更改Android编译时的默认配置

Android代码量非常庞大，经常只需要编译修改过的一部分代码，例如放在external目录下的，这时候可以使用mm等命令，但是问题是默认情况下是按照generic的配置来编译的，这样生成的elf在目标板上无法运行。这时候需要修改默认配置。

root@jerry-desktop:/home/jerry/sandbox/myandroid# . build/envsetup.sh   <- 注意这里是个点加空格
including device/fsl/imx5x/vendorsetup.sh
root@jerry-desktop:/home/jerry/sandbox/myandroid# choosecombo
Build for the simulator or the device?
     1. Device
     2. Simulator

Which would you like? [1]


Build type choices are:
     1. release
     2. debug

Which would you like? [1]    


Which product would you like? [generic] 这里输入你的配置名                   


Variant choices are:
     1. user
     2. userdebug
     3. eng
Which would you like? [eng] 

非常简单，但很有用...