support userdata and cache partitions using emmc/ext4 instead of mtd/yaffs

Change-Id: I827af624c9ec7c64decb702de8c0310cf19b4141
diff --git a/Android.mk b/Android.mk
index b0fefbd..4a3d285 100644
--- a/Android.mk
+++ b/Android.mk
@@ -24,6 +24,14 @@
 RECOVERY_API_VERSION := 3
 LOCAL_CFLAGS += -DRECOVERY_API_VERSION=$(RECOVERY_API_VERSION)
 
+LOCAL_STATIC_LIBRARIES :=
+
+ifeq ($(TARGET_USERIMAGES_USE_EXT4), true)
+LOCAL_CFLAGS += -DUSE_EXT4
+LOCAL_C_INCLUDES += system/extras/ext4_utils
+LOCAL_STATIC_LIBRARIES += libext4_utils libz
+endif
+
 # This binary is in the recovery ramdisk, which is otherwise a copy of root.
 # It gets copied there in config/Makefile.  LOCAL_MODULE_TAGS suppresses
 # a (redundant) copy of the binary in /system/bin for user builds.
@@ -31,7 +39,6 @@
 
 LOCAL_MODULE_TAGS := eng
 
-LOCAL_STATIC_LIBRARIES :=
 ifeq ($(TARGET_RECOVERY_UI_LIB),)
   LOCAL_SRC_FILES += default_recovery_ui.c
 else