This is an implementation of new wic subcommand 'wic cp'.

index 4161f80..945dda8 100755
@@ -341,6 +341,8 @@ def imgtype(arg):
         image, part = image.split(':')
         if '/' in part:
             part, path = part.split('/', 1)
+        if not path:
+            path = '/'
 
     if not os.path.isfile(image):
         err = "%s is not a regular file or symlink" % image

@@ -354,6 +356,20 @@ def wic_init_parser_ls(subparser):
     subparser.add_argument("-n", "--native-sysroot",
                         help="path to the native sysroot containing the tools")
 
+def imgpathtype(arg):
+    img = imgtype(arg)
+    if img.part is None:
+        raise argparse.ArgumentTypeError("partition number is not specified")
+    return img
+
+def wic_init_parser_cp(subparser):
+    subparser.add_argument("src",
+                        help="source spec")
+    subparser.add_argument("dest", type=imgpathtype,
+                        help="image spec: <image>:<vfat partition>[<path>]")
+    subparser.add_argument("-n", "--native-sysroot",
+                        help="path to the native sysroot containing the tools")
+
 def wic_init_parser_help(subparser):
     helpparsers = subparser.add_subparsers(dest='help_topic', help=hlp.wic_usage)
     for helptopic in helptopics:

index bb3c749..e93ac4b 100644
@@ -349,6 +349,68 @@ DESCRIPTION
 
 """
 
+wic_cp_usage = """
+
+ Copy files and directories to the vfat partitions
+
+ usage: wic cp <src> <image>:<vfat partition>[<path>] [--native-sysroot <path>]
+
+ This command  copies local files or directories to the vfat partitions of partitioned
+ image.
+
+ See 'wic help cp' for more detailed instructions.
+
+"""
+
+wic_cp_help = """
+
+NAME
+    wic cp - copy files and directories to the vfat partitions
+
+SYNOPSIS
+    wic cp <src> <image>:<vfat partition>
+    wic cp <src> <image>:<vfat partition><path>
+    wic cp <src> <image>:<vfat partition><path> --native-sysroot <path>
+
+DESCRIPTION
+    This command copies files and directories to the vfat partition of the
+    wic image.
+
+    The first form of it copies file or directory to the root directory of
+    the vfat partition:
+        $ wic cp test.wks tmp/deploy/images/qemux86-64/core-image-minimal-qemux86-64.wic:1
+        $ wic ls tmp/deploy/images/qemux86-64/core-image-minimal-qemux86-64.wic:1
+        Volume in drive : is boot
+         Volume Serial Number is DB4C-FD4C
+        Directory for ::/
+
+        efi          <DIR>     2017-05-24  18:15
+        loader       <DIR>     2017-05-24  18:15
+        startup  nsh        26 2017-05-24  18:15
+        vmlinuz        6926384 2017-05-24  18:15
+        test     wks       628 2017-05-24  21:22
+                5 files           6 927 038 bytes
+                                 15 677 440 bytes free
+
+    The second form of the command copies file or directory to the specified directory
+    on the vfat partition:
+       $ wic cp test tmp/deploy/images/qemux86-64/core-image-minimal-qemux86-64.wic:1/efi/
+       $ wic ls tmp/deploy/images/qemux86-64/core-image-minimal-qemux86-64.wic:1/eti/
+       Volume in drive : is boot
+        Volume Serial Number is DB4C-FD4C
+       Directory for ::/efi
+
+       .            <DIR>     2017-05-24  18:15
+       ..           <DIR>     2017-05-24  18:15
+       boot         <DIR>     2017-05-24  18:15
+       test         <DIR>     2017-05-24  21:27
+               4 files                   0 bytes
+                                15 675 392 bytes free
+
+    The -n option is used to specify the path to the native sysroot
+    containing the tools(parted and mtools) to use.
+"""
+
 wic_plugins_help = """
 
 NAME

index 95c8d1c..f8f2844 100644
@@ -309,6 +309,13 @@ def wic_ls(args, native_sysroot):
         path = args.path.path or '/'
         print(disk.dir(args.path.part, path))
 
+def wic_cp(args, native_sysroot):
+    """
+    Copy local file or directory to the vfat partition of
+    partitioned image.
+    """
+    pass
+
 def find_canned(scripts_path, file_name):
     """
     Find a file either by its path or by name in the canned files dir.

index 945dda8..5e81fad 100755
@@ -241,6 +241,12 @@ def wic_ls_subcommand(args, usage_str):
     """
     engine.wic_ls(args, args.native_sysroot)
 
+def wic_cp_subcommand(args, usage_str):
+    """
+    Command-line handling for copying files/dirs to images.
+    The real work is done by engine.wic_cp()
+    """
+    engine.wic_cp(args, args.native_sysroot)
 
 def wic_help_subcommand(args, usage_str):
     """

