# Preparing to Use the Application Development Toolkit (ADT)

In order to use the ADT, you must install it, `source` a script to set up the environment, and be sure both the kernel and filesystem image specific to the target architecture exist. This chapter describes how to be sure you meet the ADT requirements.

## Installing the ADT

The following list describes how you can install the ADT, which includes the cross-toolchain. Regardless of the installation you choose, you must `source` the cross-toolchain environment setup script before you use the toolchain. See the "Setting Up the Cross-Development Environment" section for more information.

- Use the ADT Installer Script: This method is the recommended way to install the ADT because it automates much of the process for you. For example, you can configure the installation to install the QEMU emulator and the user-space NFS, specify which root filesystem profiles to download, and define the target sysroot location.

- Use an Existing Toolchain Tarball: Using this method, you select and download an architecture-specific toolchain tarball and then hand-install the toolchain. If you use this method, you just get the cross-toolchain and QEMU - you do not get any of the other mentioned benefits had you run the ADT Installer script.

- Use the Toolchain from within a Yocto Project Build Tree: If you already have a Yocto Project build tree, you can build the cross-toolchain within tree. However, like the previous method mentioned, you only get the cross-toolchain and QEMU - you do not get any of the other benefits without taking separate steps.

### Using the ADT Installer

To run the ADT Installer, you need to first get the ADT Installer tarball and then run the ADT Installer Script.

#### Getting the ADT Installer Tarball

The ADT Installer is contained in the ADT Installer tarball. You can download the tarball into any directory from the Index of Releases, specifically at . Or, you can use BitBake to generate the tarball inside the existing Yocto Project build tree.

If you use BitBake to generate the ADT Installer tarball, you must `source` the Yocto Project environment setup script (`oe-init-build-env`) located in the Yocto Project file structure before running the `bitbake` command that creates the tarball.

The following example commands download the Yocto Project release tarball, set up the Yocto Project files structure, set up the environment while also creating the default Yocto Project build tree, and run the `bitbake` command that results in the tarball `~/yocto-project/build/tmp/deploy/sdk/adt_installer.tar.bz2`:

         $ cd ~
         $ mkdir yocto-project
         $ cd yocto-project
         $ wget &YOCTO_RELEASE_DL_URL;/&YOCTO_POKY_TARBALL;
         $ tar xjf &YOCTO_POKY_TARBALL;
         $ source &OE_INIT_PATH;
         $ bitbake adt-installer

#### Configuring and Running the ADT Installer Script

Before running the ADT Installer script, you need to unpack the tarball. You can unpack the tarball in any directory you wish. For example, this command copies the ADT Installer tarball from where it was built into the home directory and then unpacks the tarball into a top-level directory named `adt-installer`:

         $ cd ~
         $ cp ~/poky/build/tmp/deploy/sdk/adt_installer.tar.bz2 $HOME
         $ tar -xjf adt_installer.tar.bz2

Unpacking it creates the directory `adt-installer`, which contains the ADT Installer script (`adt_installer`) and its configuration file (`adt_installer.conf`).

Before you run the script, however, you should examine the ADT Installer configuration file and be sure you are going to get what you want. Your configurations determine which kernel and filesystem image are downloaded.

The following list describes the configurations you can define for the ADT Installer. For configuration values and restrictions, see the comments in the `adt-installer.conf` file:

- `YOCTOADT_REPO`: This area includes the IPKG-based packages and the root filesystem upon which the installation is based. If you want to set up your own IPKG repository pointed to by `YOCTOADT_REPO`, you need to be sure that the directory structure follows the same layout as the reference directory set up at . Also, your repository needs to be accessible through HTTP.

- `YOCTOADT_TARGETS`: The machine target architectures for which you want to set up cross-development environments.

- `YOCTOADT_QEMU`: Indicates whether or not to install the emulator QEMU.

- `YOCTOADT_NFS_UTIL`: Indicates whether or not to install user-mode NFS. If you plan to use the Yocto Eclipse IDE plug-in against QEMU, you should install NFS.

  To boot QEMU images using our userspace NFS server, you need to be running `portmap` or `rpcbind`. If you are running `rpcbind`, you will also need to add the `-i` option when `rpcbind` starts up. Please make sure you understand the security implications of doing this. You might also have to modify your firewall settings to allow NFS booting to work.

- `YOCTOADT_ROOTFS_<arch>`: The root filesystem images you want to download from the `YOCTOADT_IPKG_REPO` repository.

