--- Comment #26 from Matthias Brugger email@example.com --- (In reply to Duy Hua from comment #17)
At first, we need to run board G2Mv3.0 so we have "r8a774a3-hihope-rzg2m-ex-idk-1110wr.dts" config for this board.
I realized that we are missing config options for the serial console driver. I queued the changes for tumbleweed. This should allow you to use earlycon to see what happens on the board. As always it will take some time to be published though. If you want I can provide you with a test kernel that you can use to test in advance.