E25 gpio serial console

I’m trying to add support for the E25 board in openwrt but currently I’m facing some issues with the network driver (r8169) and I’m unable to debug further as I can’t get any serial access to the board.
Any idea how to enable serial access via GPIO ?

Hmm, regarding to this:


You have to use the usbc port for serial console, not gpio, and it is set to 115200.

thank you for the reply - unfortunately it only work during u-boot stage - then it disconnects - see logs:

[  607.283625] usb 1-2: new full-speed USB device number 6 using xhci_hcd
[  607.433925] usb 1-2: New USB device found, idVendor=1a86, idProduct=7523, bcdDevice= 2.54
[  607.433947] usb 1-2: New USB device strings: Mfr=0, Product=2, SerialNumber=0
[  607.433955] usb 1-2: Product: USB2.0-Serial
[  607.521146] usbcore: registered new interface driver usbserial_generic
[  607.522655] usbserial: USB Serial support registered for generic
[  607.528260] usbcore: registered new interface driver ch341
[  607.530642] usbserial: USB Serial support registered for ch341-uart
[  607.530928] ch341 1-2:1.0: ch341-uart converter detected
[  607.539675] usb 1-2: ch341-uart converter now attached to ttyUSB0
[  607.601090] input: PC Speaker as /devices/platform/pcspkr/input/input18
[  608.179473] input: BRLTTY 6.4 Linux Screen Driver Keyboard as /devices/virtual/input/input19
[  608.185521] usb 1-2: usbfs: interface 0 claimed by ch341 while 'brltty' sets config #1
[  608.189347] ch341-uart ttyUSB0: ch341-uart converter now disconnected from ttyUSB0
[  608.189381] ch341 1-2:1.0: device disconnected

I will search the u-boot code maybe I can find something relevant there

This is probably not because of the U-Boot, but when the kernel is loaded. Hence, what kernel is it? From OpenWRT? This image?


And what is the “initial” log text transmitted?

which distro are you using as HOST machine?
could you try to remove “brltty” package from HOST?

I’m trying to add official support in mainline openwrt - currently with kernel 6.1 but I can build any 6.x even mainline see Openwrt official support request

that did it !!!
now I have serial console via usb-C port on my ubuntu 22.04 - thank you very much !