Creating the Buildroot system for a particular target board to execute or debug EGT applications or libraries. For this you must configure your Buildroot system, enable the EGT package with their dependencies and Build the Buildroot system. Refer to section Cross Compiling With Buildroot
Once Buildroot compilation is done. The output/image folder contains all the files to boot Linux on the target board. To create an sdcard image to boot Linux on the sam9x60EK board, refer to create sdcard image.
Start Eclipse to develop, execute or debug your own custom EGT applications/libraries that will rely on the EGT library built and installed by Buildroot.

This tutorial will guide you through the installation and usage of Eclipse for developing an EGT application using Buildroot.

Eclipse Installation

At the current time, the latest stable version of Eclipse is called 2019-06. Most Linux distributions come either with an Eclipse package or allow it to be easily installed by the package manager in the distribution. However, note that this is frequently an out of date version. You can download the latest version from the central download site at http://www.eclipse.org. As an IDE, Eclipse supports many different programming languages including Java, C, C++, Python, and many others. At installation time, you need to select the version to support the package(s) that you want. To make this easier, there is an installation tool which will guide you through the steps.

Eclipse installer

Download Eclipse IDE for C/C++ Developers and follow the steps below for installation.

See also: https://www.eclipse.org/downloads/packages/

Extract the eclipse-cpp-2019-06-R-linux-gtk-x86_64.tar.gz to folder /opt

sudo tar -zxvf eclipse-cpp-2019-06-R-linux-gtk-x86_64.tar.gz -C /opt
 
sudo chown -R root:root /opt/eclipse

Create a desktop file and install it:

gedit eclipse.desktop

copy the below lines to the eclipse.desktop file

[Desktop Entry]
Name=Eclipse
Type=Application
Exec=/opt/eclipse/eclipse
Terminal=false
Icon=eclipse
Comment=Integrated Development Environment
NoDisplay=false
Categories=Development;IDE;
Name[en]=Eclipse

Set an executable permission and execute the following command to install it:

sudo desktop-file-install eclipse.desktop

Create a symlink in /usr/local/bin

sudo ln -s /opt/eclipse/eclipse /usr/local/bin/eclipse

For an eclipse icon to be displayed in dash, the eclipse icon can be added as:

sudo cp /opt/eclipse/icon.xpm /usr/share/pixmaps/eclipse.xpm

Eclipse needs to have either OpenJDK or Sun Java installed to be able to run eclipse. Here is a simple example of installing Open JDK 1.8:

sudo apt install openjdk-8-jdk

With Eclipse installed in the /opt folder, it can now be accessed by any users.

Start Eclipse and Create an EGT Project

Start Eclipse from the Ubuntu Applications tray and you will be asked where to place your workspace directory. By default, the location will be under the users home directory, i.e. /home/<user>/eclipse-workspace.

Eclipse workspace

With the workspace set, click launch and Eclipse will start with a startup screen.

Eclipse startup screen

Now we can create a new EGT project that will use a toolchain generated by Buildroot. In the example below, we created an EGT project using autotool and it is up to the developer to write the configure.ac file and Makefile.am. This allows the project to be built outside Eclipse and to use standard Unix tools as your project build system. For more information on autotools, refer to GNU Autotools

Click on "Create a new C/C++ Project" and Select "C++ Managed Build" in the New C/C++ Project window and then click Next.

Select C++ Managed Build

In the Create C/C++ Project window:

Set the project name.
In Project type, expand GNU Autotools and select Empty project.
In Toolchains, select GNU Autotools Toolchain.
Click on Next.

Create C++ Project

To cross-compile this Project using the Buildroot toolchain, we need to set a few environment variables and this can be done clicking "Advance Setting" in the Select Configurations window.

C++ Project Select Configurations

In the Properties window, expand Autotools and select Configure Settings. Under Configure Settings, select platform specifiers and set "Host platform (--host)" to "arm-buildroot-linux-gnueabi".

C++ Project Properties Autotools

Now select Environment Variables and click New. Under the New Environment Variable window, set the Buildroot toolchain path and Click OK.

Name: PATH
Value: buildroot/output/host/bin:$PATH

C++ Project Properties Autotools Environment

To enable debug options, select Advance and check the Debug(-g) option and then click Apply.

