Dowload and compile android source code implemented by qualcomm

1  dowload

What changed between releases?

Each release has its own Repo manifest and Git tag. Git's ''diff'' command can be used to view the commit history and source changes between releases.

For example to see what changed between the M7201JSDCBALYA63752001 and M7201JSDCBALYA63752003 release tags on the coconut.cupcake branch

$ repo init -u git://codeaurora.org/platform/manifest.git -b coconut.cupcake -m M7201JSDCBALYA63752003.xml $ repo sync $ repo forall -p -c 'git diff M7201JSDCBALYA63752001..M7201JSDCBALYA63752003'

How is a patch of the changes between two release tags, branches or commits generated?
The Git ''diff'' command can generate patches suitable for use with the Unix ''diff'' and ''patch'' utilities. Tags, branches and commit IDs can be used interchangeably.

For example to generate a patch of the changes made across all Android projects between the M7201JSDCBALYA63752001 and M7201JSDCBALYA63752003 release tags

$ repo init -u git://codeaurora.org/platform/manifest.git -b coconut.cupcake -m M7201JSDCBALYA63752003.xml $ repo sync $ repo forall -c 'git diff -p M7201JSDCBALYA63752001..M7201JSDCBALYA63752003' > release-delta.patch

What are the ''aosp/*'' branches?
Branches prefixed with ''aosp/'' are the upstream sources from the original Android Open Source Project releases. For example, ''aosp/donut'' is a copy of the ''donut'' branch found on android.git.kernel.org.

What is the ''m/*'' branch?
Repo uses a remote tracking branch to track the original upstream branch the workspace was initialised against. Running '''git branch''' with the '''-a''' or '''-r''' options will display Repo's ''m/*'' branch. This branch is created when a '''repo init'''
is performed and used by Repo to synchronise with the upstream source. The name of the branch corresponds to the branch name Repo was initialized with, e.g. '''repo init -u URL -b donut''' creates a local ''m/donut'' branch in your workspace.

How is a patch of all Code Aurora changes to the AOSP (Android Open Source Project) release generated?
The ''aosp/cupcake'' branch is a unmodified copy of the cupcake branch from the AOSP release. A diff of the ''aosp/cupcake'' branch with the ''cupcake'' branch will show the changes added to the base AOSP (Android Open Source Project) release. The Linux kernel
uses a different branch naming convention and must be handled separately from other AOSP projects.  

$ repo init -u git://codeaurora.org/platform/manifest.git -b coconut.cupcake -m M7201JSDCBALYA63752003.xml $ repo sync $ repo forall -c 'git diff -p caf/aosp/cupcake..caf/coconut.cupcake' > aosp-delta.patch $ repo forall -c 'git diff -p caf/aosp/android-msm-2.6.27..caf/coconut.cupcake' >> aosp-delta.patch

What files, branches or tags changed and and how to output the commit text?
In this example generate a listing of changes between the AOSP cupcake release branch and the Code Aurora carrot.cupcake release branch 

$ repo init -u git://codeaurora.org/platform/manifest.git -b coconut.cupcake -m M7201JSDCBALYA63752003.xml $ repo sync -j4 $ repo forall -c 'git log stat caf/aosp/cupcake..caf/coconut.cupcake' > aosp-delta.log

Tags, branches and commit IDs can be used interchangeably.

2  Downloading and Building from Source

Follow the Repo instructions
to download and install Repo.

Download the Android source tree by specifying the branch and manifest for a specific Code Aurora release. In this example the download the carrot.cupcake branch
using manifest ''M7201JSDCBALYA6380.xml''

$ repo init -u git://codeaurora.org/platform/manifest.git -b carrot.cupcake -m M7201JSDCBALYA6380.xml --repo-url=git://codeaurora.org/tools/repo.git $ repo sync

Build the source tree

$ source build/envsetup.sh $ choosecombo 1 1 msm7201a_surf eng $ make -j4

Running choosecombo with no arguments will prompt for Android build options and target.

Detailed Build Instructions

Make sure that the environment has been completely and correctly as described by the Android Open Source Project instructions before
attempting to build. If you get build errors about clearsilver.jni, verify the Java version and path. (javac version 1.5.0_16 is verfied as working).

Once the environment has been configured build Android as follows

$ cd <android-source-tree> $ source build/envsetup.sh

The envsetup.sh script is responsible for setting Bash environment variables required by the Android build system.

