Copyright © 2010-2011 Linux Foundation
Permission is granted to copy, distribute and/or modify this document under the terms of the Creative Commons Attribution-Share Alike 2.0 UK: England & Wales as published by Creative Commons.
| Revision History | |
|---|---|
| Revision 1.0 | 6 April 2011 |
| Released with the Yocto Project 1.0 Release. | |
| Revision 1.0.1 | 23 May 2011 |
| Released with the Yocto Project 1.0.1 Release. | |
| Revision 1.1 | 6 October 2011 |
| Released with the Yocto Project 1.1 Release. | |
Table of Contents
Table of Contents
Welcome to the Application Development Toolkit User’s Guide. This manual provides information that lets you get going with the ADT to develop projects using the Yocto Project.
Fundamentally, the ADT consists of an architecture-specific cross-toolchain and a matching sysroot that are both built by the Yocto Project build system Poky. The toolchain and sysroot are based on a metadata configuration and extensions, which allows you to cross-develop on the host machine for the target.
Additionally, to provide an effective development platform, the Yocto Project makes available and suggests other tools you can use with the ADT. These other tools include the Eclipse IDE Yocto Plug-in, an emulator (QEMU), and various user-space tools that greatly enhance your development experience.
The resulting combination of the architecture-specific cross-toolchain and sysroot along with these additional tools yields a custom-built, cross-development platform for a user-targeted product.
This section provides a brief description of what comprises the ADT.
The cross-toolchain consists of a cross-compiler, cross-linker, and cross-debugger that are used to develop user-space applications for targeted hardware. This toolchain is created either by running the ADT Installer script or through a Yocto Project build tree that is based on your metadata configuration or extension for your targeted device. The cross-toolchain works with a matching target sysroot.
The matching target sysroot contains needed headers and libraries for generating binaries that run on the target architecture. The sysroot is based on the target root filesystem image that is built by the Yocto Project's build system Poky and uses the same metadata configuration used to build the cross-toolchain.
The QEMU emulator allows you to simulate your hardware while running your application or image. QEMU is made available a number of ways:
If you use the ADT Installer script to install ADT, you can specify whether or not to install QEMU.
If you have downloaded a Yocto Project release and unpacked it to create a Yocto Project file structure and you have sourced the Yocto Project environment setup script, QEMU is installed and automatically available.
If you have installed the cross-toolchain tarball and you have sourcing the toolchain's setup environment script, QEMU is also installed and automatically available.
User-space tools are included as part of the distribution. You will find these tools helpful during development. The tools include LatencyTOP, PowerTOP, OProfile, Perf, SystemTap, and Lttng-ust. These tools are common development tools for the Linux platform.
LatencyTOP: LatencyTOP focuses on latency that causes skips in audio, stutters in your desktop experience, or situations that overload your server even when you have plenty of CPU power left. You can find out more about LatencyTOP at http://www.latencytop.org/.
PowerTOP: Helps you determine what software is using the most power. You can find out more about PowerTOP at http://www.linuxpowertop.org/.
OProfile: A system-wide profiler for Linux systems that is capable of profiling all running code at low overhead. You can find out more about OProfile at http://oprofile.sourceforge.net/about/.
Perf: Performance counters for Linux used to keep track of certain types of hardware and software events. For more information on these types of counters see https://perf.wiki.kernel.org/index.php and click on “Perf tools.”
SystemTap: A free software infrastructure that simplifies information gathering about a running Linux system. This information helps you diagnose performance or functional problems. SystemTap is not available as a user-space tool through the Yocto Eclipse IDE Plug-in. See http://sourceware.org/systemtap for more information on SystemTap.
Lttng-ust: A User-space Tracer designed to provide detailed information on user-space activity. See http://lttng.org/ust for more information on Lttng-ust.
Table of Contents
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.
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.
To run the ADT Installer, you need to first get the ADT Installer tarball and then run the ADT Installer Script.
The ADT Installer is contained in the ADT Installer tarball. You can download the tarball into any directory from http://downloads.yoctoproject.org/releases/yocto/yocto-1.1/adt_installer. 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 http://downloads.yoctoproject.org/releases/yocto/yocto-1.1/poky-edison-6.0.tar.bz2
$ tar xjf poky-edison-6.0.tar.bz2
$ source poky-edison-6.0/oe-init-build-env
$ bitbake adt-installer
Before running the ADT Installer script, you need to unpack the tarball.
