Qt offers all the necessary tools to design, develop, build, and deploy your application onto the target.

This guide describes how to use the GUIs of Qt tools to develop Linux applications on a Renesas device. It describes the overall process and provides step-by-step instructions for the following tasks:

• Designing a simple UI using Qt Design Studio.
• Creating a project in Qt Creator and utilizing a Qt Board Support Package (QBSP) for the Renesas R-Car device.
• Building and debugging the project on the target hardware.

Overview

The following figure illustrates the basic concept of the software development process when you're using Qt tools and Boot to Qt Software Stack.

• Development Host is a development computer running Qt tools on Windows, Linux, or macOS.
• Qt tools includes development tools such as Qt Creator and Qt Design Studio, and quality assurance (QA) tools such as Squish.
• QBSP SDK contains a cross-compilation toolchain that is integrated into Qt Creator, and a device image that can be used to boot your device using Boot to Qt Software Stack.
• Target HW is your development target that runs your embedded Linux application.
• Upload and debug an application (via Ethernet, Wi-Fi, or USB). Use Qt Creator to upload and debug your application on the target HW.
• Flash a QBSP image represents ways (such as SD card) to install Linux on the target hardware.

Applicable Renesas R-Car Target Devices

The instructions in this guide apply to the following Renesas target devices:

• Renesas R-Car-E3 Ebisu 4D (ebisu)
• Renesas R-Car-M3 Starter Kit Pro (m3ulcb)
• Renesas R-Car-H3 Starter Kit Premier (h3ulcb)
• Renesas Salvator-X (salvator-x)

Installing Qt

Follow the procedures in this guide to get all the required resources, including Qt Creator and Qt Design Studio.

1. Sign in to Qt Account Downloads.
2. Download the Qt online installer. The installer is available for the following hosts:
   • Linux
   • Mac
   • Windows
3. Open the installer.
4. Continue to Installation Folder and select Custom installation.
5. Select Next.
6. In Select Components, select the latest official release of Qt. The required developer and designer tools (such as Qt Creator and Qt Design Studio) are preselected in the installer.
7. Select Next.
8. Continue to Ready to Install and select Install.

Building Boot to Qt for a Renesas device

Boot to Qt for embedded Linux is built using the tools and resources from the Yocto Project. For more information on how to set up a building environment for building Boot to Qt, see Setting Up Environment for Building Boot to Qt.

This section provides an example on how to build Boot to Qt for a Renesas R-Car-H3 Starter Kit Premier (h3ulcb) device.

For more information on how to add support for a new device, see How to Add Support for New Device.

1. Initialize the build environment from the manifest repository.

   cd <BuildDir>
   repo init -u git://code.qt.io/yocto/boot2qt-manifest -m renesas/6.4.xml
   repo sync

   Note: In the example above renesas refers to the branch and 6.4.xml refers to a specific Boot to Qt version, but you can use any version that is compatible with your target device.

2. Configure the build environment for Linux.

   export MACHINE=h3ulcb && source ./setup-environment.sh

3. Populate meta-renesas with the proprietary software packages from Renesas as instructed on the R-Car Gen3 boards page.

   Note: Boot to Qt has a meta-renesas layer at $WORK/sources/meta-renesas.

4. Start building a QBSP for Boot to Qt.

   bitbake meta-b2qt-embedded-qbsp

   After the build has been completed, you can find the QBSP file at boot2qt/build-h3ulcb/tmp/deploy/qbsp/meta-b2qt-embedded-qbsp-x86_64-h3ulcb-6.4.qbsp.

Installing a QBSP Using the Qt Online Installer

Once you have built the QBSP for your host, use the Qt online installer to continue the installation process.

1. Open the Qt online installer.
2. Continue to Select Components and select Browse QBSP files.
3. Browse for the file you built and select Open. Now the file appears as an option under Boot to Qt Software Stack.
4. Select the downloaded QBSP file.
5. Continue to Ready to Install and select Install.

Creating an Application UI

You can use Qt Design Studio to create a cross-platform UI, also for embedded Linux applications.

