doc: No longer mention Wicd in OS examples.

* gnu/system/examples/desktop.tmpl,
gnu/system/examples/lightweight-desktop.tmpl: Mention NetworkManager
instead of Wicd.

system: Add Nintendo NES Classic Edition installer.

* gnu/bootloader/u-boot.scm (u-boot-nintendo-nes-classic-edition-bootloader):
New exported variable.
* gnu/packages/bootloaders.scm (u-boot-nintendo-nes-classic-edition):
New exported variable.
* gnu/system/install.scm (nintendo-nes-classic-edition-installation-os):
New exported variable.

system: Factor out embedded-installation-os.

* gnu/system/install.scm (embedded-installation-os): New variable.
(beaglebone-black-installation-os): Use it.
(a20-olinuxino-lime2-emmc-installation-os): Use it.
(a20-olinuxino-micro-installation-os): Use it.
(banana-pi-m2-ultra-installation-os): Use it.

system: Factor out agetty-default-service.

* gnu/system/install.scm (agetty-default-service): New variable.
(beaglebone-black-installation-os): Use it.
(a20-olinuxino-lime2-emmc-installation-os): Use it.
(a20-olinuxino-micro-installation-os): Use it.
(banana-pi-m2-ultra-installation-os): Use it.

system: Add A20 OLinuXino MICRO installer.

* gnu/bootloader/u-boot.scm (u-boot-a20-olinuxino-micro-bootloader): New
exported variable.
* gnu/packages/bootloaders.scm (u-boot-a20-olinuxino-micro): New exported
variable.
* gnu/system/install.scm (a20-olinuxino-micro-installation-os): New exported
variable.

system: Add A20 OLinuXino LIME2 installer.

* gnu/bootloader/u-boot.scm (u-boot-a20-olinuxino-lime2-bootloader): New
exported variable.
* gnu/packages/bootloaders.scm (u-boot-a20-olinuxino-lime2): New exported
variable.
* gnu/system/install.scm (a20-olinuxino-lime2-emmc-installation-os): New exported
variable.

system: Add Banana Pi M2 Ultra installer.

* gnu/bootloader/u-boot.scm (u-boot-banana-pi-m2-ultra-bootloader): New
exported variable.
(install-allwinner-u-boot): New variable.
(u-boot-allwinner-bootloader): New variable.
* gnu/packages/bootloaders.scm (u-boot-banana-pi-m2-ultra): New exported
variable.
* gnu/system/install.scm (banana-pi-m2-ultra-installation-os): New exported
variable.

gnu: Consistently Write ‘file system(s)’.

It is the GNU way.

* doc/guix.texi (Build Systems, DNS Services): Write ‘file system(s)’.
* gnu/build/vm.scm (create-ext-file-system, create-fat-file-system):
Likewise.
* gnu/packages/backup.scm (dirvish, rsnapshot)[description]: Likewise.
* gnu/packages/check.scm (python-testpath)[description]: Likewise.
* gnu/packages/disk.scm (pydf)[description]: Likewise.
* gnu/packages/file-systems.scm (disorderfs)[synopsis, description]: Likewise.
(glusterfs)[description]: Likewise.
* gnu/packages/haskell.scm (ghc-directory, ghc-system-fileio-bootstrap)
(ghc-system-fileio)[synopsis]: Likewise.
(ghc-fsnotify)[description]: Likewise.
* gnu/packages/linux.scm (proot)[description]: Likewise.
(jmtpfs)[synopsis, description]: Likewise.
* gnu/packages/mate.scm (caja, caja-extensions)[description]: Likewise.
* gnu/packages/storage.scm (ceph)[description]: Likewise.
* gnu/packages/sync.scm (lsyncd)[description]: Likewise.
* gnu/packages/syncthing.scm (syncthing)[synopsis]: Likewise.
(go-github-com-zillode-notify)[description]: Likewise.
* gnu/services/nfs.scm (pipefs-service-type): Likewise.
* guix/scripts/system.scm (perform-action): Likewise.

system: Extend .gdbinit to authorize extensions from /gnu/store/*/lib.

* gnu/system/shadow.scm (default-skeletons)["gdbinit"]: Add 'auto-load
safe-path' statement.

linux-boot: Add #:on-error for initrd error handling.

Suggested by Danny Milosavljevic <dannym@scratchpost.org>
in <https://bugs.gnu.org/29922>.

* gnu/build/linux-boot.scm (boot-system): Add #:on-error parameter and
pass it to 'call-with-error-handling'.
* gnu/system/linux-initrd.scm (raw-initrd): Add #:on-error and pass it.
(base-initrd): Likewise.

vm: 'vm-image' images refer to the root file system by UUID.

This avoids the hard-coded "/dev/sda1", which only made sense when the
image is run with "qemu-system-x86_64 -hda", not when it's passed to
Xen, etc.

Reported by Andreas Enge <andreas@enge.fr>.

* gnu/system/vm.scm (system-qemu-image): Define 'root-uuid', use it as
the 'device' field for "/", and pass it to 'qemu-image'.

file-systems: Move %control-groups from %base-file-systems to
%elogind-file-systems.

* gnu/system/file-systems.scm (%base-file-systems): Move %control-groups from
here, to ...
(%elogind-file-systems): ... here.

file-systems: Do not mount hugetlb cgroup filesystem.

On ARM32 without LPAE support, hugetlb control group is not supported.
As it is not needed by elogind, remove it for all platforms.

* gnu/system/file-systems.scm (%control-groups): Remove hugetlb from control
  groups platforms.

mapped-devices: 'luks-device-mapping' checks its source device.

* gnu/system/mapped-devices.scm (check-luks-device): New procedure.
(luks-device-mapping)[check]: New field.

mapped-devices: Add 'location' and 'check' fields.

* gnu/system/mapped-devices.scm (<mapped-device>)[location]: New field.
(<mapped-device-type>)[check]: New field.

system: examples: Add missing initrd to beaglebone-black.tmpl.

* gnu/system/examples/beaglebone-black.tmpl (operating-system): Add the
  initrd with "omap_hsmmc" as an extra-module.

system: examples: Add a template for BeagleBone Black.

* gnu/system/examples/beaglebone-black.tmpl: New file.
* Makefile.am (EXAMPLES): Add it.
* gnu/system/install.scm (/etc/configuration-files): Add it.

vm: Pass the host's /dev/urandom to the guest at /dev/hwrng.

* gnu/build/vm.scm (load-in-linux-vm): Use QEMU's virtio-rng-pci.
* gnu/system/vm.scm (common-qemu-options): Likewise.

gnu: system: vm: Use loose cache for 9p file system.

This improves the performance of the shared store for operations involving
lots of files, e.g. searching through the store.

* gnu/system/vm.scm (mapping->file-system): Add cache=loose to options.

system: Add BeagleBone Black installer.

* gnu/bootloader/u-boot.scm (u-boot-beaglebone-black-bootloader): New exported
  bootloader.
* gnu/system/install.scm (beaglebone-black-installation-os): New exported variable.