- `YOCTOADT_TARGET_SYSROOT_IMAGE_<arch>`: The particular root filesystem used to extract and create the target sysroot. The value of this variable must have been specified with `YOCTOADT_ROOTFS_<arch>`. For example, if you downloaded both `minimal` and `sato-sdk` images by setting `YOCTOADT_ROOTFS_<arch>` to "minimal sato-sdk", then `YOCTOADT_ROOTFS_<arch>` must be set to either `minimal` or `sato-sdk`.

- `YOCTOADT_TARGET_SYSROOT_LOC_<arch>`: The location on the development host where the target sysroot is created.

After you have configured the `adt_installer.conf` file, run the installer using the following command:

         $ ./adt_installer

The ADT Installer requires the `libtool` package to complete. If you install the recommended packages as described in "The Packages" section of The Yocto Project Quick Start, then you will have libtool installed.

Once the installer begins to run, you are asked whether you want to run in interactive or silent mode. If you want to closely monitor the installation, choose “I” for interactive mode rather than “S” for silent mode. Follow the prompts from the script to complete the installation.

Once the installation completes, the ADT, which includes the cross-toolchain, is installed. You will notice environment setup files for the cross-toolchain in `&YOCTO_ADTPATH_DIR;`, and image tarballs in the `adt-installer` directory according to your installer configurations, and the target sysroot located according to the `YOCTOADT_TARGET_SYSROOT_LOC_<arch>` variable also in your configuration file.

### Using a Cross-Toolchain Tarball

If you want to simply install the cross-toolchain by hand, you can do so by using an existing cross-toolchain tarball. If you use this method to install the cross-toolchain and you still need to install the target sysroot, you will have to install sysroot separately.

Follow these steps:

1. Go to and find the folder that matches your host development system (i.e. `i686` for 32-bit machines or `x86-64` for 64-bit machines).

2. Go into that folder and download the toolchain tarball whose name includes the appropriate target architecture. For example, if your host development system is an Intel-based 64-bit system and you are going to use your cross-toolchain for an Intel-based 32-bit target, go into the `x86_64` folder and download the following tarball:

            poky-eglibc-x86_64-i586-toolchain-gmae-&DISTRO;.tar.bz2

   As an alternative to steps one and two, you can build the toolchain tarball if you have a Yocto Project build tree. If you need GMAE, you should use the `bitbake meta-toolchain-gmae` command. The resulting tarball will support such development. However, if you are not concerned with GMAE, you can generate the tarball using `bitbake meta-toolchain`.

   Use the appropriate `bitbake` command only after you have sourced the `oe-build-init-env` script located in the Yocto Project files. When the `bitbake` command completes, the tarball will be in `tmp/deploy/sdk` in the Yocto Project build tree.

3. Make sure you are in the root directory with root privileges and then expand the tarball. The tarball expands into `&YOCTO_ADTPATH_DIR;`. Once the tarball is expanded, the cross-toolchain is installed. You will notice environment setup files for the cross-toolchain in the directory.

### Using BitBake and the Yocto Project Build Tree

A final way of installing just the cross-toolchain is to use BitBake to build the toolchain within an existing Yocto Project build tree. This method does not install the toolchain into the `/opt` directory. As with the previous method, if you need to install the target sysroot, you must do this separately.

Follow these steps to build and install the toolchain into the build tree:

1. Source the environment setup script `oe-init-build-env` located in the Yocto Project files.

2. At this point, you should be sure that the `MACHINE` variable in the `local.conf` file found in the `conf` directory of the Yocto Project build directory is set for the target architecture. Comments within the `local.conf` file list the values you can use for the `MACHINE` variable.

   You can populate the build tree with the cross-toolchains for more than a single architecture. You just need to edit the `MACHINE` variable in the `local.conf` file and re-run the BitBake command.

3. Run `bitbake meta-ide-support` to complete the cross-toolchain installation.

   If change out of your working directory after you `source` the environment setup script and before you run the `bitbake` command, the command might not work. Be sure to run the `bitbake` command immediately after checking or editing the `local.conf` but without changing out of your working directory.

   Once the `bitbake` command finishes, the tarball for the cross-toolchain is generated within the Yocto Project build tree. You will notice environment setup files for the cross-toolchain in the Yocto Project build tree in the `tmp` directory. Setup script filenames contain the strings `environment-setup`.

