This **eTSFormAbility** sample provides a widget. Users can create, update, and delete widgets on the home screen of their phones or by using their own widget host. This sample also implements widget information persistence by using lightweight data storage.
Sensors in OpenHarmony are an abstraction of underlying hardware-based sensors. Your application can access the underlying sensors via OpenHarmony sensors. Using the APIs provided by OpenHarmony sensors, you can query sensors on your device, subscribe to sensor data, customize algorithms based on sensor data, and develop various sensor-based applications, such as compass, fitness and health, and games applications.
Sensors in OpenHarmony are an abstraction of underlying hardware-based sensors. Your application can access the underlying sensors via the sensors. Using the APIs provided by sensors, you can query sensors on your device, subscribe to sensor data, customize algorithms based on sensor data, and develop various sensor-based applications, such as compass, fitness and health, and games applications.
The sensors are classified into the following categories based on their functions: motion, environment, orientation, light, body, and other categories (such as Hall effect sensors). Each category includes different sensor types. A sensor type may be a single physical sensor or a composite of multiple physical sensors.
A sensor is a device to detect events or changes in an environment and send messages about the events or changes to another device (for example, a CPU). Generally, a sensor is composed of sensitive components and conversion components. Sensors are the cornerstone of the IoT. A unified sensor management framework is required to achieve data sensing at a low latency and low power consumption, thereby keeping up with requirements of "1+8+N" products or business in the Seamless AI Life Strategy. The sensor list is as follows:
| Sensor Type | Sensor Name | Description | Usage |
| SENSOR_TYPE_ACCELEROMETER | Acceleration sensor | Measures the acceleration (including the gravity acceleration) applied to a device on three physical axes (X, Y, and Z), in the unit of m/s<sup>2</sup>.| Detecting the motion status |
| SENSOR_TYPE_ACCELEROMETER_UNCALIBRATED | Uncalibrated acceleration sensor| Measures the uncalibrated acceleration (including the gravity acceleration) applied to a device on three physical axes (X, Y, and Z), in the unit of m/s<sup>2</sup>.| Measuring the acceleration bias estimation |
| SENSOR_TYPE_LINEAR_ACCELERATION | Linear acceleration sensor | Measures the linear acceleration (excluding the gravity acceleration) applied to a device on three physical axes (X, Y, and Z), in the unit of m/s<sup>2</sup>.| Detecting the linear acceleration in each axis |
| SENSOR_TYPE_GRAVITY | Gravity sensor | Measures the gravity acceleration applied to a device on three physical axes (X, Y, and Z), in the unit of m/s<sup>2</sup>.| Measuring the gravity |
| SENSOR_TYPE_GYROSCOPE | Gyroscope sensor | Measures the rotation angular velocity of a device on three physical axes (X, Y, and Z), in the unit of rad/s.| Measuring the rotation angular velocity |
| SENSOR_TYPE_GYROSCOPE_UNCALIBRATED | Uncalibrated gyroscope sensor| Measures the uncalibrated rotation angular velocity of a device on three physical axes (X, Y, and Z), in the unit of rad/s.| Measuring the bias estimation of the rotation angular velocity |
| SENSOR_TYPE_SIGNIFICANT_MOTION | Significant motion sensor | Checks whether a device has a significant motion on three physical axes (X, Y, and Z). The value **0** means that the device does not have a significant motion, and **1** means the opposite.| Detecting significant motions of a device |
| SENSOR_TYPE_PEDOMETER_DETECTION | Pedometer detection sensor | Detects whether a user takes a step. The value can be **0** (the user does not take a step) or **1** (the user takes a step).| Detecting whether a user takes a step |
| SENSOR_TYPE_PEDOMETER | Pedometer sensor | Records the number of steps a user has walked. | Providing the number of steps a user has walked |
| SENSOR_TYPE_AMBIENT_TEMPERATURE | Ambient temperature sensor | Measures the ambient temperature, in the unit of degree Celsius (°C). | Measuring the ambient temperature |
| SENSOR_TYPE_MAGNETIC_FIELD | Magnetic field sensor | Measures the magnetic field on three physical axes (X, Y, and Z), in the unit of μT.| Creating a compass |
| SENSOR_TYPE_MAGNETIC_FIELD_UNCALIBRATED | Uncalibrated magnetic field sensor | Measures the uncalibrated magnetic field on three physical axes (X, Y, and Z), in the unit of μT.| Measuring the magnetic field bias estimation |
| SENSOR_TYPE_HUMIDITY | Humidity sensor | Measures the ambient relative humidity, in a percentage (%). | Monitoring the dew point, absolute humidity, and relative humidity |
| SENSOR_TYPE_BAROMETER | Barometer sensor | Measures the barometric pressure, in the unit of hPa or mbar. | Measuring the barometric pressure |
| SENSOR_TYPE_ORIENTATION | Orientation sensor | Measures the rotation angles of a device on three physical axes (X, Y, and Z), in the unit of rad.| Providing the three orientation angles of the screen |
| SENSOR_TYPE_ROTATION_VECTOR | Rotation vector sensor | Measures the rotation vector of a device. It is a composite sensor that generates data from the acceleration sensor, magnetic field sensor, and gyroscope sensor.| Detecting the orientation of a device in the East, North, Up (ENU) Cartesian coordinate system |
| SENSOR_TYPE_PROXIMITY | Proximity sensor | Measures the distance between a visible object and the device screen. | Measuring the distance between a person and the device during a call |
| SENSOR_TYPE_AMBIENT_LIGHT | Ambient light sensor | Measures the ambient light intensity of a device, in the unit of lux. | Automatically adjusting the screen brightness and checking whether the screen is covered on the top|
| SENSOR_TYPE_HEART_RATE | Heart rate sensor | Measures the heart rate of a user. | Providing users' heart rate data |
| SENSOR_TYPE_WEAR_DETECTION | Wear detection sensor | Checks whether a user is wearing a wearable device. | Detecting wearables |
| SENSOR_TYPE_HALL | Hall effect sensor | Detects a magnetic field around a device. | Smart cover mode of the device |
| Sensor Type | Sensor Name | Description | Usage |
| -------- | -------- | -------- | -------- |
| SENSOR_TYPE_ACCELEROMETER | Acceleration sensor | Measures the acceleration (including the gravity acceleration) applied to a device on three physical axes (X, Y, and Z), in the unit of m/s<sup>2</sup>. | Detecting the motion status |
| SENSOR_TYPE_ACCELEROMETER_UNCALIBRATED | Uncalibrated acceleration sensor | Measures the uncalibrated acceleration (including the gravity acceleration) applied to a device on three physical axes (X, Y, and Z), in the unit of m/s<sup>2</sup>. | Measuring the acceleration bias estimation |
| SENSOR_TYPE_LINEAR_ACCELERATION | Linear acceleration sensor | Measures the linear acceleration (excluding the gravity acceleration) applied to a device on three physical axes (X, Y, and Z), in the unit of m/s<sup>2</sup>. | Detecting the linear acceleration in each axis |
| SENSOR_TYPE_GRAVITY | Gravity sensor | Measures the gravity acceleration applied to a device on three physical axes (X, Y, and Z), in the unit of m/s<sup>2</sup>. | Measuring the gravity |
| SENSOR_TYPE_GYROSCOPE | Gyroscope sensor | Measures the rotation angular velocity of a device on three physical axes (X, Y, and Z), in the unit of rad/s. | Measuring the rotation angular velocity |
| SENSOR_TYPE_GYROSCOPE_UNCALIBRATED | Uncalibrated gyroscope sensor | Measures the uncalibrated rotation angular velocity of a device on three physical axes (X, Y, and Z), in the unit of rad/s. | Measuring the bias estimation of the rotation angular velocity |
| SENSOR_TYPE_SIGNIFICANT_MOTION | Significant motion sensor | Checks whether a device has a significant motion on three physical axes (X, Y, and Z). The value can be **0** (having no significant motion) or **1** (having a significant motion). | Detecting significant motions of a device |
| SENSOR_TYPE_DROP_DETECTION | Drop detection sensor | Detects the device drop status. The value can be **0** (the device is not dropped) or **1** (the device is dropped). | Detecting whether a device is dropped |
| SENSOR_TYPE_PEDOMETER_DETECTION | Pedometer detection sensor | Detects whether a user takes a step. The value can be **0** (the user does not take a step) or **1** (the user takes a step). | Detecting whether a user takes a step |
| SENSOR_TYPE_PEDOMETER | Pedometer sensor | Records the number of steps a user has walked. | Providing the number of steps a user has walked |
## Working Principles
The following modules work cooperatively to implement OpenHarmony sensors: Sensor API, Sensor Framework, Sensor Service, and HDF layer.
