64b4af5296 ("kmod-blacklist-ubuntu: 22-1.1ubuntu1 -> 28-1ubuntu4")
doubled the size of the default initramfs. This happened because the
upgrade introduced this configuration:
remove iwlwifi \
(/sbin/lsmod | grep -o -e ^iwlmvm -e ^iwldvm -e ^iwlwifi | xargs /sbin/rmmod) \
&& /sbin/modprobe -r mac80211
This meant that the grep and xargs substitutions, which had been
inactive for years, suddenly became active again and became part of
kmod-blacklist-ubuntu's closure.
Since we're already using /run/booted-system for the kmod binaries,
I think it's okay to use it for grep and xargs as well. Both are
required NixOS packages, so they're guaranteed to be there.
Large increases in initramfs size are problematic, because it's often
not possible for users to do anything about them. It's not always
possible to increase the size of /boot, because some filesystems like
ZFS don't support being shrunk to make way for a bigger /boot.
This reverts commit 0307c27219.
The only change was blacklisting bochs-drm, but that breaks our VM setup
and I don't see a good reason to do that on the Ubuntu issue
(just some PowerPC failure).
Defaulting to qxl driver might be better anyway, but I'm not venturing
such changes now.
