diff --git a/yocto-poky/scripts/lib/devtool/standard.py b/yocto-poky/scripts/lib/devtool/standard.py
index 5464d7b..77a82d5 100644
--- a/yocto-poky/scripts/lib/devtool/standard.py
+++ b/yocto-poky/scripts/lib/devtool/standard.py
@@ -20,13 +20,16 @@
 import sys
 import re
 import shutil
+import subprocess
 import tempfile
 import logging
 import argparse
+import argparse_oe
 import scriptutils
 import errno
+import glob
 from collections import OrderedDict
-from devtool import exec_build_env_command, setup_tinfoil, check_workspace_recipe, use_external_build, setup_git_repo, DevtoolError
+from devtool import exec_build_env_command, setup_tinfoil, check_workspace_recipe, use_external_build, setup_git_repo, recipe_to_append, get_bbclassextend_targets, DevtoolError
 from devtool import parse_recipe
 
 logger = logging.getLogger('devtool')
@@ -37,21 +40,62 @@
     import bb
     import oe.recipeutils
 
-    if args.recipename in workspace:
-        raise DevtoolError("recipe %s is already in your workspace" %
-                            args.recipename)
+    if not args.recipename and not args.srctree and not args.fetch and not args.fetchuri:
+        raise argparse_oe.ArgumentUsageError('At least one of recipename, srctree, fetchuri or -f/--fetch must be specified', 'add')
 
-    reason = oe.recipeutils.validate_pn(args.recipename)
-    if reason:
-        raise DevtoolError(reason)
+    # These are positional arguments, but because we're nice, allow
+    # specifying e.g. source tree without name, or fetch URI without name or
+    # source tree (if we can detect that that is what the user meant)
+    if '://' in args.recipename:
+        if not args.fetchuri:
+            if args.fetch:
+                raise DevtoolError('URI specified as positional argument as well as -f/--fetch')
+            args.fetchuri = args.recipename
+            args.recipename = ''
+    elif args.srctree and '://' in args.srctree:
+        if not args.fetchuri:
+            if args.fetch:
+                raise DevtoolError('URI specified as positional argument as well as -f/--fetch')
+            args.fetchuri = args.srctree
+            args.srctree = ''
+    elif args.recipename and not args.srctree:
+        if os.sep in args.recipename:
+            args.srctree = args.recipename
+            args.recipename = None
+        elif os.path.isdir(args.recipename):
+            logger.warn('Ambiguous argument %s - assuming you mean it to be the recipe name')
 
-    # FIXME this ought to be in validate_pn but we're using that in other contexts
-    if '/' in args.recipename:
-        raise DevtoolError('"/" is not a valid character in recipe names')
+    if args.fetch:
+        if args.fetchuri:
+            raise DevtoolError('URI specified as positional argument as well as -f/--fetch')
+        else:
+            # FIXME should show a warning that -f/--fetch is deprecated here
+            args.fetchuri = args.fetch
 
-    srctree = os.path.abspath(args.srctree)
-    if os.path.exists(srctree):
-        if args.fetch:
+    if args.recipename:
+        if args.recipename in workspace:
+            raise DevtoolError("recipe %s is already in your workspace" %
+                               args.recipename)
+        reason = oe.recipeutils.validate_pn(args.recipename)
+        if reason:
+            raise DevtoolError(reason)
+
+        # FIXME this ought to be in validate_pn but we're using that in other contexts
+        if '/' in args.recipename:
+            raise DevtoolError('"/" is not a valid character in recipe names')
+
+    if args.srctree:
+        srctree = os.path.abspath(args.srctree)
+        srctreeparent = None
+        tmpsrcdir = None
+    else:
+        srctree = None
+        srctreeparent = get_default_srctree(config)
+        bb.utils.mkdirhier(srctreeparent)
+        tmpsrcdir = tempfile.mkdtemp(prefix='devtoolsrc', dir=srctreeparent)
+
+    if srctree and os.path.exists(srctree):
+        if args.fetchuri:
             if not os.path.isdir(srctree):
                 raise DevtoolError("Cannot fetch into source tree path %s as "
                                    "it exists and is not a directory" %
@@ -60,55 +104,108 @@
                 raise DevtoolError("Cannot fetch into source tree path %s as "
                                    "it already exists and is non-empty" %
                                    srctree)
-    elif not args.fetch:
-        raise DevtoolError("Specified source tree %s could not be found" %
-                           srctree)
+    elif not args.fetchuri:
+        if args.srctree:
+            raise DevtoolError("Specified source tree %s could not be found" %
+                               args.srctree)
+        elif srctree:
+            raise DevtoolError("No source tree exists at default path %s - "
+                               "either create and populate this directory, "
+                               "or specify a path to a source tree, or a "
+                               "URI to fetch source from" % srctree)
+        else:
+            raise DevtoolError("You must either specify a source tree "
+                               "or a URI to fetch source from")
 
