Tasks USB Serial Adapter driver

Develop a USB driver for a common USB Serial Adapter.

• Status: Complete ✅
• Difficulty: Medium
• Language: C
• Mentor: @ErikBjorge
• Suggested by: @jljusten

Table of Contents Status Details Development environment Test environment OVMF with FTDI emulated device QEMU/OVMF with real hardware Real UEFI system Sub-goals Example Products Further Discussion See Also

Status

• Completed ✅ (For FTDI).
• Work done by @ashedesimone as a GSoC2012 Student.
• Available at edk2-platforms/Drivers/OptionRomPkg/Bus/Usb/FtdiUsbSerialDxe.

Details

Today there are many inexpensive USB Serial adapters available, and most systems are built with USB ports available. But at the same time, the dedicated Serial port is becoming less common to find available in a system.

A serial port can still be useful for software debugging purposes. (debug trace messages)

It can also be useful in providing a secondary terminal to the UEFI system.

This task would involve writing a USB driver which interfaces with a USB Serial Adapter.

Ideally, this project should enable a driver that will attach to the USB Serial Adapter and produce the SerialIo protocol to enable the UEFI terminal to become available through the USB Serial adapter.

The MdeModulePkg/Bus/Usb/UsbKbDxe (USB Keyboard) driver may provide a useful starting point for your project.

Development environment

Building: This project can be completed on any edk2 supported OS or toolchain.

Test environment

OVMF with FTDI emulated device

With QEMU you can use the '-usb -usbdevice serial::vc' parameters to add an emulated FTDI into the system.

Support for the FTDI device was worked on during GSoC2012. The latest code is currently available at:

• https://github.com/AshleyDeSimone/edk2/tree/ftdi-usb-serial
• Look for the driver code under OptionRomPkg/Bus/Usb/FtdiUsbSerialDxe

A quick start for building & testing this code on Linux would be:

$ OvmfPkg/build.sh
$ OvmfPkg/build.sh qemu -usb -usbdevice serial::vc

Once QEMU/OVMF starts, press Control+Alt+5 to see the 'usbserial' output.

QEMU/OVMF with real hardware

OVMF (on Linux) would probably provide the easiest environment for testing your project with real hardware. You should be able to build your driver into OVMF and then run OVMF with the USB adapter being mapped inside the virtual machine environment. If you utilize OVMF for testing, then documenting the procedure for running OVMF to attach to the USB device would be a useful 'extra' side-project.

Real UEFI system

You could also test your driver on another UEFI system by using the EFI shell 'load' command.

Sub-goals

Some possible sub-goals for the driver

• Optional: If using OVMF for testing, document the environment and commands you use to enable the adapter to show up in the VM
• recognize and attach to the adapter
• configure the serial port settings for the adapter
• send test characters out the adapter which are successfully read on the other side of the serial cable
• receive some test characters, and print them out in debug trace messages
• connect to SerialIo to enable a full terminal console

Example Products

There are many USB Serial adapters available. Some examples are listed here, but no specific adapter is required or recommended for this project.

• The QEMU virutal machine environment emulates an FTDI based device (see more details above!)
  • http://www.ftdichip.com/Drivers/D2XX.htm
• Keyspan USA-19HS
• Belkin USB to Serial adapter
• CablesToGo USB to DB9 Serial Adapter
• IOGEAR USB to Serial RS-232 Adapter

Further Discussion

This project would be for an edk2 based driver, so please discuss the project on edk2-devel.

See Also

• Tasks#USB-to-serial driver