Re: [Qemu-devel] [edk2] license for binary drivers

[Laszlo Ersek]

On 08/06/14 09:40, Reza Jelveh wrote:
> Hello,
> 
> EDK2 integrates FAT as a binary driver. What is the license of the FAT driver?

https://svn.code.sf.net/p/edk2/code/trunk/edk2/FatBinPkg/License.txt

> What are the guidelines for use of binary drivers with EDK2? Specifically if
> you want to bundle an OVMF firmware with qemu?

I'm not a lawyer. You should consult a lawyer.

That said, the binary or source code nature of the FAT driver is
inconsequential in this instance. You can actually find the source code
for the FAT driver, and build it yourself, you just need to import it in
the edk2 tree, and patch OvmfPkg*.{dsc,fdf) slightly.

https://svn.code.sf.net/p/edk2/code/trunk/edk2/FatBinPkg/ReadMe.txt
https://github.com/tianocore/edk2-FatPkg/

The main issue is that the FAT driver is not free software. It doesn't
satisfy the four freedom requirements listed here:

https://www.gnu.org/philosophy/free-sw.html

  [...]
  The freedom to run the program as you wish, for any purpose
  (freedom 0).
  [...]

The FAT driver license does not give you this freedom.

The FAT driver's license is more restrictive than the 3-clause BSDL that
it is based upon.

The 3-clause BSDL is GPL compatible:

http://en.wikipedia.org/wiki/BSD_licenses#3-clause_license_.28.22Revised_BSD_License.22.2C_.22New_BSD_License.22.2C_or_.22Modified_BSD_License.22.29

But the additional restriction in the FAT driver's license makes it
incompatible with the GPLv2 (which QEMU as a whole us released under,
see LICENSE).

The additional restriction most likely originates from
<http://msdn.microsoft.com/en-us/gg463080.aspx>, the Microsoft EFI FAT32
File System Specification:

    Note: The download license agreement permits you to use the
    Microsoft EFI FAT32 File System Specification only in connection
    with a firmware implementation of the Extensible Firmware Initiative
    Specification, v. 1.0. If you plan to implement the FAT32 File
    System specification for other purposes, you must obtain an
    additional license from Microsoft. For example, you must obtain an
    additional license in order to create a file system for reading or
    reading and writing FAT32 in digital cameras recording to flash
    media, in computer operating systems reading and writing
    internal/external hard disks or flash media, or in set-top boxes
    reading FAT-formatted media.

(This is precisely what freedom 0 would be about.)

So no, you can't ship an OVMF binary (or source tarball) that contains
the FAT driver, bundled as part of the GPLv2 (+compatible) QEMU
distribution, either in source or in binary form.

Linux distributions have moved OVMF to their non-free channels accordingly.

https://packages.debian.org/sid/ovmf
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=745698

http://packages.ubuntu.com/trusty/misc/ovmf

What you can do is build an OVMF binary that doesn't include the FAT
driver. The result will be then covered by 3-clause BSDL (further
restricted by the OpenSSL license, if you include -D SECURE_BOOT), and
that one you can bundle with QEMU. However, such an OVMF binary will be
useless, unless users themselves can augment it somehow at build time or
at runtime with some FAT driver. (The UEFI specification requires FAT32
support.)

UEFI should have standardized a preexistent, but unencumbered, file
system. That horse is out of the barn.

Disclaimer: I am not a lawyer, and this is my personal opinion only, not
necessarily my employer's.

Laszlo