it's annoying to rebuild on desko/lappy, and have that fail when servo
is offline/unreachable.
and it's really silly to have servo use its own cache *over the
network*.
long-term would be better to do properly distributed builds instead of
the cache.
it mostly went smooth, though i lost a .ssh key.
probably the best upgrade process is to do most of the heavy work in the
initrd:
write the new nix config, notably, configuring a tmpfs / mount
and moving the previous / to /nix.
then boot and in the initrd, move all the `/nix/nix/...` items
up a level.
this requires a patch to uboot:
- uboot thinks the drive has a capacity of 0 (i.e. 'unknown'). unclear precisely why. could be noncompliant drive firmware, or a timeout somewhere.
and a patch to the rpi bootloader:
- in order to trampoline into the rpi-4 uboot.
and custom kernel modules in the initrd:
- in order to detect the USB hub (rpi fw).
additionally, i'm MANUALLY placing `bcm2711-rpi-400.dtb` into `/boot/nixos/..-linux-5.10.111-dtbs/broadcom`.
i'll want to do this automatically over time.
i hope to simplify much of this over time: this is just the first thing which works after a couple days of hacking at it.
