diff --git a/core/Makefile b/core/Makefile
index 2aab143..62da48a 100644
--- a/core/Makefile
+++ b/core/Makefile
@@ -613,6 +613,7 @@
 $(if $(INTERNAL_USERIMAGES_EXT_VARIANT),$(hide) echo "fs_type=$(INTERNAL_USERIMAGES_EXT_VARIANT)" >> $(1))
 $(if $(BOARD_SYSTEMIMAGE_PARTITION_SIZE),$(hide) echo "system_size=$(BOARD_SYSTEMIMAGE_PARTITION_SIZE)" >> $(1))
 $(if $(BOARD_USERDATAIMAGE_PARTITION_SIZE),$(hide) echo "userdata_size=$(BOARD_USERDATAIMAGE_PARTITION_SIZE)" >> $(1))
+$(if $(BOARD_CACHEIMAGE_PARTITION_SIZE),$(hide) echo "cache_size=$(BOARD_CACHEIMAGE_PARTITION_SIZE)" >> $(1))
 $(if $(INTERNAL_USERIMAGES_SPARSE_EXT_FLAG),$(hide) echo "extfs_sparse_flag=$(INTERNAL_USERIMAGES_SPARSE_EXT_FLAG)" >> $(1))
 $(if $(mkyaffs2_extra_flags),$(hide) echo "mkyaffs2_extra_flags=$(mkyaffs2_extra_flags)" >> $(1))
 endef
@@ -767,7 +768,7 @@
 endif
 
 systemimage_intermediates := \
-	$(call intermediates-dir-for,PACKAGING,systemimage)
+    $(call intermediates-dir-for,PACKAGING,systemimage)
 BUILT_SYSTEMIMAGE := $(systemimage_intermediates)/system.img
 
 # $(1): output file
@@ -877,10 +878,10 @@
 # -----------------------------------------------------------------
 # data partition image
 INTERNAL_USERDATAIMAGE_FILES := \
-	$(filter $(TARGET_OUT_DATA)/%,$(ALL_DEFAULT_INSTALLED_MODULES))
+    $(filter $(TARGET_OUT_DATA)/%,$(ALL_DEFAULT_INSTALLED_MODULES))
 
 userdataimage_intermediates := \
-	$(call intermediates-dir-for,PACKAGING,userdata)
+    $(call intermediates-dir-for,PACKAGING,userdata)
 BUILT_USERDATAIMAGE_TARGET := $(PRODUCT_OUT)/userdata.img
 
 define build-userdataimage-target
@@ -926,6 +927,35 @@
 
 
 # -----------------------------------------------------------------
+# cache partition image
+INTERNAL_CACHEIMAGE_FILES := \
+    $(filter $(TARGET_OUT_CACHE)/%,$(ALL_DEFAULT_INSTALLED_MODULES))
+
+cacheimage_intermediates := \
+    $(call intermediates-dir-for,PACKAGING,cache)
+BUILT_CACHEIMAGE_TARGET := $(PRODUCT_OUT)/cache.img
+
+define build-cacheimage-target
+  $(call pretty,"Target cache fs image: $(INSTALLED_CACHEIMAGE_TARGET)")
+  @mkdir -p $(TARGET_OUT_CACHE)
+  @mkdir -p $(cacheimage_intermediates) && rm -rf $(cacheimage_intermediates)/cache_image_info.txt
+  $(call generate-userimage-prop-dictionary, $(cacheimage_intermediates)/cache_image_info.txt)
+  $(hide) PATH=$(foreach p,$(INTERNAL_USERIMAGES_BINARY_PATHS),$(p):)$$PATH \
+      ./build/tools/releasetools/build_image.py \
+      $(TARGET_OUT_CACHE) $(cacheimage_intermediates)/cache_image_info.txt $(INSTALLED_CACHEIMAGE_TARGET)
+  $(hide) $(call assert-max-image-size,$(INSTALLED_CACHEIMAGE_TARGET),$(BOARD_CACHEIMAGE_PARTITION_SIZE),yaffs)
+endef
+
+# We just build this directly to the install location.
+INSTALLED_CACHEIMAGE_TARGET := $(BUILT_CACHEIMAGE_TARGET)
+$(INSTALLED_CACHEIMAGE_TARGET): $(INTERNAL_USERIMAGES_DEPS) $(INTERNAL_CACHEIMAGE_FILES)
+	$(build-cacheimage-target)
+
+.PHONY: cacheimage-nodeps
+cacheimage-nodeps: | $(INTERNAL_USERIMAGES_DEPS)
+	$(build-cacheimage-target)
+
+# -----------------------------------------------------------------
 # bring in the installer image generation defines if necessary
 ifeq ($(TARGET_USE_DISKINSTALLER),true)
 include bootable/diskinstaller/config.mk
@@ -1006,6 +1036,7 @@
 		$(INSTALLED_RECOVERYIMAGE_TARGET) \
 		$(INSTALLED_SYSTEMIMAGE) \
 		$(INSTALLED_USERDATAIMAGE_TARGET) \
+		$(INSTALLED_CACHEIMAGE_TARGET) \
 		$(INSTALLED_ANDROID_INFO_TXT_TARGET) \
 		$(built_ota_tools) \
 		$(APKCERTS_FILE) \
diff --git a/core/envsetup.mk b/core/envsetup.mk
index b564ce6..8457880 100644
--- a/core/envsetup.mk
+++ b/core/envsetup.mk
@@ -214,6 +214,8 @@
 TARGET_OUT_DATA_STATIC_LIBRARIES:= $(TARGET_OUT_STATIC_LIBRARIES)
 TARGET_OUT_DATA_NATIVE_TESTS := $(TARGET_OUT_DATA)/nativetest
 
