[bug#48314] [PATCH v5] Install guix system on Raspberry Pi

[Stefan]

Hi Petr!

> Shoudn't the initrd be placed in the EFI partition?

No. As on a PC, the /boot/grub/grub.cfg lists the location of the initrd in the 
store, as it does for the kernel as well. Grub is able to read from most 
file-systems and load the initrd.

> Should I copy it and modify the Grub entry?

No.

> Unfortunately I get error about missing file:
> 
> ```
> error: file /gnu/store/xxx-raw-initrd/initrd.cpio.gz not found
> Press any key to continue ...
> ```

Is this error from GRUB? Is that file actually existing?

> I formatted it with fat32 and ext4. Ran `guix system init config.scm /init`.
> 
> I selected `(initrd-modules (list "xhci_pci" "pcie_brcmstb"))` in the config 
> and rebooted.

Was there maybe some error message about missing kernel-modules?

Was the GRUB screen as usual with a background graphic? Because that is loaded 
from the store as well.

If not, then GRUB is not able to access the store. Check the content of 
/boot/efi/efi/boot/grub.cfg. It contains two lines: one to search for the right 
file-system containing the /boot/grub/grub.cfg, and another to load it.

The search line is usually referring to an fs-uuid determined during the 
bootloader installation with the help of the grub-probe command. However, there 
is the risk grub-probe does not find an fs-uuid. In that case as a fallback the 
search command will look for a /boot/grub/grub.cfg on any readable file-system. 
Maybe it found one on a wrong file-system?

> The goal here is to run completly from USB then there won't be any need for 
> SD card.


From what you wrote, U-Boot is able to boot from USB and load GRUB. I’m just 
not absolutely sure, if GRUB is able to boot from USB on the RPi 4, but I would 
think so.


Bye

Stefan