Building for OpenHarmony

Get the OpenHarmony tools

Building for OpenHarmony requires the following:

1. The OpenHarmony SDK. This is sufficient to compile servo as a shared library for OpenHarmony.
2. The hvigor build tool to compile an application into an app bundle and sign it.

Setting up the OpenHarmony SDK

The OpenHarmony SDK is required to compile applications for OpenHarmony. The minimum version of SDK that Servo currently supports is v5.0 (API-12).

Downloading via DevEco Studio

DevEco Studio is an IDE for developing applications for HarmonyOS NEXT and OpenHarmony. It supports Windows and MacOS. You can manage installed OpenHarmony SDKs by clicking File->Settings and selecting "OpenHarmony SDK". After setting a suitable installation path, you can select the components you want to install for each available API version. DevEco Studio will automatically download and install the components for you.

Manual installation of the OpenHarmony SDK (e.g. on Linux)

1. Go to the OpenHarmony release notes and select the version you want to compile for.
2. Scroll down to the section "Acquiring Source Code from Mirrors" and click the download link for the version of "Public SDK package for the standard system" matching your host system.
3. Extract the archive to a suitable location.
4. Switch into the SDK folder with cd <sdk_folder>/<your_operating_system>.
5. Create a sub-folder with the same name as the API version (e.g 12 for SDK v5.0) and switch into it.
6. Unzip the zip files of the individual components into the folder created in the previous step. Preferably use the unzip command on the command-line, or manually ensure that the unzipped bundles are called e.g. native and not native-linux-x64-5.x.y.z.

The following snippet can be used as a reference for steps 4-6:

cd ~/ohos-sdk/linux
for COMPONENT in "native toolchains ets js previewer" do
    echo "Extracting component ${COMPONENT}"
    unzip ${COMPONENT}-*.zip
    API_VERSION=$(cat ${COMPONENT}/oh-uni-package.json | jq -r '.apiVersion')
    mkdir -p ${API_VERSION}
    mv ${COMPONENT} "${API_VERSION}/"
done

On windows, it is recommended to use 7zip to unzip the archives, since the windows explorer unzip tool is extremely slow.

Manual installation of the HarmonyOS NEXT commandline tools

The HarmonyOS NEXT commandline tools contain the OpenHarmony SDK and the following additional tools:

• codelinter (linter)
• hstack (crash dump stack analysis tool)
• hvigor / hvigorw (build tool)
• ohpm (package manager)

Currently, the commandline tools package is not publicly available and requires a chinese Huawei account to download.

Manual installation of hvigor without the commandline tools

hvigor (not the wrapper hvigorw) is also available via npm.

1. Install the same nodejs version as the commandline-tools ship. For HarmonyOS NEXT Node 18 is shipped. Ensure that the node binary is in PATH.

2. Install Java using the recommended installation method for your OS. The build steps are known to work with OpenJDK v17, v21 and v23. On MacOS, if you install Homebrew's OpenJDK formula, the following additional command may need to be run after the installation:

   # For the system Java wrappers to find this JDK, symlink it with
   sudo ln -sfn $HOMEBREW_PREFIX/opt/openjdk/libexec/openjdk.jdk /Library/Java/JavaVirtualMachines/openjdk.jdk
   

3. Edit your .npmrc to contain the following line:

   @ohos:registry=https://repo.harmonyos.com/npm/
   

4. Install hvigor and the hvigor-ohos-plugin. This will create a node_modules directory in the current directory.

   npm install @ohos/hvigor
   npm install @ohos/hvigor-ohos-plugin
   

5. Now you should be able to run hvigor.js in your OpenHarmony project to build a hap bundle:

   /path/to/node_modules/@ohos/hvigor/bin/hvigor.js assembleHap
   

Configuring hdc on Linux

hdc is the equivalent to adb for OpenHarmony devices. You can find it in the toolchains directory of your SDK. For convenience purposes, you might want to add toolchains to your PATH. Among others, hdc can be used to open a shell or transfer files between a device and the host system. hdc needs to connect to a physical device via usb, which requires the user has permissions to access the device.

It's recommended to add a udev rule to allow hdc to access the corresponding device without needing to run hdc as root. This stackoverflow answer also applies to hdc. Run lsusb and check the vendor id of your device, and then create the corresponding udev rule. Please note that your user should be a member of the group you specify with GROUP="xxx". Depending on your Linux distributions you may want to use a different group.