You can unpack the tarball in any directory you wish.
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 http://adtrepo.yoctoproject.org.
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.
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
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
/opt/poky/1.1,
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.
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:
Go to
http://www.yoctoproject.org/downloads/yocto-1.1/toolchain
and find the folder that matches your host development system
(i.e. i586 for 32-bit machines or
x86_64 for 64-bit machines).
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:
yocto-eglibc-x86_64-i586-toolchain-1.1.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.
Make sure you are in the root directory with root privileges and then expand
the tarball.
The tarball expands into /opt/poky/1.1.
Once the tarball is expanded, the cross-toolchain is installed.
You will notice environment setup files for the cross-toolchain in the directory.
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:
Source the environment setup script
oe-init-build-env located in the Yocto Project
files.
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.
MACHINE variable in the
local.conf file and re-run the BitBake
command.Run bitbake meta-ide-support to complete the
cross-toolchain installation.
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.
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 /opt/poky/1.1
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:
/opt/poky/1.1/environment-setup-x86_64-poky-linux
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.
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 - http://www.yoctoproject.org/downloads/yocto-1.1/machines/
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:
Be sure the ADT is installed as described in the "Installing the ADT" section.
Set up the cross-development environment as described in the "Setting Up the Cross-Development Environment" section.
Get the tcf-agent source code, which is
stored using the Subversion SCM, using the following command:
$ svn checkout svn://dev.eclipse.org/svnroot/dsdp/org.eclipse.tm.tcf/trunk/agent \
<-r #rev_number>
Modify the Makefile.inc file
for the cross-compilation environment by setting the
OPSYS and MACHINE
variables according to your target.
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.
Deploy the agent into the image's 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.
Table of Contents
Because the Yocto Project is suited for embedded Linux development, it is likely that you will need to customize your development packages installation. For example, if you are developing a minimal image, then you might not need certain packages (e.g. graphics support packages). Thus, you would like to be able to remove those packages from your target sysroot.
The Yocto Project supports the generation of sysroot files using three different Package Management Systems (PMS):
OPKG: A less well known PMS whose use
originated in the OpenEmbedded and OpenWrt embedded Linux projects.
This PMS works with files packaged in an .ipk format.
See http://en.wikipedia.org/wiki/Opkg for more
information about OPKG.
RPM: A more widely known PMS intended for GNU/Linux
distributions.
This PMS works with files packaged in an .rms format.
The Yocto Project currently installs through this PMS by default.
See http://en.wikipedia.org/wiki/RPM_Package_Manager
for more information about RPM.
Debian: The PMS for Debian-based systems
is built on many PMS tools.
The lower-level PMS tool dpkg forms the base of the Debian PMS.
For information on dpkg see
http://en.wikipedia.org/wiki/Dpkg.
Whichever PMS you are using, you need to be sure that the
PACKAGE_CLASSES variable in the conf/local.conf
file is set to reflect that system.
The first value you choose for the variable specifies the package file format for the root
filesystem at sysroot.
Additional values specify additional formats for convenience or testing.
See the configuration file for details.
package*.bbclass
in
The Yocto Project Reference Manual.
As an example, consider a scenario where you are using OPKG and you want to add
the libglade package to the target sysroot.
First, you should generate the ipk file for the
libglade package and add it
into a working opkg repository.
Use these commands:
$ bitbake libglade
$ bitbake package-index
Next, source the environment setup script found in the Yocto Project files.
Follow that by setting up the installation destination to point to your
sysroot as <sysroot_dir>.
Finally, have an OPKG configuration file <conf_file>
that corresponds to the opkg repository you have just created.
The following command forms should now work:
$ opkg-cl –f <conf_file> -o <sysroot_dir> update
$ opkg-cl –f <cconf_file> -o <sysroot_dir> \
--force-overwrite install libglade
$ opkg-cl –f <cconf_file> -o <sysroot_dir> \
--force-overwrite install libglade-dbg
$ opkg-cl –f <conf_file> -o <sysroot_dir> \
--force-overwrite install libglade-dev
Table of Contents
The Eclipse IDE is a popular development environment and it fully supports development using Yocto Project. When you install and configure the Eclipse Yocto Project Plug-in into the Eclipse IDE, you maximize your Yocto Project design experience. Installing and configuring the Plug-in results in an environment that has extensions specifically designed to let you more easily develop software. These extensions allow for cross-compilation, deployment, and execution of your output into a QEMU emulation session. You can also perform cross-debugging and profiling. The environment also supports a suite of tools that allows you to perform remote profiling, tracing, collection of power data, collection of latency data, and collection of performance data.