+TARGET_OUT_CACHE := $(PRODUCT_OUT)/cache
+
 TARGET_OUT_VENDOR := $(PRODUCT_OUT)/$(TARGET_COPY_OUT_VENDOR)
 TARGET_OUT_VENDOR_EXECUTABLES:= $(TARGET_OUT_VENDOR)/bin
 TARGET_OUT_VENDOR_OPTIONAL_EXECUTABLES:= $(TARGET_OUT_VENDOR)/xbin
diff --git a/core/main.mk b/core/main.mk
index e35f228..057c11b 100644
--- a/core/main.mk
+++ b/core/main.mk
@@ -743,6 +743,9 @@
 .PHONY: userdatatarball
 userdatatarball: $(INSTALLED_USERDATATARBALL_TARGET)
 
+.PHONY: cacheimage
+cacheimage: $(INSTALLED_CACHEIMAGE_TARGET)
+
 .PHONY: bootimage
 bootimage: $(INSTALLED_BOOTIMAGE_TARGET)
 
diff --git a/tools/releasetools/build_image.py b/tools/releasetools/build_image.py
index b5140a9..8ef8975 100755
--- a/tools/releasetools/build_image.py
+++ b/tools/releasetools/build_image.py
@@ -83,6 +83,9 @@
   elif mount_point == "data":
     if "userdata_size" in glob_dict:
       d["partition_size"] = str(glob_dict["userdata_size"])
+  elif mount_point == "cache":
+    if "cache_size" in glob_dict:
+      d["partition_size"] = str(glob_dict["cache_size"])
 
   return d
 
@@ -117,6 +120,8 @@
     mount_point = "system"
   elif image_filename == "userdata.img":
     mount_point = "data"
+  elif image_filename == "cache.img":
+    mount_point = "cache"
 
   image_properties = ImagePropFromGlobalDict(glob_dict, mount_point)
   if not BuildImage(in_dir, image_properties, out_file):
diff --git a/tools/releasetools/common.py b/tools/releasetools/common.py
index 4957354..1049591 100644
--- a/tools/releasetools/common.py
+++ b/tools/releasetools/common.py
@@ -138,6 +138,7 @@
   makeint("blocksize")
   makeint("system_size")
   makeint("userdata_size")
+  makeint("cache_size")
   makeint("recovery_size")
   makeint("boot_size")
 
diff --git a/tools/releasetools/img_from_target_files b/tools/releasetools/img_from_target_files
index 4388f69..7292d55 100755
--- a/tools/releasetools/img_from_target_files
+++ b/tools/releasetools/img_from_target_files
@@ -80,6 +80,34 @@
   os.rmdir(temp_dir)
 
 
+def AddCache(output_zip):
+  """Create an empty cache image and store it in output_zip."""
+
+  print "creating cache.img..."
+
+  # The name of the directory it is making an image out of matters to
+  # mkyaffs2image.  So we create a temp dir, and within it we create an
+  # empty dir named "cache", and build the image from that.
+  temp_dir = tempfile.mkdtemp()
+  user_dir = os.path.join(temp_dir, "cache")
+  os.mkdir(user_dir)
+  img = tempfile.NamedTemporaryFile()
+
+  image_props = build_image.ImagePropFromGlobalDict(OPTIONS.info_dict,
+                                                    "cache")
+  fstab = OPTIONS.info_dict["fstab"]
+  if fstab:
+    image_props["fs_type" ] = fstab["/cache"].fs_type
+  succ = build_image.BuildImage(user_dir, image_props, img.name)
+  assert succ, "build cache.img image failed"
+
+  common.CheckSize(img.name, "cache.img", OPTIONS.info_dict)
+  output_zip.write(img.name, "cache.img")
+  img.close()
+  os.rmdir(user_dir)
+  os.rmdir(temp_dir)
+
+
 def AddSystem(output_zip):
   """Turn the contents of SYSTEM into a system image and store it in
   output_zip."""
@@ -163,6 +191,7 @@
   if not bootable_only:
     AddSystem(output_zip)
     AddUserdata(output_zip)
+    AddCache(output_zip)
     CopyInfo(output_zip)
 
   print "cleaning up..."