To check if hdc is now working, you can run hdc list targets and it should show your device serial number. If it doesn't work, try rebooting.

Please note that your device needs to be in "Developer mode" with USB debugging enabled. The process here is exactly the same as one android:

1. Tap the build number multiple times to enable developer mode.
2. Then navigate to the developer options and enable USB debugging.
3. When you connect your device for the first time, confirm the pop-up asking you if you want to trust the computer you are connecting to.

Signing configuration

Most devices require that the HAP is digitally signed by the developer to be able to install it. When using the hvigor tool, this can be accomplished by setting a static signingConfigs object in the build-profile.json5 file or by dynamically creating the signingConfigs array on the application context object in the hvigorfile.ts script.

The signingConfigs property is an array of objects with the following structure:

{
    "name": "default",
    "type": "<OpenHarmony or HarmonyOS>",
    "material": {
        "certpath": "/path/to/app-signing-certificate.cer",
        "storePassword": "<encrypted password>",
        "keyAlias": "debugKey",
        "keyPassword": "<encrypted password>",
        "profile": "/path/to/signed-profile-certificate.p7b",
        "signAlg": "SHA256withECDSA",
        "storeFile": "/path/to/java-keystore-file.p12"
    }
}

Here <encrypted password> is a hexadecimal string representation of the plaintext password after being encrypted. The key and salt used to encrypt the passwords are generated by DevEco Studio IDE and are stored on-disk alongside the certificate files and keystore, usually under <USER HOME>/.ohos/config/openharmony.

You can use the IDE to generate the information needed for password encryption, the required application and profile certificate files, and the keystore itself.

1. Open Project Structure dialog from File > Project Structure menu.
2. Under the 'Signing Config' tab, enable the 'Automatically generate signature' checkbox.

NOTE: The signature autogenerated above is intended only for development and testing. For production builds and distribution via an App Store, the relevant configuration needs to be obtained from the App Store provider.

Once generated, it is necessary to point mach to the above "signing material" configuration using the SERVO_OHOS_SIGNING_CONFIG environment variable. The value of the variable must be a file path to a valid .json file with the same structure as the signingConfigs property given above, but with certPath, storeFile and profile given as paths relative to the json file, instead of absolute paths.

Building servoshell

Before building servo you will need to set some environment variables. direnv is a convenient tool that can automatically set these variables based on an .envrc file, but you can also use any other method to set the required environment variables.

.envrc:

    export OHOS_SDK_NATIVE=/path/to/openharmony-sdk/platform/api-version/native

    # Required if the HAP must be signed. See the signing configuration section above.
    export SERVO_OHOS_SIGNING_CONFIG=/path/to/signing-configs.json

    # Required only when building for HarmonyOS:
    export DEVECO_SDK_HOME=/path/to/command-line-tools/sdk # OR /path/to/DevEcoStudio/sdk OR on MacOS /Applications/DevEco-Studio.app/Contents/sdk

    # Required only when building for OpenHarmony:
    # Note: The openharmony sdk is under ${DEVECO_SDK_HOME}/default/openharmony
    # Presumably you would need to replicate this directory structure
    export OHOS_BASE_SDK_HOME=/path/to/openharmony-sdk/platform

    # If you have the command-line tools installed:
    export PATH="${PATH}:/path/to/command-line-tools/bin/"
    export NODE_HOME=/path/to/command-line-tools/tool/node

    # Alternatively, if you do NOT have the command-line tools installed:
    export HVIGOR_PATH=/path/to/parent/directory/containing/node_modules  # Not required if `hvigorw` is in $PATH

If you use direnv and an .envrc file, please remember to run direnv allow . after modifying the .envrc file. Otherwise, the environment variables will not be loaded.

The following command can then be used to compile the servoshell application for a 64-bit ARM device or emulator:

./mach build --ohos --release [--flavor=harmonyos]

In mach build, mach install and mach package commands, --ohos is an alias for --target aarch64-unknown-linux-ohos. To build for an emulator running on an x86-64 host, use --target x86_64-unknown-linux-ohos. The default ohos build / package / install targets OpenHarmony. If you want to build for HarmonyOS you can add --flavor=harmonyos. Please check the Signing configuration and add a configuration with "name": "hos" and "type": "HarmonyOS"" and the respective signing certificates.

Installing and running on-device

The following command can be used to install previously built servoshell application on a 64-bit ARM device or emulator:

./mach install --ohos --release [--flavor=harmonyos]

Further reading

OpenHarmony Glossary