wic: Add RootfsPlugin

Implement RootfsPlugin class. The do_prepare_partition() method
is implemented using code in Wic_PartData class.

This class have 'rootfs' name, which is the name that should
be used in the --source parameters of the .wks partition commands.

(From OE-Core rev: 68dd66849bbaca6e3a0cf00beec0dba1c08e9070)

Signed-off-by: João Henrique Ferreira de Freitas <joaohf@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

scripts/lib/mic/plugins/source/rootfs.py

@@ -0,0 +1,58 @@
+# ex:ts=4:sw=4:sts=4:et
+# -*- tab-width: 4; c-basic-offset: 4; indent-tabs-mode: nil -*-
+#
+# Copyright (c) 2014, Intel Corporation.
+# All rights reserved.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License version 2 as
+# published by the Free Software Foundation.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along
+# with this program; if not, write to the Free Software Foundation, Inc.,
+# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+#
+# DESCRIPTION
+# This implements the 'rootfs' source plugin class for 'wic'
+#
+# AUTHORS
+# Tom Zanussi <tom.zanussi (at] linux.intel.com>
+# Joao Henrique Ferreira de Freitas <joaohf (at] gmail.com>
+#
+
+import os
+import shutil
+import re
+import tempfile
+
+from mic import kickstart, chroot, msger
+from mic.utils import misc, fs_related, errors, runner, cmdln
+from mic.conf import configmgr
+from mic.plugin import pluginmgr
+from mic.utils.partitionedfs import PartitionedMount
+import mic.imager.direct as direct
+from mic.pluginbase import SourcePlugin
+from mic.utils.oe.misc import *
+from mic.imager.direct import DirectImageCreator
+
+class RootfsPlugin(SourcePlugin):
+    name = 'rootfs'
+
+    @classmethod
+    def do_prepare_partition(self, part, cr, cr_workdir, oe_builddir, bootimg_dir,
+                             kernel_dir, rootfs_dir, native_sysroot):
+        """
+        Called to do the actual content population for a partition i.e. it
+        'prepares' the partition to be incorporated into the image.
+        In this case, prepare content for legacy bios boot partition.
+        """
+        if part.rootfs:
+            rootfs_dir = part.rootfs 
+
+        part.prepare_rootfs(cr_workdir, oe_builddir, rootfs_dir, native_sysroot)
+