@@ -277,6 +283,9 @@ helptopics = {
     "ls":        [wic_help_topic_subcommand,
                   wic_help_topic_usage,
                   hlp.wic_ls_help],
+    "cp":        [wic_help_topic_subcommand,
+                  wic_help_topic_usage,
+                  hlp.wic_cp_help],
     "list":      [wic_help_topic_subcommand,
                   wic_help_topic_usage,
                   hlp.wic_list_help]

@@ -390,6 +399,10 @@ subcommands = {
                   hlp.wic_ls_usage,
                   hlp.wic_ls_help,
                   wic_init_parser_ls],
+    "cp":        [wic_cp_subcommand,
+                  hlp.wic_cp_usage,
+                  hlp.wic_cp_help,
+                  wic_init_parser_cp],
     "help":      [wic_help_subcommand,
                   wic_help_topic_usage,
                   hlp.wic_help_help,

index e3701c4..f24fb9a 100644
@@ -237,6 +237,7 @@ class Disk:
         self.native_sysroot = native_sysroot
         self._partitions = None
         self._mdir = None
+        self._mcopy = None
         self._partimages = {}
 
         # find parted

@@ -280,6 +281,10 @@ class Disk:
     def mdir(self):
         return self._prop('mdir')
 
+    @property
+    def mcopy(self):
+        return self._prop("mcopy")
+
     def _get_part_image(self, pnum):
         if pnum not in self.partitions:
             raise WicError("Partition %s is not in the image")

index f8f2844..e3701c4 100644
@@ -267,13 +267,18 @@ class Disk:
 
         return self._partitions
 
+    def _prop(self, name):
+        """Get path to the executable in a lazy way."""
+        aname = "_%s" % name
+        if getattr(self, aname) is None:
+            setattr(self, aname, find_executable(name, self.paths))
+            if not getattr(self, aname):
+                raise WicError("Can't find executable {}".format(name))
+        return getattr(self, aname)
+
     @property
     def mdir(self):
-        if self._mdir is None:
-            self._mdir = find_executable("mdir", self.paths)
-            if not self._mdir:
-                raise WicError("Can't find executable mdir")
-        return self._mdir
+        return self._prop('mdir')
 
     def _get_part_image(self, pnum):
         if pnum not in self.partitions:

index 8fe302a..8719f44 100644
@@ -530,9 +530,18 @@ def filemap(image, log=None):
     except ErrorNotSupp:
         return FilemapSeek(image, log)
 
-def sparse_copy(src_fname, dst_fname, offset=0, skip=0,
+def sparse_copy(src_fname, dst_fname, skip=0, seek=0,
                 length=0, api=None):
-    """Efficiently copy sparse file to or into another file."""
+    """
+    Efficiently copy sparse file to or into another file.
+
+    src_fname: path to source file
+    dst_fname: path to destination file
+    skip: skip N bytes at thestart of src
+    seek: seek N bytes from the start of dst
+    length: read N bytes from src and write them to dst
+    api: FilemapFiemap or FilemapSeek object
+    """
     if not api:
         api = filemap
     fmap = api(src_fname)

@@ -554,7 +563,7 @@ def sparse_copy(src_fname, dst_fname, offset=0, skip=0,
             start = skip
 
         fmap._f_image.seek(start, os.SEEK_SET)
-        dst_file.seek(offset + start - skip, os.SEEK_SET)
+        dst_file.seek(seek + start - skip, os.SEEK_SET)
 
         chunk_size = 1024 * 1024
         to_read = end - start

index f2e6127..3cdedd1 100644
@@ -550,7 +550,7 @@ class PartitionedImage():
             source = part.source_file
             if source:
                 # install source_file contents into a partition
-                sparse_copy(source, self.path, part.start * self.sector_size)
+                sparse_copy(source, self.path, seek=part.start * self.sector_size)
 
                 logger.debug("Installed %s in partition %d, sectors %d-%d, "
                              "size %d sectors", source, part.num, part.start,

index 8719f44..764dbbe 100644
@@ -563,6 +563,13 @@ def sparse_copy(src_fname, dst_fname, skip=0, seek=0,
             start = skip
 
         fmap._f_image.seek(start, os.SEEK_SET)
+
+        written += start - skip - written
+        if length and written >= length:
+            dst_file.seek(seek + length, os.SEEK_SET)
+            dst_file.close()
+            return
+
         dst_file.seek(seek + start - skip, os.SEEK_SET)
 
         chunk_size = 1024 * 1024

index f24fb9a..6a4f55f 100644
@@ -300,6 +300,11 @@ class Disk:
 
         return self._partimages[pnum]
 
