diff --git a/config/functions b/config/functions
index 757259bb20..27c2c16ad6 100644
--- a/config/functions
+++ b/config/functions
@@ -661,8 +661,7 @@ do_autoreconf() {
 get_pkg_variable() {
   if [ -n "$1" -a -n "$2" ] ; then
     if [ "$1" != "$PKG_NAME" ]; then
-      cd $ROOT
-      . config/options $1 &>/dev/null
+      source_package "${1}"
     fi
     echo "${!2}"
   fi
@@ -803,6 +802,108 @@ pkg_call_optional() {
   pkg_call ${1} || return 0
 }
 
+unset_functions() {
+  local target
+
+  unset -f configure_package
+
+  unset -f pre_unpack unpack post_unpack
+  unset -f pre_patch post_patch
+
+  for target in target host init bootstrap; do
+    unset -f pre_build_${target}
+    unset -f pre_configure_${target} configure_${target} post_configure_${target}
+    unset -f pre_make_${target} make_${target} post_make_${target}
+    unset -f pre_makeinstall_${target} makeinstall_${target} post_makeinstall_${target}
+  done
+
+  unset -f pre_install post_install
+
+  unset -f addon
+}
+
+# p1: name of package to be sourced
+source_package() {
+  local opwd="${PWD}"
+
+  # Don't use BUILD_WITH_DEBUG in "global" package.mk - instead, call the function
+  # build_with_debug() directly as the function depends on various package.mk
+  # variables that will be in the process of being configured. Once package.mk is
+  # fully sourced we can set this variable and use it in situations where we know the
+  # package has already been sourced.
+  unset BUILD_WITH_DEBUG
+
+  reset_pkg_vars
+  unset_functions
+
+  if [ -n "${1}" ]; then
+    PKG_DIR="$(get_pkg_directory ${1})"
+
+    [ -n "$PKG_DIR" -a -r $PKG_DIR/package.mk ] || die "FAILURE: unable to source package - ${1}/package.mk does not exist"
+
+    cd "${ROOT}"
+    . ${PKG_DIR}/package.mk || die "FAILURE: an error occurred while sourcing ${PKG_DIR}/package.mk"
+    cd "${opwd}"
+
+    [ -z "$PKG_SHORTDESC" ] && PKG_SHORTDESC="$PKG_NAME (autogenerated)"
+    [ -z "$PKG_LONGDESC" ] &&  PKG_LONGDESC="$PKG_NAME (autogenerated)"
+
+    if [ "$PKG_IS_ADDON" = "yes" -o "$PKG_IS_ADDON" = "embedded" ] ; then
+      [ -z $PKG_SECTION ] && PKG_ADDON_ID="$PKG_NAME" || PKG_ADDON_ID="${PKG_SECTION//\//.}.$PKG_NAME"
+      [ "$PKG_ADDON_IS_STANDALONE" != "yes" ] && PKG_NEED_UNPACK="${PKG_NEED_UNPACK} $(get_pkg_directory $MEDIACENTER)"
+    fi
+
+    # Automatically set PKG_SOURCE_NAME unless it is already defined.
+    # PKG_SOURCE_NAME will be automatically set to a name based on
+    # the $PKG_NAME-$PKG_VERSION convention.
+    #
+    # Any $PKG_URL that references more than a single url will abort
+    # the build as these are no longer supported - use mkpkg instead.
+    if [ -n "$PKG_URL" -a -z "$PKG_SOURCE_NAME" ]; then
+      if [[ $PKG_URL =~ .*\ .* ]]; then
+        echo "Error - packages with multiple urls are no longer supported, use mkpkg."
+        echo "$PKG_URL"
+        die
+      fi
+      if [[ ${PKG_URL} =~ .git$ || ${PKG_URL} =~ ^git:// ]]; then
+        PKG_SOURCE_NAME=${PKG_NAME}-${PKG_VERSION}
+      elif [[ ${PKG_URL} =~ ^file:// ]]; then
+        PKG_SOURCE_NAME=${PKG_URL#file://}
+        # if no specific PKG_TAR_COPY_OPTS then default to excluding .git and .svn as they can be huge
+        [ -z "${PKG_TAR_COPY_OPTS+x}" ] && PKG_TAR_COPY_OPTS="--exclude=.git --exclude=.svn"
+      else
+        PKG_SOURCE_NAME="${PKG_URL##*/}"
+        case $PKG_SOURCE_NAME in
+          ${PKG_NAME}-${PKG_VERSION}.*)
+            PKG_SOURCE_NAME=$PKG_SOURCE_NAME
+            ;;
+          *.tar | *.tbz | *.tgz | *.txz | *.7z | *.zip)
+            PKG_SOURCE_NAME=${PKG_NAME}-${PKG_VERSION}.${PKG_SOURCE_NAME##*\.}
+            ;;
+          *.tar.bz2 | *.tar.gz | *.tar.xz)
+            PKG_SOURCE_NAME=${PKG_NAME}-${PKG_VERSION}.tar.${PKG_SOURCE_NAME##*\.}
+            ;;
+          *.diff | *.patch | *.diff.bz2 | *.patch.bz2 | patch-*.bz2 | *.diff.gz | *.patch.gz | patch-*.gz)
+            PKG_SOURCE_NAME=$PKG_SOURCE_NAME
+            ;;
+          *)
+            PKG_SOURCE_NAME=${PKG_NAME}-${PKG_VERSION}.${PKG_SOURCE_NAME##*\.}
+            ;;
+        esac
+      fi
+    fi
+
+    PKG_BUILD="$BUILD/${PKG_NAME}-${PKG_VERSION}"
+  fi
+
+  build_with_debug && BUILD_WITH_DEBUG="yes" || BUILD_WITH_DEBUG="no"
+
+  # Late variable binding - allow the package to now evaluate any variables
+  # that we may have initialised after sourcing the package, typically
+  # PKG_BUILD etc.
+  [ -n "${PKG_NAME}" ] && pkg_call_optional configure_package || true
+}
+
 
 ### KERNEL HELPERS ###
 kernel_path() {