| Sensor Type | Sensor Name | Description | Usage |
| -------- | -------- | -------- | -------- |
| SENSOR_TYPE_AMBIENT_TEMPERATURE | Ambient temperature sensor. | Measures the ambient temperature, in the unit of degree Celsius (°C). | Measuring the ambient temperature |
| SENSOR_TYPE_MAGNETIC_FIELD | Magnetic field sensor | Measures the magnetic field on three physical axes (X, Y, and Z), in the unit of μT. | Creating a compass |
| SENSOR_TYPE_MAGNETIC_FIELD_UNCALIBRATED | Uncalibrated magnetic field sensor | Measures the uncalibrated magnetic field on three physical axes (X, Y, and Z), in the unit of μT. | Measuring the magnetic field bias estimation |
| SENSOR_TYPE_HUMIDITY | Humidity sensor | Measures the ambient relative humidity, in a percentage (%). | Monitoring the dew point, absolute humidity, and relative humidity |
| SENSOR_TYPE_BAROMETER | Barometer sensor | Measures the barometric pressure, in the unit of hPa or mbar. | Measuring the barometric pressure |
| SENSOR_TYPE_SAR | Specific Absorption Rate (SAR) sensor | Measures the SAR, in the unit of W/kg. | Measuring the SAR of electromagnetic waves for a device |
| Sensor Type | Sensor Name | Description | Usage |
| -------- | -------- | -------- | -------- |
| SENSOR_TYPE_6DOF | Degrees of Freedom (DoF) sensor | Measures the forward/backward, up/down, and left/right translational movement of a device on the three axes (X, Y, and Z) in the unit of m or mm as well as the roll, pitch, and yaw rotation angles on the three axes (X, Y, and Z) in the unit of rad. | Positioning an object by detecting its freedom of translational and rotational motions, for example, VR |
| SENSOR_TYPE_SCREEN_ROTATION | Screen rotation sensor | Checks the rotation status of the device screen. | Detecting whether the device screen is rotating |
| SENSOR_TYPE_DEVICE_ORIENTATION | Device orientation sensor | Measures the rotation angles of the device, in the unit of rad. | Measuring the angles that a device has rotated |
| SENSOR_TYPE_ORIENTATION | Orientation sensor | Measures the rotation angles of a device on three physical axes (X, Y, and Z), in the unit of rad. | Providing the three orientation angles of the screen |
| SENSOR_TYPE_ROTATION_VECTOR | Rotation vector sensor | Measures the rotation vector of a device. It is a composite sensor that generates data from the acceleration sensor, magnetic field sensor, and gyroscope sensor. | Detecting the orientation of a device in the East, North, Up (ENU) Cartesian coordinate system |
| SENSOR_TYPE_GAME_ROTATION_VECTOR<br/>SENSOR_TYPE_GEOMAGNETIC_ROTATION_VECTOR | Game rotation vector sensor<br/>Geomagnetic rotation vector sensor | Measures the game rotation vector of a device. It is a composite sensor that generates data from the acceleration sensor and gyroscope sensor.<br/>Measures the geomagnetic rotation vector of a device. It is a composite sensor that generates data from the acceleration sensor and magnetic field sensor. | Applied in games<br/>Measuring the geomagnetic rotation vector |
| Sensor Type | Sensor Name | Description | Usage |
| -------- | -------- | -------- | -------- |
| SENSOR_TYPE_PROXIMITY | Proximity sensor | Measures the distance between a visible object and the device screen. | Measuring the distance between a person and the device during a call |
| SENSOR_TYPE_TOF | Time of flight (ToF) sensor | Measures the time required for light to travel a distance in the medium. | Facial recognition |
| SENSOR_TYPE_AMBIENT_LIGHT | Ambient light sensor | Measures the ambient light intensity of a device, in the unit of lux. | Automatically adjusting the screen brightness and checking whether the screen is covered on the top |
| SENSOR_TYPE_COLOR_TEMPERATURE | Color temperature sensor | Measures the ambient color temperature. | Image processing on the device |
| SENSOR_TYPE_COLOR_RGB | RGB color sensor | Measures the ambient RGB color values. | Color detection implemented by the reflectance of RGB colors |
| SENSOR_TYPE_COLOR_XYZ | XYZ color sensor | Measures the ambient XYZ color values. | Identifying true-color spots to reproduce more natural colors |
**Table5** Body - ohos.sensor.agent.CategoryBodyAgent
| Sensor Type | Sensor Name | Description | Usage |
| -------- | -------- | -------- | -------- |
| SENSOR_TYPE_HEART_RATE | Heart rate sensor | Measures the heart rate of a user. | Providing users' heart rate data |
| SENSOR_TYPE_WEAR_DETECTION | Wear detection sensor | Checks whether a user is wearing a wearable device. | Detecting wearables |
**Table6** Others
| Sensor Type | Sensor Name | Description | Usage |
| -------- | -------- | -------- | -------- |
| SENSOR_TYPE_HALL | Hall effect sensor | Detects a magnetic field around a device. | Smart cover mode of the device |
| SENSOR_TYPE_GRIP_DETECTOR | Grip detection sensor | Detects grip force applied on a device. | Detecting whether the device is gripped on its sides |
| SENSOR_TYPE_MAGNET_BRACKET | Magnet bracket sensor | Checks whether a device is magnetized. | Detecting an in-vehicle or indoor device |
| SENSOR_TYPE_PRESSURE_DETECTOR | Pressure detection sensor | Detects pressure force applied on a device. | Detecting pressure on the top of the device |
## How a Service Is Shared Using Huawei Share
The following modules work cooperatively to implement OpenHarmony sensors: Sensor API, Sensor Framework, Sensor Service, and HD_IDL.
