Former Platform Migration

This chapter describes the steps to migrate a former MicroEJ Platform in its latest form described in Platform Creation chapter.

As a reminder, this new form brings two main features:

Former MicroEJ Platforms were usually distributed by MicroEJ Corp. in an all-in-one ZIP file also called fullPackaging.

In this document, the MicroEJ Platform for STMicroelectronics STM32F746G-DISCO board will be used as an example.

The following figure shows the fullPackaging structure once extracted.


STM32F746G-DISCO Platform Full Packaging Structure

The migration steps are:

  1. Create a Module Repository to store the MicroEJ Architecture and MicroEJ Packs used by the Platform.
  2. Import the Platform Configuration Additions into the Platform Configuration project.
  3. Update the Front Panel project configuration.
  4. Configure the BSP Connection.
  5. Add the Build Script and Run Script.


The migration of a Platform requires at least the version 5.4.0 of the SDK.

Create an Architecture Repository

The first step is to create an Architecture Repository containing the Architecture and Packs provided in the platformArchitecture directory of the fullPackaging package.


If the Architecture and Packs used by the Platform are already stored in the module repositories provided by MicroEJ Corp (Central Repository, Developer Repository), or in your organization’s repositories, then move to the next step.

By default, we provide the steps to extend the default MicroEJ SDK settings file configuration with local Architecture and Packs modules. The following steps can be adapted to custom settings file.

  • Create a new empty project named architecture-repository

  • Create a new file named ivysettings.xml with the following content and update the included settings file according to your MicroEJ SDK version (see SDK Version)

    <?xml version="1.0" encoding="UTF-8"?>
      <property name="local.repo.url" value="${ivy.settings.dir}" override="false"/>
          Include default settings file for MicroEJ SDK version:
          - MICROEJ SDK 5.4.0 or higher: ${user.home}/.microej/microej-ivysettings-5.4.xml
          - MICROEJ SDK 5.0.0 to 5.3.1: ${user.home}/.microej/microej-ivysettings-5.xml
          - MICROEJ SDK 4.1.x: ${user.home}/.ivy2/microej-ivysettings-4.1.xml
      <include file="${user.home}/.microej/microej-ivysettings-5.xml"/>
      <settings defaultResolver="ArchitectureResolver"/>
        <chain name="ArchitectureResolver">
          <filesystem m2compatible="true">
            <artifact pattern="${local.repo.url}/${microej.artifact.pattern}" />
            <ivy pattern="${local.repo.url}/${microej.ivy.pattern}" />
          <resolver ref="${microej.default.resolver}"/>
  • Copy the Architecture file (.xpf) into the correct directory following its naming convention).

    • Open or extract the Architecture file (.xpf)
    • Open the file to retrieve the naming convention mapping:
      • architecture is the ISA (e.g. CM7)
      • toolchain is the TOOLCHAIN (e.g. CM7hardfp_ARMCC5)
      • name is the UID (e.g. flopi7A21)
      • version is the VERSION (e.g. 7.11.0)

    For example, in the STM32F746G-DISCO Platform, the Architecture file flopi7A21-eval.xpf shall be copied and renamed to architecture-repository/com/microej/architecture/CM7/CM7hardfp_ARMCC5/flopi7A21/7.11.0/flopi7A21-7.11.0-eval.xpf.

  • Copy the Architecture Specific Packs files (.xpfp) into the correct directory following MicroEJ Naming Convention (see Pack Import) with the exception of the Standalone pack that should not be imported (e.g. named flopi7A21Standalone.xpfp).

    • Open or extract the Architecture Specific Pack (.xpfp).


      The Architecture Specific Packs have the UID of the Architecture in their name (e.g. flopi7A21UI.xpfp) and their file contains the information of the Architecture.

    • Open the file to retrieve the naming convention mapping:

      • architecture is the ISA (e.g. CM7)
      • toolchain is the TOOLCHAIN (e.g. CM7hardfp_ARMCC5)
      • name is the UID (e.g. flopi7A21)
      • packName is the NAME (e.g. ui)
      • packVersion is the VERSION (e.g. 12.0.1)

    For example, in the STM32F746G-DISCO Platform, the Architecture Specific Pack UI flopi7A21UI.xpfp shall be copied and renamed to architecture-repository/com/microej/architecture/CM7/CM7hardfp_ARMCC5/flopi7A21-ui-pack/12.0.1/flopi7A21-ui-pack-12.0.1.xpfp.

  • Copy the Legacy Generic Packs (.xpfp files) into the correct directory following MicroEJ Naming Convention (see Pack Import).

    • Open or extract the Generic Pack (.xpfp).


      The of Legacy Generic Packs does not contain information about Architecture.

    • Open the file:

      • packName is the NAME (e.g. fs)
      • packVersion is the VERSION (e.g. 4.0.2)

    For example, in the STM32F746G-DISCO Platform, the Legacy Generic Pack FS fs.xpfp shall be copied and renamed to architecture-repository/com/microej/pack/fs/4.0.2/fs-4.0.2.xpfp.