This section describes how to install and configure the Eclipse IDE Yocto Plug-in and how to use it to develop your Yocto Project.
To develop within the Eclipse IDE, you need to do the following:
Install the optimal version of the Eclipse IDE.
Configure the Eclipse IDE.
Install the Eclipse Yocto Plug-in.
Configure the Eclipse Yocto Plug-in.
It is recommended that you have the Indigo 3.7 version of the Eclipse IDE installed on your development system. If you don’t have this version, you can find it at http://www.eclipse.org/downloads. From that site, choose the Eclipse Classic version particular to your development host. This version contains the Eclipse Platform, the Java Development Tools (JDT), and the Plug-in Development Environment.
Once you have downloaded the tarball, extract it into a clean
directory.
For example, the following command unpacks and installs the Eclipse IDE
into a clean directory using the default name eclipse:
$ tar -xzvf ~/Downloads/Eclipse-SDK-3.7-linux-gtk-x86_64.tar.gz
One issue exists that you need to be aware of regarding the Java Virtual machine’s garbage collection (GC) process. The GC process does not clean up the permanent generation space (PermGen). This space stores metadata descriptions of classes. The default value is set too small and it could trigger an out-of-memory error such as the following:
Java.lang.OutOfMemoryError: PermGen space
This error causes the application to hang.
To fix this issue, you can use the --vmargs
option when you start Eclipse to increase the size of the permanent generation space:
eclipse --vmargs --XX:PermSize=256M
Before installing and configuring the Eclipse Yocto Plug-in, you need to configure the Eclipse IDE. Follow these general steps to configure Eclipse:
Start the Eclipse IDE.
Make sure you are in your Workbench and select "Install New Software" from the "Help" pull-down menu.
Select indigo - http://download.eclipse.org/releases/indigo
from the "Work with:" pull-down menu.
Expand the box next to Programming Languages
and select the Autotools Support for CDT (incubation)
and C/C++ Development Tools boxes.
Complete the installation and restart the Eclipse IDE.
After the Eclipse IDE restarts and from the Workbench, select "Install New Software" from the "Help" pull-down menu.
Click the "Available Software Sites" link.
Check the box next to
http://download.eclipse.org/tm/updates/3.3
and click "OK".
Select http://download.eclipse.org/tm/updates/3.3
from the "Work with:" pull-down menu.
Check the box next to TM and RSE Main Features.
Expand the box next to TM and RSE Optional Add-ons
and select every item except RSE Unit Tests and
RSE WinCE Services (incubation).
Complete the installation and restart the Eclipse IDE.
If necessary, select "Install New Software" from the "Help" pull-down menu so you can click the "Available Software Sites" link again.
After clicking "Available Software Sites", check the box next to
http://download.eclipse.org/tools/cdt/releases/indigo
and click "OK".
Select http://download.eclipse.org/tools/cdt/releases/indigo
from the "Work with:" pull-down menu.
Check the box next to CDT Main Features.
Expand the box next to CDT Optional Features
and select C/C++ Remote Launch and
Target Communication Framework (incubation).
Complete the installation and restart the Eclipse IDE.
You can install the Eclipse Yocto Plug-in one of three methods: as new software from within the Eclipse IDE, from the Yocto Project source repositories, or as a built zip file.
To install the Eclipse Yocto Plug-in directly into the Eclipse IDE, follow these steps:
Start up the Eclipse IDE.
In Eclipse, select "Install New Software" from the "Help" menu.
Click "Add..." in the "Work with:" area.
Enter
http://www.yoctoproject.org/downloads/eclipse-plugin/1.1
in the URL field and provide a meaningful name in the "Name" field.
Click "OK" to have the entry added to the "Work with:" drop-down list.
Select the entry for the plug-in from the "Work with:" drop-down list.
