The USB stack is the component which provides the communication between USB devices and their respective drivers and applications. It consists of multiple files, each with a distinct function. The USB stack in ReactOS is currently limited. This page documents the development of the new USB stack. Development work on a USB 3 stack is in progress.
NOTE: There is a known issue with booting ReactOS from the internal HDD with a USB storage device connected which causes ROS to lose the boot device. Until this problem is fixed or a workaround is developed, please unplug any USB storage devices during boot!
The goal is to develop a USB stack which:
- is USB 1.1 – 2.0 compliant
- uses WDM (NT 5) API
- is compatible with all USB devices and drivers (which adhere to the standard)
The entire stack will be fully documented and the implementation progress detailed on this page.
- Primary Goal: USBHID (human input devices) and storage functionality working (Alpha).
- Secondary Goal: Audio and other support added.
- Beyond: testing and debugging.
Due to the complexity and size, no release dates will be provided as of now.
USB Core Status
- There are 2 USB specifications for the USB 1.1 standard. Devices which are used in this standard are mice, keyboards, etc.
- EHCI (Enhanced Host Controller Interface) – Implemented transfer types: bulk & control. Interrupt & Isochronous transfers are not implemented. Due to the missing transfer types, devices who utilize those transfer types will not be available.
- USBHUB – driver for managing port and hubs – Implementation state is unknown – michel martin has more information on that
USB Mass Storage Support Status
USB Mass Storage is implemented in USBSTOR driver and is fully working. Tested in WinXP + USBEHCI + USBSTOR. Mass storage support requires bulk and control transfers, which are implemented in USBEHCI.
The HID framework is built on 5 drivers
- HIDUSB – this is the interface driver for the USB bus. Currently supported devices are mice. Basic keyboard support should also work currently.
- HIDCLASS – this is the class driver for HIDUSB and others. Functionality for mice & keyboard is implemented, though support for sending output reports is not implemented.
- MOUHID – mouse function driver for USB hid standard – Fully implemented and working.
- KBDHID – keyboard function driver for the hid standard – 90% implemented, needs KbdHid_InsertScanCodes implemented for keyboard scan code dispatching to kbdclass and led status indicator support (which requires sending output reports).
- HIDPARSE – driver for parsing report descriptors – functionality implemented for mice, keyboard support needs HidParser_TranslateUsage fully implemented for modifier state (caps lock, num lock, scroll lock).
What already works
- Mouse support has been tested in WinXP with ReactOS USBOHCI + HIDUSB + HIDCLASS + MOUHID + HIDPARSE and is working. The USB + HID stack also works in ReactOS.
- Basic Keyboard support is nearly ready.
- USB Mass storage support – Needs mountmgr / partmgr driver implemented. Will also need mountvol and other missing PnP stuff. - needs a few more issues to be resolved
- USB Todo List