  • Configure MicroEJ Module Manager to use the Architecture Repository:

    • Go to Window > Preferences > MicroEJ > Module Manager
    • In Module Repository set Settings File: to ${workspace_loc:architecture-repository/ivysettings.xml}.
    • Apply and Close

Here is the layout of the Architecture Repository for the STM32F746G-DISCO Platform.


Architecture Repository for STM32F746G-DISCO fullPackaging

Import the Former Platform Sources

  • Go to File > Import… > General > Existing Projects into Workspace.

  • Browse to the archive file that contains the platform sources, like in the example below.

  • Select the -configuration, -fp and -bsp projects prefixed with the Platform name (e.g., STM32F746GDISCO-Full-CM7_ARMCC-FreeRTOS).

  • Click Finish.

Install the Platform Configuration Additions

  • Rename the file located in the Platform Configuration Project to (save it for later).
  • Install Platform Configuration Additions, by following instructions described at Files within the content folder have to be copied to the -configuration project (e.g. STM32F746GDISCO-Full-CM7_ARMCC-FreeRTOS-configuration).
  • Edit the file and set com.microej.platformbuilder.platform.filename to the name of the platform configuration file (e.g. STM32F746GDISCO.platform).
  • Update the default name of the Platform module in the module.ivy. Replace with <info organisation="" module="Platform" status="integration" revision="1.0.0">.
  • Update the module.ivy with the Architecture and Packs dependencies.

Here is the module dependencies declared for the STM32F746G-DISCO Platform.

  <!-- MicroEJ Architecture -->
  <dependency org="com.microej.architecture.CM7.CM7hardfp_ARMCC5" name="flopi7A21" rev="7.11.0">
    <artifact name="flopi7A21" m:classifier="${com.microej.platformbuilder.architecture.usage}" ext="xpf"/>

  <!-- MicroEJ Architecture Specific Packs  -->
  <dependency org="com.microej.architecture.CM7.CM7hardfp_ARMCC5" name="flopi7A21-ui-pack" rev="12.0.1">
    <artifact name="flopi7A21-ui-pack" ext="xpfp"/>
  <dependency org="com.microej.architecture.CM7.CM7hardfp_ARMCC5" name="flopi7A21-net-pack" rev="6.1.5">
    <artifact name="flopi7A21-net-pack" ext="xpfp"/>

  <!-- Legacy MicroEJ Generic Packs -->
  <dependency org="com.microej.pack" name="fs" rev="4.0.2">
    <artifact name="fs" ext="xpfp"/>
  <dependency org="com.microej.pack" name="hal" rev="2.0.1">
    <artifact name="hal" ext="xpfp"/>


Update the Front Panel Configuration

  • In -configuration/frontpanel/ set the to the folder name that contains the front-panel (e.g.

At this state, the Platform is not connected to the BSP yet, but you can check that everything is properly configured so far by building it:

  • Right-click on the -configuration project and select Build Module
  • Import the Platform built into the workspace by following the instructions available at the end of the build logs (see logs example below).
    [echo]     ============================================================================================================
    [echo]     Platform has been built in this directory 'C:\STM32F746GDISCO-Platform-CM7hardfp_ARMCC5-0.1.0'.
    [echo]     To import this project in your MicroEJ SDK workspace (if not already available):
    [echo]      - Select 'File' > 'Import...' > 'General' > 'Existing Projects into Workspace' > 'Next'
    [echo]      - Check 'Select root directory' and browse 'C:\STM32F746GDISCO-Platform-CM7hardfp_ARMCC5-0.1.0' > 'Finish'
    [echo]     ============================================================================================================

At this stage the Platform is built and imported in the workspace, so you can create a Standalone Application and run it on the Simulator (see Create a MicroEJ Standalone Application).


If the build failed, it might be because the Architecture and Packs can not be retrieved from the Architecture Repository. Ensure that the Architecture Repository is correctly configured and that it contains the required artifacts (as described in the first step).

Configure the BSP Connection

This section explains how to configure a full BSP Connection on the STM32F746G-DISCO Platform. See BSP Connection for more information.

