# Third-Party SDK Integration<a name="EN-US_TOPIC_0000001051612018"></a>

-   [Planning a Directory Structure](#section1736472718351)
-   [Building the Service libs](#section442815485351)
-   [Compiling Adaptation Code](#section3984721113613)
-   [Compiling Code](#section830417531286)
-   [Compiling a Script](#section13500201173710)
-   [Compiling Service Code](#section8754114803918)
-   [Runtime](#section7737749184012)
-   [End](#section153301392411)

To build a more open and complete Internet of Things \(IoT\) ecosystem, OpenHarmony has opened up a group of directories to integrate SDKs provided by different vendors. This guide describes how to integrate SDKs into OpenHarmony based on the Hi3861 board.

## Planning a Directory Structure<a name="section1736472718351"></a>

A third-party SDK consists of a static library and the adaption code. The SDK service logic is compiled to obtain the static library  **libs**  through the hardware module tool chain. Each module has its corresponding  **libs**. The southbound APIs of the SDK are different from the APIs of OpenHarmony. The difference can be shielded by using the adaptation code  **adapter**. Different modules can share the same  **adapter**.

Based on the preceding features, third-party SDK directories can be divided as follows in the OpenHarmony directory structure:

-   domains/iot/link/: The  **adapter**  is stored in this directory and is decoupled from the module.
-   device/hisilicon/hispark\_pegasus/sdk\_liteos/3rd\_sdk/: The service library  **libs**  is stored in this directory and is bound to the module.

You must perform the following steps before adaptation. The following uses the demolink SDK as an example.

1.  Create vendor directories,  **domains/iot/link/demolink/**  and  **device/hisilicon/hispark\_pegasus/sdk\_liteos/3rd\_sdk/demolink/**, to isolate different vendors.
2.  Create the  **domains/iot/link/demolink/BUILD.gn**  file to build the adaptation code.
3.  Create the  **device/hisilicon/hispark\_pegasus/sdk\_liteos/3rd\_sdk/demolink/libs/**  directory to store the service library  **libs**.

```
.
├── domains
│   └── iot
│       └── link
│           ├── demolink
│           │   └── BUILD.gn
│           ├── libbuild
│           │   └── BUILD.gn
│           └── BUILD.gn
└── device
     └── hisilicon
         └── hispark_pegasus
             └── sdk_liteos
                 └── 3rd_sdk
                     └── demolink
                         └── libs
```

## Building the Service  **libs**<a name="section442815485351"></a>

Generally, the platform SDK service is provided as a static library. After obtaining the OpenHarmony code, the platform vendor needs to compile the service library  **libs**  based on the corresponding hardware module vendor and save the compilation result to the  **device/hisilicon/hispark\_pegasus/sdk\_liteos/3rd\_sdk/demolink/libs/**  directory. The following describes how to build the service library  **libs**.

OpenHarmony has planned the  **domains/iot/link/libbuild/**  directory for compiling the service library  **libs**. This directory contains the  **domains/iot/link/libbuild/BUILD.gn**  and  **domains/iot/link/BUILD.gn**  files. The directory structure is as follows:

```
.
└── domains
    └── iot
        └── link
            ├── demolink
            │   └── BUILD.gn
            ├── libbuild
            │   └── BUILD.gn
            └── BUILD.gn
```

Before building  **libs**, you must perform the following steps:

1.  Place the service source code files \(including  **.c**  and  **.h**  files\) in the  **domains/iot/link/libbuild/**  directory.

    ```
    .
    └── domains
        └── iot
            └── link
                ├── demolink
                │   ├── demosdk_adapter.c
                │   ├── demosdk_adapter.h
                │   └── BUILD.gn
                ├── libbuild
                │   ├── demosdk.c
                │   ├── demosdk.h
                │   └── BUILD.gn
                └── BUILD.gn
    ```

2.  Adapt to the  **domains/iot/link/libbuild/BUILD.gn**  file and restore the file after the compilation is complete.

    In the  **BUILD.gn**  file,  **sources**  specifies the source file to build and  **include\_dirs**  specifies the path of the dependent header file so that the target build result is the static library  **libdemosdk.a**.