-    appendpath = os.path.join(config.workspace_path, 'appends')
-    if not os.path.exists(appendpath):
-        os.makedirs(appendpath)
-
-    recipedir = os.path.join(config.workspace_path, 'recipes', args.recipename)
-    bb.utils.mkdirhier(recipedir)
-    rfv = None
     if args.version:
         if '_' in args.version or ' ' in args.version:
             raise DevtoolError('Invalid version string "%s"' % args.version)
-        rfv = args.version
-    if args.fetch:
-        if args.fetch.startswith('git://'):
-            rfv = 'git'
-        elif args.fetch.startswith('svn://'):
-            rfv = 'svn'
-        elif args.fetch.startswith('hg://'):
-            rfv = 'hg'
-    if rfv:
-        bp = "%s_%s" % (args.recipename, rfv)
-    else:
-        bp = args.recipename
-    recipefile = os.path.join(recipedir, "%s.bb" % bp)
+
     if args.color == 'auto' and sys.stdout.isatty():
         color = 'always'
     else:
         color = args.color
     extracmdopts = ''
-    if args.fetch:
-        source = args.fetch
-        extracmdopts = '-x %s' % srctree
+    if args.fetchuri:
+        source = args.fetchuri
+        if srctree:
+            extracmdopts += ' -x %s' % srctree
+        else:
+            extracmdopts += ' -x %s' % tmpsrcdir
     else:
         source = srctree
+    if args.recipename:
+        extracmdopts += ' -N %s' % args.recipename
     if args.version:
         extracmdopts += ' -V %s' % args.version
     if args.binary:
         extracmdopts += ' -b'
+    if args.also_native:
+        extracmdopts += ' --also-native'
+    if args.src_subdir:
+        extracmdopts += ' --src-subdir "%s"' % args.src_subdir
+
+    tempdir = tempfile.mkdtemp(prefix='devtool')
     try:
-        stdout, _ = exec_build_env_command(config.init_path, basepath, 'recipetool --color=%s create -o %s "%s" %s' % (color, recipefile, source, extracmdopts))
-    except bb.process.ExecutionError as e:
-        raise DevtoolError('Command \'%s\' failed:\n%s' % (e.command, e.stdout))
+        try:
+            stdout, _ = exec_build_env_command(config.init_path, basepath, 'recipetool --color=%s create -o %s "%s" %s' % (color, tempdir, source, extracmdopts))
+        except bb.process.ExecutionError as e:
+            if e.exitcode == 15:
+                raise DevtoolError('Could not auto-determine recipe name, please specify it on the command line')
+            else:
+                raise DevtoolError('Command \'%s\' failed:\n%s' % (e.command, e.stdout))
 
-    _add_md5(config, args.recipename, recipefile)
+        recipes = glob.glob(os.path.join(tempdir, '*.bb'))
+        if recipes:
+            recipename = os.path.splitext(os.path.basename(recipes[0]))[0].split('_')[0]
+            if recipename in workspace:
+                raise DevtoolError('A recipe with the same name as the one being created (%s) already exists in your workspace' % recipename)
+            recipedir = os.path.join(config.workspace_path, 'recipes', recipename)
+            bb.utils.mkdirhier(recipedir)
+            recipefile = os.path.join(recipedir, os.path.basename(recipes[0]))
+            appendfile = recipe_to_append(recipefile, config)
+            if os.path.exists(appendfile):
+                # This shouldn't be possible, but just in case
+                raise DevtoolError('A recipe with the same name as the one being created already exists in your workspace')
+            if os.path.exists(recipefile):
+                raise DevtoolError('A recipe file %s already exists in your workspace; this shouldn\'t be there - please delete it before continuing' % recipefile)
+            if tmpsrcdir:
+                srctree = os.path.join(srctreeparent, recipename)
+                if os.path.exists(tmpsrcdir):
+                    if os.path.exists(srctree):
+                        if os.path.isdir(srctree):
+                            try:
+                                os.rmdir(srctree)
+                            except OSError as e:
+                                if e.errno == errno.ENOTEMPTY:
+                                    raise DevtoolError('Source tree path %s already exists and is not empty' % srctree)
+                                else:
+                                    raise
+                        else:
+                            raise DevtoolError('Source tree path %s already exists and is not a directory' % srctree)
+                    logger.info('Using default source tree path %s' % srctree)
+                    shutil.move(tmpsrcdir, srctree)
+                else:
+                    raise DevtoolError('Couldn\'t find source tree created by recipetool')
+            bb.utils.mkdirhier(recipedir)
+            shutil.move(recipes[0], recipefile)
+            # Move any additional files created by recipetool
+            for fn in os.listdir(tempdir):
+                shutil.move(os.path.join(tempdir, fn), recipedir)
+        else:
+            raise DevtoolError('Command \'%s\' did not create any recipe file:\n%s' % (e.command, e.stdout))
+        attic_recipe = os.path.join(config.workspace_path, 'attic', recipename, os.path.basename(recipefile))
+        if os.path.exists(attic_recipe):
+            logger.warn('A modified recipe from a previous invocation exists in %s - you may wish to move this over the top of the new recipe if you had changes in it that you want to continue with' % attic_recipe)
+    finally:
+        if tmpsrcdir and os.path.exists(tmpsrcdir):
+            shutil.rmtree(tmpsrcdir)
+        shutil.rmtree(tempdir)
 
-    if args.fetch and not args.no_git:
+    for fn in os.listdir(recipedir):
+        _add_md5(config, recipename, os.path.join(recipedir, fn))
+
+    if args.fetchuri and not args.no_git:
         setup_git_repo(srctree, args.version, 'devtool')
 
     initial_rev = None
@@ -121,7 +218,10 @@
     if not rd:
         return 1
 
-    appendfile = os.path.join(appendpath, '%s.bbappend' % bp)
+    if args.src_subdir:
+        srctree = os.path.join(srctree, args.src_subdir)
+
+    bb.utils.mkdirhier(os.path.dirname(appendfile))
     with open(appendfile, 'w') as f:
         f.write('inherit externalsrc\n')
         f.write('EXTERNALSRC = "%s"\n' % srctree)
@@ -138,7 +238,18 @@
             f.write('    rm -f ${D}/singletask.lock\n')
             f.write('}\n')
 
