suggestion for customized initramfs

[mortonP]

I got this old installation for creating initramfs

[NeddySeagoon]

mortonP,

Do it yourself.
Your initramfs can be like firmware, fixed for the life of of the system. No kernel modules included.

My systems last so long, I forget how to do it from one to the next.

That guide does not yet cover LUKS. Feel free to contribute.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

[bstaletic]

[NeddySeagoon]

mortonP,

5 years ... is that all ?
The update will teach you things about portage you can learn no other way.

There is no need to 'faff about' with git any longer if your kernel supports squashfs.
There are old snapshots on line, back to April 2016.

You may have problems finding older source files.

The idea is to do the updates you missed in 6 month or so steps.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

[zen_desu]

If you don't want to make it fully custom, I recommend my tool ugrd: https://github.com/desultory/ugrd

I think it does most of what you want. It avoids systemd/udev, makes tiny images, and it has a rather robust kmod dependency/ignore system.

it's integrated with installkernel and automatically handles most LUKS config for you so "just works".

I'm considering removing this 'feature' but at the moment, it leaves the build dir in /tmp/initramfs_build where you can modify or repack it. This is a bit of a vestigial feature, as ugrd was designed using the custom initrmafs wiki page as a guide. Now, it implements its own CPIO packer and does not need to copy files, but does to make the build more transparent to the user.

ugrd allows users to disable all builtin modules and simply use it as an automated dependency resolution script (runs lddtree, etc)

the LUKS key handling stuff already works by key command injection https://github.com/desultory/ugrd/blob/main/src/ugrd/crypto/gpg.toml#L9

it's also designed so users can specify a custom key command without actually making a new module.
_________________
µgRD dev
Wiki writer

[sdauth]

Although the repo is now read-only, I've been using this for years now: https://github.com/fff7d1bc/better-initramfs
It builds a tiny initramfs with binaries statically linked (musl)
Assuming no modules is needed, this is a good choice. In my case, everything crucial is built-in so I only need cryptsetup + busybox for my setup.
The whole xz compressed initramfs is 1.7M (4.0M uncompressed)

[mortonP]

[zen_desu]

If you want to try ugrd, you can simply add the USE flag to installkernel, and make install on sources or running emerge --config on dist-kernel should handle the rest for you.

It autodetects LUKS mounts and requires no additional config unless keyfiles are used.

Unlike genkernel it does not make any attempt to configure your kernel, but will attempt to pull required kmods or check that they are builtin.
_________________
µgRD dev
Wiki writer

[mortonP]

[zen_desu]

[sublogic]

[zen_desu]

[NeddySeagoon]

mortonP,

A monolithic kernel is not required for the DIY initrd approach.
As there is nowhere to load modules from until root is mounted, the kernel code to achieve mounting root must be built in. Other things can sttll be modules.

zen_desu,
The kernel provided script

[zen_desu]