On Tue, Jan 10, 2023 at 08:31:21PM +0000, Alyssa Ross wrote:
> On Mon, Jan 09, 2023 at 04:34:33PM +0200, Ivan Nikolaenko wrote:
> > This patch makes it possible to use custom linux kernel.
> > This is needed in case of porting Spectrum OS to the other
> > hardware than generic-x86.
> >
> > To override rootfs kernel, define "spectrum_kernel" in the
> > customization overlay.
> >
> > Signed-off-by: Ivan Nikolaenko <ivan.nikolaenko@unikie.com>
> > ---
> >  host/rootfs/default.nix | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
>
> Did you change your mind from the approach you suggested in your
> previous email? [1]  I liked that approach, because it didn't require
> adding something custom to the global Nixpkgs namespace that's only used
> in one place, outside of Nixpkgs.

Actually, I'm guessing the reason for doing it this way is that then
even if you want to import e.g. release/live rather than host/rootfs,
it's still easy to override the kernel.

So to preserve that nice property, there are a couple of possibilities
for how we could approach this:

 - Just override linux_latest in your overlay.  The advantage to that is
   that it means Spectrum doesn't have to worry about the concept of a
   custom kernel, but the disadvantage is that it might mean unecessary
   rebuilds or other problems caused by packages that don't expect
   linux_latest to be something custom.

 - Add a "hostKernel" option to the config attribute set.  This would
   work very similarly to what you have here.  It just means that we're
   using our own namespace rather than the Nixpkgs one.

The first option is best for me, because it means no changes to Spectrum
are required, but if it's causing you problems, then I wouldn't mind
adding the config option.

> [1]: https://spectrum-os.org/lists/archives/spectrum-devel/4d41315a-05d2-747c-3708-37f7c8c34684@unikie.com/
>
> >
> > diff --git a/host/rootfs/default.nix b/host/rootfs/default.nix
> > index 0a84f55..b853250 100644
> > --- a/host/rootfs/default.nix
> > +++ b/host/rootfs/default.nix
> > @@ -81,7 +81,7 @@ let
> >      imports = [ (modulesPath + "/profiles/all-hardware.nix") ];
> >    });
> >
> > -  kernel = pkgs.linux_latest;
> > +  kernel = pkgs.spectrum_kernel or pkgs.linux_latest;
> >
> >    appvm = import ../../img/app {
> >      inherit config;
> > --
> > 2.34.1
> >
> >