**Figure1** Working principles for OpenHarmony sensors
- Sensor API: provides APIs for performing basic operations on sensors, including querying the sensor list, subscribing to or unsubscribing from sensor data, and executing control commands. This module makes application development simpler.
...
...
@@ -90,22 +45,22 @@ The following modules work cooperatively to implement OpenHarmony sensors: Senso
- Sensor Service: interacts with the HD_IDL module to receive, parse, and distribute data, manages foreground and background policies and sensors of a device, and controls sensor permissions.
- HD_IDL: selects proper policies based on the hardware first in first out (FIFO) and frequency, and adapts to different devices.
- HDF layer: selects proper policies based on the hardware first in first out (FIFO) and frequency, and adapts to different devices.
## Limitations and Constraints
## Constraints
To obtain data of the following sensors, you must claim the required permissions.
1.To obtain data of the following sensors, you must claim the required permissions.
| Acceleration sensor, uncalibrated acceleration sensor, and linear acceleration sensor| ohos.permission.ACCELEROMETER | system_grant | Allows your application to subscribe to data of these acceleration-related sensors in the motion category.|
| Gyroscope sensor and uncalibrated gyroscope sensor | ohos.permission.GYROSCOPE | system_grant | Allows an application to subscribe to data of the gyroscope-related sensors in the motion category.|
| Pedometer sensor | ohos.permission.ACTIVITY_MOTION | user_grant | Allows an application to subscribe to the motion status. |
| Heart rate sensor | ohos.permission.READ_HEALTH_DATA | user_grant | Allows an application to read health data. |
| Acceleration sensor, uncalibrated acceleration sensor, and linear acceleration sensor | ohos.permission.ACCELEROMETER | system_grant | Allows your application to subscribe to data of these acceleration-related sensors in the motion category. |
| Gyroscope sensor and uncalibrated gyroscope sensor | ohos.permission.GYROSCOPE | system_grant | Allows your application to subscribe to data of these gyroscope-related sensors in the motion category. |
| Pedometer sensor | ohos.permission.ACTIVITY_MOTION | user_grant | Allows your application to subscribe to the motion status. |
| Heart rate sensor | ohos.permission.READ_HEALTH_DATA | user_grant | Allows your application to read health data. |
The APIs for subscribing to and unsubscribing from sensor data work in pairs. If you do not need sensor data, call the unsubscription API to stop sensor data reporting.
2.The APIs for subscribing to and unsubscribing from sensor data work in pairs. If you do not need sensor data, call the unsubscription API to stop sensor data reporting.
| ohos.vibrator | vibrate(duration: number): Promise<void> | Triggers vibration with the specified duration. This API uses a promise to return the result.|
| ohos.vibrator | vibrate(duration: number, callback?: AsyncCallback<void>): void | Triggers vibration with the specified duration. This API uses a callback to return the result.|
| ohos.vibrator | vibrate(effectId: EffectId): Promise<void> | Triggers vibration with the specified effect. This API uses a promise to return the result.|
| ohos.vibrator | vibrate(effectId: EffectId, callback?: AsyncCallback<void>): void | Triggers vibration with the specified effect. This API uses a callback to return the result.|
| ohos.vibrator | stop(stopMode: VibratorStopMode): Promise<void> | Stops vibration. This API uses a promise to return the result.|
| ohos.vibrator | stop(stopMode: VibratorStopMode, callback?: AsyncCallback<void>): void | Stops vibration. This API uses a callback to return the result.|
## How to Develop
1. Declare the permissions required for controlling vibrators on the hardware device in the **config.json** file.
1. Declare the permissions required for controlling vibrators on the hardware device in the **config.json** file.
```
"reqPermissions":[
{
...
...
@@ -58,26 +58,26 @@ You can set different vibration effects as needed, for example, customizing vibr
- Vibrator API: provides basic vibrator APIs, including the APIs for querying the vibrator list, querying the vibrator by effect, and triggering and stopping vibration.
...
...
@@ -17,9 +18,9 @@ The vibrator is a Misc device that consists of four modules: Vibrator API, Vibra
- Vibrator Service: manages services of vibrators.
- HD_IDL: adapts to different devices.
- HDF layer: adapts to different devices.
## Constraints
When using a vibrator, you need to declare and obtain the **ohos.permission.VIBRATE** permission first so that you can control the vibration effect.
When using a vibrator, you must declare the **ohos.permission.VIBRATE** permission before you can control the vibration effect. The sensitivity level of this permission is **system_grant**.
@@ -20,9 +20,22 @@ Note: Video playback requires hardware capabilities such as display, audio, and
2. The third-party application transfers the surface ID to the VideoPlayer JS.
3. The media service flushes the frame data to the surface buffer.
## Compatibility
You are advised to use the mainstream playback formats and resolutions, rather than custom or abnormal streams to avoid playback failure, frame freezing, and artifacts. The system is not affected by incompatibility issues. If such an error occurs, you can exit stream playback mode.
The table below lists the mainstream playback formats and resolutions.
| Video Container Specification| Specification Description | Resolution |
@@ -39,7 +39,7 @@ This document provides a Page ability instance with two pages. For more informat
## Tool Preparation
1. Install the latest version of [DevEco Studio](https://developer.harmonyos.com/cn/develop/deveco-studio#download_beta).
1. Install the latest version of [DevEco Studio](https://developer.harmonyos.com/cn/develop/deveco-studio#download_beta_openharmony).
2. Install DevEco Studio and configure the development environment. For details, see [Configuring the OpenHarmony SDK](https://developer.harmonyos.com/en/docs/documentation/doc-guides/ohos-setting-up-environment-0000001263160443).
> To use eTS, your DevEco Studio must be V3.0.0.601 Beta1 or later.
>
> For best possible results, use [DevEco Studio V3.0.0.900 Beta3](https://developer.harmonyos.com/cn/develop/deveco-studio#download_beta) for your development.
> For best possible results, use [DevEco Studio V3.0.0.900 Beta3](https://developer.harmonyos.com/cn/develop/deveco-studio#download_beta_openharmony) for your development.
> This feature will be available in DevEco Studio V2.2 Beta1 and later versions.
>
> For best possible results, use [DevEco Studio V3.0.0.900 Beta3](https://developer.harmonyos.com/cn/develop/deveco-studio#download_beta) for your development.
> For best possible results, use [DevEco Studio V3.0.0.900 Beta3](https://developer.harmonyos.com/cn/develop/deveco-studio#download_beta_openharmony) for your development.
On the OpenHarmony low-code development pages, you can design your app UI in an efficient, intuitive manner, with a wide array of UI editing features complying with [JS Development Specifications](../reference/apis).
