Add target flag to bootloader

system/base-system.scm

@@ -317,6 +317,33 @@
           (modify-services %base-services
             (nscd-service-type config => %metznet-nscd-configuration))))
 
+(define install-grub-efi-fix
+  #~(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
+                        "--target=x86_64-efi"
+                        "--bootloader-id=Guix"
+                        "--efi-directory" target-esp)))))
+
+(define grub-efi-bootloader-fix
+  (bootloader
+   (inherit grub-efi-bootloader)
+   (installer install-grub-efi-fix)))
+
 (define %metznet-base-operating-system
   (operating-system
     ;; Hostname and localization information
@@ -332,7 +359,7 @@
     (initrd microcode-initrd)
     ;; Grub UEFI Bootloader installed to /boot/efi
     (bootloader (bootloader-configuration
-                  (bootloader grub-efi-bootloader)
+                  (bootloader grub-efi-bootloader-fix)
                   (targets '("/boot/efi"))
                   (keyboard-layout keyboard-layout)))
     (file-systems (cons* (file-system