+    def _put_part_image(self, pnum):
+        """Put partition image into partitioned image."""
+        sparse_copy(self._partimages[pnum], self.imagepath,
+                    seek=self.partitions[pnum].start)
+
     def dir(self, pnum, path):
         return exec_cmd("{} -i {} ::{}".format(self.mdir,
                                                self._get_part_image(pnum),

index 764dbbe..6d11355 100644
@@ -549,7 +549,11 @@ def sparse_copy(src_fname, dst_fname, skip=0, seek=0,
         dst_file = open(dst_fname, 'r+b')
     except IOError:
         dst_file = open(dst_fname, 'wb')
-        dst_file.truncate(os.path.getsize(src_fname))
+        if length:
+            dst_size = length + seek
+        else:
+            dst_size = os.path.getsize(src_fname) + seek - skip
+        dst_file.truncate(dst_size)
 
     written = 0
     for first, last in fmap.get_mapped_ranges(0, fmap.blocks_cnt):

index 6a4f55f..a48c4ad 100644
@@ -310,6 +310,14 @@ class Disk:
                                                self._get_part_image(pnum),
                                                path))
 
+    def copy(self, src, pnum, path):
+        """Copy partition image into wic image."""
+        cmd = "{} -i {} -snop {} ::{}".format(self.mcopy,
+                                              self._get_part_image(pnum),
+                                              src, path)
+        exec_cmd(cmd)
+        self._put_part_image(pnum)
+
 def wic_ls(args, native_sysroot):
     """List contents of partitioned image or vfat partition."""
     disk = Disk(args.path.image, native_sysroot)

@@ -329,7 +337,8 @@ def wic_cp(args, native_sysroot):
     Copy local file or directory to the vfat partition of
     partitioned image.
     """
-    pass
+    disk = Disk(args.dest.image, native_sysroot)
+    disk.copy(args.src, args.dest.part, args.dest.path)
 
 def find_canned(scripts_path, file_name):
     """

index e908c07..3a611c1 100644
@@ -28,7 +28,7 @@ import sys
 import unittest
 
 from glob import glob
-from shutil import rmtree
+from shutil import rmtree, copy
 from functools import wraps, lru_cache
 from tempfile import NamedTemporaryFile
 

@@ -845,3 +845,47 @@ part /etc --source rootfs --ondisk mmcblk0 --fstype=ext4 --exclude-path bin/ --r
         result = runCmd("wic ls %s:1/ -n %s" % (images[0], sysroot))
         self.assertEqual(0, result.status)
         self.assertEqual(6, len(result.output.split('\n')))
+
+    def test_wic_cp(self):
+        """Test copy files and directories to the the wic image."""
+        self.assertEqual(0, runCmd("wic create wictestdisk "
+                                   "--image-name=core-image-minimal "
+                                   "-D -o %s" % self.resultdir).status)
+        images = glob(self.resultdir + "wictestdisk-*.direct")
+        self.assertEqual(1, len(images))
+
+        sysroot = get_bb_var('RECIPE_SYSROOT_NATIVE', 'wic-tools')
+
+        # list directory content of the first partition
+        result = runCmd("wic ls %s:1/ -n %s" % (images[0], sysroot))
+        self.assertEqual(0, result.status)
+        self.assertEqual(6, len(result.output.split('\n')))
+
+        with NamedTemporaryFile("w", suffix=".wic-cp") as testfile:
+            testfile.write("test")
+
+            # copy file to the partition
+            result = runCmd("wic cp %s %s:1/ -n %s" % (testfile.name, images[0], sysroot))
+            self.assertEqual(0, result.status)
+
+            # check if file is there
+            result = runCmd("wic ls %s:1/ -n %s" % (images[0], sysroot))
+            self.assertEqual(0, result.status)
+            self.assertEqual(7, len(result.output.split('\n')))
+            self.assertTrue(os.path.basename(testfile.name) in result.output)
+
+            # prepare directory
+            testdir = os.path.join(self.resultdir, 'wic-test-cp-dir')
+            testsubdir = os.path.join(testdir, 'subdir')
+            os.makedirs(os.path.join(testsubdir))
+            copy(testfile.name, testdir)
+
+            # copy directory to the partition
+            result = runCmd("wic cp %s %s:1/ -n %s" % (testdir, images[0], sysroot))
+            self.assertEqual(0, result.status)
+
+            # check if directory is there
+            result = runCmd("wic ls %s:1/ -n %s" % (images[0], sysroot))
+            self.assertEqual(0, result.status)
+            self.assertEqual(8, len(result.output.split('\n')))
+            self.assertTrue(os.path.basename(testdir) in result.output)