-    _add_md5(config, args.recipename, appendfile)
+        if bb.data.inherits_class('npm', rd):
+            f.write('do_install_append() {\n')
+            f.write('    # Remove files added to source dir by devtool/externalsrc\n')
+            f.write('    rm -f ${NPM_INSTALLDIR}/singletask.lock\n')
+            f.write('    rm -rf ${NPM_INSTALLDIR}/.git\n')
+            f.write('    rm -rf ${NPM_INSTALLDIR}/oe-local-files\n')
+            f.write('    for symlink in ${EXTERNALSRC_SYMLINKS} ; do\n')
+            f.write('        rm -f ${NPM_INSTALLDIR}/${symlink%%:*}\n')
+            f.write('    done\n')
+            f.write('}\n')
+
+    _add_md5(config, recipename, appendfile)
 
     logger.info('Recipe %s has been automatically created; further editing may be required to make it fully functional' % recipefile)
 
@@ -238,7 +349,7 @@
         return 1
 
     srctree = os.path.abspath(args.srctree)
-    initial_rev = _extract_source(srctree, args.keep_temp, args.branch, rd)
+    initial_rev = _extract_source(srctree, args.keep_temp, args.branch, False, rd)
     logger.info('Source tree extracted to %s' % srctree)
 
     if initial_rev:
@@ -246,6 +357,28 @@
     else:
         return 1
 
+def sync(args, config, basepath, workspace):
+    """Entry point for the devtool 'sync' subcommand"""
+    import bb
+
+    tinfoil = _prep_extract_operation(config, basepath, args.recipename)
+    if not tinfoil:
+        # Error already shown
+        return 1
+
+    rd = parse_recipe(config, tinfoil, args.recipename, True)
+    if not rd:
+        return 1
+
+    srctree = os.path.abspath(args.srctree)
+    initial_rev = _extract_source(srctree, args.keep_temp, args.branch, True, rd)
+    logger.info('Source tree %s synchronized' % srctree)
+
+    if initial_rev:
+        return 0
+    else:
+        return 1
+
 class BbTaskExecutor(object):
     """Class for executing bitbake tasks for a recipe
 
@@ -261,7 +394,7 @@
     def exec_func(self, func, report):
         """Run bitbake task function"""
         if not func in self.executed:
-            deps = self.rdata.getVarFlag(func, 'deps')
+            deps = self.rdata.getVarFlag(func, 'deps', False)
             if deps:
                 for taskdepfunc in deps:
                     self.exec_func(taskdepfunc, True)
@@ -269,14 +402,51 @@
                 logger.info('Executing %s...' % func)
             fn = self.rdata.getVar('FILE', True)
             localdata = bb.build._task_data(fn, func, self.rdata)
-            bb.build.exec_func(func, localdata)
+            try:
+                bb.build.exec_func(func, localdata)
+            except bb.build.FuncFailed as e:
+                raise DevtoolError(str(e))
             self.executed.append(func)
 
 
-def _prep_extract_operation(config, basepath, recipename):
+class PatchTaskExecutor(BbTaskExecutor):
+    def __init__(self, rdata):
+        self.check_git = False
+        super(PatchTaskExecutor, self).__init__(rdata)
+
+    def exec_func(self, func, report):
+        from oe.patch import GitApplyTree
+        srcsubdir = self.rdata.getVar('S', True)
+        haspatches = False
+        if func == 'do_patch':
+            patchdir = os.path.join(srcsubdir, 'patches')
+            if os.path.exists(patchdir):
+                if os.listdir(patchdir):
+                    haspatches = True
+                else:
+                    os.rmdir(patchdir)
+
+        super(PatchTaskExecutor, self).exec_func(func, report)
+        if self.check_git and os.path.exists(srcsubdir):
+            if func == 'do_patch':
+                if os.path.exists(patchdir):
+                    shutil.rmtree(patchdir)
+                    if haspatches:
+                        stdout, _ = bb.process.run('git status --porcelain patches', cwd=srcsubdir)
+                        if stdout:
+                            bb.process.run('git checkout patches', cwd=srcsubdir)
+
+            stdout, _ = bb.process.run('git status --porcelain', cwd=srcsubdir)
+            if stdout:
+                bb.process.run('git add .; git commit -a -m "Committing changes from %s\n\n%s"' % (func, GitApplyTree.ignore_commit_prefix + ' - from %s' % func), cwd=srcsubdir)
+
+
+def _prep_extract_operation(config, basepath, recipename, tinfoil=None):
     """HACK: Ugly workaround for making sure that requirements are met when
        trying to extract a package. Returns the tinfoil instance to be used."""
-    tinfoil = setup_tinfoil(basepath=basepath)
+    if not tinfoil:
+        tinfoil = setup_tinfoil(basepath=basepath)
+
     rd = parse_recipe(config, tinfoil, recipename, True)
     if not rd:
         return None
@@ -293,7 +463,7 @@
     return tinfoil
 
 
-def _extract_source(srctree, keep_temp, devbranch, d):
+def _extract_source(srctree, keep_temp, devbranch, sync, d):
     """Extract sources of a recipe"""
     import bb.event
     import oe.recipeutils
@@ -312,21 +482,26 @@
 
     _check_compatible_recipe(pn, d)
 
-    if os.path.exists(srctree):
-        if not os.path.isdir(srctree):
-            raise DevtoolError("output path %s exists and is not a directory" %
-                               srctree)
-        elif os.listdir(srctree):
-            raise DevtoolError("output path %s already exists and is "
-                               "non-empty" % srctree)
+    if sync:
+        if not os.path.exists(srctree):
+                raise DevtoolError("output path %s does not exist" % srctree)
+    else:
+        if os.path.exists(srctree):
+            if not os.path.isdir(srctree):
+                raise DevtoolError("output path %s exists and is not a directory" %
+                                   srctree)
+            elif os.listdir(srctree):
+                raise DevtoolError("output path %s already exists and is "
+                                   "non-empty" % srctree)
 
