定制android版本有问题

我正在尝试定制构建(如移植指南中所述)- http://source.android.com/porting/build_new_device.html make:***无规则生成目标 vendor/company/emh-board/kernel', needed by out/target/product/emh board/kernel'。停下。

有人知道为什么会这样吗。我开始使用“makeproductemh user”构建 我的AndroidBoard.mk 看起来像

# make file for new hardware  from 
#
LOCAL_PATH := $(call my-dir)
#
# this is here to use the pre-built kernel
ifeq ($(TARGET_PREBUILT_KERNEL),)
TARGET_PREBUILT_KERNEL := $(LOCAL_PATH)/kernel
endif
#

file := $(INSTALLED_KERNEL_TARGET)
ALL_PREBUILT += $(file)
$(file) : $(TARGET_PREBUILT_KERNEL) | $(ACP)
        $(transform-prebuilt-to-target)

#
# no boot loader, so we don't need any of that stuff..  
#
LOCAL_PATH := vendor/company/emh-board
#
include $(CLEAR_VARS)
#
# include more board specific stuff here? Such as Audio parameters.     
#