The live usb is stuck on "Welcome to GRUB!"

The live usb is stuck on "Welcome to GRUB!"

[Paul Iannetta via]

Hi Guix,
(If you answer please don't forget to add me in CC, since I am not registered yet)
tl;dr
I seem unable to make GRUB work and would like to know whether it is possible to generate an image which would use extlinux/syslinux instead.
---
I am trying to install guix on a pretty old box (an HP Pavilion dv6000 series from circa 2010) with no efi support. I've been running funtoo on it for the last 5 years or so and everything is okay, the bootloader is GRUB.
As first, I tried to surgically snipe (by overwriting) the `grub.cfg` on the iso (directly with dd and the offset of grub.cfg on the iso) to not use gfxmode, to no avail. The file was properly overwritten but it seemed to not be sufficient.

Secondly, I installed the package manager guix on funtoo and tried to create an image myself.  That proved more tricky than I expected because since guix is running on a foreign distro there is no initial system configuration... and doing `guix system image -t iso9660 install.scm` fails by telling you that there is no file `install.scm` even though the file is in the current directory.
From that point, I looked up (with `locate`) the location of `install.scm` files on my system, and there was a couple in /gnu/store/xxx-guix/.../gnu/system/, I used the one which looks like this ( https://github.com/lfam/guix/blob/master/gnu/system/install.scm ). After some fiddling (some deprecated syntax (targets instead of target) and missing fields (missing description here [1]), the part with the loopback required an `addresses` field, etc.) It worked to create an image, but it was still grub.
I tried replacing `grub-bootloader` on line 455 by `extlinux-bootloader` and added `#:use-module (gnu bootloader extlinux)` at the top of the file. I could generate an image from that file but same as before the bootloader was still grub.
At that point, I tried the various options of grub to modify the gfx resolution (I suspect that grub fails to find the correct resolution of my screen and stops at the welcome screen), it worked and was reflected in the `grub.cfg` of the image. Nevertheless, the boot did not proceed any further :(
I would really like to try building an image with syslinux/extlinux to see whether I can go further but I am currently stuck now.
The last solution would be to overwrite my current distribution by guix and replace the init system by sheperd.

[1]: https://github.com/lfam/guix/blob/master/gnu/system/install.scm#L251
Regards,Paul

Re: The live usb is stuck on "Welcome to GRUB!"

[pelzflorian (Florian Pelz)]

Hello Paul.

On Thu, May 19, 2022 at 04:14:52PM +0000, Paul Iannetta via wrote:
> I seem unable to make GRUB work and would like to know whether it is
> possible to generate an image which would use extlinux/syslinux
> instead.

When creating an iso9660 image, Guix always uses grub-mkrescue to
build the image.


> […]
> The last solution would be to overwrite my current distribution by
> guix and replace the init system by sheperd.

Yes, just `guix system reconfigure` from an existing distro.

Regards,
Florian

Re: The live usb is stuck on "Welcome to GRUB!"

[Paul Iannetta]

Hi Florian,

Thank you for your kind answer!

On Saturday, May 21, 2022, 04:50:20 PM GMT+2, pelzflorian (Florian Pelz) <pelzflorian@pelzflorian.de> wrote: 

>On Thu, May 19, 2022 at 04:14:52PM +0000, Paul Iannetta via wrote:
>> I seem unable to make GRUB work and would like to know whether it is
>> possible to generate an image which would use extlinux/syslinux
>> instead.
>
>When creating an iso9660 image, Guix always uses grub-mkrescue to
build the image.

Yes, I was told the same when I asked in irc.  I think that should be underlined in the manual because it is very confusing.  I was really wondering what I was doing wrong.  In fact, I should have read the code directly.

>> […]
>> The last solution would be to overwrite my current distribution by
>> guix and replace the init system by sheperd.
>
>Yes, just `guix system reconfigure` from an existing distro.

I've been able to install archlinux which uses syslinux as its bootloader, I plan to keep the base install of archlinux in a first time and guix for the rest, and when I am be a bit more familiar with guix and can confidently generate a syslinux based bootloader configuration I'll use `guix system reconfigure` as you suggested. 

I've tried other grub based live-usbs, and all fail at the same point whatever the setup of GRUB so I think this is a GRUB bug (probably introduced fairly recently because my previous bootloader was GRUB and it worked perfectly).

Regards,
Paul