XRUSB
XRUSB is the USB device stack inside LibXR. It is built from platform-side USB device/endpoint implementations plus upper-layer USB device classes, and it is mainly oriented toward device-side development.
Main Characteristics
- modern C++ implementation
- lock-free data structures where appropriate
- double-buffer and DMA-oriented transfer paths
- endpoint numbers set by each class's constructor; endpoints taken from the endpoint pool when a configuration is selected
- one-shot construction-time memory allocation
- interrupt-driven and ISR-safe design
Supported Device Classes
| Protocol | Status | Notes |
|---|---|---|
| CDC-ACM | supported | exposed as LibXR UART adapters |
| HID | supported | keyboard / mouse / gamepad paths are ready to use; other HID types should derive their own class |
| UAC | supported | UAC1 microphone |
| GSUSB | supported (CAN/FDCAN) | oriented toward Linux SocketCAN |
| DAPLinkV1 | supported (SWD; JTAG once a backend is set with SetJtag()) | oriented toward CMSIS-DAP v1 HID host tooling |
| DFU Runtime | supported | handles runtime DETACH and deferred jump to bootloader |
| DFU Bootloader | supported | supports DNLOAD / UPLOAD / GETSTATUS / ABORT / CLRSTATUS / manifest flows |
| DAPLinkV2 | supported (SWD; JTAG once a backend is set with SetJtag()) | oriented toward CMSIS-DAP v2 bulk host tooling |
BOS / Platform Capability Support
| Capability | Status | Notes |
|---|---|---|
| WebUSB | supported | mainly used by DFU runtime / bootloader paths |
| WinUSB MS OS 2.0 | supported | used by DAPLinkV2 and current DFU runtime / bootloader paths on Windows |
Additional notes:
- The tables list the capabilities present in the device-class and BOS code.
- Whether a specific BOS capability is actually published by a device instance still depends on constructor choices such as WebUSB landing-page parameters or the selected/default WinUSB metadata scope.
Platform Support
| Platform | Device class / controller | Status | Tested hardware |
|---|---|---|---|
| STM32 | STM32USBDeviceDevFs / FSDEV | supported | STM32F103 / STM32G431 |
| STM32 | STM32USBDeviceOtgFS / USB_OTG_FS | supported (Device) | STM32F401 / STM32F407 |
| STM32 | STM32USBDeviceOtgHS / USB_OTG_HS | supported (Device) | STM32F407 / STM32H750 |
| ESP32-S3 | ESP32USBDevice / USB_OTG_FS | supported (Device) | ESP32-S3 |
| CH32 | CH32USBDeviceFS / USB_DEVICE_FS | supported | CH32V203 |
| CH32 | CH32USBOtgFS / USBFS | supported (Device) | CH32V307 / CH32V203 / CH32V208 |
| CH32 | CH32USBOtgHS / USBHS | supported (Device) | CH32V305 / CH32V307 |
Contents
Notes
- the platform-specific pages focus on how USB device and endpoint implementations are realized on different MCU / SoC targets;
- the device-class pages focus on the behavior and interfaces of each USB device class;
- the
VID/PIDpage covers the default XRUSB conventions, not every special identification strategy such as CMSIS-DAP compatibility choices. - This section covers the device-side (Device) stack only.