Making a custom gentoo livecd

bperegrine · n00b Joined: 23 Dec 2017 Posts: 37

I was wondering what the essential packages (ebuilds) are for a stripped-down (lightweight) gentoo livecd ?
My intent would be to make a gentoo livecd that fits on a standard cd (not DVD !). Also, it should be stripped to its essentials, but still be practical for use by everyday users. A generic x86 version and a generic x86_64 version would need to be made (by generic I mean it should run on any x86 architecture, so the x86 version for example should need to be able to run on intel pentium 2, 3, 4, D, M as well as AMD Athlon, Zen, Ryzen, ...). I heard making such a small livecd should be possible (uncompressed a size of 1,2 gb is possible, and when this is compressed, as always the case on a livecd, it should be possible to have the size reduced to say 500 mb or so).

I made a list of packages (ebuilds) that definitely need to be in the livecd, see
https://github.com/ecocomputing/TAZ/blob/master/gentoo_ebuilds_and_tbz2s/Catalyst_specfile.txt

Can you guys tell me what packages are still missing and which I need for a fully functional gentoo distro ?

Once I have a list of all the needed ebuilds, I would need to download all the ebuilds, upload them to github, and then make binaries from them (tbz2's), using my cflags text. These would be uploaded to github again, and then the livecd would be made using the tbz2's and the image of the livecd would be uploaded again to github.

How do I best go about this ? I don't have gentoo running on my pc, nor have I ever used it in the past (I'm new to it).

PS: Note that one of the reasons why I want to use tbz2's is because that way, a sort of "many-in-one iso" livecd can be made. This allows to load only those programs that are needed for that computing session. See the 8 boot setups mentioned at the catalyst specfile link.
I assume this will be possible in gentoo ?

NeddySeagoon · Posted: Mon Dec 25, 2017 10:59 am Post subject:

bperegrine,

Welcome to Gentoo

The gentoo solution to this is the catalyst tool.
Its scrpit driven and it used by all the autobuilds. LiveCD, LiveDVD and stages.

bperegrine · n00b Joined: 23 Dec 2017 Posts: 37

NeddySeagoon · Posted: Mon Dec 25, 2017 7:40 pm Post subject:

bperegrine,

An ebuild is a recipe for the portage package manager to build a package and install it in Gentoo.
Itself, its a single file but on its own its not complete. You can't use it wiithout a Gentoo install.

There are several Gentoo LiveCDs. The traditional minimal CD only provides enough to install Gentoo at the ronsole.
System Rescue CD is gentoo based and gives you a GUI.

Older PCs can boot from CD, but the method is a bit convoluted. You can't use syslinux but need to create a bootable floppy image that contains the kernel and initrd.
That's a challenge with modern software, since you will have at most 2.88Mb and possibly only 1.44Mb to work with.
It might be possible just to include a boot loader in that image.
Then there is the complication that the floppy image needs to be in the right place on the CD.

That github link is the Gentoo ebuild repository.
_________________
Regards,

NeddySeagoon

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

bperegrine · n00b Joined: 23 Dec 2017 Posts: 37

NeddySeagoon · Posted: Tue Dec 26, 2017 1:07 pm Post subject:

bperegrine,

The entire repo is available as a read only squashfs image.
You may not need it all but you will go mad trying to get single ebuilds. Each ebuild lists almost all the packages that the given package depends on.
Its 'almost' as ebuilds are permitted to assume that the @system set is always available.
A lot of the complexity is hidden in eclasses, which are like libraries called by ebuilds.

bperegrine · n00b Joined: 23 Dec 2017 Posts: 37

NeddySeagoon · Posted: Tue Dec 26, 2017 5:11 pm Post subject:

bperegrine,

You need to understand how portage works.
The portage package manager works with the Gentoo repo and overlays to build the distro that you have designed.

Catalyst is a layer on top of the portage package manager and Gentoo repo to automate rebuilding the distro that you have designed.

You need to use Portage and the Gentoo repo to get to grips with how it works.
Portage, the Gentoo repo, the toolchain, headers and so on are required at build time, they are not required at run time.
Thus building Gentoo and running Gentoo can be two different things.

Try the minimal CD. It is a running Gentoo. You can't use it for building things. It runs almost anywhere but only has the tools needed to install Gentoo.
That does not include the Gentoo repo, the toolchain, headers ... Its run time only.
The System Rescue CD is similar.

You are repeating work that others have already done. In the open source way, you should build on that or you will repeat it.

Portage allows per package settings, including CFLAGS. CFLAGS do not affect the dependency tree.
They change how gcc works, not what it works on.

You will not understand how portage works without using it.

Catalyst outputs an .ISO file if that's what you want.
_________________
Regards,

NeddySeagoon

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

bperegrine · n00b Joined: 23 Dec 2017 Posts: 37

NeddySeagoon · Posted: Fri Dec 29, 2017 4:09 pm Post subject:

bperegrine,

1) Install Gentoo and get a feel for it.
2) Make your ISO distribution system support zsync.
_________________
Regards,

NeddySeagoon

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

stolar · Posted: Thu Oct 11, 2018 9:50 pm Post subject:

NeddySeagoon,

Could You please leave a tip here on how to modify a Gentoo LiveCD so that it contains a specified kernel drivers?
Shortly speaking, i wanted to use current minimalCD to install Gentoo on some old x86 laptop. Unfortunately neither the current MinimalCD nor the one from 2011 works for me to boot on this laptop since it uses PCMCIA CD-ROM. However, my oldest found Gentoo 2004 CD boots on this laptop (after passing