gnu: grub-efi-bootloader: Specialize grub-install invocation.

* gnu/bootloader/grub.scm (install-grub-efi): Fix grub-install invocation for
  EFI systems.
* gnu/system/examples/bare-bones.tmpl: Use the newer
"bootloader-configuration" syntax.
* gnu/system/examples/desktop.tmpl: Use bootloader-configuration sytax.  Also,
use the same label for the LUKS-mapped device and the root partition.  Remove
unneeded "title" field for the file-system based on LUKS; as noted in the
manual, the "title" field is ignored for mapped devices.
* gnu/system/examples/lightweight-desktop.tmpl: Use bootloader-configuration,
and use grub-efi-bootloader.

gnu/bootloader/grub.scm

@@ -389,7 +389,20 @@ submenu \"GNU system, old configurations...\" {~%")
         (unless (zero? (system* grub "--no-floppy"
                                 "--boot-directory" install-dir
                                 device))
-          (error "failed to install GRUB")))))
+          (error "failed to install GRUB (BIOS)")))))
+
+(define install-grub-efi
+  #~(lambda (bootloader efi-dir mount-point)
+      ;; 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")))
+        ;; Tell 'grub-install' that there might be a LUKS-encrypted /boot or
+        ;; root partition.
+        (setenv "GRUB_ENABLE_CRYPTODISK" "y")
+        (unless (zero? (system* grub-install "--boot-directory" install-dir
+                                "--efi-directory" efi-dir))
+          (error "failed to install GRUB (EFI)")))))
 
 
 
@@ -408,6 +421,7 @@ submenu \"GNU system, old configurations...\" {~%")
 (define* grub-efi-bootloader
   (bootloader
    (inherit grub-bootloader)
+   (installer install-grub-efi)
    (name 'grub-efi)
    (package grub-efi)))
 

gnu/system/examples/bare-bones.tmpl

@@ -12,7 +12,9 @@
 
   ;; Assuming /dev/sdX is the target hard disk, and "my-root" is
   ;; the label of the target root file system.
-  (bootloader (grub-configuration (device "/dev/sdX")))
+  (bootloader (bootloader-configuration
+                (bootloader grub-bootloader)
+                (device "/dev/sdX")))
   (file-systems (cons (file-system
                         (device "my-root")
                         (title 'label)

gnu/system/examples/desktop.tmpl

@@ -13,19 +13,20 @@
 
   ;; Assuming /dev/sdX is the target hard disk, and "my-root"
   ;; is the label of the target root file system.
-  (bootloader (grub-configuration (device "/dev/sdX")))
+  (bootloader (bootloader-configuration
+                (bootloader grub-bootloader)
+                (device "/dev/sdX")))
 
   ;; Specify a mapped device for the encrypted root partition.
   ;; The UUID is that returned by 'cryptsetup luksUUID'.
   (mapped-devices
    (list (mapped-device
           (source (uuid "12345678-1234-1234-1234-123456789abc"))
-          (target "the-root-device")
+          (target "my-root")
           (type luks-device-mapping))))
 
   (file-systems (cons (file-system
                         (device "my-root")
-                        (title 'label)
                         (mount-point "/")
                         (type "ext4")
                         (dependencies mapped-devices))

gnu/system/examples/lightweight-desktop.tmpl

@@ -12,9 +12,10 @@
   (locale "en_US.utf8")
 
   ;; Use the UEFI variant of GRUB with the EFI System
-  ;; Partition on /dev/sda1.
+  ;; Partition mounted on /boot/efi.
-  (bootloader (grub-configuration (grub grub-efi)
+  (bootloader (bootloader-configuration
-                                  (device "/dev/sda1")))
+                (bootloader grub-efi-bootloader)
+                (device "/boot/efi")))
 
   ;; Assume the target root file system is labelled "my-root".
   (file-systems (cons* (file-system