linux-modules: Correctly propagate error code from 'init_module'.

* gnu/packages/patches/guile-linux-syscalls.patch (scm_load_linux_module):
  Leave 'errno' unchanged when ERR != 0.
* gnu/build/linux-modules.scm (load-linux-module*): Check for the errno
  value of ARGS to determine whether the module was already loaded.

linux-boot: Load modules and their dependencies, à la 'modprobe'.

* gnu/build/linux-boot.scm: Use (gnu build linux-modules).
  (load-linux-module*): Remove.
  (boot-system): Add #:linux-module-directory parameter.
  [lookup-module]: New procedure.
  Call 'current-module-debugging-port'.  Pass #:lookup-module to
  'load-linux-module*'.  Map LOOKUP-MODULE on LINUX-MODULES.
* gnu/system/linux-initrd.scm (base-initrd): Adjust 'boot-system' call
  accordingly.  Adjust #:modules argument as well.
* gnu/system.scm (operating-system-activation-script)[%modules]: Likewise.
* gnu/system/vm.scm (expression->derivation-in-linux-vm): Likewise.

system: Add (gnu build linux-modules).

* gnu/build/linux-modules.scm: New file.
* gnu-system.am (GNU_SYSTEM_MODULES): Add it.

linux-boot: Call 'pre-mount' before 'mount-root-file-system'.

Partly fixes <http://bugs.gnu.org/19190>.
Reported by Nikita Karetnikov <nikita@karetnikov.org>.

* gnu/build/linux-boot.scm (boot-system): Move PRE-MOUNT call before
  'mount-root-file-system' is called.

linux-boot: Error out when 'pre-mount' returns #f.

* gnu/build/linux-boot.scm (boot-system): Call 'error' when PRE-MOUNT
  returns #f.

linux-boot: Don't catch exceptions thrown by 'mount-root-file-system'.

* gnu/build/linux-boot.scm (mount-root-file-system): Remove 'catch #t'
  around body.  This was unneeded and even inconvenient because this
  procedure is called from within 'call-with-error-handling' already.

file-systems: Always write the options field in /etc/mtab.

* gnu/build/file-systems.scm (mount-file-system): When OPTIONS is false,
  write "rw" to /etc/mtab.  This fixes a bug whereby 'remove-from-mtab'
  in (guix syscalls) would otherwise raise a 'match-error' because of
  the missing field.  This affected file systems mounted from the
  initrd, such as devtmpfs, which has options == #f.

vm: Set the boot flag on the root partition.

Reported by nebuli on #guix.

* gnu/build/vm.scm (initialize-partition-table): Add #:bootable?
  parameter and honor it.
  (initialize-hard-disk): Likewise.

linux-boot: Make more disk partition block devices.

Reported by nebuli on #guix.

* gnu/build/linux-boot.scm (make-disk-device-nodes): Make 16 block
  devices for disk partitions.

activation: Set the firmware search path.

* gnu/build/activation.scm (activate-firmware): New procedure.
* gnu/system.scm (<operating-system>)[firmware]: New field.
  (directory-union): New procedure.
  (%base-firmware): New variable.
  (operating-system-activation-script): Use 'directory-union', and call
  'activate-firmware'.
* doc/guix.texi (operating-system Reference): Document 'firmware'.

system: Allow Linux-libre to find our 'modprobe' command.

Fixes <http://bugs.gnu.org/18525>.
Reported by Mark H Weaver <mhw@netris.org>.

* gnu/build/activation.scm (activate-modprobe): New procedure.
* gnu/system.scm (modprobe-wrapper): New procedure.
  (operating-system-activation-script): Use both.

system: Add support for boot-time mapped devices.

* gnu/build/linux-boot.scm (boot-system): Add #:pre-mount parameter and
  honor it.
* gnu/system/linux-initrd.scm (base-initrd): Add #:mapped-devices
  parameter.  Add 'device-mapping-commands' variable, and use it to
  build the #:pre-mount argument of 'boot-system'.
* gnu/system.scm (mapped-device-user,
  operating-system-user-mapped-devices,
  operating-system-boot-mapped-devices): New procedures.
  (device-mapping-services): Use 'operating-system-user-mapped-devices'
  instead of 'operating-system-mapped-devices'.
  (operating-system-initrd-file): Call the initrd with #:mapped-devices.

activation: Ensure existing user accounts have the right settings.

* gnu/build/activation.scm (modify-user, ensure-user): New procedures.
  (activate-users+groups): Systematically call 'ensure-user'.

linux-boot: Ask fsck for a progress bar.

* gnu/build/file-systems.scm (check-file-system): Pass '-C 0' to FSCK.
  Suggested by Mark H. Weaver.

linux-initrd: Remove now obsolete #:guile-modules-in-chroot? parameter.

* gnu/build/linux-boot.scm (boot-system): Remove
  #:guile-modules-in-chroot? and related code.
* gnu/system/linux-initrd.scm (base-initrd): Likewise.
* gnu/system/vm.scm (expression->derivation-in-linux-vm): Remove
  #:guile-modules-in-chroot? argument in 'base-initrd' call.

Merge branch 'master' into core-updates

Conflicts:
	gnu-system.am

activation: Honor $GUIX_NEW_SYSTEM for use by 'guix system reconfigure'.

* gnu/build/activation.scm (activate-current-system): Honor
  $GUIX_NEW_SYSTEM by default.
* guix/scripts/system.scm (switch-to-system): Set $GUIX_NEW_SYSTEM
  before loading SCRIPT.

Merge branch 'master' into core-updates

Conflicts:
	gnu/packages/image.scm

activation: Set the permissions of /etc/sudoers to 440.

* gnu/build/activation.scm (activate-etc): Move 'rm-f' to a local
  'define'.  When TARGET is "sudoers", make it 440.

activation: Make the /bin/sh symlink at activation time.

* gnu/build/install.scm (directives): Remove "/bin/sh".
* gnu/build/activation.scm (activate-/bin/sh): New procedure.
* gnu/system.scm (operating-system-activation-script): Use it.