

    It shouldn't take longer than 30-40 seconds. I see this line in your boot logs: init: Starting service 'console'.... If it doesn't work after this, please check your wiring.

    Is this documented?

    We have a little bit of documentation here: https://help.emteria.com/kb/devices-rpi-3#custom-screen-resolution

  • M95DM95D

    Erased card (full erase), wrote OS, booted with HDMI TV connected - didn't work. Same blank screen.
    Erased card, wrote OS, deleted HDMI-related config options, booted with DSI touchscreen - works! Shut down, connected HDMI TV - now works with TV too!
    I guess there must be some incompatibility between default config.txt and my TV.

    Thank you.

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