install: Add a service to back the store with the target disk.

Fixes <http://bugs.gnu.org/18061>.
Reported by Adam Pribyl <pribyl@lowlevel.cz>.

* gnu/services/dmd.scm (dmd-configuration-file)[config]: Import (guix
  build utils).
* gnu/system/install.scm (make-cow-store, cow-store-service): New
  procedures.
  (installation-services): Use it.
  (%backing-directory): New variable.
* doc/guix.texi (System Installation): Add the 'deco start cow-store
  /mnt' phase.

system: Add missing exports to (gnu system file-systems).

* gnu/system/file-systems.scm (%pseudo-terminal-file-system)
  (%shared-memory-file-system): Add to export list.

system: Add /dev/shm.

* gnu/system/file-systems.scm (%shared-memory-file-system): New
  variable.
  (%base-file-systems): Add it.
* doc/guix.texi (File Systems): Document it.

system: Add 'file-system' decl. for /dev/pts, and use the right options.

Fixes <http://bugs.gnu.org/18081>.

* gnu/system/file-systems.scm (%devtmpfs-file-system): Add
  'needed-for-boot?' field.
  (%tty-gid, %pseudo-terminal-file-system): New variables.
  (%base-file-systems): Add %PSEUDO-TERMINAL-FILE-SYSTEM.
* gnu/services/base.scm (udev-service): Remove dependency on
  'file-system-/dev'.
* gnu/system/shadow.scm (%base-groups): Add 'id' field for group 'tty'.
* guix/build/linux-initrd.scm (boot-system): Remove 'mount' call for
  /dev/pts.
* doc/guix.texi (File Systems): Add %pseudo-terminal-file-system.

system: Add 'create-mount-point?' file system option.

* gnu/system/file-systems.scm (<file-system>)[create-mount-point?]: New
  field.
* gnu/services/base.scm (file-system-service): Add #:create-mount-point?
  parameter and honor it.
* gnu/system.scm (other-file-system-services): Update
  'file-system-service' call accordingly.
* doc/guix.texi (File Systems): Document it.

system: Add '%devtmpfs-file-system' for udev, and '%base-file-systems'.

Suggested by Adam Pribyl <pribyl@lowlevel.cz>.

* gnu/services/base.scm (udev-service)[requirement]: Add
  'file-system-/dev'.
* gnu/system/file-systems.scm (%devtmpfs-file-system,
  %base-file-systems): New variables.
* gnu/system/install.scm (installation-services)[file-systems]: Use
  %base-file-systems.
* build-aux/hydra/demo-os.scm (file-systems): Likewise.
* doc/guix.texi (System Installation): Show %BASE-FILE-SYSTEMS in the
  example.
  (Using the Configuration System): Likewise.
  (File Systems): Document %base-file-systems, %devtmpfs-file-system,
  %binary-format-file-system, and %fuse-control-file-system.

install: Add wireless-tools package.

* gnu/system/install.scm (installation-os): Add wireless-tools to packages.

linux-initrd: Add AHCI modules.

* gnu/system/linux-initrd (linux-modules): Add them.

install: Show the "System Installation" node.

* gnu/system/install.scm (log-to-info): Go to the new 'System
  Installation' node.

doc: Add "Initial RAM Disk" section.

* doc/guix.texi (Initial RAM Disk): New node.
* gnu/system/linux-initrd.scm (expression->initrd): Adjust docstring.

services: Add 'console-font-service'.

* gnu/services/base.scm (unicode-start, console-font-service): New
  procedures.
  (%base-services): Call 'console-font-service' for TTY1 to TTY6.
* gnu/system/install.scm (installation-services): Add comment about the
  console font.  Call 'console-font-service' for TTY1 to TTY6.

install: Remove GNU fdisk from the image.

* gnu/system/install.scm (installation-os): Remove FDISK.

vm: Make sure disk image initrds load 'usb-storage.ko'.

Reported by David Thompson <dthompson2@worcester.edu>.

* gnu/system/vm.scm (system-disk-image): Add usb-storage.ko to the
  initrd.

linux-initrd: Allow extra modules to be passed to 'base-initrd'.

* gnu/system/linux-initrd.scm (base-initrd): Add #:extra-modules
  parameter.

vm: Add support for i686.

Partially fixes <http://bugs.gnu.org/18002>.
Reported by David Thompson <dthompson2@worcester.edu>.

* guix/build/vm.scm (qemu-command): Add optional 'system' parameter.
  Special-case "^i[3456]86$".
* gnu/system/vm.scm (system-qemu-image/shared-store-script): Use it.

system: Allow root to use 'groupadd' & co. without authenticating.

This fixes a bug whereby, if #:allow-root-passwords was #f, 'groupadd'
would ask for a password.  This is particularly problematic during
activation.

* gnu/system/linux.scm (rootok-pam-service): New procedure.
  (base-pam-services): Use it for all the user* and group* commands.

system: Add "netdev" group.

* gnu/system/shadow.scm (%base-groups): Add "netdev".

vm: Enable QEMU support in the freestanding VM image.

* gnu/system/vm.scm (system-qemu-image): Add 'initrd' field.

linux-initrd: Rename 'qemu-initrd' to 'base-initrd'.

* gnu/system/linux-initrd.scm (qemu-initrd): Rename to...
  (base-initrd): ... this.
* gnu/system.scm (<operating-system>)[initrd]: Update accordingly.
* gnu/system/vm.scm (expression->derivation-in-linux-vm,
  system-disk-image, virtualized-operating-system): Likewise.

linux-initrd: Disable QEMU networking by default.

* gnu/system/linux-initrd.scm (qemu-initrd): Remove default value for
  #:qemu-networking?.
* gnu/system/vm.scm (expression->derivation-in-linux-vm): Pass
  #:qemu-networking? #t.
  (system-disk-image): Remove #:qemu-networking? #f.
  (virtualized-operating-system): Pass #:qemu-networking? #t.