1，device/qcom/m1/XX.mk

PRODUCT_DEFAULT_DEV_CERTIFICATE := device/qcom/vendor/private-key/releasekey

2, android/build/makefile

+#ifeq ($(DEFAULT_SYSTEM_DEV_CERTIFICATE),build/target/product/security/testkey)

+#BUILD_KEYS := test-keys

+ifeq ($(DEFAULT_SYSTEM_DEV_CERTIFICATE),device/qcom/vendor/private-key/releasekey)

+BUILD_KEYS := releasekey

3, add device/qcom/vendor/private-key/releasekey

4, private-key/releasekey,可以用google的工具生成
 系统默认的key如下，首先需要产生以下4种我们项目自己的OTA签名key文件，每一种类型的key都是成对生成的，.509.pem后缀名的是公钥，.pk8后缀名的是私钥。
 testkey -- a generic key for packages that do not otherwise specify a key.  
 platform -- a test key for packages that are part of the core platform.  
 shared -- a test key for things that are shared in the home/contacts process.  
 media -- a test key for packages that are part of the media/download system.

 Android 源码包里面提供了生成key的工具，development/tools/make_key, 命令如下：
  make_key testkey  '/C=US/ST=California/L=Mountain View/O=Android/OU=Android/CN=Android/[email protected]'
  make_key platform '/C=US/ST=California/L=Mountain View/O=Android/OU=Android/CN=Android/[email protected]'
  make_key shared   '/C=US/ST=California/L=Mountain View/O=Android/OU=Android/CN=Android/[email protected]'
  make_key media    '/C=US/ST=California/L=Mountain View/O=Android/OU=Android/CN=Android/[email protected]'

 在development/tools/目录下会生成相应的key，比如运行 make_key releasekey
 ./make_key releasekey  '/C=CN/ST=ShanDong/L=GaoXin View/O=Android/OU=Android/CN=Android/[email protected]'

   releasekey.pk8
   releasekey.x509.pem

5，最新10.0的需要生成这些key

media.pk8       networkstack.pk8       platform.pk8       releasekey.pk8       shared.pk8       testkey.pk8       verity_key  verity.x509.pem
media.x509.pem  networkstack.x509.pem  platform.x509.pem  releasekey.x509.pem  shared.x509.pem  testkey.x509.pem  verity.pk8