Possible alternate uart to see uboot on OPc+ (fried default one)

[Pieter]

Hi,

 

I seem to have "fried" the default Debug TTL UART (the 3 pins next to the hdmi connector).

(connecting the ground of the usb-ttl to TX of the UART and leaving it there for a few minutes is not a good idea it seems :-)).

 

The orangepipc+ still works when booting from emmc (armbian 5.17 debian jessie, kernel 4.7.3) but does not seem to want to boot from microsd (tried console only 5.17/4.7.3, 5.21/4.8.1). So I would like to debug that but whatever usb-ttl I connect I don't see anything (tried 3 different usb-ttl to make sure it was not the usb-ttl device)>

 

My question: is it possible to see uboot messages (or at least the kernel boot) via a different port then the Debug TTL UART? And if so, how?

[lanefu]

Okay here's a few bread crumbs.

 

You're going to have to patch the u-boot dts file for your board and make sure the resulting dtb is what u-boot is using.

 

look for arch/arm/dts/sun8i-h3-orangepi-pc.dts in the u-boot source pulled with your ambian build tools  and hopefully you can just switch the &uart0 refernces to &uart1 or whatever

 

http://orange314.com/images/thumb/c/cf/Opi_gpio.png/500px-Opi_gpio.png

 

I haven't done it, but please share your success--i've been curious about leveraging alternate UARTS.. I'm still confused about whether or not you can have more than 1 active UART with the h3

[Pieter]

Well, I've changed  arch/arm/dts/sun8i-h3-orangepi-pc.dts and changed serial0 = &uart0; to serial0 = &uart1;

Build a new armbian image (5.24, kernel 4.8.4) and booted with the usb-ttl connected to pins 37 (TX), 39 (GND) and 40 (RX).

 

Alas, that did not work. I did not see anything in minicom, neither does the device seem to claim a ip-address (nothing shows on my home-router).