android 几个快速编译images指令

Android比较重要的三个img文件：

• make systemimage - system.img
• make userdataimage - userdata.img
• make ramdisk - ramdisk.img
• make snod - 快速打包system.img (with this command, it will build a new system.img very quickly. well, you cannot use “make snod” for all the situations. it would not check the dependences. if you change some code in the framework which will effect other applications)

因为system.img 是从 out/target/product/xxxx/system 做出來的。
如果改了这个 folder 的內容，想要重新产生 system.img。不要管 system folde 里面的 文件 的 dependency，可以用 snod 這個 target:：

• make snod

定义在 build/core/Makefile 可以看到 snod 这个target:
(有说明是： make system.img ignoring depencies)

.PHONY: systemimage-nodeps snod
systemimage-nodeps snod: $(filter-out systemimage-nodeps snod,$(MAKECMDGOALS)) \
| $(INTERNAL_MKUSERFS)
@echo "make $@: ignoring dependencies"
$(call build-systemimage-target,$(INSTALLED_SYSTEMIMAGE))
$(hide) $(call assert-max-image-size,$(INSTALLED_SYSTEMIMAGE),$(BOARD_SYSTEMIMAGE_PARTITION_SIZE),yaffs)

Ref:
http://hi.baidu.com/kyan/blog/item/df7ea8d346f5c839960a163c.html
http://r40eubuntu.blogspot.com/2010/10/systemimg.html