## Setting Up the Cross-Development Environment

Before you can develop using the cross-toolchain, you need to set up the cross-development environment by sourcing the toolchain's environment setup script. If you used the ADT Installer or used an existing ADT tarball to install the ADT, then you can find this script in the `&YOCTO_ADTPATH_DIR;` directory. If you installed the toolchain in the build tree, you can find the environment setup script for the toolchain in the Yocto Project build tree's `tmp` directory.

Be sure to run the environment setup script that matches the architecture for which you are developing. Environment setup scripts begin with the string “`environment-setup`” and include as part of their name the architecture. For example, the toolchain environment setup script for a 64-bit IA-based architecture would be the following:

         &YOCTO_ADTPATH_DIR;/environment-setup-x86_64-poky-linux

## Securing Kernel and Filesystem Images

You will need to have a kernel and filesystem image to boot using your hardware or the QEMU emulator. Furthermore, if you plan on booting your image using NFS or you want to use the root filesystem as the target sysroot, you need to extract the root filesystem.

### Getting the Images

To get the kernel and filesystem images, you either have to build them or download pre-built versions. You can find examples for both these situations in the "A Quick Test Run" section of The Yocto Project Quick Start.

The Yocto Project provides basic kernel and filesystem images for several architectures (`x86`, `x86-64`, `mips`, `powerpc`, and `arm`) that you can use unaltered in the QEMU emulator. These kernel images reside in the Yocto Project release area - and are ideal for experimentation within Yocto Project. For information on the image types you can build using the Yocto Project, see the "Reference: Images" appendix in The Yocto Project Reference Manual.

If you plan on remotely deploying and debugging your application from within the Eclipse IDE, you must have an image that contains the Yocto Target Communication Framework (TCF) agent (`tcf-agent`). By default, the Yocto Project provides only one type pre-built image that contains the `tcf-agent`. And, those images are SDK (e.g.`core-image-sato-sdk`).

If you want to use a different image type that contains the `tcf-agent`, you can do so one of two ways:

- Modify the `conf/local.conf` configuration in the Yocto Project build directory and then rebuild the image. With this method, you need to modify the `EXTRA_IMAGE_FEATURES` variable to have the value of "tools-debug" before rebuilding the image. Once the image is rebuilt, the `tcf-agent` will be included in the image and is launched automatically after the boot.

- Manually build the `tcf-agent`. To build the agent, follow these steps:

  1. Be sure the ADT is installed as described in the "Installing the ADT" section.

  2. Set up the cross-development environment as described in the "Setting Up the Cross-Development Environment" section.

  3. Get the `tcf-agent` source code using the following commands:

              $ git clone http://git.eclipse.org/gitroot/tcf/org.eclipse.tcf.agent.git
              $ cd agent

  4. Modify the `Makefile.inc` file for the cross-compilation environment by setting the `OPSYS` and `MACHINE` variables according to your target.

  5. Use the cross-development tools to build the `tcf-agent`. Before you "Make" the file, be sure your cross-tools are set up first. See the "Makefile-Based Projects" section for information on how to make sure the cross-tools are set up correctly.

     If the build is successful, the `tcf-agent` output will be `obj/$(OPSYS)/$(MACHINE)/Debug/agent`.

  6. Deploy the agent into the image's root filesystem.

### Extracting the Root Filesystem

You must extract the root filesystem if you want to boot the image using NFS or you want to use the root filesystem as the target sysroot. For example, the Eclipse IDE environment with the Eclipse Yocto Plug-in installed allows you to use QEMU to boot under NFS. Another example is if you want to develop your target application using the root filesystem as the target sysroot.

To extract the root filesystem, first `source` the cross-development environment setup script and then use the `runqemu-extract-sdk` command on the filesystem image. For example, the following commands set up the environment and then extract the root filesystem from a previously built filesystem image tarball named `core-image-sato-sdk-qemux86-2011091411831.rootfs.tar.bz2`. The example extracts the root filesystem into the `$HOME/qemux86-sato` directory:

         $ source $HOME/poky/build/tmp/environment-setup-i586-poky-linux
         $ runqemu-extract-sdk \
            tmp/deploy/images/core-image-sato-sdk-qemux86-2011091411831.rootfs.tar.bz2 \
            $HOME/qemux86-sato

In this case, you could now point to the target sysroot at `$HOME/qemux86-sato`.