  • Open -configuration/bsp/

  • Comment out and set the following variables:

    • root.dir
    • microejapp.relative.dir
    • microejlib.relative.dir
    • microejinc.relative.dir
    • microejscript.relative.dir

    For example:

    # Specify the MicroEJ Application file ('microejapp.o') parent directory.
    # This is a '/' separated directory relative to 'bsp.root.dir'.
    # Specify the MicroEJ Platform runtime file ('microejruntime.a') parent directory.
    # This is a '/' separated directory relative to 'bsp.root.dir'.
    # Specify MicroEJ Platform header files ('*.h') parent directory.
    # This is a '/' separated directory relative to 'bsp.root.dir'.
    # Specify BSP external scripts files ('build.bat' and 'run.bat') parent directory.
    # This is a '/' separated directory relative to 'bsp.root.dir'.
    # Specify the BSP root directory. Can use ${project.parent.dir} which target the parent of platform configuration project
    # For example, '${project.parent.dir}/PROJECT-NAME-bsp' specifies a BSP project beside the '-configuration' project

The paths to microejXXX.relative.dir can be inferred by looking at the output.dir value in saved earlier. For example on the STM32F746G-DISCO project, its value is ${workspace}/${project.prefix}-bsp/Projects/STM32746G-Discovery/Applications/MicroEJ/platform.

  • The BSP project path ${workspace}/${project.prefix}-bsp becomes ${project.parent.dir}/STM32F746GDISCO-Full-CM7_ARMCC-FreeRTOS-bsp/.
  • Projects/STM32746G-Discovery/Applications/MicroEJ/platform is the path to the Application file, Platform header and runtime files. MicroEJ convention is to put the Application file and Platform runtime files to platform/lib/ and the Platform header files to platform/inc/.
  • Build Script File and Run Script File are PCA-specific and did not exist before. By convention we put them in a scripts/ directory.

The paths to microejXXX.relative.dir can be also be checked by looking at the C TOOLCHAIN configuration of the BSP. For example on the STM32F746G-DISCO project, the BSP configuration is located at STM32F746GDISCO-Full-CM7_ARMCC-FreeRTOS-bsp/Projects/STM32746G-Discovery/Applications/MicroEJ/MDK-ARM/Project.uvprojx.

  • In Project > Options for Target ‘standalone’… > C/C++ > Include Paths contains ../platform/inc. This corresponds to the microejinc.relative.dir relative the TOOLCHAIN project’s file.
  • In the Project pane, there is a folder MicroEJ/Libs that contains microejruntime.lib and microejapp.o.
    • Right-click on microejruntime.lib > Options for File ‘XXX’…. The Path is ../platform/lib/microejruntime.lib. This corresponds to the microejlib.relative.dir.
    • Right-click on microejapp.o > Options for File ‘XXX’…. The Path is ../platform/lib/microejapp.o. This corresponds to the microejapp.relative.dir.
  • Rebuild the platform (Right-click on the -configuration project and select Build Module)

At this stage the Platform is connected to the BSP so you can build and program a Firmware (see Run on the Device).

Add the Build and Run Scripts

The final stage consists of adding the Build Script, to automate the build of a Firmware, and the Run Script, to automate the programming of a MicroEJ Firmware onto the device.

The Platform Qualification Tools provides examples of Build Script and Run Script for various C TOOLCHAIN here. This tutorial also describes the steps to create and use these scripts.

On the STM32F746G-DISCO, the C TOOLCHAIN used is Keil uVision.

  • Create the directory pointed by microejscript.relative.dir (e.g. STM32F746GDISCO-Full-CM7_ARMCC-FreeRTOS-bsp\Projects\STM32746G-Discovery\Applications\MicroEJ\scripts).
  • Copy the example scripts from the Platform Qualification Tools for the C TOOLCHAIN of the BSP (e.g. PlatformQualificationTools/framework/platform/scripts/KEILuV5/)
  • Configure the scripts. Refer to the documentation in the scripts comments for this step.
  • Enable the execution of the build script:
    • Go to Run > Run Configurations…
    • Select the launch configuration
    • Go to Configuration > Device > Deploy
    • Ensure Execute the MicroEJ build script (build.bat) at a location known by the 3rd-party BSP project. is checked.

Use the Platform in Module Projects

Module projects may require the Platform, for example to build an Application or to run a Test Suite. One way of selecting the Platform in a module project is to declare it as a module dependency (see Platform Selection).

In case a former Platform is loaded this way in your existing module projects, the dependency has to be updated. In this example, the Platform would now be selected like this:

<dependency org="" name="Platform" rev="1.0.0" conf="platform->default" transitive="false"/>

This also requires that your module projects use a compatible version of the associated build type (the build type relates to the Module Natures). As stated before, loading a Platform in its latest form requires at least the version 5.4.0 of the SDK. Therefore, make sure to use versions of the build types that come with the SDK 5.4.0 and above. Here is a brief summary of the minimum version for the most common module natures:

  • Add-On Library: build type com.is2t.easyant.buildtypes#build-microej-javalib version 5.0.0 and above.
  • Standalone Application: build type com.is2t.easyant.buildtypes#build-firmware-singleapp version 1.4.0 and above.
  • Sandboxed Application: build type com.is2t.easyant.buildtypes#build-application version 8.0.0 and above.

Going further

Now that the Platform is connected to the BSP it can leverage the Java Test Suites provided by the Platform Qualification Tools. See Run a Test Suite on a Device for a step by step explanation on how to do so.