Now use choosecombo to set the desired build by specifying Build, Type, Product and Variant.

$ choosecombo

Choosecombo is interactive or it can take arguments on the commandline

$ choosecombo 1 1 msm7201a_surf eng

Start the build

$ make -j4

By default, the build system uses the tip of kernel source from <platform>/kernel directory, including any modifications you've made.

If you want to compile the kernel with a specific configuration file other than the one defined in vendor/qcom/<product>/AndroidBoard.mk (e.g. msm7201a_defconfig) pass the KERNEL_DEFCONFIG flag on the Make command line.

$ make -j4 KERNEL_DEFCONFIG=your_defconfig

The kernel objects, vmlinux and zImage will be at <platform>/out/target/product/msm7201a_surf/obj/KERNEL_OBJ and its subdirectories.

You can override the TARGET_PREBUILT_KERNEL flag with your own kernel image to build android with your kernel, as follows:

$ make -j4 TARGET_PREBUILT_KERNEL="<your_kernel_tree>/arch/arm/boot/zImage"

You can also build ''tiny android'' which is an Android build with a limited user-space environment useful for kernel development and verification. The ''tiny android'' build will not boot into the full UI. It will stay at one of the loading screens. ADB will
be active, allowing you to run unit tests, etc. The build time for ''tiny android'' is significantly less than a full Android build.

$ BUILD_TINY_ANDROID=true make -j4

You can also tell the build system to echo to stdout the full commands and parameters that it would use in building each file without actually building the file. This is useful to see all the compiler options provided

$ make --just-print

3  Introduce and some other articles

（1）Qualcomm Reference Designs (QRD) provide access to third-party software applications and third-party hardware components, optimized designs
and an extensive pool of potential vendors —technology and tools you need to differentiate your products.
（2）Qualcomm
CDMA Technologies (QCT)：QCT offers solutions for CDMA, UMTS, GSM and LTE technologies, providing support for both 3G and 4G networks
and devices.

website: https://www.codeaurora.org/xwiki/bin/QAEP/
For example: 

chip: 8625 

Tag/Build ID: M8625SSNSKMLYA2030

repo init -u git://codeaurora.org/platform/manifest.git -b release  -m M8625SSNSKMLYA2030.xml --repo-url=git://codeaurora.org/tools/repo.git

Three
Parts of MSM7625 Android Code

a
Baseband Processor (ARM9)

   https://downloads.cdmatech.com/
       Documents
and Downloads/Library/7625/SW/MSM7625 Linux/Release/M76XXMSNCJNLYM221

b Application Processor

Documents and Downloads/Library/7625/SW/MSM7625 Linux/Release/M76XXMSNCJNLYA2210

$ repo init -u git://codeaurora.org/platform/manifest.git -b donut -m M76XXMSNCJNLYA2211.xml
/* The following is msm8610 codes based on android 4.3 */
$ repo init -u git://codeaurora.org/platform/manifest.git -b release -m LNX.LA.3.2.1-01910-8x10.0.xml

4  Downloading the Source

The Android source tree is located in a Git repository hosted by Google. This document describes how to download the source tree for a specific Android code-line.

Installing Repo

Repo is a tool that makes it easier to work with Git in the context of Android. For more information about Repo, see the Developingsection.
To install Repo:

Make sure you have a bin/ directory in your home directory and that it is included in your path:

$ mkdir ~/bin
$ PATH=~/bin:$PATH

Download the Repo tool and ensure that it is executable:

$ curl https://dl-ssl.google.com/dl/googlesource/git-repo/repo > ~/bin/repo
$ chmod a+x ~/bin/repo

For version 1.17, the SHA-1 checksum for repo is ddd79b6d5a7807e911b524cb223bc3544b661c28
For version 1.19, the SHA-1 checksum for repo is 92cbad8c880f697b58ed83e348d06619f8098e6c

Initializing a Repo client

After installing Repo, set up your client to access the Android source repository:

Create an empty directory to hold your working files. If you're using MacOS, this has to be on a case-sensitive filesystem. Give it any name you like:

$ mkdir WORKING_DIRECTORY
$ cd WORKING_DIRECTORY

Run 

repo init

 to bring down the latest version of Repo with all its most recent bug fixes. You must specify a URL for the manifest, which
specifies where the various repositories included in the Android source will be placed within your working directory.

