Hi all,

This patch is intended to be merged alongside the introduction of sys-kernel/installkernel-gentoo-8. Version 8 introduces:
- UKI compatibility
- The ability to use /etc/kernel/preinst.d plugins, to complement the
existing /etc/kernel/postinst.d plugins
- An optional dracut preinst.d plugin that is intended to be toggle-able
with USE=dracut, similar to the existing GRUB postinst.d plugin that is toggle-able with USE=grub

This last change is what the eclass patch below is for. This patch
encapsulates the initrd related code from the dist-kernel-utils and kernel-install eclasses in a "if has_version "<=sys-kernel/installkernel-gentoo-7";".
Offloading the initrd/uki generation to installkernel plugins gives
users the ability to use initrd generators other than dracut. And also
allows users of manually configured and compiled kernels to
automatically generate an accompanying initrd/uki if desired (make
install calls installkernel which can call an initrd/uki plugin if one
is installed).

Note that sys-kernel/installkernel-systemd already has a plugin to run
dracut on kernel installation, installed by sys-kernel/dracut itself, so
no further changes are required there.

I'm aware some people have strong feelings about what installkernel
should and should not do, and what should be automagic and what not.
I've done my very best to accommodate all needs and concerns, and I
believe the latest iteration[1] should make everyone happy. Nonetheless,
I'll give everyone some more time to complain, provided there are no insurmountable objections I'll merge [1] in about 7-10 days and release
the new version 8 shortly after.

A follow-up eclass patch that cleans-up the eclasses and drops support
for <=sys-kernel/installkernel-gentoo-7 will follow later once version 8
is stable, a sneak-preview of this patch can already be found in my PR[2].

[1] https://github.com/projg2/installkernel-gentoo/pull/10
[2] https://github.com/gentoo/gentoo/pull/33727


From 948a66a862f29b1356e530f95078c48c5bedbae0 Mon Sep 17 00:00:00 2001
From: Andrew Ammerlaan <andrewammerlaan@gentoo.org>
Date: Wed, 8 Nov 2023 14:46:19 +0100
Subject: [PATCH] eclass/(dist-)kernel{-utils,-install}: More flexible
initrd generation

We only need to call dracut to generate an initrd/uki if we are using <=sys-kernel/installkernel-gentoo-7. sys-kernel/installkernel-systemd
already calls dracut via its plugin system if it is installed. sys-kernel/installkernel-gentoo-8[dracut] now also contains the code
required to generate an initrd or uki.

This change makes it possible for users to use other/custom initrd
generators with our dist kernels.

Signed-off-by: Andrew Ammerlaan <andrewammerlaan@gentoo.org>
---
eclass/dist-kernel-utils.eclass | 50 ++++++++++++++++++++-------------
eclass/kernel-install.eclass | 30 ++++++++++++++------
2 files changed, 52 insertions(+), 28 deletions(-)

diff --git a/eclass/dist-kernel-utils.eclass
b/eclass/dist-kernel-utils.eclass
index 76a2f8d48cdf1..62750d1721a2c 100644
--- a/eclass/dist-kernel-utils.eclass
+++ b/eclass/dist-kernel-utils.eclass
@@ -116,21 +116,23 @@ dist-kernel_install_kernel() {
local image=${2}
local map=${3}

- # if dracut is used in uefi=yes mode, initrd will actually
- # be a combined kernel+initramfs UEFI executable. we can easily
- # recognize it by PE magic (vs cpio for a regular initramfs)
- local initrd=${image%/*}/initrd
- local magic
- [[ -s ${initrd} ]] && read -n 2 magic < "${initrd}"
- if [[ ${magic} == MZ ]]; then
- einfo "Combined UEFI kernel+initramfs executable found"
- # install the combined executable in place of kernel
- image=${initrd%/*}/uki.efi
- mv "${initrd}" "${image}" || die
-
- if [[ $