bootloader: Use <menu-entry> for the bootloader side.

* gnu/bootloader.scm (menu-entry-device-mount-point): New variable.  Export it.
(<menu-entry>: New field "device".
* gnu/bootloader/grub.scm (grub-confgiuration-file): Handle <menu-entry>
entries.
* gnu/bootloader/extlinux.scm (extlinux-configuration-file): Handle
<menu-entry> entries.
* gnu/system.scm (menu->entry->boot-parameters): Delete variable.
(boot-parameters->menu-entry): New variable.  Export it.
(operating-system-bootcfg): Make OLD-ENTRIES a list of <menu-entry>.
* guix/script/system.scm (reinstall-bootloader): Fix bootcfg usage.
(perform-action): Fix bootcfg usage.

guix system: Use "image.iso" as the name of ISO images.

* guix/scripts/system.scm (system-derivation-for-action): Pass #:name to
'system-disk-image'.

guix system: Add "--file-system-type" option.

* guix/scripts/system.scm (process-action): Pass file-system-type to ...
(perform-action): ... here.  Add new keyword argument.  Pass new value to ...
(system-derivation-for-action): ... here.  Add new keyword argument.
Pass new value to system-disk-image.
* doc/guix.texi (disk-image): Document new option.

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.

bootloader: Rename boot-name to bootloader-name.

* gnu/system (<boot-parameters>)[boot-name]: Rename field to...
[bootloader-name]: ... this.  Adjust users.
* gnu/scripts/system.scm: Adjust accordingly.

Merge branch 'master' into staging

Merge branch 'version-0.13.0'

Merge branch 'master' into staging

guix system: Don't warn about old distros for "guix system init".

* guix/scripts/system.scm (process-action): Don't call
'warn-about-old-distro' when ACTION is 'init' or 'build'.

guix system: Increase image size for 'guix system vm'.

This is a followup to 9a1bfe764859365b6726f168da95b88a2d22403b.

* guix/scripts/system.scm (system-derivation-for-action): Add 40MiB to
the default size for 'vm'.

scripts: system: Display bootloader name in "list-generations".

* guix/scripts/system.scm (display-system-generation): Display
  bootloader name.

scripts: system: Adapt "switch-generation" to new bootloader API.

* guix/scripts/system.scm (reinstall-grub): Rename to
  reinstall-bootloader. Read boot-device and boot-type from parameters file to
  be able to restore the correct bootloader on specified device.
  Factorize bootloader installation code by calling install-bootloader.
 (system-bootloader-name): New procedure.
 (switch-to-system-generation): Adapt.

scripts: system: Adapt "init" to new bootloader API.

* guix/scripts/system.scm (install): Pass installer a new
argument. Rename other arguments.
Call install-bootloader instead of install-grub*.
(perform-action): Adapt.

scripts: system: Adapt "reconfigure" to new bootloader API.

* guix/scripts/system.scm (install-grub*): Rename to install-bootloader.  Use
keys to pass arguments.  Pass a new argument, "installer-drv" which is a script
in store dealing with bootloader-specific install actions.  Also call
"install-boot-config" to install the bootloader config file.

(install-bootloader-derivation): New procedure.  It returns a derivation that
builds a file containing "install-procedure" gexp.

(perform-action): Build install-proc derivation and call install-bootloader
with the resulting file.  Stop adding GRUB to PATH as bootloaders are called in
install-proc with direct store paths.

bootloader: Add extlinux support.

* gnu/bootloader.scm: New file.
* gnu/bootloader/extlinux.scm: New file.
* gnu/bootloader/grub.scm: New file.
* gnu/local.mk: Build new files.
* gnu/system.scm: Adapt to new bootloader api.
* gnu/scripts/system.scm: Adapt to new bootloader api.
* gnu.scm: Remove (gnu system grub) and replace by (gnu bootloader) and (gnu
bootloader grub) modules.
* gnu/system/grub.scm: Moved content to gnu/bootloader/grub.scm.
* gnu/system/vm: Replace (gnu system grub) module by (gnu bootloader).
* gnu/tests.scm: Ditto.
* gnu/tests/nfs.scm: Ditto.

Merge branch 'master' into staging

scripts: Warn about old distro.

Fixes <http://bugs.gnu.org/25852>.
Suggested by Mark H Weaver <mhw@netris.org>.

* guix/scripts.scm (%distro-age-warning): New variable.
(warn-about-old-distro): New procedure.
* guix/scripts/package.scm (process-actions): Call
'warn-about-old-distro'.
* guix/scripts/system.scm (process-action): Likewise.

scripts: Remove profile-grub-entries.

* guix/scripts/system.scm (profile-grub-entries): Delete variable.

system: grub: Use boot-parameters instead of menu-entry where possible.

* gnu/system/grub.scm (boot-parameters->menu-entry): New variable.
(grub-configuration-file): Use boot-parameters
instead of menu-entry where possible.
* guix/scripts/system.scm (profile-boot-parameters): Update docstring.
(reinstall-grub): Use profile-boot-parameters.
(perform-action): Use profile-boot-parameters.

scripts: Make boot-parameters label include generation number and time.

* guix/scripts/system.scm (system->boot-parameters): Make label include
generation number and time.