Re: Supergrub2disk helped me to have the choice at startup

[hub.lombard@free.fr]

Hello Guix people :) 

Thanks again Josuha and Maxim for your answers \o

I realize that my last post shows a certain lack of knowledge of the subject from me but I have the impression of having progressed a little.

I have tried to inser menu-entry into (or after?) (bootloader but I have obtained several errors...  
"unbound variable", "invalid field initialized"... etc.

Here is how far I have been able to explore, without success for now:

root@gnu ~# guix system reconfigure /etc/config.scm
/etc/config.scm:9:0: error: extraneous file initializers (menu-entries)

Excerpt :

----------------------------------------------------------------
;; Operating system configuration for a full
;; "desktop" environment with gnome and
;; gnome-shell

(use-modules (gnu) (gnu system nss))
(use-service-modules desktop networking ssh)
(use-package-modules bootloaders certs gnome screen ssh)              

(operating-system
  (host-name "gnu")
  (timezone "Europe/Paris")
  (locale "en_US.utf8")

;; Assuming /dev/sda is the target hard disk, and "my-root" is
;; the label of the target root file system, and /dev/sda6 
;; the target partition for the GuixSD-0.16
;; installation. 
(bootloader (bootloader-configuration
              (bootloader grub-bootloader)
              (target "/dev/sda")))
            (menu-entries
              (list
                (menu-entry
                 (label "Debian GNU/Linux")
                 (linux "/boot/old/vminuz-4.19.0-1-amd64")
                 (linux-arguments '("root=/dev/sda1")
                 (initrd "/boot/old/initrd.img-4.19.0-1-amd64")))))                     

(file-systems (cons (file-system
                      (device "my-root")
                      (title 'label)
                      (mount-point "/")
                      (type "ext4"))
                     %base-file-systems))
------------------------------------------------------------------------

root@gnu ~# guix system reconfigure /etc/config.scm
/etc/config.scm:9:0: error: extraneous file initializers (menu-entries)

I have consulted a lot of documentation and examples but several things still escape me :)

Do you know where I should explore?

Hubert, an end user of GuixSD enthusiastic

----- Mail original -----
De: "hub lombard" <hub.lombard@free.fr>
À: "Maxim Cournoyer" <maxim.cournoyer@gmail.com>
Cc: "Help Guix" <help-guix@gnu.org>
Envoyé: Dimanche 20 Janvier 2019 10:10:13
Objet: Re: Supergrub2disk helped me to have the choice at startup

Hello Maxim :)

 Thank you for your answer, maybe I will make a test like :


;; Operating system configuration for a full
;; "desktop" environment with gnome and
;; gnome-shell

(use-modules (gnu) (gnu system nss))
(use-service-modules desktop networking ssh)
(use-package-modules certs gnome screen ssh)

(menu-entries                                         ;To obtain the relevant informations about
  (list                                               ;label, linux, linux-arguments and initrd
    (menu-entry                                       ;I had a look to the grub.cfg's Debian.
    (label "Debian GNU/Linux")                        ;What about the '/old' reposiory?
    (linux "/boot/old/vmlinuz-4.19.0-1-amd64")        ;Like the exemple given by Joshua and Maxim,
    (linux-arguments '("root=/dev/sda1"))             ;I think to put it in the same place.
    (initrd "/boot/old/initrd.img-4.19.0-1-amd64")))  ;Not tested yet

(operating-system
  (host-name "gnu")
  (timezone "Europe/Paris")
  (locale "en_US.utf8")

;; Assuming /dev/sda is the target hard disk, and "my-root" is
;; the label of the target root file system, and /dev/sda6 the
;; target partition for the GuixSD's installation.
(bootloader (grub-configuration (target "/dev/sda")))
(file-systems (cons (file-system
                      (device "my-root")
                      (title 'label)
                      (mount-point "/")
                      (type "ext4"))
                    %base-file-systems))


----- Mail original -----
De: "Maxim Cournoyer" <maxim.cournoyer@gmail.com>
À: "hub lombard" <hub.lombard@free.fr>
Cc: "Help Guix" <help-guix@gnu.org>
Envoyé: Samedi 19 Janvier 2019 17:53:16
Objet: Re: Supergrub2disk helped me to have the choice at startup

Hello Hubert!

hub.lombard@free.fr writes:

> Hi Guix :)
>
> A few days ago, I managed to install GuixSD 0.16 next to debian testing on a Packard Bell 'EasyNote TE' laptop.
> At reboot, Grub only offers GuixSD.
> To have the choice at startup, I used the 'supergrub2disk' that I downloaded and put on a USB key, positioned as the first boot device.
> SuperGRUB2disk gives me the choice between GuixSD and debian, and I can start either one without any problem.
>
> For now, I keep the USB key inserted in the computer and everything is fine, having nevertheless planned to address the problem of the restoration of GRUB. 
>
> Would someone have a track that would enlighten me a bit?

In GuixSD, the way to handle dual (or more) boot is to define a list of
menu-entries for the bootloader configuration in your OS config. It's
documented here:
https://www.gnu.org/software/guix/manual/en/html_node/Bootloader-Configuration.html.

For an actual example, this post might give you some idea:
https://lists.gnu.org/archive/html/help-guix/2017-04/msg00045.html.

Good luck!

Maxim