-    if 'noexec' in (d.getVarFlags('do_unpack', False) or []):
-        raise DevtoolError("The %s recipe has do_unpack disabled, unable to "
-                           "extract source" % pn)
+        if 'noexec' in (d.getVarFlags('do_unpack', False) or []):
+            raise DevtoolError("The %s recipe has do_unpack disabled, unable to "
+                               "extract source" % pn)
 
-    # Prepare for shutil.move later on
-    bb.utils.mkdirhier(srctree)
-    os.rmdir(srctree)
+    if not sync:
+        # Prepare for shutil.move later on
+        bb.utils.mkdirhier(srctree)
+        os.rmdir(srctree)
 
     # We don't want notes to be printed, they are too verbose
     origlevel = bb.logger.getEffectiveLevel()
@@ -352,7 +527,7 @@
             # We don't want to move the source to STAGING_KERNEL_DIR here
             crd.setVar('STAGING_KERNEL_DIR', '${S}')
 
-        task_executor = BbTaskExecutor(crd)
+        task_executor = PatchTaskExecutor(crd)
 
         crd.setVar('EXTERNALSRC_forcevariable', '')
 
@@ -366,6 +541,8 @@
             task_executor.exec_func('do_kernel_checkout', False)
         srcsubdir = crd.getVar('S', True)
 
+        task_executor.check_git = True
+
         # Move local source files into separate subdir
         recipe_patches = [os.path.basename(patch) for patch in
                           oe.recipeutils.get_recipe_patches(crd)]
@@ -399,13 +576,6 @@
 
         scriptutils.git_convert_standalone_clone(srcsubdir)
 
-        patchdir = os.path.join(srcsubdir, 'patches')
-        haspatches = False
-        if os.path.exists(patchdir):
-            if os.listdir(patchdir):
-                haspatches = True
-            else:
-                os.rmdir(patchdir)
         # Make sure that srcsubdir exists
         bb.utils.mkdirhier(srcsubdir)
         if not os.path.exists(srcsubdir) or not os.listdir(srcsubdir):
@@ -425,18 +595,47 @@
 
         bb.process.run('git tag -f devtool-patched', cwd=srcsubdir)
 
-        if os.path.exists(patchdir):
-            shutil.rmtree(patchdir)
-            if haspatches:
-                bb.process.run('git checkout patches', cwd=srcsubdir)
-
-        # Move oe-local-files directory to srctree
-        if os.path.exists(os.path.join(tempdir, 'oe-local-files')):
-            logger.info('Adding local source files to srctree...')
-            shutil.move(os.path.join(tempdir, 'oe-local-files'), srcsubdir)
+        kconfig = None
+        if bb.data.inherits_class('kernel-yocto', d):
+            # Store generate and store kernel config
+            logger.info('Generating kernel config')
+            task_executor.exec_func('do_configure', False)
+            kconfig = os.path.join(crd.getVar('B', True), '.config')
 
 
-        shutil.move(srcsubdir, srctree)
+        tempdir_localdir = os.path.join(tempdir, 'oe-local-files')
+        srctree_localdir = os.path.join(srctree, 'oe-local-files')
+
+        if sync:
+            bb.process.run('git fetch file://' + srcsubdir + ' ' + devbranch + ':' + devbranch, cwd=srctree)
+
+            # Move oe-local-files directory to srctree
+            # As the oe-local-files is not part of the constructed git tree,
+            # remove them directly during the synchrounizating might surprise
+            # the users.  Instead, we move it to oe-local-files.bak and remind
+            # user in the log message.
+            if os.path.exists(srctree_localdir + '.bak'):
+                shutil.rmtree(srctree_localdir, srctree_localdir + '.bak')
+
+            if os.path.exists(srctree_localdir):
+                logger.info('Backing up current local file directory %s' % srctree_localdir)
+                shutil.move(srctree_localdir, srctree_localdir + '.bak')
+
+            if os.path.exists(tempdir_localdir):
+                logger.info('Syncing local source files to srctree...')
+                shutil.copytree(tempdir_localdir, srctree_localdir)
+        else:
+            # Move oe-local-files directory to srctree
+            if os.path.exists(tempdir_localdir):
+                logger.info('Adding local source files to srctree...')
+                shutil.move(tempdir_localdir, srcsubdir)
+
+            shutil.move(srcsubdir, srctree)
+
+        if kconfig:
+            logger.info('Copying kernel config to srctree')
+            shutil.copy2(kconfig, srctree)
+
     finally:
         bb.logger.setLevel(origlevel)
 
@@ -468,7 +667,7 @@
     import bb.utils
     origfile = os.path.join(config.workspace_path, '.devtool_md5')
     newfile = os.path.join(config.workspace_path, '.devtool_md5_new')
-    preservepath = os.path.join(config.workspace_path, 'attic')
+    preservepath = os.path.join(config.workspace_path, 'attic', recipename)
     with open(origfile, 'r') as f:
         with open(newfile, 'w') as tf:
             for line in f.readlines():
@@ -503,18 +702,7 @@
         raise DevtoolError("recipe %s is already in your workspace" %
                            args.recipename)
 
