Re: Porting GuixSD to ARM article.

[Mathieu Othacehe <m.othacehe@gmail.com>]

Hi Andreas,

> I am reading it only now (since I wish to install GuixSD on an ARM board
> of mine, but better late than never...). Very nice work and write-up!

Thank you :)

> But I still have a few questions:
> - Now that there is a release 0.14, could the images not be made available
>   on the website?

I just saw that Danny proposed a patch about it!

> - In my case, I own an Olimex Lime 1. I think that this might correspond
>   to a20-olinuxino-micro-installation-os. Whatever it is, it does not have
>   integrated memory, but needs to run directly from the micro SD card.
>   So how do I install it, since I cannot boot from one medium and install
>   easily to another one? Should I attach an SD card reader to install onto
>   a second SD card, then boot from that in a second step?

I guess you can do like I did in "Preparing a dedicated system
configuration" section of the article. That means preparing a config.scm
that suits your needs, run a "guix system disk-image
--system=armhf-linux config.scm" and dd the image obtained on a SD
card. There is no "installation image" per-se, you build the system that
you'll directly use once booted.

>   Would it not make sense to provide not installation images, but installed
>   images? These could be used to directly boot the machines, and then instead
>   of doing "guix system init", one should be able to do a "guix system
>   reconfigure". To develop a bit more, the two-step installation (first
>   creating a disk image, then installing onto the hard drive) could be seen
>   as an artefact of installing on bigger machines with their more complicated
>   setting using grub, and where taking out the hard disk and copying an image
>   with dd onto it is not so practical... Why should it not be easier to
>   directly boot the final GuixSD on an ARM machine?

Unless I don't get you right, it's already working! You don't need to
run "guix system init" like I said before. Once you booted the mpd
server, you can reconfigure it to add a new package, there's no init
involved.

>   Notice that the last section of the blog post does not solve the problem:
>   As I realised by trial and error when trying to use a disk-image for a
>   virtual machine, it really is only an installation-image, since user data
>   is stored in an overlay file system that is lost upon reboot.

It's only true if your image is including "%installation-services" that
provides "cow-store-service". That's why in the mpd.scm from the article
the system is not inherited from beaglebone-black-installation-os. By
starting from mpd.scm you should be able to write a system config that
can boot and be used directly without any further installation step.

> - Suggestion in that context: Rename "guix system disk-image" to "guix system
>   installation-image".

Unless I'm wrong above, "guix system disk-image" is used to provide both
"ready-to-use" images and "installation-images" (and possibly other kind
of images too), so I don't think that would be a good idea.

> Thank you again for the post, and I am looking forward to more instructions
> for the other boards!
>

Thanks, I hope you will be able to produce a working GuixSD image for
your target. Don't hesitate to ask other questions!

Mathieu