gnu: bootloader: Support multiple targets.

Fixes <https://issues.guix.gnu.org/40997>.

* gnu/bootloader.scm (<bootloader-configuration>): New 'targets' field.
(%bootloader-configuration-target): New procedure.
(bootloader-configuration-target): Add deprecation warning.
(bootloader-configuration-targets): New procedure.
* guix/scripts/system.scm (install): Access targets via
bootloader-configuration-targets.
(perform-action)[bootloader-target]: Remove unused argument and update doc.
Access targets via bootloader-configuration-targets and fix indentation.
(process-action): Access targets via bootloader-configuration-targets.
Do not provide the unused BOOTLOADER-TARGET argument when applying
`perform-action'.
* guix/scripts/system/reconfigure.scm (install-bootloader-program): Rename
DEVICE argument to DEVICES.  Adjust doc and comment.  Apply `installer' and
`disk-installer' for every DEVICES.
(install-bootloader): Access targets via bootloader-configuration-targets and
rename variable from DEVICE to DEVICES.
* gnu/tests/install.scm: Adjust accordingly.
* tests/guix-system.sh: Likewise.
* gnu/tests/reconfigure.scm (run-install-bootloader-test): Adjust the DEVICES
argument so that it is a list.
* doc/guix.texi: Update doc.

2 files changed, 23 insertions, 19 deletions

diff --git a/guix/scripts/system.scm b/guix/scripts/system.scm
index 40401d7e03..83bbefd3dc 100644
--- a/guix/scripts/system.scm
+++ b/guix/scripts/system.scm
@@ -253,7 +253,7 @@ the ownership of '~a' may be incorrect!~%")
                               #:target target)
           (return
            (info (G_ "bootloader successfully installed on '~a'~%")
-                 (bootloader-configuration-target bootloader))))))))
+                 (bootloader-configuration-targets bootloader))))))))
 
 
 ;;;
@@ -768,14 +768,13 @@ and TARGET arguments."
                          skip-safety-checks?
                          install-bootloader?
                          dry-run? derivations-only?
-                         use-substitutes? bootloader-target target
+                         use-substitutes? target
                          full-boot?
                          container-shared-network?
                          (mappings '())
                          (gc-root #f))
   "Perform ACTION for IMAGE.  INSTALL-BOOTLOADER? specifies whether to install
-bootloader; BOOTLOADER-TAGET is the target for the bootloader; TARGET is the
-target root directory.
+bootloader; TARGET is the target root directory.
 
 FULL-BOOT? is used for the 'vm' action; it determines whether to
 boot directly to the kernel or to the bootloader.  CONTAINER-SHARED-NETWORK?
@@ -856,13 +855,13 @@ static checks."
                                      #:target (or target "/"))
                  (return
                   (info (G_ "bootloader successfully installed on '~a'~%")
-                        (bootloader-configuration-target bootloader))))
+                        (bootloader-configuration-targets bootloader))))
                (with-shepherd-error-handling
-                 (upgrade-shepherd-services local-eval os)
-                 (return (format #t (G_ "\
+                (upgrade-shepherd-services local-eval os)
+                (return (format #t (G_ "\
 To complete the upgrade, run 'herd restart SERVICE' to stop,
 upgrade, and restart each service that was not automatically restarted.\n")))
-                 (return (format #t (G_ "\
+                (return (format #t (G_ "\
 Run 'herd status' to view the list of services on your system.\n"))))))
             ((init)
              (newline)
@@ -1218,9 +1217,9 @@ resulting from command-line parsing."
          (target-file (match args
                         ((first second) second)
                         (_ #f)))
-         (bootloader-target
+         (bootloader-targets
                       (and bootloader?
-                           (bootloader-configuration-target
+                           (bootloader-configuration-targets
                             (operating-system-bootloader os)))))
 
     (define (graph-backend)
@@ -1269,7 +1268,6 @@ resulting from command-line parsing."
                                                       opts)
                                #:install-bootloader? bootloader?
                                #:target target-file
-                               #:bootloader-target bootloader-target
                                #:gc-root (assoc-ref opts 'gc-root)))))
           #:target target
           #:system system)))
diff --git a/guix/scripts/system/reconfigure.scm b/guix/scripts/system/reconfigure.scm
index 49da6ecb16..bf23fb06af 100644
--- a/guix/scripts/system/reconfigure.scm
+++ b/guix/scripts/system/reconfigure.scm
@@ -207,10 +207,10 @@ services as defined by OS."
 
 (define (install-bootloader-program installer disk-installer
                                     bootloader-package bootcfg
-                                    bootcfg-file device target)
+                                    bootcfg-file devices target)
   "Return an executable store item that, upon being evaluated, will install
-BOOTCFG to BOOTCFG-FILE, a target file name, on DEVICE, a file system device,
-at TARGET, a mount point, and subsequently run INSTALLER from
+BOOTCFG to BOOTCFG-FILE, a target file name, on DEVICES, a list of file system
+devices, at TARGET, a mount point, and subsequently run INSTALLER from
 BOOTLOADER-PACKAGE."
   (program-file
    "install-bootloader.scm"
@@ -254,11 +254,17 @@ BOOTLOADER-PACKAGE."
                    ;; The bootloader might not support installation on a
                    ;; mounted directory using the BOOTLOADER-INSTALLER
                    ;; procedure. In that case, fallback to installing the
-                   ;; bootloader directly on DEVICE using the
+                   ;; bootloader directly on DEVICES using the
                    ;; BOOTLOADER-DISK-IMAGE-INSTALLER procedure.
                    (if #$installer
-                       (#$installer #$bootloader-package #$device #$target)
-                       (#$disk-installer #$bootloader-package 0 #$device)))
+                       (for-each (lambda (device)
+                                   (#$installer #$bootloader-package device
+                                                #$target))
+                                 '#$devices)
+                       (for-each (lambda (device)
+                                   (#$disk-installer #$bootloader-package
+                                                     0 device))
+                                 '#$devices)))
                  (lambda args
                    (delete-file new-gc-root)
                    (match args
@@ -284,7 +290,7 @@ additional configurations specified by MENU-ENTRIES can be selected."
          (disk-installer (and run-installer?
                               (bootloader-disk-image-installer bootloader)))
          (package (bootloader-package bootloader))
-         (device (bootloader-configuration-target configuration))
+         (devices (bootloader-configuration-targets configuration))
          (bootcfg-file (bootloader-configuration-file bootloader)))
     (eval #~(parameterize ((current-warning-port (%make-void-port "w")))
               (primitive-load #$(install-bootloader-program installer
@@ -292,7 +298,7 @@ additional configurations specified by MENU-ENTRIES can be selected."
                                                             package
                                                             bootcfg
                                                             bootcfg-file
-                                                            device
+                                                            devices
                                                             target))))))