    ```
    static_library("demosdk") {
        sources = [
            "demosdk.c"
        ]
        include_dirs = [
            "//domains/iot/link/libbuild",
            "//domains/iot/link/demolink"
        ]
    }
    ```

3.  Adapt to the  **domains/iot/link/BUILD.gn**  file and restore the file after the compilation is complete.

    The  **BUILD.gn**  file is used to specify build entries. You need to enter all static library entries to be compiled in  **features**  so that the  **domains/iot/link/libbuild/BUILD.gn**  file is used in the build.

    ```
    import("//build/lite/config/subsystem/lite_subsystem.gni")
    import("//build/lite/config/component/lite_component.gni")
    lite_subsystem("iot") {
        subsystem_components = [
            ":link"
        ]
    }
    lite_component("link") {
        features = [
            "libbuild:demosdk"
        ]
    }
    ```


After the preceding operations are complete, run the  **hb build -T //domains/iot/link:iot**  command in the root directory of the code and then check whether the target library file is generated in the  **out/hispark\_pegasus/wifiiot\_hispark\_pegasus/libs/**  directory.

![](figures/en-us_image_0000001078563230.png)

Copy the library file to the  **device/hisilicon/hispark\_pegasus/sdk\_liteos/3rd\_sdk/demolink/libs/**  directory and delete the  **.c**  and  **.h**  files from the  **domains/iot/link/libbuild/**  directory.

## Compiling Adaptation Code<a name="section3984721113613"></a>

## Compiling Code<a name="section830417531286"></a>

The APIs used in the platform SDK are different from the OpenHarmony APIs and cannot be directly used. Therefore, the adaptation code  **adapter**  is required for intermediate conversion. This section uses  **DemoSdkCreateTask**  in  **domains/iot/link/demolink/demosdk\_adapter.c**  as an example to describe how to compile adaptation code on OpenHarmony.

1.  Check the description, parameters, and return values of the  **DemoSdkCreateTask**  API to adapt.

    ```
    struct TaskPara {
        char *name;
        void *(*func)(char* arg);
        void *arg;
        unsigned char prio;
        unsigned int size;
    };
    
    /*
     * Create a thread for the IoT OS.
     * Return 0 if the operation is successful; return a non-zero value otherwise.
     */
    int DemoSdkCreateTask(unsigned int *handle, const struct TaskPara *para);
    ```

2.  Check the OpenHarmony API document, select an API with similar features, and compare the parameters and usage. This guide uses  **osThreadNew**  as an example. By comparing this API with  **DemoSdkCreateTask**, you can find that the parameters on which the two APIs depend are basically the same, but the structures to which the parameters belong are different.

    ```
    typedef struct {
        const char                   *name;   ///< name of the thread
        uint32_t                 attr_bits;   ///< attribute bits
        void                      *cb_mem;    ///< memory for control block
        uint32_t                   cb_size;   ///< size of provided memory for control block
        void                   *stack_mem;    ///< memory for stack
        uint32_t                stack_size;   ///< size of stack
        osPriority_t              priority;   ///< initial thread priority (default: osPriorityNormal)
        TZ_ModuleId_t            tz_module;   ///< TrustZone module identifier
        uint32_t                  reserved;   ///< reserved (must be 0)
    } osThreadAttr_t;
    
    /// Create a thread and add it to Active Threads.
    /// \param[in]     func          thread function.
    /// \param[in]     argument      pointer that is passed to the thread function as start argument.
    /// \param[in]     attr          thread attributes; NULL: default values.
    /// \return thread ID for reference by other functions or NULL in case of error.
    osThreadId_t osThreadNew (osThreadFunc_t func, void *argument, const osThreadAttr_t *attr);
    ```

3.  Perform code adaptation to shield the difference.

    ```
    int DemoSdkCreateTask(unsigned int *handle, const struct TaskPara *para)
    {
        osThreadAttr_t attr = {0};
        osThreadId_t threadId;
        if (handle == 0 || para == 0) {
            return DEMOSDK_ERR;
        }
        if (para->func == 0) {
            return DEMOSDK_ERR;
        }
        if (para->name == 0) {
            return DEMOSDK_ERR;
        }
        attr.name = para->name;
        attr.priority = para->prio;
        attr.stack_size = para->size;
        threadId = osThreadNew((osThreadFunc_t)para->func, para->arg, &attr);
        if (threadId == 0) {
            printf("osThreadNew fail\n");
            return DEMOSDK_ERR;
        }
        *(unsigned int *)handle = (unsigned int)threadId;
        return DEMOSDK_OK;
    }
    ```