-    if not args.extract and not os.path.isdir(args.srctree):
-        raise DevtoolError("directory %s does not exist or not a directory "
-                           "(specify -x to extract source from recipe)" %
-                           args.srctree)
-    if args.extract:
-        tinfoil = _prep_extract_operation(config, basepath, args.recipename)
-        if not tinfoil:
-            # Error already shown
-            return 1
-    else:
-        tinfoil = setup_tinfoil(basepath=basepath)
-
+    tinfoil = setup_tinfoil(basepath=basepath)
     rd = parse_recipe(config, tinfoil, args.recipename, True)
     if not rd:
         return 1
@@ -526,12 +714,23 @@
         raise DevtoolError("recipe %s is already in your workspace" %
                            pn)
 
+    if args.srctree:
+        srctree = os.path.abspath(args.srctree)
+    else:
+        srctree = get_default_srctree(config, pn)
+
+    if args.no_extract and not os.path.isdir(srctree):
+        raise DevtoolError("--no-extract specified and source path %s does "
+                           "not exist or is not a directory" %
+                           srctree)
+    if not args.no_extract:
+        tinfoil = _prep_extract_operation(config, basepath, pn, tinfoil)
+        if not tinfoil:
+            # Error already shown
+            return 1
+
     recipefile = rd.getVar('FILE', True)
-    appendname = os.path.splitext(os.path.basename(recipefile))[0]
-    if args.wildcard:
-        appendname = re.sub(r'_.*', '_%', appendname)
-    appendpath = os.path.join(config.workspace_path, 'appends')
-    appendfile = os.path.join(appendpath, appendname + '.bbappend')
+    appendfile = recipe_to_append(recipefile, config, args.wildcard)
     if os.path.exists(appendfile):
         raise DevtoolError("Another variant of recipe %s is already in your "
                            "workspace (only one variant of a recipe can "
@@ -542,29 +741,28 @@
 
     initial_rev = None
     commits = []
-    srctree = os.path.abspath(args.srctree)
-    if args.extract:
-        initial_rev = _extract_source(args.srctree, False, args.branch, rd)
+    if not args.no_extract:
+        initial_rev = _extract_source(srctree, False, args.branch, False, rd)
         if not initial_rev:
             return 1
         logger.info('Source tree extracted to %s' % srctree)
         # Get list of commits since this revision
-        (stdout, _) = bb.process.run('git rev-list --reverse %s..HEAD' % initial_rev, cwd=args.srctree)
+        (stdout, _) = bb.process.run('git rev-list --reverse %s..HEAD' % initial_rev, cwd=srctree)
         commits = stdout.split()
     else:
-        if os.path.exists(os.path.join(args.srctree, '.git')):
+        if os.path.exists(os.path.join(srctree, '.git')):
             # Check if it's a tree previously extracted by us
             try:
-                (stdout, _) = bb.process.run('git branch --contains devtool-base', cwd=args.srctree)
+                (stdout, _) = bb.process.run('git branch --contains devtool-base', cwd=srctree)
             except bb.process.ExecutionError:
                 stdout = ''
             for line in stdout.splitlines():
                 if line.startswith('*'):
-                    (stdout, _) = bb.process.run('git rev-parse devtool-base', cwd=args.srctree)
+                    (stdout, _) = bb.process.run('git rev-parse devtool-base', cwd=srctree)
                     initial_rev = stdout.rstrip()
             if not initial_rev:
                 # Otherwise, just grab the head revision
-                (stdout, _) = bb.process.run('git rev-parse HEAD', cwd=args.srctree)
+                (stdout, _) = bb.process.run('git rev-parse HEAD', cwd=srctree)
                 initial_rev = stdout.rstrip()
 
     # Check that recipe isn't using a shared workdir
@@ -575,8 +773,7 @@
         srcsubdir = os.path.relpath(s, workdir).split(os.sep, 1)[1]
         srctree = os.path.join(srctree, srcsubdir)
 
-    if not os.path.exists(appendpath):
-        os.makedirs(appendpath)
+    bb.utils.mkdirhier(os.path.dirname(appendfile))
     with open(appendfile, 'w') as f:
         f.write('FILESEXTRAPATHS_prepend := "${THISDIR}/${PN}:"\n')
         # Local files can be modified/tracked in separate subdir under srctree
@@ -593,7 +790,12 @@
             f.write('EXTERNALSRC_BUILD_pn-%s = "%s"\n' % (pn, srctree))
 
         if bb.data.inherits_class('kernel', rd):
-            f.write('SRCTREECOVEREDTASKS = "do_validate_branches do_kernel_checkout do_fetch do_unpack do_patch"\n')
+            f.write('SRCTREECOVEREDTASKS = "do_validate_branches do_kernel_checkout '
+                    'do_fetch do_unpack do_patch do_kernel_configme do_kernel_configcheck"\n')
+            f.write('\ndo_configure_append() {\n'
+                    '    cp ${B}/.config ${S}/.config.baseline\n'
+                    '    ln -sfT ${B}/.config ${S}/.config.new\n'
+                    '}\n')
         if initial_rev:
             f.write('\n# initial_rev: %s\n' % initial_rev)
             for commit in commits:
@@ -603,6 +805,8 @@
 
     logger.info('Recipe %s now set up to build from %s' % (pn, srctree))
 
+    tinfoil.shutdown()
+
     return 0
 
 def _get_patchset_revs(args, srctree, recipe_path):
@@ -735,6 +939,33 @@
     return (updated, added, existing_patches)
 
