gnu: linux-initrd: Make /dev/{mem,kmem}.

* guix/build/linux-initrd.scm (make-essential-device-nodes): Make
  dev/{mem,kmem}.

gnu: xorg-server: Use /var as $localstatedir.

* gnu/packages/xorg.scm (xorg-server): Pass --localstatedir=/var.  In
  'configure' phase, patch 'hw/xfree86/Makefile.in'.

gnu: vm: Add support for running a VM that shares its store with the host.

* gnu/system/vm.scm (qemu-image): Check whether GUIX is #f.
  (operating-system-build-gid, operating-system-default-contents): New
  procedures.
  (system-qemu-image): Use 'operating-system-build-gid'.
  (system-qemu-image/shared-store,
  system-qemu-image/shared-store-script): New procedures.
* gnu/system.scm: Add missing exports.

gnu: linux-initrd: Allow the root file system to be volatile.

* gnu/system/linux-initrd.scm (qemu-initrd): Add 'volatile-root?'
  parameter.
* guix/build/linux-initrd.scm (boot-system): Likewise.  Honor it.

gnu: linux: Really build 9p/virtio modules.

* gnu/packages/linux.scm (linux-libre): Add CONFIG_NET_9P and
  CONFIG_9P_FS.

gnu: linux-initrd: Recognize 9p file systems.

* gnu/system/linux-initrd.scm (qemu-initrd)[virtio-9p-modules]: New
  variable.
  [linux-modules]: Append VIRTIO-9P-MODULES when a 9p file system is in
  MOUNTS.
* guix/build/linux-initrd.scm (mount-qemu-9p): New procedure.
  (boot-system): Recognize '9p' in MOUNTS, and use 'mount-qemu-9p'.

gnu: linux-initrd: Match kernel module file names exactly.

* gnu/system/linux-initrd.scm (expression->initrd)[string->regexp]: New
  procedure.  Use it in the call to 'find-files'.

gnu: linux-initrd: Properly distinguish between /dev/sda* and /dev/vda*.

* guix/build/linux-initrd.scm (make-essential-device-nodes): Rename
  devices with major = 8 to /dev/sda*.  Make /dev/vda* devices.
* gnu/system/vm.scm (qemu-image): Change '/dev/vda' to '/dev/sda'.
* gnu/system.scm (operating-system-derivation): Likewise.

gnu: linux-initrd: Start a REPL when the root could not be mounted.

* guix/build/linux-initrd.scm (boot-system): Catch errors when mounting
  ROOT and call 'start-repl' upon error.

gnu: linux-libre: Build more virtio modules.

* gnu/packages/linux.scm (linux-libre): Append CONFIG_NET_9P_VIRTIO and
  CONFIG_VIRTIO_{NET,BLK,BALLOON} to '.config'.

gnu: vm: Run QEMU with '-enable-kvm'.

* gnu/system/vm.scm (expression->derivation-in-linux-vm): Pass QEMU
  '-enable-kvm'.

gnu: Add GNU Octave.

* gnu/packages/maths.scm (octave): New variable.

Signed-off-by: Ludovic Courtès <ludo@gnu.org>

gnu: linux-libre: Build virtio modules.

* gnu/packages/linux.scm (linux-libre): Build modules matching
  CONFIG.*VIRTIO.

gnu: linux-libre: Upgrade to 3.13.

* gnu/packages/linux.scm (linux-libre): Upgrade to 3.13.

gnu: gnunet: Add gnurl 7.34.0.

* gnu/packages/gnunet.scm (gnurl): New variable. Thanks to Zerwas for
  the initial recipe.

Co-authored-by: Ludovic Courtès <ludo@gnu.org>
Signed-off-by: Ludovic Courtès <ludo@gnu.org>

gnu: libgcrypt: Upgrade to 1.6.1.

* gnu/packages/gnupg.scm (libgcrypt): Upgrade to 1.6.1.

gnu: linux-initrd: Factorize boot code.

* guix/build/linux-initrd.scm (boot-system): New procedure.
* gnu/system/linux-initrd.scm (qemu-initrd): Add keyword parameters
  'guile-modules-in-chroot?' and 'mounts'.  Change builder to simply
  call 'boot-system'.
  (gnu-system-initrd): Change to a simple call to 'qemu-initrd'.
* gnu/system/vm.scm (expression->derivation-in-linux-vm): Call
  'qemu-initrd' with #:guile-modules-in-chroot?.

gnu: Lower initrd makers from packages to monadic procedures.

* gnu/packages/linux-initrd.scm: Remove.
* gnu/system/linux-initrd.scm: New file.
* gnu-system.am (GNU_SYSTEM_MODULES): Adjust accordingly.
* gnu/system.scm (<operating-system>): Change default 'initrd' value
  to (gnu-system-initrd).
  (operating-system-derivation): Bind 'operating-system-initrd'.  Pass
  'menu-entry' an initrd file name instead of a package.
* gnu/system/grub.scm (grub-configuration-file): Expect 'initrd' to be
  file name.

monads: Add 'imported-modules' and 'compiled-modules'.

* guix/monads.scm (package-file): Fix typo.
  (imported-modules, compiled-modules): New procedures.

gnu: qemu-initrd: Adjust to allow booting with a non-empty /root.

* gnu/packages/linux-initrd.scm (qemu-initrd): Use 'mkdir-p' instead of
  'mkdir' for /root/xchg and /root/{share,lib}.  When TO-LOAD is a
  symlink, resolve it.
  (gnu-system-initrd): Fix typo in message.