diff --git a/utils/emulator/README b/utils/emulator/README
new file mode 100644
index 0000000..b3e17a0
--- /dev/null
+++ b/utils/emulator/README
@@ -0,0 +1,8 @@
+Precondition: android SDK must be installed in ~/Android/SDK
+
+lunch omni_emulator-userdebug
+make
+vendor/omni/utils/emulator/create_emulator_image.sh
+cp /tmp/omni_emulator.zip to the device where you have installed android SDK
+unzip into /tmp
+run /tmp/generic_x86/start_emulator_image.sh
diff --git a/utils/emulator/create_emulator_image.sh b/utils/emulator/create_emulator_image.sh
index ae27d8b..ae0f23d 100755
--- a/utils/emulator/create_emulator_image.sh
+++ b/utils/emulator/create_emulator_image.sh
@@ -23,6 +23,7 @@
 cd $ANDROID_BUILD_TOP
 cp -r vendor/omni/utils/emulator/skins $ANDROID_PRODUCT_OUT
 cat vendor/omni/utils/emulator/start_emulator_image.sh | sed -e "s/vbmeta/$DIGEST/" > $ANDROID_PRODUCT_OUT/start_emulator_image.sh
+chmod 755 $ANDROID_PRODUCT_OUT/start_emulator_image.sh
 cp -r vendor/omni/utils/emulator/advancedFeatures.ini $ANDROID_PRODUCT_OUT
 
 cd $ANDROID_PRODUCT_OUT/..