 
+def _create_kconfig_diff(srctree, rd, outfile):
+    """Create a kconfig fragment"""
+    # Only update config fragment if both config files exist
+    orig_config = os.path.join(srctree, '.config.baseline')
+    new_config = os.path.join(srctree, '.config.new')
+    if os.path.exists(orig_config) and os.path.exists(new_config):
+        cmd = ['diff', '--new-line-format=%L', '--old-line-format=',
+               '--unchanged-line-format=', orig_config, new_config]
+        pipe = subprocess.Popen(cmd, stdout=subprocess.PIPE,
+                                stderr=subprocess.PIPE)
+        stdout, stderr = pipe.communicate()
+        if pipe.returncode == 1:
+            logger.info("Updating config fragment %s" % outfile)
+            with open(outfile, 'w') as fobj:
+                fobj.write(stdout)
+        elif pipe.returncode == 0:
+            logger.info("Would remove config fragment %s" % outfile)
+            if os.path.exists(outfile):
+                # Remove fragment file in case of empty diff
+                logger.info("Removing config fragment %s" % outfile)
+                os.unlink(outfile)
+        else:
+            raise bb.process.ExecutionError(cmd, pipe.returncode, stdout, stderr)
+        return True
+    return False
+
+
 def _export_local_files(srctree, rd, destdir):
     """Copy local files from srctree to given location.
        Returns three-tuple of dicts:
@@ -755,6 +986,7 @@
     updated = OrderedDict()
     added = OrderedDict()
     removed = OrderedDict()
+    local_files_dir = os.path.join(srctree, 'oe-local-files')
     git_files = _git_ls_tree(srctree)
     if 'oe-local-files' in git_files:
         # If tracked by Git, take the files from srctree HEAD. First get
@@ -765,11 +997,32 @@
                         env=dict(os.environ, GIT_WORK_TREE=destdir,
                                  GIT_INDEX_FILE=tmp_index))
         new_set = _git_ls_tree(srctree, tree, True).keys()
-    elif os.path.isdir(os.path.join(srctree, 'oe-local-files')):
+    elif os.path.isdir(local_files_dir):
         # If not tracked by Git, just copy from working copy
         new_set = _ls_tree(os.path.join(srctree, 'oe-local-files'))
         bb.process.run(['cp', '-ax',
                         os.path.join(srctree, 'oe-local-files', '.'), destdir])
+    else:
+        new_set = []
+
+    # Special handling for kernel config
+    if bb.data.inherits_class('kernel-yocto', rd):
+        fragment_fn = 'devtool-fragment.cfg'
+        fragment_path = os.path.join(destdir, fragment_fn)
+        if _create_kconfig_diff(srctree, rd, fragment_path):
+            if os.path.exists(fragment_path):
+                if fragment_fn not in new_set:
+                    new_set.append(fragment_fn)
+                # Copy fragment to local-files
+                if os.path.isdir(local_files_dir):
+                    shutil.copy2(fragment_path, local_files_dir)
+            else:
+                if fragment_fn in new_set:
+                    new_set.remove(fragment_fn)
+                # Remove fragment from local-files
+                if os.path.exists(os.path.join(local_files_dir, fragment_fn)):
+                    os.unlink(os.path.join(local_files_dir, fragment_fn))
+
     if new_set is not None:
         for fname in new_set:
             if fname in existing_files:
@@ -857,15 +1110,15 @@
                     'changes')
 
     _remove_source_files(args, remove_files, destpath)
+    return True
 
-def _update_recipe_patch(args, config, srctree, rd, config_data):
+def _update_recipe_patch(args, config, workspace, srctree, rd, config_data):
     """Implement the 'patch' mode of update-recipe"""
     import bb
     import oe.recipeutils
 
     recipefile = rd.getVar('FILE', True)
-    append = os.path.join(config.workspace_path, 'appends', '%s.bbappend' %
-                          os.path.splitext(os.path.basename(recipefile))[0])
+    append = workspace[args.recipename]['bbappend']
     if not os.path.exists(append):
         raise DevtoolError('unable to find workspace bbappend for recipe %s' %
                            args.recipename)
@@ -959,10 +1212,12 @@
             elif not updatefiles:
                 # Neither patches nor recipe were updated
                 logger.info('No patches or files need updating')
+                return False
     finally:
         shutil.rmtree(tempdir)
 
     _remove_source_files(args, remove_files, destpath)
+    return True
 
 def _guess_recipe_update_mode(srctree, rdata):
     """Guess the recipe update mode to use"""
@@ -1011,15 +1266,16 @@
         mode = args.mode
 
     if mode == 'srcrev':
-        _update_recipe_srcrev(args, srctree, rd, tinfoil.config_data)
+        updated = _update_recipe_srcrev(args, srctree, rd, tinfoil.config_data)
     elif mode == 'patch':
-        _update_recipe_patch(args, config, srctree, rd, tinfoil.config_data)
+        updated = _update_recipe_patch(args, config, workspace, srctree, rd, tinfoil.config_data)
     else:
         raise DevtoolError('update_recipe: invalid mode %s' % mode)
 
-    rf = rd.getVar('FILE', True)
-    if rf.startswith(config.workspace_path):
-        logger.warn('Recipe file %s has been updated but is inside the workspace - you will need to move it (and any associated files next to it) out to the desired layer before using "devtool reset" in order to keep any changes' % rf)
+    if updated:
+        rf = rd.getVar('FILE', True)
+        if rf.startswith(config.workspace_path):
+            logger.warn('Recipe file %s has been updated but is inside the workspace - you will need to move it (and any associated files next to it) out to the desired layer before using "devtool reset" in order to keep any changes' % rf)
 
