OVMF FAQ - lzeng14/tianocore GitHub Wiki

What is Open Virtual Machine Firmware (OVMF)?

OVMF is a project to enable support for UEFI within Virtual Machines. It is built upon the EDK II code base.

What source code license does OVMF use?

OVMF follows the EDK II project in using the open source BSD license.

Note: A binary of the UEFI FAT driver may be included with OVMF builds. The source code to this driver uses the BSD license with an additional term.

What does OVMF provide?

  • Libraries and drivers related to virtual machines
  • An entire firmware implementation with supports UEFI on open source virtual machines.

Are OVMF releases fully UEFI compliant?

While the goal is to be as fully UEFI compliant as possible, you should not assume that an OVMF release is fully UEFI compliant unless the particular release states full compliance.

For virtual machines, there are some challenging areas in achieving full UEFI compliance. For example, UEFI 'non-volatile' variables may be difficult to fully support in some virtual machine environments if a flash memory device is not emulated.

Does OVMF support legacy booting, legacy option ROMs, CSM?

No. While OVMF may have UEFI firmware drivers for some legacy hardware, there is no planned legacy compatibility for OVMF. One reason for this is that there is currently no open source CSM module which could be used within OVMF. Another reason is that we would like to use OVMF to help drive out some legacy assumptions which might be made by software layers above the system firmware.

What quality level is the OVMF code? (Alpha, Beta, Production?)

The quality level of the OvmfPkg within the edk2 source code repository may change over time. Therefore, the best way to determine the current quality level of the source repository is to look at the README document under the OvmfPkg source directory or ask the EDK II dev email list. Binary releases of OVMF may indicate a code quality level, and should also indicate the versions of the source code repositories used to produce that binary release.

What virtual machines are supported by the OVMF firmware builds?

Hopefully this will improve over time, but initially the QEMU virtual machine will be supported while emulating a IA32 (x86) or X64 (x86-64) based system. The README text file included under the OvmfPkg source tree should contain the most up to date list of supported virtual machine environments. The README text file included with binary releases should also document the supported virtual machine environments which are supported for that release.

Are only open source virtual machines supported?

We have chosen the BSD license to enable easy incorporation of any of the piece of our code within nearly any type of product. But, it is likely that the firmware images produced by OvmfPkg under edk2 will only support open source virtual machines.

How can I use OVMF with a VM?

Pre-built binaries of OVMF are available under the 'OVMF' folder in the 'Documents & files' area of the EDK II project. The binaries of OVMF are intended to replace the normal firmware/bios that a VM would use when booting the VM. The README file included in the downloaded archive file will explain how to run the OVMF firmware image with the supported VM.

More detailed instructions for running OVMF can be found on the running OVMF wiki page.

Where is the source code to OVMF?

The source code to OVMF is under the OvmfPkg directory within the EDK II source repository. Changes to other EDK II packages (directories) will be driven by the OVMF project as required.

If I work on a Virtual Machine, how can I make use of OVMF?

At the minimum, you can utilize OVMF as a sample platform for how a VM firmware can be built with EDK II. If you find that the OVMF platform and/or EDK II code base does not provide adequate support for building your VM firmware, please open a discussion on the EDK II dev email list.

Where can I find the current status and roadmap of OVMF?

Please look in the README file under the OvmfPkg source directory.

What build environments are supported by OVMF?

OVMF's goal is to support all the build environments which the main EDK II project supports. This includes support for building under the Linux, Mac OS X and Windows operating systems. Toolchain support includes GCC, Visual Studio (2003 or 2005), WINDDK, ICC (Intel Compiler) and GCC under CYGWIN.

If you are new to EDK II development, this page may help you get a build environment up and running. OVMF will also require an ASL compiler to be installed on the system. The Intel ASL compiler is compatible with many operating systems, and is available from http://www.acpica.org.

Where can I ask additional questions and discuss OVMF?

Questions and discussion related to OVMF should be directed to the EDK II dev email list.

How can I contribute to OVMF?

Please refer to the Getting Started page.

How do I build OVMF?

Refer to the README document under the OvmfPkg directory within the EDK II source repository or on the building OVMF wiki page.

How do I enable source level debugging with OVMF?

Please refer to EDK II-Source Level Debug & How to debug OVMF with QEMU using GDB.