Thermal Scene Customization

Overview

Introduction

By default, OpenHarmony provides the thermal scene feature. During device usage, for example, gaming, photographing, or calling, the system will try to balance the performance, temperature, and power consumption. The thermal policy is usually scenario-specific. For example, the thermal policy in the gaming scenario does not decrease the screen brightness. However, the thermal scene definition varies according to product specifications. To address this issue, OpenHarmony provides the thermal scene customization function.

Constraints

The configuration path for battery level customization is subject to the configuration policy. In this development guide, /vendor is used as an example of the configuration path. During actual development, you need to modify the customization path based on the product configuration policy.

How to Develop

Setting Up the Environment

Hardware requirements:

Development board running the standard system, for example, the DAYU200 or Hi3516D V300 open source suite.

Environment requirements:

For details about the requirements on the Linux environment, see Quick Start.

Getting Started with Development

The following uses DAYU200 as an example to illustrate thermal scene customization.

1. Create the thermal folder in the product directory /vendor/hihope/rk3568.

2. Create a target folder by referring to the default thermal scene configuration folder, and install it in //vendor/hihope/rk3568/thermal. The content is as follows:

   profile
   ├── BUILD.gn
   ├── thermal_service_config.xml
   

3. Write the custom thermal_service_config.xml file by referring to the thermal_service_config.xml file in the default thermal scene configuration folder. The following table describes the related configuration items.

   Table 1 Configuration items for the thermal scene

**screen** and **charge** indicate the thermal status of the application; and specifically, whether the screen is turned on and whether the battery is being charged.

```shell
<state>
    <item name="scene" param="cam,call,game"/>
    <item name="screen"/>
    <item name="charge"/>
</state>
```

4. An external system can call the UpdateThermalState API of the thermal service to set the thermal status.

bool UpdateThermalState(const std::string& tag, const std::string& val, bool isImmed = false)

5. Write the BUILD.gn file by referring to the BUILD.gn file in the default thermal scene configuration folder to pack the thermal_service_config.xml file to the /vendor/etc/thermal_config directory. The configuration is as follows:

   import("//build/ohos.gni")                      # Reference build/ohos.gni.
   
   ohos_prebuilt_etc("thermal_service_config") {
       source = "thermal_service_config.xml"
       relative_install_dir = "thermal_config"
       install_images = [ chipset_base_dir ]       # Required configuration for installing the thermal_service_config.xml file in the vendor directory.
       part_name = "product_rk3568"                # Set part_name to product_rk3568 for subsequent build. You can change it as required.
   }
   

6. Add the build target to module_list in ohos.build. For example:

   {
       "parts": {
           "product_rk3568": {
               "module_list": [
                   "//vendor/hihope/rk3568/default_app_config:default_app_config",
                   "//vendor/hihope/rk3568/image_conf:custom_image_conf",
                   "//vendor/hihope/rk3568/preinstall-config:preinstall-config",
                   "//vendor/hihope/rk3568/resourceschedule:resourceschedule",
                   "//vendor/hihope/rk3568/etc:product_etc_conf",
                   "//vendor/hihope/rk3568/thermal/profile:thermal_service_config", // Add the configuration for building of thermal_service_config.
               ]
           }
       },
       "subsystem": "product_hihope"
   }
   

   In the preceding code, //vendor/hihope/rk3568/thermal/ is the folder path, profile is the folder name, and thermal_service_config is the build target.

7. Build the customized version by referring to Quick Start.

   ./build.sh --product-name rk3568 --ccache
   

8. Burn the customized version to the DAYU200 development board.

Debugging and Verification

1. After startup, run the following command to launch the shell command line:

   hdc shell
   

2. Obtain the current thermal scene information.

   hidumper -s 3303 -a -s
   

   The following is the reference thermal scene result after customization:

   -------------------------------[ability]-------------------------------
   
   
   ----------------------------------ThermalService---------------------------------
   name: scene  params: cam,call,game
   name: screen
   name: charge
   

Reference

During development, you can refer to the default thermal scene configuration.

Packing path: /vendor/etc/thermal_config/hdf