Building Android from source - emulator and AVDs [closed]_问答_开发者

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I have built the Android source for the emulator. I read in the Android Source documentation that the path to 'emulator' is added autmatically during a successful build. However I have two questions about this:

If I open a new shell or close my existing shell, 'emulator' is no longer found. Surely I don't have to build each time I want to run the emulator?
If the emulator requires an AVD how do I create and manage these given there is no Android SDK on my machine?

Thanks, Jack

SOLUTION to part 2.

I needed to create an environment variable called ANDROID_PRODUCT_OUT. From the the following command:

emulator -help-build-images

I read...

The emulator detects that you are working from the Android build system by looking at the ANDROID_PRODUCT_OUT variable in your environment.

If it is defined, it should point to the product-specific directory that contains the generated system images.

I then did a search for 'system.ing' in my 'out' directory. since I am building for the emulator the image was in:

out/target/product/generic

I added the following line to my .bashrc file:

export ANDROID_PRODUCT_OUT=/home/jack.wootton/code/out/target/product/generic

I was then able to run the emulator from:

/h开发者_运维问答ome/jack.wootton/code/out/host/linux-x86/bin

SOLUTION to part 1.

I don't know about Android Virtual Devices, so this question still stands - however I did not need to provide one to run the emulator after doing a successful build and setting the ANDROID_PRODUCT_OUT environment variable.

Update to solutions

Apparently variables such as ANDROID_PRODUCT_OUT should be automatically created during a build and using the envSetup.sh script. I guess something has gone wrong with my environment setup for this not to happen.

You shared that:

Apparently variables such as ANDROID_PRODUCT_OUT should be automatically created during a build and using the envSetup.sh script. I guess something has gone wrong with my environment setup for this not to happen.

I ALSO ATTEMPTED to get this to work and LEARNED that:

lunch full-eng sets up all the appropriate env
to check it, simply run:
env | grep ANDROID
and you will see all the appropriate env variables setup.
These are local to the current shell only!
emulator then does what it should.

When I came back to the shell later, I simply ran lunch full-eng again to restore my environment.
I hope this helps others as well!

Just do the following:

source build/envsetup.sh or . build/envsetup.sh
setpaths

That does the trick. Make sure you run it from your source directory.

To check my built sources for emulator I've created the following script in the root folder of the project. I run it from another command line and it does not require to run all the time running . build/envsetup.sh and lunch full-eng commands. You can edit this script for your needs and if you need to run other device - simply change folder.

out/host/linux-x86/bin/emulator -sysdir out/target/product/generic/ -system out/target/product/generic/system.img -ramdisk out/target/product/generic/ramdisk.img -data out/target/product/generic/userdata.img -kernel prebuilt/android-arm/kernel/kernel-qemu -sdcard sdcard.img -skindir sdk/emulator/skins -skin WVGA800 -scale 0.7 -memory 512 -partition-size 1024

You can add these to your .bashrc file

export ANDROID_PRODUCT_OUT=$ANDROID_SRC/out/target/product/generic
export ANDROID_BIN=$ANDROID_SRC/out/host/linux-x86/bin
PATH=$ANDROID_BIN:$PATH

In fact, the program "emulator" is just a wrapper for the real emulator-qemu, such as emulator-arm or emulator-x86. The "emulator" you invoked will collect the arguments you typed in and find the proper emulator-qemu to execute.

The problem you met is that you did not explicitly describe which image/avd you want to start. You can either using the argument "@avd YOUR-AVD_NAME" or "ANDROID_PRODUCT_OUT" environment variable to set the dir where your avd is placed. BTW, avd dir contains some files to describe how this device looks like.

". build/envsetup.sh" is the script that set the environment variables for the Android build process. So it is easy to understand why "ANDROID_PRODUCT_OUT" will be set at that time. Its default value should be "PATH/TO/ANDROID/out/target/product/generic".

PS: If you want to know more, you can refer to the source file: "PATH/TO/ANDROID/external/qemu/android/main-emulator.c". You can find the emulator main there.