Subject: [PATCH] grub-configfile tested

From: "S.Karrmann" <[email-masked]>
Date: Thu, 2 Feb 2023 20:04:21 +0100

now I generated this patch by:

git pull
git format-patch -o patches --ignore-space-at-eol origin/master..HEAD

My Emacs deletes intentionally all space at eol. Therefore, the other patch
may work with:
git apply --whitespace=warn grub-configfile.patch

---
 doc/guix.texi             | 19 +++++++++++++++++++
 gnu/bootloader.scm        | 29 +++++++++++++++++++++++++----
 gnu/bootloader/grub.scm   | 11 +++++++++++
 tests/boot-parameters.scm | 11 +++++++++++
 4 files changed, 66 insertions(+), 4 deletions(-)

diff --git a/doc/guix.texi b/doc/guix.texi
index 64873db00b..937f7c54cb 100644
--- a/doc/guix.texi
+++ b/doc/guix.texi
@@ -112,6 +112,7 @@ Copyright @copyright{} 2022 John Kehayias@*
 Copyright @copyright{} 2022 Ivan Vilata-i-Balaguer@*
 Copyright @copyright{} 2023 Giacomo Leidi@*
 Copyright @copyright{} 2022 Antero Mejr@*
+Copyright @copyright{} 2023 Dr. Stefan Karrmann@*

 Permission is granted to copy, distribute and/or modify this document
 under the terms of the GNU Free Documentation License, Version 1.3 or
@@ -38666,6 +38667,24 @@ The list of commands for loading Multiboot modules.  For example:
              @dots{}))
 @end lisp

+@item @code{config-file} (default: @code{#f})
+A string that can be accepted by @code{grub}'s @code{configfile}
+directive. This has no effect if either @code{linux} or
+@code{multiboot-kernel} fields are specified. The following is an
+example of switching to a different GNU/GRUB menu.
+
+@lisp
+(bootloader
+ (bootloader-configuration
+  ;; @dots{}
+  (menu-entries
+   (list
+    (menu-entry
+     (label "GNU/Linux")
+     (device (uuid "5cbb9a70-a3c8-4384-a085-9e6896058343"))
+     (config-file "/boot/grub/grub.cfg"))))))
+@end lisp
+
 @item @code{chain-loader} (default: @code{#f})
 A string that can be accepted by @code{grub}'s @code{chainloader}
 directive. This has no effect if either @code{linux} or
diff --git a/gnu/bootloader.scm b/gnu/bootloader.scm
index 2c36d8c6cf..7c24fd2ebf 100644
--- a/gnu/bootloader.scm
+++ b/gnu/bootloader.scm
@@ -6,6 +6,7 @@
 ;;; Copyright © 2020 Jan (janneke) Nieuwenhuizen <[email-masked]>
 ;;; Copyright © 2022 Josselin Poiret <[email-masked]>
 ;;; Copyright © 2022 Reza Alizadeh Majd <[email-masked]>
+;;; Copyright © 2022 Dr. Stefan Karrmann <[email-masked]>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -49,6 +50,7 @@ (define-module (gnu bootloader)
             menu-entry-multiboot-arguments
             menu-entry-multiboot-modules
             menu-entry-chain-loader
+            menu-entry-config-file

             menu-entry->sexp
             sexp->menu-entry
@@ -109,8 +111,10 @@ (define-record-type* <menu-entry>
   (multiboot-modules menu-entry-multiboot-modules
                      (default '()))        ; list of multiboot commands, where
                                            ; a command is a list of <string>
+  (config-file      menu-entry-config-file
+                    (default #f))          ; string, path of grub.cfg file
   (chain-loader     menu-entry-chain-loader
-                    (default #f)))         ; string, path of efi file
+                    (default #f)))          ; string, path of efi file

 (define (report-menu-entry-error menu-entry)
   (raise
@@ -126,6 +130,7 @@ (define (report-menu-entry-error menu-entry)
 @code{linux-arguments} and @code{linux-modules},
 @item multiboot by specifying fields @code{multiboot-kernel},
 @code{multiboot-arguments} and @code{multiboot-modules},
+@item config-file by specifying field @code{config-file}.
 @item chain-loader by specifying field @code{chain-loader}.
 @end enumerate"))))))

