Hi,

 

can anybody please help me with device tree overlays to enable serial uarts?

 

Maybe I'm missing a step or I'm doing it wrong? UART3 and UART4 are not working on Cubieboard2 and Cubietruck running the latest mainline armbian image.

 

I've added the dto by following command:

echo overlays=uart3 uart4 >> /boot/armbianEnv.txt

dmesg shows they are enabled:

root@cubieboard2:~# dmesg | grep tty
[    0.000000] Kernel command line: root=UUID=871ffecf-ac1f-4168-bca0-f4ba6a2d8f33 rootwait rootfstype=ext4 console=tty1 console=ttyS0,115200 hdmi.audio=EDID:0 disp.screen0_output_mode=1920x1080p60 panic=10 consoleblank=0 loglevel=1 ubootpart=efa8d984-01 ubootsource=mmc   sunxi_ve_mem_reserve=0 sunxi_g2d_mem_reserve=0 sunxi_fb_mem_reserve=16 cgroup_enable=memory swapaccount=1
[    0.001059] console [tty1] enabled
[    3.728936] console [ttyS0] disabled
[    3.749124] 1c28000.serial: ttyS0 at MMIO 0x1c28000 (irq = 44, base_baud = 1500000) is a U6_16550A
[    3.749186] console [ttyS0] enabled
[    3.772691] 1c28c00.serial: ttyS1 at MMIO 0x1c28c00 (irq = 45, base_baud = 1500000) is a U6_16550A
[    3.796192] 1c29000.serial: ttyS4 at MMIO 0x1c29000 (irq = 46, base_baud = 1500000) is a U6_16550A
[    6.337168] systemd[1]: Expecting device dev-ttyS0.device...

 

Trying to get any output in Putty via FTDI USB adapter connected to PG6 & PG7 / PG10 & PG11 shows nothing. Also picocom doesn't show any output.

 

If you neet more info I'll provide it asap.

 

Best Regards

We are not clairvoyant or mind readers  Please describe your setup as best as possible so we know what your operating environment is like.

 

1. Logs, when you can boot the board: armbianmonitor -u (paste URL to your forum post)

2. If your board does not boot, provide a log from serial console or at least make and attach a picture, where it stops.

3. Describe the problem the best you can and provide all necessary info that we can reproduce the problem.

uart3 overlay is currently partially broken in the stable repository (it attaches to any free tty i.e. ttyS1): https://github.com/armbian/build/issues/769

In addition there are different pinmux options that are currently not implemented.