C++ Project Properties Autotools Advance

Now expand the C/C++ Build. Select Environment and click Add. In the New Variable window, set the Buildroot toolchain path using the below details. Click OK and "Apply and Close" and then click Finish.

Name: PATH
Value: buildroot/output/host/bin:$PATH
Check Add to all configurations

C++ Project Properties Build Environment

Create source files in the Project by right Clicking on the Project name and select New -> Source File.

New C++ Source file

In the New Source File window, set the File name basic.cpp and click Finish

Enter filename

Copy the lines below to basic.cpp file:

#include <egt/ui>
 
int main(int argc, char** argv)
{
    egt::Application app(argc, argv);
 
    egt::TopWindow window;
    egt::Button button(window, "Press Me");
    egt::center(button);
    window.show();
 
    return app.run();
}

Create cpp file

Similarly, create a new configure.ac file and copy the below lines:

AC_PREREQ(2.59)
AC_INIT(basic, 1.0)
AC_PROG_CXX
 
AM_INIT_AUTOMAKE([1.10 foreign])
 
PKG_CHECK_MODULES(EGT, [libegt])
AC_SUBST(EGT_LIBS)
AC_SUBST(EGT_CFLAGS)
 
AC_CONFIG_FILES([Makefile])
AC_OUTPUT

Create configure.ac file

Now create a new Makefile.am file and copy the below lines:

bin_PROGRAMS=basic
 
basic_SOURCES=basic.cpp
basic_CPPFLAGS = $(EGT_CFLAGS)
basic_LDADD = $(EGT_LIBS) -lpthread

Create Makefile.am file

Save all using file->saveall or press (shift + Ctrl + S).

To Build this Project, first invoke the Autoreconf tool by right clicking on the project and selecting Invoke Autotools->Invoke Autoreconf. This operation will call the autotools to generate the configure script and Makefile.in files. This operation has to be done again if you make changes to configure.ac or Makefile.am.

Invoke autoreconf

Set the "-i -v -f" option to the autoreconf window and click OK. This tells autoreconf to automatically install additional scripts and files that are needed for correct operation of the configure script.

Set autoreconf arguments

Now we can see in the console that the autoreconf command finished successfully and the configure and Makefile.in files have generated in the project folder.

Autoreconf success

Now reconfigure the project by right clicking on the project and selecting Reconfigure Project. This will call the configure script with the argument –host option and set Environment variable values to ensure that your project will be cross-compiled with the Buildroot toolchain. You may define additional options in the project properties.

Reconfigure project

In the console, we can see that the operation finished successfully and Makefile generated in the Project folder.

Reconfigure project finished

Finally, to build this project, select Project-> "Build All" or Press (Ctrl-b).

Build project

Executing EGT application on a Target Remotely

Eclipse will execute an EGT application on a target board by transfering the application binary using SSH. SSH server must have been installed on the target board.

Buildroot offers you two choices:

The Dropbear package can be enabled in Networking applications -> dropbear.
The full-blown SSH implementation, OpenSSH, can be enabled in Networking applications -> openssh.

Most SSH servers do not allow log in as root with an empty password. To set the root password, log in on the target board and type the below commands:

# passwd
Changing password for root
New password:
Bad password: too short
Retype password:
Password for root changed by root

Type the below commands to configure the Ethernet interface and to make sure the host machine and target board are connected.

# ifconfig eth0 192.168.1.12 up

The first step is to create a new run configuration. Right click your EGT project and click on Run As->Run Configurations...

Run as

Double click on "C/C++ Remote Application" to create a Run configuration for the target board.

New launch configuration

To setup an ssh connection with the target, click “New” under connection and select SSH and click on Okay.

SSH connection setup

In the New Connection window, set the below details and click Finish.

Connection Name: Remote Host
Host: IP Address of a target board.
User: root
Check public key based authentication.
passphrase: root password of target board.

Finish launch configuration

Set the Remote Absolute File Path to /root/basic and click Run.

Wait while the application is copied to the target using SSH protocols.

Coping application to target

Finally, in the Console, see the traces and EGT application running on the target board.