> For best possible results, use [DevEco Studio V3.0.0.900 Beta3](https://developer.harmonyos.com/cn/develop/deveco-studio#download_beta) for your development.
> For best possible results, use [DevEco Studio V3.0.0.900 Beta3](https://developer.harmonyos.com/cn/develop/deveco-studio#download_beta_openharmony) for your development.
> The initial APIs of this module are supported since API version 8. Newly added APIs will be marked with a superscript to indicate their earliest API version.
| type | string | Yes| Event type. The value is **notify**.|
| callback | Callback<number> | No| Callback used to return the field strength state. If this parameter is not specified, all callbacks associated with the specified event will be unregistered.|
Deletes a widget. This API uses a promise to return the result. After this API is called, the application can no longer use the widget, and the Widget Manager will not retain the widget information.
**System capability**:
SystemCapability.Ability.Form
**Parameters**
| Name| Type | Mandatory| Description |
| ------ | ------ | ---- | ------- |
| formId | string | Yes | ID of a widget.|
**System capability**:
**Return value**
SystemCapability.Ability.Form
| Type| Description|
| -------- | -------- |
| Promise<void> | Promise used to return the result indicating whether the API is successfully called.|
Instructs the widget framework to make a widget visible. This API uses a promise to return the result. After this API is called, **onVisibilityChange** is invoked to notify the widget provider.
**System capability**:
SystemCapability.Ability.Form
**Parameters**
| Name| Type | Mandatory| Description |
| ------ | ------ | ---- | ------- |
| formId | string | Yes | ID of a widget.|
**System capability**:
**Return value**
SystemCapability.Ability.Form
| Type| Description|
| -------- | -------- |
| Promise<void> | Promise used to return the result indicating whether the API is successfully called.|
Instructs the widget framework to make a widget invisible. This API uses a promise to return the result. After this API is called, **onVisibilityChange** is invoked to notify the widget provider.
**System capability**:
SystemCapability.Ability.Form
**Parameters**
| Name| Type | Mandatory| Description |
| ------ | ------ | ---- | ------- |
| formId | string | Yes | ID of a widget.|
**System capability**:
**Return value**
SystemCapability.Ability.Form
| Type| Description|
| -------- | -------- |
| Promise<void> | Promise used to return the result indicating whether the API is successfully called.|
Instructs the widget framework to make a widget to be updatable. This API uses a promise to return the result. After this API is called, the widget is in the enabled state and can receive updates from the widget provider.
**System capability**:
SystemCapability.Ability.Form
**Parameters**
| Name| Type | Mandatory| Description |
| ------ | ------ | ---- | ------- |
| formId | string | Yes | ID of a widget.|
**System capability**:
**Return value**
SystemCapability.Ability.Form
| Type| Description|
| -------- | -------- |
| Promise<void> | Promise used to return the result indicating whether the API is successfully called.|
Instructs the widget framework to make a widget not to be updatable. This API uses a promise to return the result. After this API is called, the widget is in the disabled state and cannot receive updates from the widget provider.
**System capability**:
SystemCapability.Ability.Form
**Parameters**
| Name| Type | Mandatory| Description |
| ------ | ------ | ---- | ------- |
| formId | string | Yes | ID of a widget.|
**System capability**:
**Return value**
SystemCapability.Ability.Form
| Type| Description|
| -------- | -------- |
| Promise<void> | Promise used to return the result indicating whether the API is successfully called.|
**Example**
...
...
@@ -509,6 +556,12 @@ Checks whether the system is ready. This API uses a promise to return the result
SystemCapability.Ability.Form
**Return value**
| Type| Description|
| -------- | -------- |
| Promise<void> | Promise used to return the result indicating whether the API is successfully called.|
Unregisters a callback with the corresponding query condition by using the handle, so that no callback is triggered when the media attributes change.
- Parameters
| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| type | boolean | Yes| Must enter the string **change**.|
| callback | Callback<MediaQueryResult> | No| Callback to be unregistered. If the default value is used, all callbacks of the handle are unregistered.|
- Example
```
import mediaquery from '@ohos.mediaquery'
listener = mediaquery.matchMediaSync('(orientation: landscape)'); // Listen for landscape events.
A digit-to-analog converter (DAC) is a device that converts a digital signal into an analog signal in electronics.
The DAC APIs provide a set of methods for DAC data transfer, including:
- Opening or closing a DAC device
- Setting the target digital-to-analog (DA) value
### Basic Concepts
The DAC module provides the output channel for the process control computer system. It connects to the executor to implement automatic control of the production process. It is also an important module in the analog-to-digital converter using feedback technologies.
- Resolution
The number of binary bits that can be converted by a DAC. A greater number of bits indicates a higher resolution.
- Conversion precision
Difference between the actual output value of the DAC and the theoretical value when the maximum value is added to the input end. The conversion precision of a DAC converter varies depending on the structure of the chip integrated on the DAC and the interface circuit configuration. The ideal conversion precision value should be as small as possible. To achieve optimal DAC conversion precision, the DAC must have high resolution. In addition, errors in the devices or power supply of the interface circuits will affect the conversion precision. When the error exceeds a certain degree, a DAC conversion error will be caused.
- Conversion speed
The conversion speed is determined by the setup time. The setup time is the period from the time the input suddenly changes from all 0s to all 1s to the time the output voltage remains within the FSR ± ½LSB (or FSR ± x%FSR). It is the maximum response time of the DAC, and hence used to measure the conversion speed.
The full scale range (FSR) is the maximum range of the output signal amplitude of a DAC. Different DACs have different FSRs, which can be limited by positive and negative currents or voltages.
The least significant byte (LSB) refers to bit 0 (the least significant bit) in a binary number.
### Working Principles
In the Hardware Driver Foundation (HDF), the DAC module uses the unified service mode for API adaptation. In this mode, a device service is used as the DAC manager to handle access requests from the devices of the same type in a unified manner. The unified service mode applies to the scenario where there are many device objects of the same type. If the independent service mode is used, more device nodes need to be configured and memory resources will be consumed by services. The figure below shows the unified service mode.
The DAC module is divided into the following layers:
- The interface layer provides APIs for opening or closing a device and writing data.
- The core layer provides the capabilities of binding, initializing, and releasing devices.
- The adaptation layer implements other functions.
NOTE<br/>The core layer can call the functions of the interface layer and uses the hook to call functions of the adaptation layer. In this way, the adaptation layer can indirectly call the functions of the interface layer, but the interface layer cannot call the functions of the adaptation layer.
Currently, the DAC module supports only the kernels (LiteOS) of mini and small systems.
## Development Guidelines
### When to Use
The DAC module converts digital signals into analog signals in the form of current, voltage, or charge. It is mainly used in audio devices. Audio players and headsets use the DAC module as the digital-to-analog conversion channels.
### Available APIs
The table below describes the APIs of the DAC module. For more details, see API Reference.
A digit-to-analog converter (DAC) is a device that converts a digital signal into an analog signal in electronics.
