USB Driver Development Kit (USB DDK) is a tool kit provided by OpenHarmony to help you develop USB device drivers for your applications based on the user mode. It provides a series of device access APIs, which implement functions such as opening and closing USB interfaces, performing non-isochronous and isochronous data transfer, and implementing control transfer and interrupt transfer over USB pipes, etc.
| OH_Usb_GetConfigDescriptor(uint64_t deviceId, uint8_t configIndex, struct UsbDdkConfigDescriptor **const config) | Obtains the configuration descriptor. To avoid memory leakage, use **OH_Usb_FreeConfigDescriptor()** to release a descriptor after use.|
| OH_Usb_FreeConfigDescriptor(const struct UsbDdkConfigDescriptor *const config) | Releases a configuration descriptor. To avoid memory leakage, release a descriptor after use.|
| OH_Usb_ClaimInterface(uint64_t deviceId, uint8_t interfaceIndex, uint64_t *interfaceHandle) | Declares a USB interface.|
| OH_Usb_ReleaseInterface(uint64_t interfaceHandle) | Releases a USB interface.|
| OH_Usb_SendPipeRequest(const struct UsbRequestPipe *pipe, UsbDeviceMemMap *devMmap) | Sends a pipe request. This API works in a synchronous manner. It applies to interrupt transfer and bulk transfer.|
| OH_Usb_CreateDeviceMemMap(uint64_t deviceId, size_t size, UsbDeviceMemMap **devMmap) | Creates a buffer. To avoid memory leakage, use **OH_Usb_DestroyDeviceMemMap()** to destroy a buffer after use.|
| OH_Usb_DestroyDeviceMemMap(UsbDeviceMemMap *devMmap) | Destroys a buffer. To avoid resource leakage, destroy a buffer in time after use.|
For details about the APIs, see [USB DDK](../reference/native-apis/_usb_ddk.md).
## How to Develop
To develop a USB driver using the USB DDK in OpenHarmony, perform the following steps:
1. Obtain the device descriptor. Initialize the DDK by calling **OH_Usb_Init** of **usb_ddk_api.h**, and obtain the device descriptor by calling **OH_Usb_GetDeviceDescriptor**.
```c++
// Initialize the USB DDK.
OH_Usb_Init();
struct UsbDeviceDescriptor devDesc;
uint64_t deviceId = 0;
// Obtain the device descriptor.
OH_Usb_GetDeviceDescriptor(deviceId, &devDesc);
```
2. Obtain the configuration descriptor, and declare the USB interface. Obtain the configuration descriptor **config** by calling **OH_Usb_GetConfigDescriptor** of **usb_ddk_api.h**, and declare the USB interface by calling **OH_Usb_ClaimInterface**.
```c++
struct UsbDdkConfigDescriptor *config = nullptr;
// Obtain the configuration descriptor.
OH_Usb_GetConfigDescriptor(deviceId, 1, &config);
// Obtain the index of the target USB interface based on the configuration descriptor.
3. Create a device memory map, and send a request. Create the device memory map **devMmap** by calling **OH_Usb_CreateDeviceMemMap** of **usb_ddk_api.h**, and send a request by calling **OH_Usb_SendPipeRequest**.
// Obtain the target endpoint based on the configuration descriptor.
pipe.endpoint = 128;
pipe.timeout = UINT32_MAX;
// Send a request.
OH_Usb_SendPipeRequest(&pipe, devMmap);
```
4. Release resources. After all requests are processed and before the application exits, destroy the buffer by calling **OH_Usb_DestroyDeviceMemMap** of **usb_ddk_api.h** to release resources. Release the USB interface by calling **OH_Usb_ReleaseInterface**. Release the USB DDK by calling **OH_Usb_Release**.
The **ethernet** module provides wired network capabilities, which allow users to set the IP address, subnet mask, gateway, and Domain Name System (DNS) server of a wired network.
The **ethernet** module provides wired network capabilities, which allow users to set the IP address, subnet mask, gateway, and Domain Name System (DNS) server, and HTTP proxy of a wired network.
> **NOTE**
> The initial APIs of this module are supported since API version 9. Newly added APIs will be marked with a superscript to indicate their earliest API version.
@@ -476,6 +486,7 @@ Defines the network configuration for the Ethernet connection.
| gateway | string | Yes| Gateway of the Ethernet connection. The value must be an IPv4 address, which is a 32-bit number displayed in dotted decimal notation and each 8-bit field ranges from 0 to 255. This parameter does not need to be configured in DHCP mode.|
| netMask | string | Yes| Subnet mask of the Ethernet connection. The value must be an IPv4 address, which is a 32-bit number displayed in dotted decimal notation and each 8-bit field ranges from 0 to 255. This parameter does not need to be configured in DHCP mode.|
| dnsServers | string | Yes| DNS server addresses of the Ethernet connection. The value must be an IPv4 address. This parameter does not need to be configured in DHCP mode. Multiple addresses are separated by commas (,).|
| httpProxy<sup>10+</sup> | [HttpProxy](js-apis-net-connection.md#httpproxy) | No| HTTP proxy of the Ethernet connection. By default, no proxy is configured.|
| data | [CdmaCellInformation](#cdmacellinformation8)\|[GsmCellInformation](#gsmcellinformation8)\|[LteCellInformation](#ltecellinformation8)\|[NrCellInformation](#nrcellinformation8)\|[TdscdmaCellInformation](#tdscdmacellinformation8) | Yes | CDMA cell information\|GSM cell information\|LTE cell information\|NR cell information\|TD-SCDMA cell information<br>**System API**: This is a system API.|
The **resourceManager** module provides APIs to obtain information about application resources based on the current configuration, including the language, region, screen direction, MCC/MNC, as well as device capability and density.
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@@ -3506,7 +3506,7 @@ For details about the error codes, see [Resource Manager Error Codes](../errorco
