Yocto Programming with CodeBlocks

DART-MX8M-MINI - Yocto Programming with Code::Blocks

Code::Blocks is a free C/C++ IDE built around a plugin framework, designed to be very extensible and fully configurable.

This guide demonstrates how to create and debug a C++ application using Code::Blocks on the DART-MX8M-MINI.

Create your rootfs with Code::Blocks debug support

Debugging with Code::Blocks requires your preferred SSH server (openssh, dropbear, etc.), gdb, and gdbserver installed on the target device.
Append the following to the conf/local.conf file in your Yocto build directory:

EXTRA_IMAGE_FEATURES = " \
    tools-debug \
    ssh-server-dropbear \
    "

Now bitbake your image.

Setup Host Computer Environment

Please follow the steps below to prepare a fresh Ubuntu 20.04 installation for Code::Blocks debugging:

Install Dependencies

$ sudo apt-get -y update
$ sudo apt-get -y install build-essential gdb gdb-multiarch git

Install Code::Blocks

$ sudo apt install codeblocks codeblocks-contrib

Install Yocto Toolchain

A toolchain is necessary for cross compiling applications. To install the toolchain, follow Variscite's Yocto Toolchain installation guide.

Configure Code::Blocks

This section uses the default toolchain path, assuming you followed the default instruction in Variscite's Yocto Toolchain installation guide.

Changes may be required if you installed the toolchain in a different path or used different distro settings.

Configure the debugger

From the menu, click on "Settings" and then on "Debugger..."

In the "Debugger settings" window, select "GDB/CDB debugger" and click on "Create Config".

In the "Create config" window, enter the new debugger's name and click on "OK".

Select the new configuration in the left pane, and fill in the "Executables path" field.

The default path is:

/opt/fslc-xwayland/3.1/sysroots/x86_64-fslcsdk-linux/usr/bin/aarch64-fslc-linux/aarch64-fslc-linux-gdb

Then, add the set sysroot command in the "Debugger initialization commands" section, to speedup the gdb startup.

The default path is:

set sysroot /opt/fslc-xwayland/3.1/sysroots/aarch64-fslc-linux

Finally, click on "OK".

Configure the compiler

The next steps depend on the previous section: here we assume the debugger is already configured.

From the menu, click on "Settings" and then on "Compiler..."

In the "Global compiler settings" window, click on "Copy".

In the "Add new compiler" window, enter the new compiler's name and click on "OK".

A popup windows will remind you to update the "Toolchain executables" page - just click on "OK".

Click on the "Toolchain executables" tab and fill in the fields according your Yocto toolchain.

For the Debugger, in the drop-down list you should select the one created above.

The default settings are

• Compiler's installation directory: /opt/fslc-xwayland/3.1/sysroots/x86_64-fslcsdk-linux/usr/bin/aarch64-fslc-linux
• C compiler: aarch64-fslc-linux-gcc
• C++ compiler: aarch64-fslc-linux-g++
• Linker for dynamic libs: aarch64-fslc-linux-g++
• Linker for static libs: aarch64-fslc-linux-ar
• Debugger: GDB/CDB debugger: Variscite GDB
• Resource compiler: <empty>
• Make program: make

Click on the "Compiler settings" tab, then on the "Other compiler options" tab, and finally, add the right options.

The default setting is:

--sysroot=/opt/fslc-xwayland/3.1/sysroots/aarch64-fslc-linux

Click on the "Linker settings" tab, then on the "Other linker options" tab, and finally, add the right options.

As above, the default setting is:

--sysroot=/opt/fslc-xwayland/3.1/sysroots/aarch64-fslc-linux

Create the reference helper scripts to deploy and debug with Code::Blocks

Here, we will create the following files:

/home/user/bin/var-sdk.conf	configuration file hosting target parameters
/home/user/bin/var-sdk-deploy.sh	script to automate binary deploy
/home/user/bin/var-sdk-debug.sh	script to automate binary debug

Create the file /home/user/bin/var-sdk.conf using the right IP address of the board:

TARGET_DIR="/home/root"
TARGET_IP="192.168.73.165"
TARGET_PORT="3000"
SSH_OPTIONS="-oStrictHostKeyChecking=no"

Create the file /home/user/bin/var-sdk-deploy.sh:

#!/bin/bash

readonly PROGRAM="$1"
PROGRAMNAME="$(basename $PROGRAM)"

. /home/user/bin/var-sdk.conf

echo "Deploying to target"

# prevent "Host key verification failed"
ssh-keygen -f "${HOME}/.ssh/known_hosts" -R "${TARGET_IP}"

# delete old binary
ssh ${SSH_OPTIONS} root@${TARGET_IP} "sh -c 'rm -rf ${TARGET_DIR}/${PROGRAMNAME}'"

# send the program to the target
scp ${PROGRAM} root@${TARGET_IP}:${TARGET_DIR}/${PROGRAMNAME}

Create the file /home/user/bin/var-sdk-debug.sh:

#!/bin/bash

readonly PROGRAM="$1"
PROGRAMNAME="$(basename $PROGRAM)"

. /home/user/bin/var-sdk.conf

echo "Starting GDB Server on Target"

# kill gdbserver on target
ssh ${SSH_OPTIONS} root@${TARGET_IP} "sh -c '/usr/bin/killall -q gdbserver'"

# start gdbserver on target and fork
ssh ${SSH_OPTIONS} -t root@${TARGET_IP} "sh -c 'XDG_RUNTIME_DIR=/run/user/0 gdbserver localhost:${TARGET_PORT} ${TARGET_DIR}/${PROGRAMNAME}'" &

Finally, make all of them executable:

$ chmod +x /home/user/bin/var-sdk*

Create a sample "Console application" project with Code::Blocks

From the Menu, click on "New" and then on "Project"

In the "New from template" window, select "Console application" and click on "Go".

Unless you prefer changing something, click "Next" in the "Welcome" and "Language" windows.

Populate the Project window according your needs and click on "Next".

Select from the drop-down list the compiler configured in the previous section and click on "Finish".

A sample HelloWorld project will show up in the IDE.

Configure the project

From the previous view, right click on the project name and then click on "Properties...".

In the "Project/targets options" window, click on the "Build targets" tab, and then click on the "Build options..." button.

In the "Project build options" window, ensure that "Debug" is selected in the left pane. Select the "Compiler settings" tab, then select "Use target options only" from the Policy drop-down list.

Once done, ensure that "Release" is selected in the left pane, then repeat the previous step.

In the "Project build options" window, ensure that "Debug" is selected in the left pane. Select the "Linker settings" tab, then select "Use target options only" from the Policy drop-down list.

Once done, ensure that "Release" is selected in the left pane, then repeat the previous step.

In the "Project build options" window, ensure that "Debug" is selected in the left pane, then click on the "Pre/post build steps" and add the following under "Post-build steps":

/home/user/bin/var-sdk-deploy.sh $(TARGET_OUTPUT_FILE)

Once done, ensure that "Release" is selected in the left pane, then repeat the previous step, and finally, click on "OK".

In the "Project/targets option" window, scroll the tabs and click on the "Debugger" tab, then ensure "<Project>" is selected in the left pane.
In the "Remote connection" area, populate the TARGET_IP and the TARGET_PORT that must match the value stored in file /home/user/bin/var-sdk.conf

Still in the same window, click on the "Additional shell commands" area and add the following under "Before connection":

/home/user/bin/var-sdk-debug.sh $(TARGET_OUTPUT_FILE)

Then click on "OK".

Debug the project

As the last step of our example, enable a breakpoint by clicking on the right of the line number you want stop at and start the debugger.