How To Make Changes to Android Source (Now With More Questions)
Mike Lissner
I end up recompiling the whole thing, which takes an hour. Can others
please look this over and make sure that I'm not leaving out any
steps, and that I have the right ideas? I would expect to find this at
the end of the "Get source" page, but maybe I'm misunderstanding how
this all works.
From what I understand, to make (and test) changes to the Android
code, the process is this:
1. Download the source per the instructions here: http://source.android.com/download
2. Make changes to the source
2. cd ~/mydroid
3. source build/envsetup.sh
4. make -j4 sdk (with 4 being twice the number of processors in my
machine)
5. /out/host/linux-x86/bin/emulator (test the changes)
6. Make more changes
7. Recompile as necessary with something like: mmm packages/apps/Email
or mmm framework/base/core/res
8. Sync the changes into the emulator, or simply restart it. To sync
it: adb remount; adb shell stop; adb sync; adb shell start
9. Debug using ddms or the ddms perspective in Eclipse
10. Repeat steps 6-9
Questions:
1. Somewhere, I've left out the "lunch 1" command that does
something....but where, and is it important?
2. I'm a little confused why anybody would run make without running
make sdk. Seems like you'd almost always want to make the sdk, but I'm
probably missing something here.
3. Once this is all done, the home button won't work unless a change
is made to include SdkSetup. Therefore the 0th step should be to make
the change mentioned here:
http://groups.google.com/group/android-porting/browse_thread/thread/2e8fb948cfc29a5f?pli=1
4. Once this is all done, an emulator should have been created that
has an SD card, allows GPS emulation, and pretty much all-around
works. Correct?
Other facts:
1. AVDs aren't necessary because "the build system configures the
locally built emulator to automatically pick the locally built system
image without going through any AVD." (source: JBQ at
http://groups.google.com/group/android-platform/t/293945cb8dcf1151)
André Oriani
>
> Questions:
> 1. Somewhere, I've left out the "lunch 1" command that does
> something....but where, and is it important?
complaing about avds
> 2. I'm a little confused why anybody would run make without running
> make sdk. Seems like you'd almost always want to make the sdk, but I'm
> probably missing something here.
> 3. Once this is all done, the home button won't work unless a change
> is made to include SdkSetup. Therefore the 0th step should be to make
Jean-Baptiste Queru
an SDK downloaded from d.android.com - that's not normally used for
platform development.
my workflow:
(download source)
source build/envsetup.sh
lunch generic-eng #generic-eng is the default value
(modify files, commit them)
make -j8 #I have a quad-core
emulator&
(whatever makes sense from this point, local changes, incremental
builds, adb sync...)
Yeah, the SdkSetup part is screwed up, that's a good local change to
make if you want your "device" to be provisioned (and use the home
key, have a lock screen, and a number of other things).
The SD card may or may not work - this has been a hit-and-miss affair.
I haven't tested it recently on an open-source emulator.
JBQ
Jean-Baptiste M. "JBQ" Queru
Software Engineer, Android Open-Source Project, Google.
Questions sent directly to me that have no reason for being private
will likely get ignored or forwarded to a public forum with no further
warning.
Christopher Tate
On Wed, Aug 12, 2009 at 4:23 PM, Mike Lissner<mjli...@gmail.com> wrote:
>
> Questions:
> 1. Somewhere, I've left out the "lunch 1" command that does
> something....but where, and is it important?
'lunch' is a shell command provided by the env_setup.sh configuration
step. It allows you to select among various products and build
flavors (eng, user, etc), and configures your environment
appropriately. Within Google's Android team, for example, this is
used all the time to switch between e.g. doing dream (G1 type
hardware) versus sapphire (Magic type hardware) builds, between
T-Mobile US vs Vodafone etc product bundles, etc.
If you just type 'lunch' with no argument, you should be presented
with a pick list of the most common / relevant options.
> 2. I'm a little confused why anybody would run make without running
> make sdk. Seems like you'd almost always want to make the sdk, but I'm
> probably missing something here.
I think the opposite: nobody working with the main source base should
ever run 'make sdk' unless they're engaged in editing and publishing a
new formal SDK. When you're working within the platform sources
themselves, the distinction between public and private APIs is not
particularly relevant. The primary 'make' build will enforce the
current, existing API so that you don't inadvertently break anything,
and that's all you need to worry about.
(Note that typically nobody at Google runs 'make sdk' unless they are
part of the group putting together a new SDK package.)
> 3. Once this is all done, the home button won't work unless a change
> is made to include SdkSetup. Therefore the 0th step should be to make
> the change mentioned here:
> http://groups.google.com/group/android-porting/browse_thread/thread/2e8fb948cfc29a5f?pli=1
Aha, yes, for the AOSP situation you're probably right that this is
Step 0. jbq or someone, can you confirm?
> 4. Once this is all done, an emulator should have been created that
> has an SD card, allows GPS emulation, and pretty much all-around
> works. Correct?
Hrm. This does not create an sdcard image; you have to create one by
hand. However, the emulator takes a command line argument "-sdcard"
that lets you specify the image by path, no AVDs involved. AVDs are
not part of the daily (or weekly or monthly or...) life of the Android
framework engineers at Google.
--
chris tate
android framework engineer
Dianne Hackborn
7. Recompile as necessary with something like: mmm packages/apps/Email
or mmm framework/base/core/res
If you are changing the framework itself, my preference is "mmm framework/base/core/res snod" and then you can re-run the emulator with the new system image created by snod.
Actually, for most of my work on the framework I just do:
make framework-res framework services snod
emulator
This ensures the framework resources, code, and service code are all build and stuffed into a new system image.
--
Dianne Hackborn
Android framework engineer
hac...@android.com
Note: please don't send private questions to me, as I don't have time to provide private support, and so won't reply to such e-mails. All such questions should be posted on public forums, where I and others can see and answer them.
Jean-Baptiste Queru
it might still work but I'm not sure.
As for the sdcard, once you've built you should be able to create an
SD image with mksdcard (run it with no arguments for the list of
arguments), and use the resulting image with the -sdcard emulator
argument that Chris mentioned.
JBQ
Mike Lissner
is valuable. This should get me off to a better start with my
modifications to the code. I am quite pleased to get so many answers
directly from the horse's mouth (so to speak)!
The one question that I have now is why this process isn't on the
android development site? It took me a good deal of research to figure
out the above post, and it seems like the kind of hurdle that all
developers are going to have to jump right when they are starting to
get their feet wet.
Thanks again,
Mike
On Aug 12, 5:18 pm, Jean-Baptiste Queru <j...@android.com> wrote:
> I can confirm that the step 0 as mentioned used to be the right one -
> it might still work but I'm not sure.
>
> As for the sdcard, once you've built you should be able to create an
> SD image with mksdcard (run it with no arguments for the list of
> arguments), and use the resulting image with the -sdcard emulator
> argument that Chris mentioned.
>
> JBQ
>
>
>
> On Wed, Aug 12, 2009 at 4:35 PM, Christopher Tate<ct...@google.com> wrote:
>
> > My impressions, as a mostly-outsider to this discussion....
>
Jean-Baptiste Queru
source.android.com to host that information, because it's indeed
missing, and it's an unnecessarily steep part of the learning curve.
JBQ
Jey Michael
search" link, that enables search within the "package:android" It
will save everybody's time too.
-Jey
Jean-Baptiste Queru
(FWIW, we're investigating the possibility of storing the files for
source.android.com directly in the source tree, so that anyone can
contribute improvements to the web site).
JBQ