A recent commit seems to indicate that HDMI output from U-Boot is now supported.
Is it feasible to get output on the internal screen? What would be required?
I was working on getting ArchLinux ARM running (Spoiler: Unless you have a kernel with I suspect at least the PCIe clock patch, USB and Wifi won’t work; the internal panel doesn’t work on ALARM 12.3 either.) and the U-Boot experience isn’t great.
The serial connector is on the bottom, but the only way to turn on the SOM I found is by using the keyboard (Circle, 1) on the other side. Restarting the SOM is possible with a button on the back.
Saving the U-Boot environment doesn’t seem to work (I saw comments around MMC/SD for env storage and crashes when trying to save on SD), so I had to copy commands during testing and then recompile U-Boot and add it to the SD to hardcode working commands.
I’m not sure on the preferred way to handle testing (typing commands on the internal keyboard without copy/paste would be tedious and error prone as well), but for general boot I’m considering changing U-Boot to read a script file from SD/MMC, writing U-Boot to MMC and changing the boot order on the SOM to set boot from MMC as default as hinted at in Advanced Chapter of the handbook.