1. Open Qt Design Studio.
2. Select Create Project.
3. In Presets, select General.
   • Name your project (also notice the project path to open it with Qt Creator).
   • Adjust display resolution and orientation to suit your display.
4. Make sure your Target Qt Version matches the version of Qt installed on your machine.
5. Select Create.

Now you can modify your UI as you wish. Once it is ready, select Save All to make sure that you can open your UI project in Qt Creator.

Installing Boot to Qt on the Target Device

Before you can test your Qt applications on the target device, you must flash the target device with an image containing the Boot to Qt Software Stack. After you have successfully flashed your device, \B2QDL appears on the screen when you power on the device.

Flashing Boot to Qt Image to a microSD Card

Before flashing the Boot to Qt image to a microSD card, make sure that the target device is compatible with Boot to Qt. Use the firmware files included in the QBSP to update the target device. For detailed instructions, see R-Car H3SK flashing firmware.

The Boot to Qt image contains the Boot to Qt Software Stack for the Renesas R-Car device. Flash the image to a microSD card as follows:

1. Insert a microSD card into your host PC.
2. Open Qt Creator.
3. Select Tools > Flash Boot to Qt Device.
4. Select Next.

After you have flashed the image to a microSD card, insert the card into your target HW and turn on your device.

The Renesas R-Car device starts with Boot to Qt application by default and if it is connected to the Ethernet network, the application shows the IP address of the device.

Setting Up a Device

A Boot to Qt device can be connected either via USB, Ethernet, or Wi-Fi. The sections below provide instructions on how to set up a device using either USB, Ethernet, or Wi-Fi connectivity.

Setting Up a Device via USB

The target device can be connected to the host via USB On-the-Go (OTG). Once connected via a USB network, the device is automatically added to the Devices in Qt Creator.

The USB access to the target device supports two different USB protocols. The default RNDIS protocol can be used when connecting the target device to either a Linux or Windows host. When you want to connect the target device to a macOS host, you need to change to the CDC-ECM protocol.

For more information on connecting a device via USB, see Setting Up USB Ethernet on Target Device.

Setting Up a Device via Ethernet or Wi-Fi

The target device can be connected to network either via Ethernet or Wi-Fi connectivity. After the target device is connected and has an IP address, you can set it up to Qt Creator with the following steps:

1. Open Qt Creator.
2. Select Edit > Preferences.
3. In the Preferences window:
   1. Select Devices.
   2. Select Add > Boot2Qt Device > Start Wizard.
4. In the Boot2Qt Network Device Setup window:
   1. Enter the Device name.
   2. Enter the Device address (IP address of the Renesas R-Car device).
   3. Select Finish.
5. On the Devices tab:
   • Select OK.

Configuring and Building an Application

1. Open Qt Creator.
2. Navigate to the project you created with Qt Design Studio.
3. Select CMakeLists.txt to open the project.
4. In the Configure Project window:
   1. Select your Renesas R-Car kit.
   2. Select Configure Project.

Finally, select Build > Build Project to build the project you configured.

Running an Application on a Device

After setting up your device, you can upload and start your application on the Renesas R-Car device.

1. Open Qt Creator.
2. Select File > Open File or Project.
3. Navigate to the project you configured earlier and select Open.
4. In the Projects window:
   1. Edit the Run Settings if necessary.
   2. Select Run.

Debugging an Application

For more information on using Qt Creator to debug an application, see Debugging.

Using a Renesas R-Car Device With QBSP

You can use the Qt Maintenance Tool to install the latest Qt release for your Renesas R-Car device.

For details on how to customize and build QBSPs from sources, see How to Customize a Boot to Qt Image.

For more information on how to add QBSP support for new hardware, see How to Add Support for New Device.

Troubleshooting

If you have any issues with your Renesas device, such as how to setup boot switches or connect the debug terminal, turn to R-Car H3/M3 community or R-Car for more information.

For more information on troubleshooting Boot to Qt, see Troubleshooting.