Move <boot-parameters> to (gnu system).

* guix/scripts/system.scm (previous-grub-entries)
  (display-system-generation): Use accessors instead of matching
  <boot-parameters>.
  (boot-parameters, boot-parameters?, boot-parameters-label)
  (boot-parameters-root-device, boot-parameters-kernel)
  (boot-parameters-kernel-arguments, read-boot-parameters): Move to...
* gnu/system.scm: ... here. Export them.

gnu/system.scm

@@ -88,6 +88,14 @@
             operating-system-locale-directory
             operating-system-boot-script
 
+            boot-parameters
+            boot-parameters?
+            boot-parameters-label
+            boot-parameters-root-device
+            boot-parameters-kernel
+            boot-parameters-kernel-arguments
+            read-boot-parameters
+
             local-host-aliases
             %setuid-programs
             %base-packages
@@ -709,4 +717,37 @@ this file is the reconstruction of GRUB menu entries for old configurations."
                                     #$(operating-system-kernel-arguments os))
                                    (initrd #$initrd)))))
 
+
+;;;
+;;; Boot parameters
+;;;
+
+(define-record-type* <boot-parameters>
+  boot-parameters make-boot-parameters boot-parameters?
+  (label            boot-parameters-label)
+  (root-device      boot-parameters-root-device)
+  (kernel           boot-parameters-kernel)
+  (kernel-arguments boot-parameters-kernel-arguments))
+
+(define (read-boot-parameters port)
+  "Read boot parameters from PORT and return the corresponding
+<boot-parameters> object or #f if the format is unrecognized."
+  (match (read port)
+    (('boot-parameters ('version 0)
+                       ('label label) ('root-device root)
+                       ('kernel linux)
+                       rest ...)
+     (boot-parameters
+      (label label)
+      (root-device root)
+      (kernel linux)
+      (kernel-arguments
+       (match (assq 'kernel-arguments rest)
+         ((_ args) args)
+         (#f       '())))))                       ;the old format
+    (x                                            ;unsupported format
+     (warning (_ "unrecognized boot parameters for '~a'~%")
+              system)
+     #f)))
+
 ;;; system.scm ends here

guix/scripts/system.scm

@@ -1,5 +1,6 @@
 ;;; GNU Guix --- Functional package management for GNU
 ;;; Copyright © 2014, 2015 Ludovic Courtès <ludo@gnu.org>
+;;; Copyright © 2016 Alex Kost <alezost@gmail.com>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -189,39 +190,6 @@ the ownership of '~a' may be incorrect!~%")
       (mwhen grub?
         (install-grub* grub.cfg device target)))))
 
-
-;;;
-;;; Boot parameters
-;;;
-
-(define-record-type* <boot-parameters>
-  boot-parameters make-boot-parameters boot-parameters?
-  (label            boot-parameters-label)
-  (root-device      boot-parameters-root-device)
-  (kernel           boot-parameters-kernel)
-  (kernel-arguments boot-parameters-kernel-arguments))
-
-(define (read-boot-parameters port)
-  "Read boot parameters from PORT and return the corresponding
-<boot-parameters> object or #f if the format is unrecognized."
-  (match (read port)
-    (('boot-parameters ('version 0)
-                       ('label label) ('root-device root)
-                       ('kernel linux)
-                       rest ...)
-     (boot-parameters
-      (label label)
-      (root-device root)
-      (kernel linux)
-      (kernel-arguments
-       (match (assq 'kernel-arguments rest)
-         ((_ args) args)
-         (#f       '())))))                       ;the old format
-    (x                                            ;unsupported format
-     (warning (_ "unrecognized boot parameters for '~a'~%")
-              system)
-     #f)))
-
 
 ;;;
 ;;; Reconfiguration.
@@ -285,22 +253,24 @@ it atomically, and then run OS's activation script."
   "Return a list of 'menu-entry' for the generations of PROFILE."
   (define (system->grub-entry system number time)
     (unless-file-not-found
-     (let ((file (string-append system "/parameters")))
+     (let* ((file             (string-append system "/parameters"))
-       (match (call-with-input-file file read-boot-parameters)
+            (params           (call-with-input-file file
-         (($ <boot-parameters> label root kernel kernel-arguments)
+                                read-boot-parameters))
-          (menu-entry
+            (label            (boot-parameters-label params))
-           (label (string-append label " (#"
+            (root             (boot-parameters-root-device params))
-                                 (number->string number) ", "
+            (kernel           (boot-parameters-kernel params))
-                                 (seconds->string time) ")"))
+            (kernel-arguments (boot-parameters-kernel-arguments params)))
-           (linux kernel)
+       (menu-entry
-           (linux-arguments
+        (label (string-append label " (#"
-            (cons* (string-append "--root=" root)
+                              (number->string number) ", "
-                   #~(string-append "--system=" #$system)
+                              (seconds->string time) ")"))
-                   #~(string-append "--load=" #$system "/boot")
+        (linux kernel)
-                   kernel-arguments))
+        (linux-arguments
-           (initrd #~(string-append #$system "/initrd"))))
+         (cons* (string-append "--root=" root)
-         (#f                                      ;invalid format
+                #~(string-append "--system=" #$system)
-          #f)))))
+                #~(string-append "--load=" #$system "/boot")
+                kernel-arguments))
+        (initrd #~(string-append #$system "/initrd"))))))
 
   (let* ((numbers (generation-numbers profile))
          (systems (map (cut generation-file-name profile <>)
@@ -366,18 +336,17 @@ list of services."
   (unless (zero? number)
     (let* ((generation (generation-file-name profile number))
            (param-file (string-append generation "/parameters"))
-           (params     (call-with-input-file param-file read-boot-parameters)))
+           (params     (call-with-input-file param-file read-boot-parameters))
+           (label      (boot-parameters-label params))
+           (root       (boot-parameters-root-device params))
+           (kernel     (boot-parameters-kernel params)))
       (display-generation profile number)
       (format #t (_ "  file name: ~a~%") generation)
       (format #t (_ "  canonical file name: ~a~%") (readlink* generation))
-      (match params
+      ;; TRANSLATORS: Please preserve the two-space indentation.
-        (($ <boot-parameters> label root kernel)
+      (format #t (_ "  label: ~a~%") label)
-         ;; TRANSLATORS: Please preserve the two-space indentation.
+      (format #t (_ "  root device: ~a~%") root)
-         (format #t (_ "  label: ~a~%") label)
+      (format #t (_ "  kernel: ~a~%") kernel))))
-         (format #t (_ "  root device: ~a~%") root)
-         (format #t (_ "  kernel: ~a~%") kernel))
-        (_
-         #f)))))
 
 (define* (list-generations pattern #:optional (profile %system-profile))
   "Display in a human-readable format all the system generations matching