Remove dummy kernel files

[talex5]

The mirage-firewall distribution includes dummy modules.img and initramfs files. These were needed on Qubes 3 for it to accept something as a kernel.

On Qubes 4 (according to https://www.qubes-os.org/doc/managing-vm-kernel/):

All the files besides vmlinuz are optional.

We should remove these dummy files from the build and installation instructions.

[marmot1791]

As of today on Qubes R4.0 with all updates dom0 still requires the dummy initramfs to start a mirage qube, but modules.img is not required.

[marmot1791]

Opened question of whether this is a bug or a docs issue over at qubes-issues: https://github.com/QubesOS/qubes-issues/issues/5516

[marmot1791]

This is partially blocked until Qubes R4.1. Until that is released initramfs is still required.

[hannesm]

Since Qubes 4.0 is end of life now, IMHO it would be good to remove the initramfs file. This also means that our packaging and install instructions can be much simpler (we'll only distribute a single binary, and no need for tar).

Does this make sense @palainp?

[palainp]

This should be right according to the documentation, but I was unable to boot without it some times algo :/

[palainp]

This is still the case, I have the following:

$ qvm-start mirage-fw
Missing file: /var/lib/qubes/vm-kernels/mirage-fw/initramfs

[palainp]

The existence of initramfs is checked in https://github.com/QubesOS/qubes-core-admin/blob/c177aacbe1afc35034826ef538c0e49ed40b6bc7/qubes/storage/kernels.py#L140 See: https://github.com/QubesOS/qubes-issues/issues/5516

[hannesm]

Thanks @palainp for your investigations :)