defaultenv: simplify env dependencies

Finding out whether to rebuild the environment is a difficult task
since we have to track all files in a directory. Instead of trying
this, just rebuild the environment during every build and only if
it differs to the last one overwrite the target. This way make
only sees a change when the environment is changed.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

1 files changed, 10 insertions, 2 deletions

diff --git a/scripts/genenv b/scripts/genenv
index c14cd87a8c..d0b0ffd47f 100755
--- a/scripts/genenv
+++ b/scripts/genenv
@@ -10,7 +10,8 @@ basedir=$1
 target=$3
 shift 3
 
-tempdir="$objtree/.barebox_default_env"
+tempdir="${target}.genenv.tmp"
+tmpfile="$(mktemp)"
 
 mkdir -p "$tempdir"
 
@@ -26,6 +27,13 @@ done
 
 find $tempdir -name '.svn' -o -name '*~' -delete
 
-$objtree/scripts/bareboxenv -s $tempdir $target
+$objtree/scripts/bareboxenv -s $tempdir ${tmpfile}
+
+diff "${tmpfile}" "${target}" >/dev/null 2>/dev/null
+if [ $? != 0 ]; then
+	mv "${tmpfile}" "${target}"
+else
+	rm ${tmpfile}
+fi
 
 rm -r $tempdir