image: Add support for 32bit UEFI.

* gnu/bootloader/grub.scm (grub-efi32-bootloader): New variable.
(install-grub-efi32): New variable.
* gnu/build/bootloader.scm (install-efi): Add a 'targets' keyword
argument.
(install-efi-loader): Likewise.
* gnu/build/image.scm (initialize-efi32-partition): New procedure.
* gnu/packages/bootloaders.scm (grub-efi32): New variable.
* gnu/system/image.scm (esp32-partition): New variable
(efi32-disk-image): New variable.
(efi32-raw-image-type): New variable.
(system-disk-image)[partition-image]: Set '#:grub-efi32' when
calling the partition initializer.

Signed-off-by: Mathieu Othacehe <othacehe@gnu.org>

1 files changed, 32 insertions, 0 deletions

diff --git a/gnu/bootloader/grub.scm b/gnu/bootloader/grub.scm
index 65d7171432c..4f18c9b5183 100644
--- a/gnu/bootloader/grub.scm
+++ b/gnu/bootloader/grub.scm
@@ -8,6 +8,7 @@
 ;;; Copyright © 2020 Maxim Cournoyer <maxim.cournoyer@gmail.com>
 ;;; Copyright © 2020 Stefan <stefan-guix@vodafonemail.de>
 ;;; Copyright © 2022 Karl Hallsby <karl@hallsby.com>
+;;; Copyright © 2022 Denis 'GNUtoo' Carikli <GNUtoo@cyberdimension.org>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -57,6 +58,7 @@
             grub-bootloader
             grub-efi-bootloader
             grub-efi-removable-bootloader
+            grub-efi32-bootloader
             grub-efi-netboot-bootloader
             grub-mkrescue-bootloader
             grub-minimal-bootloader
@@ -636,6 +638,29 @@ fi~%"))))
                         "--bootloader-id=Guix"
                         "--efi-directory" target-esp)))))
 
+(define install-grub-efi32
+  #~(lambda (bootloader efi-dir mount-point)
+      ;; There is nothing useful to do when called in the context of a disk
+      ;; image generation.
+      (when efi-dir
+        ;; Install GRUB onto the EFI partition mounted at EFI-DIR, for the
+        ;; system whose root is mounted at MOUNT-POINT.
+        (let ((grub-install (string-append bootloader "/sbin/grub-install"))
+              (install-dir (string-append mount-point "/boot"))
+              ;; When installing Guix, it's common to mount EFI-DIR below
+              ;; MOUNT-POINT rather than /boot/efi on the live image.
+              (target-esp (if (file-exists? (string-append mount-point efi-dir))
+                              (string-append mount-point efi-dir)
+                              efi-dir)))
+          ;; Tell 'grub-install' that there might be a LUKS-encrypted /boot or
+          ;; root partition.
+          (setenv "GRUB_ENABLE_CRYPTODISK" "y")
+          (invoke/quiet grub-install "--boot-directory" install-dir
+                        "--bootloader-id=Guix"
+                        (cond ((target-x86?) "--target=i386-efi")
+                              ((target-arm?) "--target=arm-efi"))
+                        "--efi-directory" target-esp)))))
+
 (define (install-grub-efi-netboot subdir)
   "Define a grub-efi-netboot bootloader installer for installation in SUBDIR,
 which is usually efi/Guix or efi/boot."
@@ -768,6 +793,13 @@ considered for security aspects."
    (name 'grub-efi-removable-bootloader)
    (installer install-grub-efi-removable)))
 
+(define grub-efi32-bootloader
+  (bootloader
+   (inherit grub-efi-bootloader)
+   (installer install-grub-efi32)
+   (name 'grub-efi32)
+   (package grub-efi32)))
+
 (define grub-efi-netboot-bootloader
   (bootloader
    (inherit grub-efi-bootloader)