[bug#48314] [PATCH v3] Install guix system on Raspberry Pi

[Stefan]

Hi Petr!

> the issue seems to be connected to my guix instance on the host.

Glad to hear you figured it out.

> Then it switches to black screen

That should mean that the graphic-card is not set up properly. 

But additionally U-Boot, GRUB or the kernel could be hanging. :-/ 

> I'm testing this on Raspberry Pi 4.

I prepared everything for a 3b monthes ago. Potentially this does not match the 
current firmware or kernel anymore or does not fit the 4.

Take a look at grub-efi-bootloader-chain-raspi-64 in 
gnu/packages/raspberry-pi.scm. Read the notes there.

Take a look at raspi-custom-txt and the others there as well. You probably have 
to use it to set some parameters.

I use these with an older kernel:

dtoverlay=disable-wifi
dtoverlay=vc4-fkms-v3d,cma-64
enable_uart=1 

My best guess is a missing dtoverlay=vc4-fkms-v3d. I just noticed that there is 
meanwhile a vc4-fkms-v3d-pi4. Try that first. There are also flavours without 
the f(ake).

Attention with enable_uart, it is set in %raspi-u-boot-bootloader-txt to 1 
already. There was once a U-Boot version working without enable_uart, but the 
recent one seems to require it again.

If this does not help, then maybe the kernel needs to be customized. I never 
heard of somone else running the linux-libre kernel on a Raspberry Pi. :-)

The kernel configuration in gnu/system/examples/raspberry-pi-64.tmpl has some 
comments regarding possible customizations.


Bye

Stefan