bootloader: Add 'disk-image-installer'.

* gnu/bootloader.scm (<bootloader>)[disk-image-installer]: New field,
(bootloader-disk-image-installer): export it.
* gnu/bootloader/grub.scm (install-grub-disk-image): New procedure ...
(grub-bootloader): ... used as "disk-image-installer" here.
(grub-efi-bootloader): set "disk-image-installer" to #f.
* gnu/system/image.scm (root-partition?, find-root-partition): Move to
"Helpers" section.
(root-partition-index): New procedure.
(system-disk-image): Honor disk-image-installer, and
use it to install the bootloader directly on the disk-image, if supported.

1 files changed, 4 insertions, 1 deletions

diff --git a/gnu/bootloader.scm b/gnu/bootloader.scm
index 01bdd4acaa9..668caa7fc3f 100644
--- a/gnu/bootloader.scm
+++ b/gnu/bootloader.scm
@@ -1,6 +1,6 @@
 ;;; GNU Guix --- Functional package management for GNU
 ;;; Copyright © 2017 David Craven <david@craven.ch>
-;;; Copyright © 2017 Mathieu Othacehe <m.othacehe@gmail.com>
+;;; Copyright © 2017, 2020 Mathieu Othacehe <m.othacehe@gmail.com>
 ;;; Copyright © 2017 Leo Famulari <leo@famulari.name>
 ;;; Copyright © 2019 Ludovic Courtès <ludo@gnu.org>
 ;;;
@@ -42,6 +42,7 @@
             bootloader-name
             bootloader-package
             bootloader-installer
+            bootloader-disk-image-installer
             bootloader-configuration-file
             bootloader-configuration-file-generator
 
@@ -125,6 +126,8 @@ record."
   (name                            bootloader-name)
   (package                         bootloader-package)
   (installer                       bootloader-installer)
+  (disk-image-installer            bootloader-disk-image-installer
+                                   (default #f))
   (configuration-file              bootloader-configuration-file)
   (configuration-file-generator    bootloader-configuration-file-generator))