Complete the remaining software installation steps and then restart the Eclipse IDE to finish the installation of the plug-in.
To install the Eclipse Yocto Plug-in from the Yocto Project source repositories, follow these steps:
Open a shell and create a Git repository with:
$ git clone git://git.yoctoproject.org/eclipse-poky yocto-eclipse
For this example, the repository is named
~/yocto-eclipse.
In Eclipse, select "Import" from the "File" menu.
Expand the "General" box and pick "existing projects into workspace".
Select the root directory and browse to "~/yocto-eclipse/plugins".
There will be three things there. Select each one and install one at a time. Do all three.
Restart everything.
At this point you should be able to invoke Eclipse from the shell using the following:
$ cd ~/eclipse
$ ./eclipse -vmargs -XX:PermSize=256M
The left navigation pane shows the default projects. Right-click on one of these projects and run it as an Eclipse application. This brings up a second instance of Eclipse IDE that has the Yocto Plug-in.
To install the Eclipse Yocto Plug-in by building and installing a plug-in zip file, follow these steps:
Open a shell and create a Git repository with:
$ git clone git://git.yoctoproject.org/eclipse-poky yocto-eclipse
For this example, the repository is named
~/yocto-eclipse.
Locate the build.sh script in the
Git repository you created in the previous step.
The script is located in the scripts.
Be sure to set and export the ECLIPSE_HOME environment
variable to the top-level directory in which you installed the Indigo
version of Eclipse.
For example, if your Eclipse directory is $HOME/eclipse,
use the following:
$ export ECLIPSE_HOME=$HOME/eclipse
Run the build.sh script and provide the
name of the Git branch along with the Yocto Project release you are
using.
Here is an example that uses the master Git repository
and the 1.1M4 release:
$ scripts/build.sh master 1.1M4
After running the script, the file
org.yocto.sdk-<release>-<date>-archive.zip
is in the current directory.
If necessary, start the Eclipse IDE and be sure you are in the Workbench.
Select "Install New Software" from the "Help" pull-down menu.
Click "Add".
Provide anything you want in the "Name" field.
For the "Archive" field, select the ZIP file you built in step
4.
This ZIP file should not be "unzipped", and must be the
*archive.zip file created by running the
build.sh script.
Select the new entry in the installation window and complete the installation.
Restart the Eclipse IDE if necessary.
At this point you should be able to configure the Eclipse Yocto Plug-in as described in the next section.
Configuring the Eclipse Yocto Plug-in involves setting the Cross Compiler options and the Target options. The configurations you choose become the default settings for all projects. You do have opportunities to change them later when you configure the project (see the following section).
To start, you need to do the following from within the Eclipse IDE:
Choose Windows -> Preferences to display
the Preferences Dialog
Click Yocto ADT
To configure the Cross Compiler Options, you must select the type of toolchain, point to the toolchain, specify the sysroot location, and select the target architecture.
Selecting the Toolchain Type:
Choose between Standalone pre-built toolchain
and Build system derived toolchain for Cross
Compiler Options.
Standalone Pre-built Toolchain:
Select this mode when you are using a stand-alone cross-toolchain.
For example, suppose you are an application developer and do not
need to build a target image.
Instead, you just want to use an architecture-specific toolchain on an
existing kernel and target root filesystem.
Build System Derived Toolchain:
Select this mode if the cross-toolchain has been installed and built
as part of the Yocto Project build tree.
When you select Build system derived toolchain,
you are using the toolchain bundled
inside the Yocto Project build tree.
Point to the Toolchain:
If you are using a stand-alone pre-built toolchain, you should be pointing to the
/opt/poky/1.1 directory.
This is the location for toolchains installed by the ADT Installer or by hand.
Sections "Configuring
and Running the ADT Installer Script" and
"Using a Cross-Toolchain
Tarball" describe two ways to install
a stand-alone cross-toolchain in the
/opt/poky directory.
/opt/poky.
However, doing so is discouraged.If you are using a system-derived toolchain, the path you provide
for the Toolchain Root Location
field is the Yocto Project's build directory.
See section "Using
BitBake and the Yocto Project Build Tree" for
information on how to install the toolchain into the Yocto
Project build tree.
Specify the Sysroot Location: This location is where the root filesystem for the target hardware is created on the development system by the ADT Installer. The QEMU user-space tools, the NFS boot process, and the cross-toolchain all use the sysroot location.