@@ -141,7 +146,7 @@ (define (device->sexp device)
   (match entry
     (($ <menu-entry> label device mount-point
                      (? identity linux) linux-arguments (? identity initrd)
-                     #f () () #f)
+                     #f () () #f #f)
      `(menu-entry (version 0)
                   (label ,label)
                   (device ,(device->sexp device))
@@ -151,7 +156,7 @@ (define (device->sexp device)
                   (initrd ,initrd)))
     (($ <menu-entry> label device mount-point #f () #f
                      (? identity multiboot-kernel) multiboot-arguments
-                     multiboot-modules #f)
+                     multiboot-modules #f #f)
      `(menu-entry (version 0)
                   (label ,label)
                   (device ,(device->sexp device))
@@ -159,13 +164,20 @@ (define (device->sexp device)
                   (multiboot-kernel ,multiboot-kernel)
                   (multiboot-arguments ,multiboot-arguments)
                   (multiboot-modules ,multiboot-modules)))
-    (($ <menu-entry> label device mount-point #f () #f #f () ()
+    (($ <menu-entry> label device mount-point #f () #f #f () () #f
                      (? identity chain-loader))
      `(menu-entry (version 0)
                   (label ,label)
                   (device ,(device->sexp device))
                   (device-mount-point ,mount-point)
                   (chain-loader ,chain-loader)))
+    (($ <menu-entry> label device mount-point #f () #f #f () ()
+                     (? identity config-file) #f)
+     `(menu-entry (version 0)
+                  (label ,label)
+                  (device ,(device->sexp device))
+                  (device-mount-point ,mount-point)
+                  (config-file ,config-file)))
     (_ (report-menu-entry-error entry))))

 (define (sexp->menu-entry sexp)
@@ -204,6 +216,15 @@ (define (sexp->device device-sexp)
       (multiboot-kernel multiboot-kernel)
       (multiboot-arguments multiboot-arguments)
       (multiboot-modules multiboot-modules)))
+    (('menu-entry ('version 0)
+                  ('label label) ('device device)
+                  ('device-mount-point mount-point)
+                  ('config-file config-file) _ ...)
+     (menu-entry
+      (label label)
+      (device (sexp->device device))
+      (device-mount-point mount-point)
+      (config-file config-file)))
     (('menu-entry ('version 0)
                   ('label label) ('device device)
                   ('device-mount-point mount-point)
diff --git a/gnu/bootloader/grub.scm b/gnu/bootloader/grub.scm
index ecd44e7f3c..7ed0d155d8 100644
--- a/gnu/bootloader/grub.scm
+++ b/gnu/bootloader/grub.scm
@@ -9,6 +9,7 @@
 ;;; Copyright © 2020 Stefan <[email-masked]>
 ;;; Copyright © 2022 Karl Hallsby <[email-masked]>
 ;;; Copyright © 2022 Denis 'GNUtoo' Carikli <[email-masked]>
+;;; Copyright © 2022 Dr. Stefan Karrmann <[email-masked]>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -377,6 +378,7 @@ (define (menu-entry->gexp entry)
           (device (menu-entry-device entry))
           (device-mount-point (menu-entry-device-mount-point entry))
           (multiboot-kernel (menu-entry-multiboot-kernel entry))
+          (config-file (menu-entry-config-file entry))
           (chain-loader (menu-entry-chain-loader entry)))
       (cond
        (linux
@@ -417,6 +419,15 @@ (define (menu-entry->gexp entry)
                     #$root-index (string-join (list #$@arguments) " " 'prefix)
                     (string-join (map string-join '#$modules)
                                  "\n  module " 'prefix))))
+       (config-file
+        #~(format port "
+menuentry ~s {
+  ~a
+  config-file ~a
+}~%"
+                  #$label
+                  #$(grub-root-search device config-file)
+                  #$config-file))
        (chain-loader
         #~(format port "
 menuentry ~s {
diff --git a/tests/boot-parameters.scm b/tests/boot-parameters.scm
index 03a1d01aff..f2d1453b2c 100644
--- a/tests/boot-parameters.scm
+++ b/tests/boot-parameters.scm
@@ -1,6 +1,7 @@
 ;;; GNU Guix --- Functional package management for GNU
 ;;; Copyright © 2019, 2020 Miguel Ángel Arruga Vivas <[email-masked]>
 ;;; Copyright © 2022 Josselin Poiret <[email-masked]>
+;;; Copyright © 2022 Dr. Stefan Karrmann <[email-masked]>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -318,6 +319,12 @@ (define %file-system-label-menu-entry
    (linux "/boot/bzImage")
    (initrd "/boot/initrd.cpio.gz")))

+(define %config-file-menu-entry
+  (menu-entry
+   (label "test-config-file")
+   (device (uuid "6d5b13d4-6092-46d0-8be4-073dc07413cc"))
+   (config-file "/boot/grub/grub.cfg")))
+
 (test-equal "menu-entry roundtrip, uuid"
   %uuid-menu-entry
   (sexp->menu-entry (menu-entry->sexp %uuid-menu-entry)))
@@ -326,4 +333,8 @@ (define %file-system-label-menu-entry
   %file-system-label-menu-entry
   (sexp->menu-entry (menu-entry->sexp %file-system-label-menu-entry)))

+(test-equal "menu-entry roundtrip, config-file"
+  %config-file-menu-entry
+  (sexp->menu-entry (menu-entry->sexp %config-file-menu-entry)))
+
 (test-end "boot-parameters")
--
2.39.1