Re: Initramfs Scripts

On Thu, Jun 5, 2025 at 1:39 PM Rahul Chandra <[email protected]> wrote:
>
> Currently the initramfs scripts in BLFS are entirely broken, meaning
> even the limited subset of features we say to use an initramfs for
> (drive encryption, network boot, and LVM) don't function. Here is a
> list of the issues
>
> 1. /etc/group missing -- The default 50-default-udev rule requires the
> base groups from LFS in order to load properly
> 2. Missing libkmod.so files, udev (at least on systemd) can't load
> modules without a library link to kmod
> 3. Missing cgroup mount -- Control groups are almost required nowadays
> to load modules properly, we need to add a control group mount in
> /sys/fs/cgroup to fix this
> 4. udevadm trigger command. I don't know when this changed but udevadm
> trigger doesn't load modules anymore, you need to add the --action=add
> flag for it to actually load the modules
>
> Other fixes I did a long time ago
> 5. This is an issue I had fixed a few years ago in my homebrewed
> version of the initramfs scripts -- The initramfs scripts currently
> pick a subset of modules on the system. In this version, it
> dynamically finds the modules currently loaded and adds them to the
> initramfs
> 6. Firmware -- Loading firmware in the initramfs (required for some
> RAID cards and network cards) was not supported with the old scripts.
> These one's copy the firmware based on the modules that are currently
> loaded.
>
> Other nice to haves  in this version
> 7. Forceful early module load -- I added a /etc/early-modules-load.conf file
> cat > /etc/early-modules-load.conf << EOF
> # This file is for loading modules in the early boot stages in the initramfs
> EARLY_LOAD_MODULES=""
> EOF
> To allow for loading modules that aren't required for the system (e.g
> vfio or kvmgt for gvt-g/iommu)
> 8. Modprobe.d support -- to support the last point, config files in
> /etc/modprobe.d are obeyed.
>
> If someone could test this on sysv and let me know how it goes I can
> push this to the book and file an errata.
>
> See attached, you can diff the current one from
> https://www.linuxfromscratch.org/blfs/view/stable-systemd/postlfs/initramfs.html
> and this one to see the changes.


One more modification I forgot to mention. This one also has a --live
parameter that behaves like Arch and Debian's "Fallback" initramfs. It
includes all modules instead of dynamically figuring out which one's
to include. It's useful for live-cds and moving an existing LFS drive
to a new system



-- 
Rahul

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