MIME-Version: 1.0
References: <CAE49SAjvDAjEsyGCVpsQHY-_t0yrG_rRZRut+Zus59eESfP3YA@mail.gmail.com>
In-Reply-To: <CAE49SAjvDAjEsyGCVpsQHY-_t0yrG_rRZRut+Zus59eESfP3YA@mail.gmail.com>
From: Konstantin Kulikov <k.kulikov2@gmail.com>
Date: Wed, 4 May 2022 21:45:06 +0300
Message-ID: <CAD+eXGQYw9P2DTe2rZwB4Ni=aoeipO=MxtJUdEpYHwxUhz5L4A@mail.gmail.com>
Subject: Re: Custom Alpine Linux build
To: Hokus Pokus <pawel.polawski@gmail.com>
Cc: ~alpine/users@lists.alpinelinux.org
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable

You've basically described initramfs. Take a look at mkinitfs, which
is what alpine uses.

https://git.alpinelinux.org/mkinitfs/tree

On Wed, May 4, 2022 at 6:12 PM Hokus Pokus <pawel.polawski@gmail.com> wrote=
:
>
> Hi all,
>
> I have a question related to custom OS based on Alpine Linux.
>
> First let me describe the current state:
> Hardware environment:
> - Dell server (PowerEdge R630)
> - 4 PCI Ethernet cards (QLogic 577xx/578xx 10Gb Ethernet BCM57800)
> - 16G RAM
> - 120G SSD
> ISO image I use: alpine-extended-3.15.4-x86_64.iso
> Everything is working fine, I am able to configure network cards,
> communicate with the world, update system etc.
> Those PCI network cards uses bnx2x modules and closed source
> firmware blobs from /lib/firmware (bnx2x package) if I am correct.
> It is working fine so far.
>
> Now the target: I want to make this install even smaller.
> The purpose of this new OS will be to:
> 1) Boot from hard drive
> 2) Load this new minimal "alpine based OS" rootfs
> with only needed set of binaries / libraries
> 3) Replace the whole init and /etc/init.d with single script
> which become new init process
> 4) This script-init will initialize all the hardware
> 5) This script-init will download encrypted disk image
> 6) This script-init will unpack encrypted disk image
> 7) This script-init will mount encrypted disk image
> 8) This script-init will chroot to encrypted disk image
> and continue there after pivot will be completed.
>
> So the new Alpine based OS I want to make will be sort of
> bootstrap for another OS (linux) and as such needs only
> minimum set of functions. I plan to remove all binaries and libraries
> which are not needed as only purpose of this OS will be
> to start hardware, get network working and download file
> from remote server. From the same reason I would like to replace
> the whole init and init.d scripts with single init.sh script called
> by kernel after boot.
>
> If someone has done something similar already and can point me which
> part of the Alpine system are core for the system functionality?
>
> Alpine is using mdev for device management. What else I need to have
> for binary blobs drivers working with linux kernel? Just /etc/mdev.conf i=
n place
> and call "mdev -s" in the init script? Or there is more complicated
> hardware initialization procedure which I need to reproduce in my "init.s=
h"
> script? Should I just copy-paste some of /etc/init.d scripts and put
> them in one file in the right order?
>
> If I can go even further - replace the kernel with it modules by the mono=
lithic
> kernel which has all needed modules compiled inside? This way if I will s=
till
> need mdev for loading external firmware blobs?
>
> I was trying to find similar question on mailing lists and general forums
> but I failed.
>
> Best regards,
> Pawel
>
> --
> Pozdrawiam
>
> Pawe=C5=82 Po=C5=82awski