### Basic Concepts<a name="3"></a>
The DAC module supports development of digital-to-analog conversion. The DAC module provides the output channel for the process control computer system. It connects to the executor to implement automatic control of the production process. It is also an important module in the analog-to-digital converter using feedback technologies.
- Resolution
The number of binary bits that can be converted by a DAC. A greater number of bits indicates a higher resolution.
- Conversion precision
Difference between the actual output value of the DAC and the theoretical value when the maximum value is added to the input end. The conversion precision of a DAC converter varies depending on the structure of the chip integrated on the DAC and the interface circuit configuration. The ideal conversion precision value should be as small as possible. To achieve optimal DAC conversion precision, the DAC must have high resolution. In addition, errors in the devices or power supply of the interface circuits will affect the conversion precision. When the error exceeds a certain degree, a DAC conversion error will be caused.
- Conversion speed
The conversion speed is determined by the setup time. The setup time is the period from the time the input suddenly changes from all 0s to all 1s to the time the output voltage remains within the FSR ± ½LSB (or FSR ± x%FSR). It is the maximum response time of the DAC, and hence used to measure the conversion speed.
The full scale range (FSR) is the maximum range of the output signal amplitude of a DAC. Different DACs have different FSRs, which can be limited by positive and negative currents or voltages.
The least significant byte (LSB) refers to bit 0 (the least significant bit) in a binary number.
### Working Principles<a name="4"></a>
In the Hardware Driver Foundation (HDF), the DAC module uses the unified service mode for API adaptation. In this mode, a device service is used as the DAC manager to handle access requests from the devices of the same type in a unified manner. The unified service mode applies to the scenario where there are many device objects of the same type. If the independent service mode is used, more device nodes need to be configured and memory resources will be consumed by services. The figure below shows the unified service mode.
The DAC module is divided into the following layers:
- The interface layer provides APIs for opening or closing a device and writing data.
- The core layer provides the capabilities of binding, initializing, and releasing devices.
- The adaptation layer implements other functions.
NOTE<br/>The core layer can call the functions of the interface layer and uses the hook to call functions of the adaptation layer. In this way, the adaptation layer can indirectly call the functions of the interface layer, but the interface layer cannot call the functions of the adaptation layer.
**Figure 1** Unified service mode<aname="fig14423182615525"></a>
![](figures/unified-service-mode.png"DAC unified service mode")
### Constraints<a name="5"></a>
Currently, the DAC module supports only the kernels (LiteOS) of mini and small systems.
## Development Guidelines<a name="6"></a>
### When to Use<a name="7"></a>
The DAC module is used for digital-to-analog conversion, audio output, and motor control. The DAC driver is used when the digital signals input by the DAC module are converted into analog signals to output.
### Available APIs<a name="8"></a>
The **DacMethod** is used to call the DAC driver functions.
| write | **device**: pointer to the DAC controller at the core layer.<br>**channel**: channel ID, which is of the uint32_t type.<br>val: data to write, which is of the uint32_t type.| - | HDF_STATUS| Writes the target digit-to-analog (DA) value.|
| start | **device**: pointer to the DAC controller at the core layer. | - | HDF_STATUS| Starts a DAC device. |
| stop | **device**: pointer to the DAC controller at the core layer. | - | HDF_STATUS| Stops a device. |
### How to Develop<a name="9"></a>
The DAC module adaptation procedure is as follows:
- Instantiate the driver entry.
- Configure attribute files.
- Instantiate the APIs of the core layer.
- Debug the driver.
1. Instantiate the driver entry.
Instantiate the driver entry. The driver entry must be a global variable of the **HdfDriverEntry** type (defined in **hdf_device_desc.h**), and the value of **moduleName** must be the same as that in **device_info.hcs**. In the HDF, the start address of each **HdfDriverEntry** object of all loaded drivers are collected to form a segment address space similar to an array for the upper layer to invoke.
Generally, the HDF calls the **Init()** function to load the driver. If **Init()** fails to be called, the HDF calls **Release()** to release driver resources and exit.
```
static struct HdfDriverEntry g_dacDriverEntry = {
.moduleVersion = 1,
.Init = VirtualDacInit,
.Release = VirtualDacRelease,
.moduleName = "virtual_dac_driver",// (Mandatory) The value must be the same as that in the .hcs file.
};
HDF_INIT(g_dacDriverEntry); // Call HDF_INIT to register the driver entry with the HDF.
```
2. Configure attribute files.
- Add the device node description to the **vendor/hisilicon/hispark_taurus/hdf_config/device_info/device_info.hcs** file.
The device attribute values are closely related to the driver implementation and the default values or restriction ranges of the **DacDevice** members at the core layer, for example, the number of device channels and the maximum transmission speed.
In the unified service mode, the first device node in the **device_info.hcs** file must be the DAC manager. The parameters must be set as follows:
| policy | **0**, which indicates that no service is published.|
| priority | Driver startup priority. The value range is 0 to 200. A larger value indicates a lower priority. If the priorities are the same, the device loading sequence is not ensured.|
| permission | Driver permission.|
| moduleName | The value is **HDF_PLATFORM_DAC_MANAGER**.|
| serviceName | The value is **HDF_PLATFORM_DAC_MANAGER**.|
| deviceMatchAttr | Reserved.|
Configure DAC controller information from the second node. This node specifies a type of DAC controllers rather than a specific DAC controller. In this example, there is only one DAC device. If there are multiple DAC devices, you need to add the **deviceNode** information to the **device_info** file and add the corresponding device attributes to the **dac_config** file.
**device_info.hcs** configuration reference
```
root {
device_dac :: device {
// device0 is the DAC manager.
device0 :: deviceNode {
policy = 0;
priority = 52;
permission = 0644;
serviceName = "HDF_PLATFORM_DAC_MANAGER";
moduleName = "HDF_PLATFORM_DAC_MANAGER";
}
}
// dac_virtual is the DAC controller.
dac_virtual :: deviceNode {
policy = 0;
priority = 56;
permission = 0644;
moduleName = "virtual_dac_driver"; // (Mandatory) Driver name, which must be the same as moduleName in the driver entry.
serviceName = "VIRTUAL_DAC_DRIVER"; // (Mandatory) Unique name of the service published by the driver.
deviceMatchAttr = "virtual_dac"; // (Mandatory) Controller private data, which must be same as that of the corresponding controller in dac_config.hcs.
}
}
```
- Configure the **dac_test_config.hcs** file.
Add a file, for example, **vendor/vendor_hisilicon/hispark_taurus/hdf_config/hdf_test/dac_test_config.hcs** and configure driver parameters.
```
root {
platform {
dac_config {
match_attr = "virtual_dac"; // (Mandatory) The value must be the same as that of deviceMatchAttr in device_info.hcs.
template dac_device {
deviceNum = 0; // Device number.
validChannel = 0x1; // Valid channel 1.
rate = 20000; // Transmission speed.
}
device_0 :: dac_device {
deviceNum = 0; // Device number.
validChannel = 0x2; // Valid channel 2.
}
}
}
}
```
3. Instantiate the APIs of the core layer.
- Initialize the **DacDevice** object.
