The Raspberry Pi boot loader was deleting all xx-initrd text files
(which simply contain the path to the actual initrd files) just after
having created them. The code was actually trying to delete real,
obsolete initrd files, which are named <hash>-initrd-initrd (after path
cleaning), but the glob was catching the other files as well.
It boots, but some things still don't work:
1) Installation of DTBs
2) Boot of initrd
Booting still needs a proper config.txt in /boot, which could probably be
managed by NixOS.
Using pkgs.lib on the spine of module evaluation is problematic
because the pkgs argument depends on the result of module
evaluation. To prevent an infinite recursion, pkgs and some of the
modules are evaluated twice, which is inefficient. Using ‘with lib’
prevents this problem.
