This adds a "Kernel" page to the installer with the option to (cross-) install
the Hurd, if applicable (only available on x86 machines for now).

* gnu/installer/newt.scm (kernel-page): New procedure.
(newt-installer)[kernel-page]: New field.
* gnu/installer/kernel.scm,
gnu/installer/newt/kernel.scm: New files.
* gnu/local.mk (INSTALLER_MODULES): Add them.
* gnu/installer.scm (installer-steps): Use them to select kernel if
applicable.
* gnu/installer/newt/partition.scm (run-label-page): Default to "msdos" when
instaling the Hurd.
(run-fs-type-page): Add ext2 for the hurd.
(run-partitioning-page-partition): Remove `entire-encrypted' option when
installing the Hurd.
* gnu/installer/services.scm (system-services->configuration): Cater for the
Hurd with %base-services/hurd, and with %base-packages/hurd that must always
be set.
(%system-services): Change to procedure.  When installing the the Hurd, do not
recommend `ntp-service-type' and USE `openssh-sans-x' package for
`openssh-service-type'.
(system-service-none): New variable.
* gnu/installer/newt/services.scm (run-network-management-page): Include it
when installing the Hurd.
(run-desktop-environments-cbt-page): When installing the Hurd, recommend to
not select any desktop enviroment.  Update users.
* gnu/installer/parted.scm (efi-installation?): Return #f when installing for
the Hurd.
(create-ext2-file-system): New procedure.
(user-fs-type-name, user-fs-type->mount-type, partition-filesystem-user-type,
format-user-partitions): Support `ext2'.
(<user-partition> partition->user-partition): Use `ext2' when installing the
Hurd.
(auto-partition!): Likewise.  No swap partition when installing the Hurd.
* gnu/installer/final.scm (install-system): Cater for cross installation of
the Hurd.
(bootloader-configuration): Use `grub-minimal-bootloader' when installing the
Hurd.
(user-partition-missing-modules): Cater for empty user-partitions.
(initrd-configuration, user-partitions->configuration): Cater for the Hurd.
* gnu/installer/steps.scm (format-configuration,
configuration->file): Cater for the Hurd.
* gnu/system/hurd.scm (%desktop-services/hurd): New variable.
* gnu/installer/tests.scm (choose-kernel): New procedure.
* gnu/tests/install.scm (gui-test-program): Use it.

Change-Id: Ifafb27b8a2f933944c77223a27ec151757237e36

* gnu/installer/tests.scm (edit-configuration-file): Fix it.

When the configuration is edited, it looks like there are some leftover
fragments from the input configuration:

Example content of config.scm after edition:

  #:imported-modules
  '((gnu services herd)
    (guix build utils)
    (guix combinators)))

unted".  The unique
  ;; file system identifiers there ("UUIDs") can be obtained
  ;; by running 'blkid' in a terminal.

...

This is strange because call-with-output-file uses the O_TRUNC flag which
resets the file size to zero. Remove the configuration file before writing it
as a work-around.

* gnu/installer/tests.scm (edit-configuration-file): Remove the configuration
file before re-writing it.

We had several bug reports with a root cause of "the clock was
incorrect" from users who used the installer to install a non-graphical
Guix System.

* gnu/installer/services.scm (%system-services): Add the ntp-service-type.
* gnu/installer/newt/services.scm (run-system-administration-cbt-page): New
variable.
(run-services-page): Use run-system-administration-cbt-page when not
installing a desktop.
* gnu/installer/tests.scm (choose-services): Add and use a
choose-misc-service?  procedure.
* gnu/tests/install.scm (installation-target-os-for-gui-tests)<services>: Add
ntp-service-type.

Currently, the installer page RUN-OTHER-SERVICES-CBT-PAGE offers to the user all
installer services that are not of the types 'desktop', 'network-management', or
'networking'. Concretely, this means that it offers the CUPS printing service,
because that is the only service of a different type defined in the installer.

In later commits, we will add some services of a new type, and we only want them
to be offered when the user is installing a non-graphical system.

At least one of these new services (NTP) is part of %DESKTOP-SERVICES. If it
was also offered on RUN-OTHER-SERVICES-CBT-PAGE, and the user had configured a
system using %DESKTOP-SERVICES, the user could accidentally add NTP to their
services twice, which is an error and would break installation.

So, this commit makes the RUN-OTHER-SERVICES-CBT-PAGE be more specific about
what services to offer. This makes it easier to discriminate between desktop and
non-desktop installations, in terms of when a given service is offered.

* gnu/installer/newt/services.scm (RUN-OTHER-SERVICES-CBT-PAGE): Rename to ...
(RUN-PRINTING-SERVICES-CBT-PAGE): ... new variable, and select only 'document' services.
(RUN-SERVICES-PAGE): Adjust accordingly.
* gnu/installer/tests.scm (CHOOSE-SERVICES): Adjust accordingly.

* gnu/installer/tests.scm (choose-services): Accept a new
choose-other-service? keyword argument, defaulting to false.
Expect an "Other services" checkbox-list.  Update docstring.

* gnu/installer/tests.scm (conclude-installation): Rename it into ...
(start-installation): ... this new procedure.
(complete-installation): New procedure.
(choose-partitioning): Add an uefi-support? argument.
* gnu/tests/install.scm (uefi-firmware): New procedure.
(run-install, qemu-command/writable-image, gui-test-program,
installation-target-os-for-gui-tests): Add an uefi-support? argument.
(%extra-packages): Add grub-efi, fatfsck/static and dosfstools.
(%test-gui-installed-os): New variable.

Note: This change requires an updated 'guix' package that contains
Linux-swap support in (gnu build file-systems).

* gnu/installer/parted.scm (user-partitions->configuration): Use UUIDs
in the 'swap-devices' field.
* gnu/installer/newt/final.scm (run-final-page)[wait-for-clients]: New
procedure.   Use it.
* gnu/installer/tests.scm (choose-partitioning): Wait for
'starting-final-step' message and move configuration file dialog
handling to...
(conclude-installation): ... here.  Send over PORT the reply
corresponding to 'starting-final-step'.
* gnu/tests/install.scm (gui-test-program): When ENCRYPTED? is false,
invoke 'swaplabel' in the marionette.
(installation-target-os-for-gui-tests): When ENCRYPTED? is false, except
a fixed UUID.

* gnu/installer/tests.scm (choose-partitioning): Use 'find' to select
the disk.

* gnu/installer/tests.scm (choose-services): Turn desktop-environments list
into a choose-desktop-environment procedure. This way, it is easier to select
all desktop-environments or none, in the same way as choose-network-service?
and choose-network-management-tool? arguments.