Select the Target Architecture:
The target architecture is the type of hardware you are
going to use or emulate.
Use the pull-down Target Architecture menu to make
your selection.
The pull-down menu should have the supported architectures.
If the architecture you need is not listed in the menu, you
will need to build the image.
See the "Building an Image" section of the
The Yocto Project Quick Start for more information.
You can choose to emulate hardware using the QEMU emulator, or you can choose to run your image on actual hardware.
QEMU: Select this option if
you will be using the QEMU emulator.
If you are using the emulator, you also need to locate the kernel
and specify any custom options.
If you selected Build system derived toolchain,
the target kernel you built will be located in the
Yocto Project build tree in tmp/deploy/images directory.
If you selected Standalone pre-built toolchain, the
pre-built image you downloaded is located
in the directory you specified when you downloaded the image.
Most custom options are for advanced QEMU users to further
customize their QEMU instance.
These options are specified between paired angled brackets.
Some options must be specified outside the brackets.
In particular, the options serial,
nographic, and kvm must all
be outside the brackets.
Use the man qemu command to get help on all the options
and their use.
The following is an example:
serial ‘<-m 256 -full-screen>’
Regardless of the mode, Sysroot is already defined as part of the
Cross Compiler Options configuration in the
Sysroot Location: field.
External HW: Select this option
if you will be using actual hardware.
Click the OK button to save your plug-in configurations.
You can create two types of projects: Autotools-based, or Makefile-based. This section describes how to create Autotools-based projects from within the Eclipse IDE. For information on creating Makefile-based projects in a terminal window, see the section "Using the Command Line".
To create a project based on a Yocto template and then display the source code, follow these steps:
Select File -> New -> Project.
Double click CC++.
Double click C Project to create the project.
Expand Yocto ADT Project.
Select Hello World ANSI C Autotools Project.
This is an Autotools-based project based on a Yocto Project template.
Put a name in the Project name: field.
Do not use hyphens as part of the name.
Click Next.
Add information in the Author and
Copyright notice fields.
Be sure the License field is correct.
Click Finish.
If the "open perspective" prompt appears, click "Yes" so that you in the C/C++ perspective.
The left-hand navigation pane shows your project. You can display your source by double clicking the project's source file.
The earlier section, "Configuring the Eclipse Yocto Plug-in", sets up the default project configurations. You can override these settings for a given project by following these steps:
Select Project -> Change Yocto Project Settings:
This selection brings up the Project Yocto Settings Dialog
and allows you to make changes specific to an individual project.
By default, the Cross Compiler Options and Target Options for a project
are inherited from settings you provide using the Preferences
Dialog as described earlier
in the "Configuring the Eclipse
Yocto Plug-in" section.
The Project Yocto Settings
Dialog allows you to override those default settings
for a given project.
Make your configurations for the project and click "OK".
Select Project -> Reconfigure Project:
This selection reconfigures the project by running
autogen.sh in the workspace for your project.
The script also runs libtoolize, aclocal,
autoconf, autoheader,
automake --a, and
./configure.
To build the project, select Project -> Build Project.
The console should update and you can note the cross-compiler you are using.
To start the QEMU emulator from within Eclipse, follow these steps:
Expose the Run -> External Tools menu.
Your image should appear as a selectable menu item.
Select your image in the navigation pane to launch the emulator in a new window.
If needed, enter your host root password in the shell window at the prompt.
This sets up a Tap 0 connection needed for running in user-space
NFS mode.
Wait for QEMU to launch.
Once QEMU launches, you can begin operating within that
environment.
For example, you could determine the IP Address
for the user-space NFS by using the ifconfig command.
Once the QEMU emulator is running the image, you can deploy your application and use the emulator to perform debugging. Follow these steps to deploy the application.
Select Run -> Debug Configurations...
In the left area, expand C/C++Remote Application.
Locate your project and select it to bring up a new
tabbed view in the Debug Configurations Dialog.
Enter the absolute path into which you want to deploy
the application.
Use the Remote Absolute File Path for C/C++Application: field.
For example, enter /usr/bin/<programname>.
Click on the Debugger tab to see the cross-tool debugger
you are using.
Click on the Main tab.
