Alternate Debug Console without CON3

In retail version of OGA, there is no UART port from CON3.
An alternate debug console from 10pin header can replace it with kernel reconfiguration.
With this debug option, kernel debug is only available and u-boot option is not ready so far.

If you want to solder 4pin connector on UART2 by yourself, please refer to this section.
4pin connector configuration

Kernel Modifications

To activate this function, you need to build kernel with one patch.

Currently, rockchip fiq debugger driver (via ttyFIQ0) is used as debug console function.
To switch output port flexibly, the following points can be adjusted for kernel.

Disable fiq-debugger

https://github.com/hardkernel/linux/blob/odroidgoA-4.4.y/arch/arm64/boot/dts/rockchip/rk3326-odroidgo2-linux.dts#L177

	fiq-debugger {
		compatible = "rockchip,fiq-debugger";
		rockchip,serial-id = <2>;
		rockchip,wake-irq = <0>;
		/* If enable uart uses irq instead of fiq */
		rockchip,irq-mode-enable = <0>;
		rockchip,baudrate = <115200>;  /* Only 115200 and 1500000 */
		interrupts = <GIC_SPI 127 IRQ_TYPE_LEVEL_LOW>;
		pinctrl-names = "default";
		pinctrl-0 = <&uart2m1_xfer>;
                /* Change this point */
		status = "disabled";
	};

Enable UART2

Add the following in rk3326-odroidgo2-linux.dts, too.

&uart2 {
	pinctrl-names = "default";
	pinctrl-0 = <&uart2m1_xfer>;
	status = "okay";
};

boot.ini Modification

Through kernel command, it's available to assign console output.
Here is an example of boot.ini.

# console device setting
setenv condev "console=ttyS2,115200n8 console=tty0"   # on uart2 / display
# setenv condev "console=ttyS1,115200n8 console=tty0"   # on uart1 / display

# Boot Arguments
setenv bootargs "root=/dev/mmcblk0p2 rootwait rw fsck.repair=yes ${condev} net.ifnames=0 fbcon=rotate:3"

HW Configuration



Reference Forum Thread

Molex 5268-04a

  • Pitch : 2.5mm
  • Circuit Size : 2 - 15

Here is a reference link of this part.
https://www.molex.com/molex/products/part-detail/pcb_headers/0022057045

It's a same part that is used for other ODROID models.
https://wiki.odroid.com/accessory/development/usb_uart_kit?s[]=4pin#odroid_port_description_of_uart_connector



For the line configuration, please refer to the previous section of this wiki page.