This commit changes the console colors implementation
to use the kernel parameters instead of relying on terminal
escape sequences. This means the palette is applied by the
kernel itself with no custom code running in the initrd
and works for all virtual terminals (not only tty0).
This commit moves all the virtual console related options
to a dedicated config/console.nix NixOS module.
Currently most of these are defined in config/i18n.nix
with a "console" prefix like `i18n.consoleFont`,
`i18n.consoleColors` or under `boot` and are implemented
in tasks/kbd.nix.
Since they have little to do with actual internationalisation
and are (informally) in an attrset already, it makes sense to
move them to a specific module.
This makes ~2.5x speed up of an empty container instantiate, hence reduces
rebuild time of system with many declarative containers.
Note that this doesn't affect production systems much, becaseu those most
likely already include `minimal.nix` profile.
The upstream session files display managers use have no concept of sessions being composed from
desktop manager and window manager. To be able to set upstream session files as default
session, we need a single option. Having two different ways to set default session would be confusing,
though, so we decided to deprecate the old method.
We also created separate script for each session, just like we already had a separate desktop
file for each one, and started using displayManager.sessionPackages mechanism to make the
session handling more uniform.
There's two ways of providing graphical sessions now:
- `displayManager.session` via. `desktopManager.session` and
`windowManager.session`
- `displayManager.sessionPackages`
`sessionPackages` doesn't make a distinction between desktop and window
managers. This makes selecting a session provided by a package using
`desktopManager.default` nonsensical.
We therefor introduce `displayManager.defaultSession` which can select a session
from either `displayManager.session` or `displayManager.sessionPackages`.
It will default to `desktopManager.default + windowManager.default` as before.
If the dm default is "none" it will select the first provided session from
`sessionPackages`.