Create a new connection to the QEMU instance
by clicking on new.
Select TCF, which means Target Communication
Framework.
Click Next.
Clear out the host name field and enter the IP Address
determined earlier.
Click Finish to close the
New Connections Dialog.
Use the drop-down menu now in the Connection field and pick
the IP Address you entered.
Click Debug to bring up a login screen
and login.
Accept the debug perspective.
As mentioned earlier in the manual, several tools exist that enhance
your development experience.
These tools are aids in developing and debugging applications and images.
You can run these user-space tools from within the Eclipse IDE through the
Window -> YoctoTools menu.
Once you pick a tool, you need to configure it for the remote target.
Every tool needs to have the connection configured.
You must select an existing TCF-based RSE connection to the remote target.
If one does not exist, click New to create one.
Here are some specifics about the remote tools:
OProfile: Selecting this tool causes
the oprofile-server on the remote target to launch on
the local host machine.
The oprofile-viewer must be installed on the local host machine and the
oprofile-server must be installed on the remote target,
respectively, in order to use.
You must compile and install the oprofile-viewer from the source code
on your local host machine.
Furthermore, in order to convert the target's sample format data into a form that the
host can use, you must have oprofile version 0.9.4 or
greater installed on the host.
You can locate both the viewer and server from http://git.yoctoproject.org/cgit/cgit.cgi/oprofileui/.
oprofile-server is installed by default on
the core-image-sato-sdk image.Lttng-ust: Selecting this tool runs
usttrace on the remote target, transfers the output data back to the
local host machine, and uses lttv-gui to graphically display the output.
The lttv-gui must be installed on the local host machine to use this tool.
For information on how to use lttng to trace an application, see
http://lttng.org/files/ust/manual/ust.html.
For Application, you must supply the absolute path name of the
application to be traced by user mode lttng.
For example, typing /path/to/foo triggers
usttrace /path/to/foo on the remote target to trace the
program /path/to/foo.
Argument is passed to usttrace
running on the remote target.
PowerTOP: Selecting this tool runs
powertop on the remote target machine and displays the results in a
new view called powertop.
Time to gather data(sec): is the time passed in seconds before data
is gathered from the remote target for analysis.
show pids in wakeups list: corresponds to the
-p argument
passed to powertop.
LatencyTOP and Perf:
latencytop identifies system latency, while
perf monitors the system's
performance counter registers.
Selecting either of these tools causes an RSE terminal view to appear
from which you can run the tools.
Both tools refresh the entire screen to display results while they run.
Table of Contents
Recall that earlier the manual discussed how to use an existing toolchain
tarball that had been installed into /opt/poky,
which is outside of the Yocto Project build tree
(see the section "Using an Existing
Toolchain Tarball)".
And, that sourcing your architecture-specific environment setup script
initializes a suitable cross-toolchain development environment.
This setup occurs by adding the compiler, QEMU scripts, QEMU binary,
a special version of pkgconfig and other useful
utilities to the PATH variable.
Variables to assist pkgconfig and autotools
are also defined so that,
for example, configure.sh can find pre-generated
test results for tests that need target hardware on which to run.
These conditions allow you to easily use the toolchain outside of the
Yocto Project build environment on both autotools-based projects and
Makefile-based projects.
For an Autotools-based project, you can use the cross-toolchain by just
passing the appropriate host option to configure.sh.
The host option you use is derived from the name of the environment setup
script in /opt/poky resulting from unpacking the
cross-toolchain tarball.
For example, the host option for an ARM-based target that uses the GNU EABI
is armv5te-poky-linux-gnueabi.
Note that the name of the script is
environment-setup-armv5te-poky-linux-gnueabi.
Thus, the following command works:
$ configure --host=armv5te-poky-linux-gnueabi \
--with-libtool-sysroot=<sysroot-dir>
This single command updates your project and rebuilds it using the appropriate cross-toolchain tools.
configure script results in problems recognizing the
--with-libtool-sysroot=<sysroot-dir> option,
regenerate the script to enable the support by doing the following and then
re-running the script:
$ libtoolize --automake
$ aclocal -I ${OECORE_NATIVE_SYSROOT}/usr/share/aclocal \
[-I <dir_containing_your_project-specific_m4_macros>]
$ autoconf
$ autoheader
$ automake -a