Can't boot without the WIFI board

[alexfreed58]

I got more luck with the just found A13-OLinuXino-buster-base-20210513-112230.img

It boots OK but only if the WIFI board is plugged in and power comes from the USB connector.
When I try to boot the standalone CPU module powering it from a nice 3.3 V lab power supply via the UART1 pin, all I get is:
U-Boot SPL 2021.04+olimex-1-20210507.081028 (May 07 2021 - 08:11:19 +0000)
DRAM:
U-Boot SPL 2021.04+olimex-1-20210507.081028 (May 07 2021 - 08:11:19 +0000)
DRAM:

forever.

What am I doing wrong? Also is there a document on compiling the kernel so that I can modify the video settings? I want to use an 800x600 9" LCD.

[LubOlimex]

I tested it today and it boots fine.

Probably insufficient power supply over the 3.3V or wonky connections. Might be corrupted file system on the card, so also try to re-write that.

Also I assume you split the GND - one wire for serial debug and the other for the power supply?

About the displays investigate the overlays here:

https://github.com/OLIMEX/olinuxino-overlays

Notice there is command in the Linux olinuxino-display - check that too.

[alexfreed58]

Thanks for the reply. Indeed the module is quite sensitive to the power quality, so that is solved.
As for the video overlays: the mentions tool "olinuxino-display" just selects one of pre-defined overlays. Is there a document on building your own?

I have compiled a kernel "Linux version 3.4.104+" following the instructions, but it fails with a kernel panic, same as the pre-built image.

My CPU board has an "old" SDRAM chip. Does that require some special handling?

[LubOlimex]

Did you use sunxi or mainline u-boot? This is the difference between compilation for different RAM chips. Check again the instructions here:

https://github.com/OLIMEX/OLINUXINO/tree/master/SOFTWARE/A13/A13-build