## Compiling a Script<a name="section13500201173710"></a>

After completing code adaptation, create the  **BUILD.gn**  file in the directory where the  **adapter**  is located. This file can be used to compile the adaptation code into a static library and link the static library to the  **bin**  package during the entire package build. In the  **domains/iot/link/demolink/BUILD.gn**  file,  **sources**  specifies the source files to be used in the build and  **include\_dirs**  specifies the path of the dependent header file so that the target build result is the static library  **libdemolinkadapter.a**.

```
import("//build/lite/config/component/lite_component.gni")
static_library("demolinkadapter") {
    sources = [
        "demosdk_adapter.c"
    ]
    include_dirs = [
        "//kernel/liteos-m/kal/cmsis",
        "//domains/iot/link/demolink"
    ]
}
```

Modify the  **domains/iot/link/BUILD.gn**  file so that the  **domain/iot/hilink/BUILD.gn**  file is used in the build.

```
import("//build/lite/config/subsystem/lite_subsystem.gni")
import("//build/lite/config/component/lite_component.gni")
lite_subsystem("iot") {
    subsystem_components = [
        ":link"
    ]
}
lite_component("link") {
    features = [
        "demolink:demolinkadapter"
    ]
}
```

## Compiling Service Code<a name="section8754114803918"></a>

After the service library  **libs**  and adaptation code are ready, compile the service entry function to call the service entry of the third-party SDK.

The following uses  **demolink**  as an example to describe how to compile code in  **applications/sample/wifi-iot/app/**  to call the  **demosdk**  entry function.

1.  Create a directory.

    Before compiling a service, you must create a directory \(or a directory structure\) in  **applications/sample/wifi-iot/app/**  to store service source code files.

    For example, add the service directory  **demolink**  to the app, and create the service entry code  **helloworld.c**  and compile the  **BUILD.gn**  file.

    ```
    .
    └── applications
        └── sample
            └── wifi-iot
                └── app
                    │── demolink
                    │    │── helloworld.c
                    │    └── BUILD.gn
                    └── BUILD.gn
    ```

2.  Compile service code.

    Compile the service entry function  **DemoSdkMain**  in the  **helloworld.c**  file, call the service entry  **DemoSdkEntry**  of  **demolink**, and call the entry function through  **SYS\_RUN\(\)**  to start the service.

    ```
    #include "hos_init.h"
    #include "demosdk.h"
    
    void DemoSdkMain(void)
    {
        DemoSdkEntry();
    }
    
    SYS_RUN(DemoSdkMain);
    ```

3.  Compile build scripts.

    Add the  **applications/sample/wifi-iot/app/demolink/BUILD.gn**  file, specify the paths of the source code and header file, and compile the static library file  **libexample\_demolink.a**.

    ```
    static_library("example_demolink") {
        sources = [
            "helloworld.c"
        ]
        include_dirs = [
            "//utils/native/lite/include",
            "//domains/iot/link/libbuild"
        ]
    }
    ```

    Modify the  **applications/sample/wifi-iot/app/BUILD.gn**  file so that  **demolink**  is used in compilation.

    ```
    import("//build/lite/config/component/lite_component.gni")
    lite_component("app") {
        features = [
            "demolink:example_demolink"
        ]
    }
    ```


## Runtime<a name="section7737749184012"></a>

Run the  **hb build**  command in the root directory of the code to compile and output the version package. Start  **demolink**. The following shows the running result, which is consistent with the expected result of  **demolink**.

```
ready to OS start
sdk ver:Hi3861V100R001C00SPC024 2020-08-05 16:30:00
formatting spiffs...
FileSystem mount ok.
wifi init success!
it is demosdk entry.
it is demo biz: hello world.
it is demo biz: hello world.
```

## End<a name="section153301392411"></a>

The third-party SDK integration is complete.

