diff --git a/meta/classes/populate_sdk_ext.bbclass b/meta/classes/populate_sdk_ext.bbclass
index 90033bab5a..0feb3b20c5 100644
--- a/meta/classes/populate_sdk_ext.bbclass
+++ b/meta/classes/populate_sdk_ext.bbclass
@@ -203,6 +203,8 @@ install_tools() {
 	install $buildtools_path ${SDK_OUTPUT}/${SDKPATH}
 
 	install ${SDK_DEPLOY}/${BUILD_ARCH}-nativesdk-libc.tar.bz2 ${SDK_OUTPUT}/${SDKPATH}
+
+	install -m 0755 ${COREBASE}/meta/files/ext-sdk-prepare.sh ${SDK_OUTPUT}/${SDKPATH}
 }
 
 # Since bitbake won't run as root it doesn't make sense to try and install
@@ -242,8 +244,9 @@ sdk_ext_postinst() {
 		# dash which is /bin/sh on Ubuntu will not preserve the
 		# current working directory when first ran, nor will it set $1 when
 		# sourcing a script. That is why this has to look so ugly.
-		sh -c ". buildtools/environment-setup* > preparing_build_system.log && cd $target_sdk_dir/`dirname ${oe_init_build_env_path}` && set $target_sdk_dir && . $target_sdk_dir/${oe_init_build_env_path} $target_sdk_dir >> preparing_build_system.log && bitbake ${SDK_TARGETS} >> preparing_build_system.log" || { echo "SDK preparation failed: see `pwd`/preparing_build_system.log" ; exit 1 ; }
+		sh -c ". buildtools/environment-setup* > preparing_build_system.log && cd $target_sdk_dir/`dirname ${oe_init_build_env_path}` && set $target_sdk_dir && . $target_sdk_dir/${oe_init_build_env_path} $target_sdk_dir >> preparing_build_system.log && $target_sdk_dir/ext-sdk-prepare.sh $target_sdk_dir '${SDK_TARGETS}' >> preparing_build_system.log 2>&1" || { echo "SDK preparation failed: see `pwd`/preparing_build_system.log" ; exit 1 ; }
 	fi
+	rm -f $target_sdk_dir/ext-sdk-prepare.sh
 	echo done
 }
 
diff --git a/meta/files/ext-sdk-prepare.sh b/meta/files/ext-sdk-prepare.sh
new file mode 100644
index 0000000000..160c71e97c
--- /dev/null
+++ b/meta/files/ext-sdk-prepare.sh
@@ -0,0 +1,20 @@
+#!/bin/sh
+
+# Prepare the build system within the extensible SDK
+
+target_sdk_dir="$1"
+sdk_targets="$2"
+
+# Avoid actually building images during this phase, but still
+# ensure all dependencies are extracted from sstate
+# This is a hack, to be sure, but we really don't need to do this here
+for sdktarget in $sdk_targets ; do
+	bbappend=`recipetool newappend $target_sdk_dir/workspace $sdktarget`
+	printf 'python do_rootfs_forcevariable () {\n    bb.utils.mkdirhier(d.getVar("IMAGE_ROOTFS", True))\n}\n' > $bbappend
+	printf 'python do_bootimg () {\n    pass\n}\n' >> $bbappend
+	printf 'python do_bootdirectdisk () {\n    pass\n}\n' >> $bbappend
+	printf 'python do_vmimg () {\n    pass\n}\n' >> $bbappend
+	printf "Created bbappend %s\n" "$bbappend"
+done
+bitbake $sdk_targets || exit 1
+rm -rf $target_sdk_dir/workspace/appends/*