Struct usb_device::descriptor::DescriptorWriter

pub struct DescriptorWriter<'a> { /* fields omitted */ }

A writer for USB descriptors.

Implementations

impl<'_> DescriptorWriter<'_>

pub fn position(&self) -> usize

Gets the current position in the buffer, i.e. the number of bytes written so far.

pub fn write(&mut self, descriptor_type: u8, descriptor: &[u8]) -> Result<()>

Writes an arbitrary (usually class-specific) descriptor.

pub fn iad(
    &mut self,
    first_interface: InterfaceNumber,
    interface_count: u8,
    function_class: u8,
    function_sub_class: u8,
    function_protocol: u8
) -> Result<()>

Writes a interface association descriptor. Call from UsbClass::get_configuration_descriptors before writing the USB class or function's interface descriptors if your class has more than one interface and wants to play nicely with composite devices on Windows. If the USB device hosting the class was not configured as composite with IADs enabled, calling this function does nothing, so it is safe to call from libraries.

Arguments

• first_interface - Number of the function's first interface, previously allocated with UsbBusAllocator::interface.
• interface_count - Number of interfaces in the function.
• function_class - Class code assigned by USB.org. Use 0xff for vendor-specific devices that do not conform to any class.
• function_sub_class - Sub-class code. Depends on class.
• function_protocol - Protocol code. Depends on class and sub-class.

pub fn interface(
    &mut self,
    number: InterfaceNumber,
    interface_class: u8,
    interface_sub_class: u8,
    interface_protocol: u8
) -> Result<()>

Writes a interface descriptor.

Arguments

• number - Interface number previously allocated with UsbBusAllocator::interface.
• interface_class - Class code assigned by USB.org. Use 0xff for vendor-specific devices that do not conform to any class.
• interface_sub_class - Sub-class code. Depends on class.
• interface_protocol - Protocol code. Depends on class and sub-class.

pub fn endpoint<'e, B: UsbBus, D: EndpointDirection>(
    &mut self,
    endpoint: &Endpoint<'e, B, D>
) -> Result<()>

Writes an endpoint descriptor.

Arguments

• endpoint - Endpoint previously allocated with UsbBusAllocator.