guix system: Add file system label and uuid to iso9660-image.

* gnu/system/vm.scm (system-disk-image): Pass root-label to ...
(iso9660-image): ... here.  Add keyword arguments #:file-system-label
and #:file-system-uuid.

linux-initrd: Avoid monadic style a bit.

* gnu/system/linux-initrd.scm (expression->initrd): Use 'program-file'
for 'init'.
(flat-linux-module-directory): Use 'computed-file' instead of
'gexp->derivation'.
(raw-initrd): Adjust accordingly.

install: Drop redundant package after c0f5eee4b2cc737be222c4ba331d0.

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

build: Add iso9660 system image generator.

* build-aux/hydra/gnu-system.scm (qemu-jobs): Add 'iso9660-image .
* gnu/build/vm.scm (make-iso9660-image): New variable.  Export it.
* gnu/system/vm.scm (iso9660-image): New variable.  Use make-iso9660-image.
(system-disk-image): Use iso9660-image.

linux-initrd: Add isofs if necessary.

* gnu/system/linux-initrd.scm (base-initrd): Add isofs.

install: Re-add /bin/sh.

Reported by Divan Santana <divan@santanas.co.za>.
/bin/sh had disappeared in commit
387e175492f960d7d86f34f3b2e43938fa72dbf3.

* gnu/system/install.scm (%installation-services): Add
'special-files-service-type' instance.

vm: Estimate the disk size by default.

* gnu/build/vm.scm (estimated-partition-size): New procedure.
* gnu/system/vm.scm (expression->derivation-in-linux-vm):
Change #:disk-image-size default to 'guess.
[builder]: When DISK-IMAGE-SIZE is 'guess, use
'estimated-partition-size' and compute and estimate of the image size.
(qemu-image): Likewise.
* guix/build/store-copy.scm (file-size, closure-size): New procedures.
* guix/scripts/system.scm (%default-options): Change 'image-size' to
'guess.
* doc/guix.texi (Building the Installation Image): Remove '--image-size'
flag from example.
(Invoking guix system): Document the image size estimate.

tests: Allow setting of qemu memory-size for system tests.

* gnu/system/vm.scm (common-qemu-options): Remove hardcoded "-m 256".
(system-qemu-image/shared-store-script): New keyword argument: #:memory-size.

mapped-devices: Cope with delayed appearance of LUKS source.

Fixes <https://bugs.gnu.org/27242>.

* gnu/system/mapped-devices.scm (open-luks-device): If
'find-partition-by-luks-uuid' fails, try again once per second, up to ten
times.

Merge branch 'master' into staging

install: Add 'passwd' to installation image.

* gnu/system/install.scm (installation-os): Add SHADOW in package list.

Merge branch 'master' into staging

vm: Increase default disk size to account for ESP partition.

Fixes a test regression introduced by ecf5d5376979fadd971559367bf553df89fcc62b.

* gnu/system/vm.scm (system-qemu-image/shared-store-script): 30MiB -> 70MiB.

vm: Increase default disk size to account for ESP partition.

Fixes a test regression introduced by ecf5d5376979fadd971559367bf553df89fcc62b.

* gnu/system/vm.scm (system-qemu-image/shared-store-script): 30MiB -> 70MiB.

vm: Add UEFI loader to disk images.

* gnu/build/vm.scm (install-efi): New procedure.
(initialize-hard-disk): Generate EFI blob when ESP is present.
* gnu/system/vm.scm (qemu-image): Append 40MiB EFI System Partition.

(cherry picked from commit ecf5d5376979fadd971559367bf553df89fcc62b)

vm: Support creating FAT partitions.

* gnu/build/vm.scm (create-ext-file-system, create-fat-file-system): New procedures.
(format-partition): Use them. Error for unknown file systems.
* gnu/system/vm.scm (qemu-image): Include DOSFSTOOLS.
* gnu/system/linux-initrd.scm (base-initrd): Always add nls_is8859-1.ko.

vm: Support arbitrary partition flags.

* gnu/build/vm.scm (<partition>): Change BOOTABLE? to FLAGS.
(initialize-partition-table): Pass each flag to parted.
(initialize-hard-disk): Locate boot partition.
* gnu/system/vm.scm (qemu-image): Adjust partition flags.

install: Enable SSH in installation image.

* gnu/system/install.scm (%installation-services): Add OPENSSH-SERVICE-TYPE.
* doc/guix.texi (Preparing for Installation)[Networking]: Document it.

maint: The 'release' target builds a VM image.

* gnu/system/examples/vm-image.tmpl: New file.
* Makefile.am (GUIXSD_VM_SYSTEMS, GUIXSD_VM_IMAGE_BASE,
GUIXSD_VM_IMAGE_SIZE): New variables.
(release): Add logic to build a VM image.
(EXAMPLES): Add 'gnu/system/examples/vm-image.tmpl'.
* doc/guix.texi (Running GuixSD in a VM, Installing GuixSD in a VM): Mention the
pre-built VM image.

doc: Update for UEFI systems.

* doc/guix.texi (USB Stick Installation): Mention UEFI.
(Preparing for Installation): Add notes about EFI System Partition, and
mounting partitions before init.
(Proceeding with the Installation): Mention the GRUB-EFI package.
(Using the Configuration System): Lightweight desktop is now a UEFI system.
(GRUB Configuration): Expand on package field. Add indexes.
* gnu/system/examples/lightweight-desktop.tmpl: Adjust to native EFI configuration.