$ repo init -u https://android.googlesource.com/platform/manifest[/code] To check out a branch other than "master", specify it with -b:
$ repo init -u https://android.googlesource.com/platform/manifest -b android-4.0.1_r1


When prompted, configure Repo with your real name and email address. To use the Gerrit code-review tool, you will need an email address that is connected with a registered
Google account. Make sure this is a live address at which you can receive messages. The name that you provide here will show up in attributions for your code submissions.

A successful initialization will end with a message stating that Repo is initialized in your working directory. Your client directory should now contain a 
.repo
 directory
where files such as the manifest will be kept.

Downloading the Android Source Tree
To pull down the Android source tree to your working directory from the repositories as specified in the default manifest, run
$ repo sync

The Android source files will be located in your working directory under their project names. The initial sync operation will take an hour or more to complete. For more about 
repo
sync
 and other Repo commands, see theDeveloping section.

Using Authentication
By default, access to the Android source code is anonymous. To protect the servers against excessive usage, each IP address is associated with a quota.
When sharing an IP address with other users (e.g. when accessing the source repositories from beyond a NAT firewall), the quotas can trigger even for regular usage patterns (e.g. if many users sync new clients from
the same IP address within a short period).
In that case, it is possible to use authenticated access, which then uses a separate quota for each user, regardless of the IP address.
The first step is to create a password from the password generator and
to save it in 
~/.netrc
 according to the instructions on that page.
The second step is to force authenticated access, by using the following manifest URI:
https://android.googlesource.com/a/platform/manifest
.
Notice how the 
/a/
 directory prefix triggers mandatory authentication. You can convert an existing client to use mandatory authentication with the following command:
$ repo init -u https://android.googlesource.com/a/platform/manifest[/code] 

Troubleshooting network issues
When downloading from behind a proxy (which is common in some corporate environments), it might be necessary to explicitly specify the proxy that is then used by repo:
$ export HTTP_PROXY=http://<proxy_user_id>:<proxy_password>@<proxy_server>:<proxy_port>
$ export HTTPS_PROXY=http://<proxy_user_id>:<proxy_password>@<proxy_server>:<proxy_port>

More rarely, Linux clients experience connectivity issues, getting stuck in the middle of downloads (typically during "Receiving objects"). It has been reported that tweaking the settings of the TCP/IP stack and
using non-parallel commands can improve the situation. You need root access to modify the TCP setting:
$ sudo sysctl -w net.ipv4.tcp_window_scaling=0
$ repo sync -j1


Using a local mirror
When using several clients, especially in situations where bandwidth is scarce, it is better to create a local mirror of the entire server content, and to sync clients from that mirror (which requires no network
access). The download for a full mirror is smaller than the download of two clients, while containing more information.
These instructions assume that the mirror is created in 
/usr/local/aosp/mirror
. The first step is to create and sync the mirror itself, which
uses close to 13GB of network bandwidth and a similar amount of disk space. Notice the 
--mirror
 flag, which can only be specified when creating a new client:
$ mkdir -p /usr/local/aosp/mirror
$ cd /usr/local/aosp/mirror
$ repo init -u https://android.googlesource.com/mirror/manifest --mirror
$ repo sync

Once the mirror is synced, new clients can be created from it. Note that it's important to specify an absolute path:
$ mkdir -p /usr/local/aosp/master
$ cd /usr/local/aosp/master
$ repo init -u /usr/local/aosp/mirror/platform/manifest.git
$ repo sync

Finally, to sync a client against the server, the mirror needs to be synced against the server, then the client against the mirror:
$ cd /usr/local/aosp/mirror
$ repo sync
$ cd /usr/local/aosp/master
$ repo sync

It's possible to store the mirror on a LAN server and to access it over NFS, SSH or Git. It's also possible to store it on a removable drive and to pass that drive around between users or between machines.

Verifying Git Tags
Load the following public key into your GnuPG key database. The key is used to sign annotated tags that represent releases.
$ gpg --import

Copy and paste the key(s) below, then enter EOF (Ctrl-D) to end the input and process the keys.
-----BEGIN PGP PUBLIC KEY BLOCK-----
Version: GnuPG v1.4.2.2 (GNU/Linux)
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=Wi5D
-----END PGP PUBLIC KEY BLOCK-----

After importing the keys, you can verify any tag with
$ git tag -v TAG_NAME

If you haven't set up ccache yet, now would be a good time
to do it.