     return 0
 
@@ -1028,7 +1284,12 @@
     """Entry point for the devtool 'status' subcommand"""
     if workspace:
         for recipe, value in workspace.iteritems():
-            print("%s: %s" % (recipe, value['srctree']))
+            recipefile = value['recipefile']
+            if recipefile:
+                recipestr = ' (%s)' % recipefile
+            else:
+                recipestr = ''
+            print("%s: %s%s" % (recipe, value['srctree'], recipestr))
     else:
         logger.info('No recipes currently in your workspace - you can use "devtool modify" to work on an existing recipe or "devtool add" to add a new one')
     return 0
@@ -1055,8 +1316,17 @@
             logger.info('Cleaning sysroot for recipe %s...' % recipes[0])
         else:
             logger.info('Cleaning sysroot for recipes %s...' % ', '.join(recipes))
+        # If the recipe file itself was created in the workspace, and
+        # it uses BBCLASSEXTEND, then we need to also clean the other
+        # variants
+        targets = []
+        for recipe in recipes:
+            targets.append(recipe)
+            recipefile = workspace[recipe]['recipefile']
+            if recipefile:
+                targets.extend(get_bbclassextend_targets(recipefile, recipe))
         try:
-            exec_build_env_command(config.init_path, basepath, 'bitbake -c clean %s' % ' '.join(recipes))
+            exec_build_env_command(config.init_path, basepath, 'bitbake -c clean %s' % ' '.join(targets))
         except bb.process.ExecutionError as e:
             raise DevtoolError('Command \'%s\' failed, output:\n%s\nIf you '
                                 'wish, you may specify -n/--no-clean to '
@@ -1066,7 +1336,7 @@
     for pn in recipes:
         _check_preserve(config, pn)
 
-        preservepath = os.path.join(config.workspace_path, 'attic', pn)
+        preservepath = os.path.join(config.workspace_path, 'attic', pn, pn)
         def preservedir(origdir):
             if os.path.exists(origdir):
                 for root, dirs, files in os.walk(origdir):
@@ -1075,58 +1345,96 @@
                         _move_file(os.path.join(origdir, fn),
                                    os.path.join(preservepath, fn))
                     for dn in dirs:
-                        os.rmdir(os.path.join(root, dn))
+                        preservedir(os.path.join(root, dn))
                 os.rmdir(origdir)
 
         preservedir(os.path.join(config.workspace_path, 'recipes', pn))
         # We don't automatically create this dir next to appends, but the user can
         preservedir(os.path.join(config.workspace_path, 'appends', pn))
 
+        srctree = workspace[pn]['srctree']
+        if os.path.isdir(srctree):
+            if os.listdir(srctree):
+                # We don't want to risk wiping out any work in progress
+                logger.info('Leaving source tree %s as-is; if you no '
+                            'longer need it then please delete it manually'
+                            % srctree)
+            else:
+                # This is unlikely, but if it's empty we can just remove it
+                os.rmdir(srctree)
+
     return 0
 
 
+def get_default_srctree(config, recipename=''):
+    """Get the default srctree path"""
+    srctreeparent = config.get('General', 'default_source_parent_dir', config.workspace_path)
+    if recipename:
+        return os.path.join(srctreeparent, 'sources', recipename)
+    else:
+        return os.path.join(srctreeparent, 'sources')
+
 def register_commands(subparsers, context):
     """Register devtool subcommands from this plugin"""
+
+    defsrctree = get_default_srctree(context.config)
     parser_add = subparsers.add_parser('add', help='Add a new recipe',
-                                       description='Adds a new recipe')
-    parser_add.add_argument('recipename', help='Name for new recipe to add')
-    parser_add.add_argument('srctree', help='Path to external source tree')
+                                       description='Adds a new recipe to the workspace to build a specified source tree. Can optionally fetch a remote URI and unpack it to create the source tree.',
+                                       group='starting', order=100)
+    parser_add.add_argument('recipename', nargs='?', help='Name for new recipe to add (just name - no version, path or extension). If not specified, will attempt to auto-detect it.')
+    parser_add.add_argument('srctree', nargs='?', help='Path to external source tree. If not specified, a subdirectory of %s will be used.' % defsrctree)
+    parser_add.add_argument('fetchuri', nargs='?', help='Fetch the specified URI and extract it to create the source tree')
     group = parser_add.add_mutually_exclusive_group()
     group.add_argument('--same-dir', '-s', help='Build in same directory as source', action="store_true")
     group.add_argument('--no-same-dir', help='Force build in a separate build directory', action="store_true")
-    parser_add.add_argument('--fetch', '-f', help='Fetch the specified URI and extract it to create the source tree', metavar='URI')
+    parser_add.add_argument('--fetch', '-f', help='Fetch the specified URI and extract it to create the source tree (deprecated - pass as positional argument instead)', metavar='URI')
     parser_add.add_argument('--version', '-V', help='Version to use within recipe (PV)')
-    parser_add.add_argument('--no-git', '-g', help='If -f/--fetch is specified, do not set up source tree as a git repository', action="store_true")
-    parser_add.add_argument('--binary', '-b', help='Treat the source tree as something that should be installed verbatim (no compilation, same directory structure)', action='store_true')
+    parser_add.add_argument('--no-git', '-g', help='If fetching source, do not set up source tree as a git repository', action="store_true")
+    parser_add.add_argument('--binary', '-b', help='Treat the source tree as something that should be installed verbatim (no compilation, same directory structure). Useful with binary packages e.g. RPMs.', action='store_true')
+    parser_add.add_argument('--also-native', help='Also add native variant (i.e. support building recipe for the build host as well as the target machine)', action='store_true')
+    parser_add.add_argument('--src-subdir', help='Specify subdirectory within source tree to use', metavar='SUBDIR')
     parser_add.set_defaults(func=add)
 
