[PATCH 1/1] busybox: add config fragments

[<Qi.Chen@windriver.com>]

From: Chen Qi <Qi.Chen@windriver.com>

Add config fragments to busybox.

Both the implementation and the use case are similar to yocto kernel's
configuration fragments.

[YOCTO #3379]

Signed-off-by: Chen Qi <Qi.Chen@windriver.com>
---
 meta/recipes-core/busybox/busybox.inc |   45 +++++++++++++++++++++++++++++++++
 1 file changed, 45 insertions(+)

diff --git a/meta/recipes-core/busybox/busybox.inc b/meta/recipes-core/busybox/busybox.inc
index 972e7d0..66044f8 100644
--- a/meta/recipes-core/busybox/busybox.inc
+++ b/meta/recipes-core/busybox/busybox.inc
@@ -112,8 +112,53 @@ do_prepare_config () {
 	fi
 }
 
+# returns all the elements from the src uri that are .cfg files
+def find_cfgs(d):
+    sources=src_patches(d, True)
+    sources_list=[]
+    for s in sources:
+        if s.endswith('.cfg'):
+            sources_list.append(s)
+
+    return sources_list
+
+# Merge config fragments
+# All config fragments for busybox should end with .cfg
+do_merge_config() {
+        SED_CONFIG_EXP="s/^\(# \)\{0,1\}\(CONFIG_[a-zA-Z0-9_]*\)[= ].*/\2/p"
+        MERGE_LIST="${@" ".join(find_cfgs(d))}"
+        if [ -n "$MERGE_LIST" ]; then
+                # Make a temp file, merge .config and .cfg files into it
+                TMP_FILE=`mktemp .tmp.config.XXXXXXXX`
+                cp .config $TMP_FILE
+                for MERGE_FILE in $MERGE_LIST; do
+                        CFG_LIST=`sed -n "${SED_CONFIG_EXP}" $MERGE_FILE`
+                        for CFG in $CFG_LIST ; do
+                                grep -q -w $CFG $TMP_FILE
+                                if [ $? -eq 0 ] ; then
+                                        PREV_VAL=`grep -w $CFG $TMP_FILE`
+                                        NEW_VAL=`grep -w $CFG $MERGE_FILE`
+                                        if [ "x$PREV_VAL" != "x$NEW_VAL" ] ; then
+                                                echo Value of $CFG is redefined by fragment $MERGE_FILE:
+                                                echo Previous  value: $PREV_VAL
+                                                echo New value:       $NEW_VAL
+                                                echo
+                                        fi
+                                        sed -i "/$CFG[ =]/d" $TMP_FILE
+                                fi
+                        done
+                        echo >> $TMP_FILE
+                        cat $MERGE_FILE >> $TMP_FILE
+                done
+                # Copy the temp file to .config, do some cleanup
+		cp $TMP_FILE .config
+		rm $TMP_FILE
+        fi
+}
+
 do_configure () {
 	do_prepare_config
+	do_merge_config
 	cml1_do_configure
 }
 
-- 
1.7.9.5