Debug EGT Application Remotely

As a preliminary step, you also need to ensure that gdbserver is present on your target. If gdbserver not present, then enable following options in Buildroot menuconfig:

Toolchain -> GDB debugger Version
Toolchain -> Build cross gdb for the host
Target packages -> Debugging, profiling and benchmark -> gdb
Target packages -> Debugging, profiling and benchmark -> gdbserver
Target packages -> Debugging, profiling and benchmark -> full debugger

To get a nice debugging experience, you may want Buildroot to build the libraries with debugging symbols. To do so, enable the Build options -> build packages with debugging symbols option.

Create remote debug configuration

The create remote debug configuration will connect to the target board and it will automatically download the compiled binary, start a gdb-server session and connect to it from within the Eclipse IDE.

Create a remote debug configuration by right clicking on Project and select "Debug As" -> "Debug Configurations…"

Select Debug Configurations

In the Debug Configurations window, double Click "C/C++ Remote Application".

Select C/C++ Remote Application

To set up the remote debugging connection, select New under Connection and Choose a connection type of SSH and configure the New Connection as follows:

setup SSH Connection

Set the Remote Absolute File Path to /root/basic.

To configure the gdb connection over ssh, go to the Debugger tab and in it you will see that the GDB debugger: gdb setting currently points to the default debugger on the host system. This is a x86_64 debugger and it does not understand the symbols and messages from the gdb-server on the target. You must change this to point to the ARM-specific gdb that is created by Buildroot. Change it to:

<buildroot>/output/host/bin/arm-buildroot-linux-gnueabi-gdb

To prevent some spurious SIGNALS and to help the GDB debugger, we have provided an initialization script. Create a gdbinit file in your project folder and copy the below line and set the gdbinit file path to the GDB command file:

handle SIGILL nostop

set sysroot buildroot/output/target

setup GDB Debugger

click on the Apply and Debug button.

Now in Eclipse you should be able to select the new Debug Configuration. If a pop up appears, click on Yes in the confirm perspective switch window. If you get an authentication Message dialog box, select Yes to accept it or else Eclipse will change to the debug perspective and the application will halt at main(). Press Resume (F8) to continue execution and the application should continue to run on the target. You can view variables and disassembly code.

Enjoying the enhanced debug experience.

Eclipse debug window

Build libegt on Host Machine

This sections describes how to build a standalone EGT library and its examples on the host machine in Eclipse using Autotools. To fetch the Source from the Git repository, refer to section Fetching Source.

Create a new CPP Project using File-> New -> Project. In the New Project window, expand C/C++ and select C/C++ Project, then click Next.

Create new cpp project

In the New C/C++ Project window, select C++ Managed Builds and click Next.

Select C++ Managed Builds

In C++ Project window,

Set the project name.
Uncheck default location.
Browse to git clone location of a EGT directory.
Select "GNU Autotools Empty project" type.
Select "GNU Autotools Toolchain" and Click on the Finish button.

Eclipse create new cpp project

Now we can see in the console Tab:

The autoreconf command finished successfully and generated configure and Makefile.in files in the Project folder.
Executed configure scripts and generated Makefiles in the project folder.

Eclipse reconfigure done

To build the libegt project, press (Ctrl-b) or select the Project->"build all" option and observe build messages in Console.

Eclipse build libegt project

Execute EGT application on Host Machine.

Before we start to execute/debug an application, we need to set the environment variable LD_LIBRARY_PATH to point to the libegt.so folder (i.e. src/.libs/).

Go to Project properties by right clicking the project and selecting Properties or Press (Alt + Enter). In the Project properties window, Expand "C/C++ Build" and Select "Environment" and then click ADD.

Add Project Environment Variables

In a New Environment variable window, set the below details and click OK and the OK again to close the Project properties window.

Name: LD_LIBRARY_PATH
PATH: project/src/.libs/:$LD_LIBRARY_PATH.
Check Add to all Configurations.

Eclipse set environment variable

We can start executing the EGT example application by right clicking on the libegt Project and selecting Run As -> "2.Local C/C++ Application".

Select Local C/C++ Application

In the "C Local Application" window, select basic under Binaries and click OK.

Select basic Application under Binaries

A new EGT window will pop up running the EGT Basic example application.

Eclipse basic example demo

Debug EGT application on Host Machine

To debug EGT example applications, right click on the libegt project and select "Debug As" -> "2.Local C/C++ Application".