This changes much of the make-disk-image.nix logic (and thus most NixOS
image building) to use LKL to set up the target directory structure rather
than a Linux VM. The only work we still do in a VM is less IO-heavy stuff
that while still time-consuming, is less of the overall load. The goal is
to kill more of that stuff, but that will require deeper changes to NixOS
activation scripts and switch-to-configuration.pl, and I don't want to
bite off too much at once.
The key distinction I'm drawing is that there's a component that deals
with the store of the machine being built, and another component for
the store building it. The inner part of it assumes nothing from the
builder (doesn't need chroot or root powers) so it can run comfortably
inside a Nix build, as well as nixos-rebuild. I have some upcoming work
that will use that to significantly speed up and streamline image builds
for NixOS, especially on virtualized hosts like EC2, but it's also a
reasonable speedup on native hosts.
Currently, if you try to build a NixOS config including channel.nix, e.g.:
nix-build -I nixpkgs=. -I nixos-config=nixos/modules/installer/cd-dvd/installation-cd-minimal.nix nixos -A config.system.build.isoImage
twice in a row, you end up with two different build results. This is
caused by the 'result' symlink of the first build affecting the channel
contents of the second build.
If we use filterSource with a predicate that ignores the 'result'
symlinks, the problem is gone. Do the same thing for VIM/Emacs
swap/backup files to avoid even more 'spurious' rebuilds.
Additionally, filter out the '.git' directory at the same time, as we
'rm -rf' it from the result anyway. This avoids a considerable amount of
unnecessary file I/O copying and deleting the .git directory.
Turns out all variants of start.elf and fixup.dat are needed (depending
on what's in config.txt). I was under the mistaken impression that you
were supposed to rename one of the variants to switch using them, but
nope.
* cpu-freq: Try powersave if ondemand is not available
* Revert "cpu-freq: Try powersave if ondemand is not available"
This reverts commit 4dc56db37e32dcfecd667ebbf88263e47b296097.
Consult available scaling governors; for freshly generated configs, this provides a better experience than relying on a default that might not work everywhere.
The profile minimal has several drawbacks: no man pages, unusual 'dbus'
lib that makes many X11 pieces to rebuild, etc.
With xz compression in the squashfs, despite these additions, the iso is
smaller than what it was in 16.09.
This needs to be included for VirtualBox to detect that it needs to start the video driver. "modesetting" is also set in virtualbox-image.nix but this line seems to take precedence over that one (even though the virtualbox-image.nix has a higher override?) This should fix the problems that I and a few others have been having with the .ova files built for nixos.org.
Fixes#20007.
`startAt = ""` as in `startAt = optionalString false ...` results
in an invalid timer unit (due to "" being promoted to a singleton
list and not filtered out).
Ref: c9941c4b5e
Since some changes to the setuid wrappers, there is a symlink involved
and it doesn't resolve correctly inside the chroot. Do the check inside
the chroot to make it work again.