Initialize the **DacDevice** member in the **VirtualDacParseAndInit** function.
```
// Custom structure of the virtual driver
struct VirtualDacDevice {
// DAC device structure
struct DacDevice device;
// DAC device number
uint32_t deviceNum;
// Valid channel
uint32_t validChannel;
// DAC rate
uint32_t rate;
};
// Parse and initialize the **DacDevice** object of the core layer.
HDF_LOGE("%s: add Dac controller failed! ret = %d", __func__, ret);
// Release the virtual space.
OsalMemFree(virtual);
// Set the virtual pointer to null.
virtual = NULL;
return ret;
}
return HDF_SUCCESS;
}
```
- Custom structure reference
The custom structure holds parameters and data for the driver. Define the custom structure based on the function parameters of the device. The HDF reads the values in the **dac_config.hcs** file using the **DacTestReadConfig()** function and initializes the structure members using **DeviceResourceIface()**. Some important values, such as the device number and bus number, are also passed to the **DacDevice** object at the core layer.
```
struct VirtualDacDevice {
struct DacDevice device;// (Mandatory) Control object at the core layer. For details, see the description below.
For details about **DacMethod**, see [Available APIs](#section752964871810).
- **Init** function
Input parameters:
**HdfDeviceObject**, an interface parameter exposed by the driver, contains the .hcs configuration file information.
Return value:
HDF_STATUS (The table below lists some status. For details about other status, see HDF_STATUS in the /drivers/framework/include/utils/hdf_base.h file.)
**HdfDeviceObject**, an interface parameter exposed by the driver, contains the .hcs configuration file information.
Return value
This function returns no value.
Function description:
Releases memory and deletes the controller. This function assigns a value to the **Release** API in the driver entry structure. If the HDF fails to call the **Init** function to initialize the driver, the **Release** function can be called to release driver resources. All forced conversion operations for obtaining the corresponding object can be successful only when the **Init** function has the corresponding value assignment operations.
To streamline your device development process, OpenHarmony provides the useful tools listed below.
**Table 1** Tools for device development
| Tool | Description | Related Resources|
| ---- | ------ | ------ |
| DevEco Device Tool | A one-stop integrated development environment (IDE) provided for developers of OpenHarmony-powered smart devices. It allows on-demand component customization, as well as code editing, compilation, burning, and debugging. The tool supports C and C++ languages and can be installed in Visual Studio Code as a plug-in.| [HUAWEI DevEco Device Tool User Guide](https://device.harmonyos.com/en/docs/documentation/guide/service_introduction-0000001050166905)|
| Docker | A containerization platform used to build and containerize applications. The Docker environments in OpenHarmony encapsulate compilation toolchains for different OpenHarmony variants, so you can start your building straightaway without having to install the compilation toolchain on your own.| [Docker Environment](gettools-acquire.md)|
OpenHarmony is an open-source project launched by the OpenAtom Foundation. The purpose of this project is to build an open, distributed operating system \(OS\) framework for smart IoT devices in the full-scenario, full-connectivity, and full-intelligence era.
The open-source code repositories are available at [https://openharmony.gitee.com](https://openharmony.gitee.com).
The open-source code repositories are available at [https://openharmony.gitee.com](https://openharmony.gitee.com).
## Overview of Source Code Acquisition<a name="section12763342204"></a>
You can use any of the following methods to acquire the OpenHarmony source code:
-**Method 1**: Acquire the source code from the Gitee code repository. You can use the **repo** or **git** tool to download the latest code from the code repository.
-**Method 2**: Acquire the source code from [DevEco Marketplace](https://repo.harmonyos.com/#/en/home). Visit [DevEco Marketplace](https://repo.harmonyos.com/#/en/home), search for your desired open-source distribution, and download the bundle list \(or customize bundles and download the bundle list\). Then use **hpm-cli** to download and install the bundles and compilation toolchain on your local PC.
-**Method 1**: Acquire the source code from the Gitee code repository. You can use the **repo** or **git** tool to download the latest code from the code repository.
-**Method 2**: Acquire the source code from [DevEco Marketplace](https://repo.harmonyos.com/#/en/home). Visit [DevEco Marketplace](https://repo.harmonyos.com/#/en/home), search for your desired open-source distribution, and download the bundle list \(or customize bundles and download the bundle list\). Then use the **hpm-cli** tool to download and install the bundles and compilation toolchain on your local PC.
-**Method 3**: Download the compressed file of a distribution from a mirror site. This method provides a fast download speed, so you can also use this method for obtaining the source code of an earlier version.
-**Method 4**: Acquire the source code from the GitHub image repository. You can use the **repo** or **git** tool to download the latest code from the code repository.
-**Method 4**: Acquire the source code from the GitHub image repository. You can use the **repo** or **git** tool to download the latest code from the code repository.
## Method 1: Acquiring Source Code from the Gitee Code Repository<a name="section537312010229"></a>
...
...
@@ -34,7 +34,7 @@ You can use any of the following methods to acquire the OpenHarmony source code:
1. Register your account with Gitee.
2. Register an SSH public key for access to Gitee.
3. Install the [git client](https://git-scm.com/book/en/v2/Getting-Started-Installing-Git) and [git-lfs](https://gitee.com/vcs-all-in-one/git-lfs?_from=gitee_search#downloading), and configure basic user information.
3. Install the [git client](https://git-scm.com/book/en/v2/Getting-Started-Installing-Git) and[git-lfs](https://gitee.com/vcs-all-in-one/git-lfs?_from=gitee_search#downloading), and configure basic user information.
```
git config --global user.name "yourname"
...
...
@@ -42,7 +42,7 @@ You can use any of the following methods to acquire the OpenHarmony source code:
git config --global credential.helper store
```
4. Run the following commands to install the **repo** tool:
4. Run the following commands to install the **repo** tool:
```
curl -s https://gitee.com/oschina/repo/raw/fork_flow/repo-py3 > /usr/local/bin/repo # If you do not have the access permission to this directory, download the tool to any other accessible directory and configure the directory to the environment variable.
...
...
@@ -53,14 +53,13 @@ You can use any of the following methods to acquire the OpenHarmony source code:
### How to Use<a name="section429012478331"></a>
**Obtaining the Source Code for Mini/Small/Standard Systems**
>Download the master code if you want to get quick access to the latest features for your development. Download the release code, which is more stable, if you want to develop commercial functionalities.
-**Obtaining OpenHarmony master code**
Method 1 \(recommended\): Use the **repo** tool to download the source code over SSH. \(You must have registered an SSH public key for access to Gitee.\)
Method 1 \(recommended\): Use the **repo** tool to download the source code over SSH. \(You must have registered an SSH public key for access to Gitee.\)
@@ -78,26 +77,26 @@ You can use any of the following methods to acquire the OpenHarmony source code:
-**Obtaining OpenHarmony release code**
For details about how to obtain the source code of an OpenHarmony release, see the [Release-Notes](../../release-notes/Readme.md).
For details about how to obtain the source code of an OpenHarmony release, see the [Release-Notes](../../release-notes/Readme.md).