     parser_modify = subparsers.add_parser('modify', help='Modify the source for an existing recipe',
-                                       description='Enables modifying the source for an existing recipe',
-                                       formatter_class=argparse.ArgumentDefaultsHelpFormatter)
-    parser_modify.add_argument('recipename', help='Name for recipe to edit')
-    parser_modify.add_argument('srctree', help='Path to external source tree')
+                                       description='Sets up the build environment to modify the source for an existing recipe. The default behaviour is to extract the source being fetched by the recipe into a git tree so you can work on it; alternatively if you already have your own pre-prepared source tree you can specify -n/--no-extract.',
+                                       group='starting', order=90)
+    parser_modify.add_argument('recipename', help='Name of existing recipe to edit (just name - no version, path or extension)')
+    parser_modify.add_argument('srctree', nargs='?', help='Path to external source tree. If not specified, a subdirectory of %s will be used.' % defsrctree)
     parser_modify.add_argument('--wildcard', '-w', action="store_true", help='Use wildcard for unversioned bbappend')
-    parser_modify.add_argument('--extract', '-x', action="store_true", help='Extract source as well')
+    group = parser_modify.add_mutually_exclusive_group()
+    group.add_argument('--extract', '-x', action="store_true", help='Extract source for recipe (default)')
+    group.add_argument('--no-extract', '-n', action="store_true", help='Do not extract source, expect it to exist')
     group = parser_modify.add_mutually_exclusive_group()
     group.add_argument('--same-dir', '-s', help='Build in same directory as source', action="store_true")
     group.add_argument('--no-same-dir', help='Force build in a separate build directory', action="store_true")
-    parser_modify.add_argument('--branch', '-b', default="devtool", help='Name for development branch to checkout (only when using -x)')
+    parser_modify.add_argument('--branch', '-b', default="devtool", help='Name for development branch to checkout (when not using -n/--no-extract) (default "%(default)s")')
     parser_modify.set_defaults(func=modify)
 
     parser_extract = subparsers.add_parser('extract', help='Extract the source for an existing recipe',
                                        description='Extracts the source for an existing recipe',
-                                       formatter_class=argparse.ArgumentDefaultsHelpFormatter)
-    parser_extract.add_argument('recipename', help='Name for recipe to extract the source for')
+                                       group='advanced')
+    parser_extract.add_argument('recipename', help='Name of recipe to extract the source for')
     parser_extract.add_argument('srctree', help='Path to where to extract the source tree')
-    parser_extract.add_argument('--branch', '-b', default="devtool", help='Name for development branch to checkout')
+    parser_extract.add_argument('--branch', '-b', default="devtool", help='Name for development branch to checkout (default "%(default)s")')
     parser_extract.add_argument('--keep-temp', action="store_true", help='Keep temporary directory (for debugging)')
-    parser_extract.set_defaults(func=extract)
+    parser_extract.set_defaults(func=extract, no_workspace=True)
+
+    parser_sync = subparsers.add_parser('sync', help='Synchronize the source tree for an existing recipe',
+                                       description='Synchronize the previously extracted source tree for an existing recipe',
+                                       formatter_class=argparse.ArgumentDefaultsHelpFormatter,
+                                       group='advanced')
+    parser_sync.add_argument('recipename', help='Name of recipe to sync the source for')
+    parser_sync.add_argument('srctree', help='Path to the source tree')
+    parser_sync.add_argument('--branch', '-b', default="devtool", help='Name for development branch to checkout')
+    parser_sync.add_argument('--keep-temp', action="store_true", help='Keep temporary directory (for debugging)')
+    parser_sync.set_defaults(func=sync)
 
     parser_update_recipe = subparsers.add_parser('update-recipe', help='Apply changes from external source tree to recipe',
-                                       description='Applies changes from external source tree to a recipe (updating/adding/removing patches as necessary, or by updating SRCREV)')
+                                       description='Applies changes from external source tree to a recipe (updating/adding/removing patches as necessary, or by updating SRCREV). Note that these changes need to have been committed to the git repository in order to be recognised.',
+                                       group='working', order=-90)
     parser_update_recipe.add_argument('recipename', help='Name of recipe to update')
     parser_update_recipe.add_argument('--mode', '-m', choices=['patch', 'srcrev', 'auto'], default='auto', help='Update mode (where %(metavar)s is %(choices)s; default is %(default)s)', metavar='MODE')
-    parser_update_recipe.add_argument('--initial-rev', help='Starting revision for patches')
+    parser_update_recipe.add_argument('--initial-rev', help='Override starting revision for patches')
     parser_update_recipe.add_argument('--append', '-a', help='Write changes to a bbappend in the specified layer instead of the recipe', metavar='LAYERDIR')
     parser_update_recipe.add_argument('--wildcard-version', '-w', help='In conjunction with -a/--append, use a wildcard to make the bbappend apply to any recipe version', action='store_true')
     parser_update_recipe.add_argument('--no-remove', '-n', action="store_true", help='Don\'t remove patches, only add or update')
@@ -1134,12 +1442,12 @@
 
     parser_status = subparsers.add_parser('status', help='Show workspace status',
                                           description='Lists recipes currently in your workspace and the paths to their respective external source trees',
-                                          formatter_class=argparse.ArgumentDefaultsHelpFormatter)
+                                          group='info', order=100)
     parser_status.set_defaults(func=status)
 
     parser_reset = subparsers.add_parser('reset', help='Remove a recipe from your workspace',
                                          description='Removes the specified recipe from your workspace (resetting its state)',
-                                         formatter_class=argparse.ArgumentDefaultsHelpFormatter)
+                                         group='working', order=-100)
     parser_reset.add_argument('recipename', nargs='?', help='Recipe to reset')
     parser_reset.add_argument('--all', '-a', action="store_true", help='Reset all recipes (clear workspace)')
     parser_reset.add_argument('--no-clean', '-n', action="store_true", help='Don\'t clean the sysroot to remove recipe output')