gasranative.blogg.se - Configure usb to serial mac

#CONFIGURE USB TO SERIAL MAC HOW TO#
#CONFIGURE USB TO SERIAL MAC DRIVERS#
#CONFIGURE USB TO SERIAL MAC DRIVER#
#CONFIGURE USB TO SERIAL MAC REGISTRATION#

In addition, in a partial configuration descriptor, an interface descriptor's bInterfaceNumber indicates the actual interface number relative to the entire device. The number of interfaces reported in the bNumInterfaces field of a partial configuration descriptor is less than the total number of interfaces defined for the entire USB composite device.

#CONFIGURE USB TO SERIAL MAC DRIVER#

In response, Usbccgp.sys retrieves a partial configuration descriptor that only contains interface descriptors and other descriptors that pertain to the specific function for which the client driver is loaded.

#CONFIGURE USB TO SERIAL MAC DRIVERS#

A client driver, which is one of the function drivers of the composite device, cannot change the configuration but the driver can still send a select-configuration request through Usbccgp.sys.īefore sending that request, the client driver must submit a URB_FUNCTION_GET_DESCRIPTOR_FROM_DEVICE request. If the USB device is a composite device, the configuration is selected by the Microsoft-provided USB Generic Parent Driver (Usbccgp.sys). **About Function Drivers for a USB Composite Device: ** You can obtain those interface descriptors by calling USBD_ParseConfigurationDescriptorEx. Obtain an interface descriptor for each interface (or its alternate setting) in the configuration. Pipes stores information about each endpoint defined in the alternate setting.

The Interface member of each structure points to an USBD_INTERFACE_INFORMATION structure that contains pipe information in its Pipes member.

The InterfaceDescriptor member of each structure points to the interface descriptor that contains the alternate setting.

The client driver specifies alternate settings in each interface to enable, in the array of USBD_INTERFACE_LIST_ENTRY structures. Initialize the array by calling RtlZeroMemory. The number of elements in the array must be one more than the number of interfaces. This information is contained in the bNumInterfaces member of the USB_CONFIGURATION_DESCRIPTOR structure.Ĭreate an array of USBD_INTERFACE_LIST_ENTRY structures. Get the number of interfaces in the configuration. Instructions Step 1: Create an array of USBD_INTERFACE_LIST_ENTRY structures. For more information, see USB Configuration Descriptors. Typically, you submit an URB of the type URB_FUNCTION_GET_DESCRIPTOR_FROM_DEVICE (see _URB_CONTROL_DESCRIPTOR_REQUEST) to retrieve information about device configuration.

Make sure you have obtained the configuration descriptor ( USB_CONFIGURATION_DESCRIPTOR structure) of the configuration to select.

To create a USBD handle call USBD_CreateHandle.

#CONFIGURE USB TO SERIAL MAC REGISTRATION#

Before sending a select-configuration request, you must have a USBD handle for your client driver's registration with the USB driver stack.

In Windows 8, USBD_SelectConfigUrbAllocateAndBuild replaces USBD_CreateConfigurationRequestEx.

The routine allocates memory for an URB, formats the URB for a select-configuration request, and returns the address of the URB to the client driver.Īlternately, you can allocate an URB structure and then format the URB manually or by calling the UsbBuildSelectConfigurationRequest macro.

#CONFIGURE USB TO SERIAL MAC HOW TO#

The procedure in this topic describes how to use the USBD_SelectConfigUrbAllocateAndBuild routine to build that URB. The client driver can then use the received handles to change configuration settings and to send I/O read and write requests to a particular endpoint.Ī client driver sends a select-configuration request in a USB Request Block (URB) of the type URB_FUNCTION_SELECT_CONFIGURATION. After the request completes, the client driver receives a handle for the selected configuration, and pipe handles for the endpoints that are defined in the active alternate setting for each interface. The USB bus driver selects each interface in the specified configuration and sets up a communication channel, or pipe, to each endpoint within the interface. The client driver packages those choices in a select-configuration request and sends the request to the Microsoft-provided USB driver stack, specifically the USB bus driver (USB hub PDO).

To select a configuration for a USB device, the client driver for the device must choose at least one of the supported configurations and specify the alternate settings of each interface to use. In this topic, you will learn about how to select a configuration in a universal serial bus (USB) device.