## Method 2: Acquiring Source Code from DevEco Marketplace<a name="section463013147412"></a>
### When to Use<a name="section26661067443"></a>
If OpenHarmony is new to you, sample solutions are helpful to your development. You can obtain an open-source distribution from [DevEco Marketplace](https://repo.harmonyos.com/#/en/home), or customize a distribution by adding or deleting bundles of an open-source distribution. Then use **hpm-cli** to download and install the bundles and compilation toolchain on your local PC.
If OpenHarmony is new to you, sample solutions are helpful to your development. You can obtain an open-source distribution from [DevEco Marketplace](https://repo.harmonyos.com/#/en/home), or customize a distribution by adding or deleting bundles of an open-source distribution. Then use the **hpm-cli** tool to download and install the bundles and compilation toolchain on your local PC.
You must install **Node.js** and HPM on your local PC. The installation procedure is as follows:
You must install **Node.js** and HPM on your local PC. The installation procedure is as follows:
1. Install **Node.js**.
1. Install **Node.js**.
Download **Node.js** from its official website and install it on your local PC.
Download **Node.js** from its official website and install it on your local PC.
The [Node.js](https://nodejs.org/) version must be 12.x \(including npm 6.14.4\) or later. An LTS version is recommended.
The [Node.js](https://nodejs.org/) version must be 12.x \(including npm 6.14.4\) or later. An LTS version is recommended.
2. Install the hpm-cli tool using **npm** delivered with **Node.js**.
2. Install the **hpm-cli** tool using **npm** delivered with**Node.js**.
Open the CMD window and run the following command:
...
...
@@ -121,54 +120,54 @@ You must install **Node.js** and HPM on your local PC. The installation proced
### How to Use<a name="section954619433333"></a>
1. Search for distributions.
1. Access [DevEco Marketplace](https://repo.harmonyos.com/#/en/home), and click **Equipment Bundle**.
2. Enter a keyword, for example, **camera**, in the search box, and click the search icon. All matched distributions will be displayed on the **Open Source Distribution** page.
3. Specify filter criteria, such as the category, OS, kernel, and board, to further filter the distributions.
1. Access [DevEco Marketplace](https://repo.harmonyos.com/#/en/home), and click **Equipment Bundle**. Then go to the **Open Source Distribution** page.
2. Enter a keyword\(for example: **camera**\) in the search box. All matched distributions are found.
3. Specify filter criteria, such as the bundle type \(for example: **Board support** or **Kernel support**\), to further filter the distributions.
4. Find your desired distribution and click it to view details.
1. Read the information about the distribution to learn its application scenarios, features, bundles, usage, and customization methods, as shown in the following figure.
2. Click **Download** to download the distribution to your local PC.
3. Click **Custom** to add or delete bundles of the distribution.
1. Read carefully the information about the distribution to learn its application scenarios, features, bundles, usage, and customization methods, as shown in the following figure.
2. Click **Download** if you want to download the distribution to your local PC.
3. Click **Custom** if you want to add or delete bundles of the distribution.
**Figure 2** Example distribution<a name="fig142484411121"></a>
1. Access the **Custom solution** page, as shown in the following figure.
2. Set the toggle switch next to a specific optional bundle to delete it from the distribution, or click **Add bundle** to add new bundles.
1. Access the **Custom solution** page, as shown in the following figure.
2. Set the toggle switch next to a specific optional bundle to delete it from the distribution, or click **Add bundle** to add new bundles.
3. Enter the basic information about your project, including the bundle name, version, and description, on the right pane.
4. Click **Download**. The system then generates the OpenHarmony code structure file \(for example, **my\_cust\_dist.zip**\) and saves it to your local PC.
4. Click **Download**. The system generates the OpenHarmony code structure file \(for example,**my\_cust\_dist.zip**\) and saves it to your local PC.
1. Decompress the downloaded code structure file using CMD on Windows \(or shell in Linux\).
2. In the generated directory, run the **hpm install** command to download and install bundles. If the **Install successful** message is displayed, the command has been executed successfully.
3.The downloaded bundles will be stored in the **ohos\_bundles** folder under the project directory. \(The source code of some bundles will be copied to a specified directory after the bundles are installed.\)
1. Decompress the downloaded code structure file using CMD on Windows (or shell in Linux).
2. In the generated directory, run the **hpm install** command to download and install bundles. If the **Install successful** message is displayed, the command has been executed successfully.
3.Obtain the bundles. The downloaded bundles are stored in the **ohos\_bundles** folder under the project directory. \(The source code of some bundles will be copied to a specified directory after the bundles are installed.\)
## Method 3: Acquiring Source Code from a Mirror Site<a name="section1186691118430"></a>
To ensure the download performance, you are advised to download the source code or the corresponding solution from the image library of the respective site listed in the table below.
The table below provides only the sites for downloading the latest OpenHarmony master and LTS code. For details about how to obtain the source code of earlier versions, see the [Release-Notes](../../release-notes/Readme.md).
The table below provides only the sites for downloading the latest OpenHarmony master and LTS code. For details about how to obtain the source code of earlier versions, see the [Release-Notes](../../release-notes/Readme.md).
<trid="row18518114121312"><tdclass="cellrowborder"valign="top"width="25%"headers="mcps1.2.5.1.1 "><pid="p4437184283419"><aname="p4437184283419"></a><aname="p4437184283419"></a>Full code base (for mini, small, and standard systems)</p>
<trid="row461814235717"><tdclass="cellrowborder"valign="top"width="25%"headers="mcps1.2.5.1.1 "><pid="p0618124216579"><aname="p0618124216579"></a><aname="p0618124216579"></a>Hi3516 standard system solution (binary)</p>
<trid="row162201392319"><tdclass="cellrowborder"valign="top"width="25%"headers="mcps1.2.5.1.1 "><pid="p2220191315"><aname="p2220191315"></a><aname="p2220191315"></a>RK3568 standard system solution (binary)</p>
@@ -328,9 +327,12 @@ The table below provides only the sites for downloading the latest OpenHarmony m
</tbody>
</table>
## Method 4: Acquiring Source Code from the GitHub Image Repository \(at 23:00 UTC Every Day\)<a name="section23448418360"></a>
## Method 4: Acquiring Source Code from the GitHub Image Repository<a name="section23448418360"></a>
Method 1 \(recommended\): Use the **repo** tool to download the source code over SSH. \(You must have registered an SSH public key for access to GitHub. For details, see [Adding a new SSH key to your GitHub account](https://docs.github.com/en/github/authenticating-to-github/connecting-to-github-with-ssh/adding-a-new-ssh-key-to-your-github-account).\)
> The image repository is synchronized at 23:00 (UTC +8:00) every day.
