system: Add 'initrd-modules' field.

* gnu/system.scm (<operating-system>)[initrd-modules]: New field.
(operating-system-initrd-file): Pass #:linux-modules to 'make-initrd'.
* gnu/system/linux-initrd.scm (default-initrd-modules): New procedure.
(%base-initrd-modules): New macro.
(base-initrd): Add #:linux-modules and honor it.
* gnu/system/install.scm (embedded-installation-os): Use
'initrd-modules' instead of 'initrd'.
* gnu/tests/install.scm (%raid-root-os): Likewise.
* doc/guix.texi (operating-system Reference): Add 'initrd-modules'.
(Initial RAM Disk): Document it.  Adjust example to not use
 #:extra-modules.

1 files changed, 5 insertions, 6 deletions

diff --git a/gnu/tests/install.scm b/gnu/tests/install.scm
index 3ac4a579da..e3bb1b46af 100644
--- a/gnu/tests/install.scm
+++ b/gnu/tests/install.scm
@@ -1,5 +1,5 @@
 ;;; GNU Guix --- Functional package management for GNU
-;;; Copyright © 2016, 2017 Ludovic Courtès <ludo@gnu.org>
+;;; Copyright © 2016, 2017, 2018 Ludovic Courtès <ludo@gnu.org>
 ;;; Copyright © 2017 Tobias Geerinckx-Rice <me@tobias.gr>
 ;;;
 ;;; This file is part of GNU Guix.
@@ -565,11 +565,10 @@ where /gnu lives on a separate partition.")
                  (bootloader grub-bootloader)
                  (target "/dev/vdb")))
     (kernel-arguments '("console=ttyS0"))
-    (initrd (lambda (file-systems . rest)
-              ;; Add a kernel module for RAID-0 (aka. "stripe").
-              (apply base-initrd file-systems
-                     #:extra-modules '("raid0")
-                     rest)))
+
+    ;; Add a kernel module for RAID-0 (aka. "stripe").
+    (initrd-modules (cons "raid0" %base-initrd-modules))
+
     (mapped-devices (list (mapped-device
                            (source (list "/dev/vda2" "/dev/vda3"))
                            (target "/dev/md0")