Rock64 <--> Rock64 Serial Connection

[mark1250]

I'm trying to troubleshoot a booting problem with my Rock64 with an openSUSE Tumbleweed install on an eMMC. When I cat /sys/firmware/fdt while using my USB UART the output is garbled. I have a second Rock64 that I'd like to use instead of my USB UART. When I hookup the tx > rx and rx > tx , both Rock64 lockup. So, is there a way to use the 2nd Rock64 in this manner? Or, is there a way to get ungarbled output with my USB UART (My USB UART, which I've had for more than 3 years has a CH340G IC on it, and I'm using 11" factory made Dupont wires).

Here's a sample of the garbled output

Code:

sh-5.1# cat /sys/firmware/fdt
�����8�t(Q�<�5d11a380e54bb488kchpine64,rock64rockch+7Pine64 Rock64memory�memoryaliases=/serial@ff110000E/serial@ff120000U/i2c@ff150000Z/i2c@ff160000_/i2c@ff170000i/ethernet@ff540000s/ethernet@ff550000}/mmc@ff500000cpus+cpu@0�cpuarm,cortex-����x�psci�
        cpu@1�cpuarm,cortex-a����x�psci��
cpu@2�cpuarm,cortex-a5����x�psci��
cpu@3�cpuarm,cortex-a5�����x�psci��
idle-statespscicpu-sleeparm,idle-state*;Rxc�l2-cache0cacheopp_table0operating-points-v2�opp-4�Q��~���@�opp-60000000�#opp-81600000�0�,�B@��@opp-1008000000�����@opp-120000000�G����(pp-129600000�M?d�� ��@analog-soundo-card�i2s��Analogokaysimple-audio-card,codearm-pmuarm,corefg'
display-subsystem:jhdmi-soundsimple-audio-card�iokayksimple-audio-card,cpusimplepsciarm,psci-1.0arm�smctimerarm,armv8-timer
xin24mfixed-clock@mDi2s@ff000000(rockchip,rk3328-i2srockchip,rk3066-i2s�)7pi2s_clki2s_hclk|okayi2s@ff010000(rockchip,rk3328-i2si2s��8pi2s_clki2s_hclk|�txrx�okayi2s@ff020000(ip,rk3066-i2s���+9i2s_hclk|Minicom2.7.1Minicom2.7.1Minicom2.7.1Minicom2.7.1Minicom2.7.1Minicom2.7.1m2.7.1Minicom2.7.1Minicom2.7.1Minicom2.7.1Minicom2.7.1�txrxlspdif@ff030000rockchip,rk3328-spdif���.:

Thanks for any assistance.

Mark