Method 1 \(recommended\): Use the **repo** tool to download the source code over SSH. \(You must have registered an SSH public key for access to GitHub. For details, see [Adding a new SSH key to your GitHub account](https://docs.github.com/en/github/authenticating-to-github/connecting-to-github-with-ssh/adding-a-new-ssh-key-to-your-github-account).\)
<tdclass="cellrowborder"valign="top"width="50%"headers="mcps1.2.3.1.2 "><pid="p390492919296"><aname="p390492919296"></a><aname="p390492919296"></a>Compiler and toolchain subsystem</p>
<tdclass="cellrowborder"valign="top"width="50%"headers="mcps1.2.3.1.2 "><pid="p390492919296"><aname="p390492919296"></a><aname="p390492919296"></a>Compiler and toolchain subsystem</p>
||**hpm remove** or **hpm rm bundlename**| Uninstalls dependent HPM Parts.|
| Viewing information| **hpm list** or **hpm ls**| Displays the dependency tree of the HPM part.|
| hpm dependencies | Generates the dependency relationship data of the HPM Part. (This command is also integrated in the **hpm ui** command. After you run the hpm ui command, a hpm UI is displayed with the dependencies.)|
|| hpm dependencies | Generates the dependency relationship data of the HPM Part. (This command is also integrated in the **hpm ui** command. After you run the hpm ui command, a hpm UI is displayed with the dependencies.)|
| Searching for HPM Parts| hpm search name | Searches for HPM Parts. **--json** is used to specify the search result in JSON format, and **-type** is used to set the target type, which can be **part**, **distribution**, or **code-segment**.|
| Setting HPM configuration items| hpm config set key value | Sets configuration items, such as the server address and network proxy.|
| Updating HPM Part versions| hpm update | Updates the versions of dependent HPM Parts.|
| hpm check-update | Checks whether version updates are available to dependent HPM Parts.|
|| hpm check-update | Checks whether version updates are available to dependent HPM Parts.|
| Building| hpm build | Builds an HPM Part.|
| hpm dist | Builds a distribution. The build depends on the **dist** script in **scripts** of **bundle.json**.|
|| hpm dist | Builds a distribution. The build depends on the **dist** script in **scripts** of **bundle.json**.|
| Packing | hpm pack | Packs dependencies of local HPM Parts.|
| Burning| hpm run flash | Burns the firmware. The firmware burning depends on the **flash** script in **scripts** of **bundle.json**.|
| Publishing| hpm publish | Publishes an HPM Part, which must be unique in the repository and has a unique version. (An account is required for login.)|
...
...
@@ -242,7 +242,7 @@ HPM Part dependencies (including indirect dependencies) can be displayed by runn
Lightweight CPU isolation enables dynamic CPU isolation based on the system load and user configuration. The kernel migrates the tasks and interrupts from the isolated CPU to other CPUs for execution. The isolated CPU enters the idle state, which reduces the power consumption. In addition, user-mode configuration and query APIs are provided for better system optimization.
## Configuration
### Enabling Lightweight CPU Isolation
Enable related configuration items and dependencies.
To enable lightweight CPU isolation, you need to enable the corresponding configuration items and dependencies during kernel compilation. The related configuration items are as follows:
```
CONFIG_CPU_ISOLATION_OPT=y
CONFIG_SCHED_CORE_CTRL=y
```
Enable the following dependencies:
```
CONFIG_SMP=y
CONFIG_SCHED_WALT=y
```
## Available APIs
APIs are provided to set the number of isolated CPU cores and record the current status. Configurations can be performed based on CPU clusters. These APIs are located in the first CPU device directory of each CPU cluster, for example, `/sys/devices/system/cpu/cpu0/core_ctl`.
The Related Thread Group (RTG) provides optimized scheduling of a group of important threads. The load of an RTG can be collected and predicted separately and the preferred CPU cluster can be set to allow the important threads to run on the optimal CPU and the kernel to select a proper CPU frequency based on the group loads.
## Configuration
### Enabling RTG
To enable RTG, you need to enable the related configuration items and dependencies during kernel compilation. The related configuration items are as follows:
```
CONFIG_SCHED_RTG=y
CONFIG_SCHED_RTG_DEBUG=y
CONFIG_SCHED_RTG_FRAME=y
CONFIG_SCHED_RTG_RT_THREAD_LIMIT=y
```
Enable the following dependencies:
```
CONFIG_SCHED_WALT=y
```
### Adding a Process or Thread to an RTG
By default, 20 RTGs are created in the kernel. The group with ID of 1 is reserved and cannot be added with any process or thread.
```Bash
// Add a process to an RTG.
echo 2 > /proc/<pid>/sched_group_id
// Remove a process from an RTG. The group with ID of 0 is not an RTG.
echo 0 > /proc/<pid>/sched_group_id
```
### Obtaining RTG Information
The RTG information includes group ID, preferred CPU cluster ID, and thread information.
```Bash
cat /proc/sched_rtg_debug
// The following information is displayed:
RTG_ID : 2 // RTG ID.
RTG_INTERVAL : UPDATE:8ms\#INVALID:4294ms // CPU frequency modulation interval and valid load duration.
RTG_CLUSTER : -1 // CPU cluster ID. The value **-1** means that the preferred cluster is not set.
RTG_THREADS: 0/1 // Total number of threads in the group.
STATE COMM PID PRIO CPU // Thread information, including the status, name, PID, priority, and CPU ID.
> 为确保运行效果，本文以使用**DevEco Studio V3.0.0.900 Beta3**版本为例，点击[此处](https://developer.harmonyos.com/cn/develop/deveco-studio#download_beta)获取下载链接。
> 为确保运行效果，本文以使用**DevEco Studio V3.0.0.900 Beta3**版本为例，点击[此处](https://developer.harmonyos.com/cn/develop/deveco-studio#download_beta_openharmony)获取下载链接。
> 为确保运行效果，本文以使用**DevEco Studio V3.0.0.900 Beta3**版本为例，点击[此处](https://developer.harmonyos.com/cn/develop/deveco-studio#download_beta)获取下载链接。
> 为确保运行效果，本文以使用**DevEco Studio V3.0.0.900 Beta3**版本为例，点击[此处](https://developer.harmonyos.com/cn/develop/deveco-studio#download_beta_openharmony)获取下载链接。
> 为确保运行效果，本文以使用**DevEco Studio V3.0.0.900 Beta3**版本为例，点击[此处](https://developer.harmonyos.com/cn/develop/deveco-studio#download_beta)获取下载链接。
> 为确保运行效果，本文以使用**DevEco Studio V3.0.0.900 Beta3**版本为例，点击[此处](https://developer.harmonyos.com/cn/develop/deveco-studio#download_beta_openharmony)获取下载链接。
> - 从API Version 6开始，该接口不再维护，可以使用接口['@ohos.data.storage'](js-apis-data-storage.md)。在API Version 9后，推荐使用新接口 ['@ohos.data.preferences'](js-apis-data-preferences.md)。
> - 从API Version 6开始，该接口不再维护，可以使用接口[`@ohos.data.storage`](js-apis-data-storage.md)。在API Version 9后，推荐使用新接口 [`@ohos.data.preferences`](js-apis-data-preferences.md)。
>
> - 本模块首批接口从API version 3开始支持。后续版本的新增接口，采用上角标单独标记接口的起始版本。
