22 Jun 2016

Opening up UEFI platform support

As some of you may know, one of the main points I have been pushing for over the past couple of years has been the availability of reference code for real platforms. Given that historically, firmware source code has simply not been available for UEFI-based computers, resolving this has been no trivial exercise.

I gave an outline presentation about this at the UEFI spring plugfest in Seattle last year, announcing that I was starting a work-in-progress tree called OpenPlatformPkg (due to lack of imagination) where I was going to start staging support for multiple platforms/devices. I created this as a separate tree holding only the platform code. As a way to keep things clean, and if I am to be honest also because this enforces deeper consideration of changes to core code. (I'm not suggesting this is the way it should be done when moving platform support into Tianocore, just that it removed several potential conflict points when interacting with organisations not used to working against a single source tree for multiple platforms.)

Since then, the most visible impact of this in the EDK2 source tree has been the removal of platform code from EDK2, as I moved it into OpenPlatformPkg. I finally started to see contributions outside of the ARM ltd. platforms a couple of months ago, and have since struggled to keep up with reviewing the patches contributed:

Over the past few weeks, I have merged support for:
  • Hisilicon D02 and D03 platforms
  • AMD Overdrive (Seattle development platform)
  • LeMaker Cello (Seattle-based 96boards EE)
I am also currently working with Semihalf to get support for Marvell Armada 7040 in.

A warning for the purists - I have not been mandating that the entirety of the platform support is provided in source form. But we do now have a tree which can be used to rebuild against newer versions of upstream EDK2, and I do mandate that each platform adds some open source bits.


We have been working with AMD over the past few months to provide a port based on the official Seattle Firmware Development Kit (FDK) - the same that is used for the commercial firmware shipped on AMD Overdrive and Softiron 3000 platforms. Since this was never originally designed to be used in an open source context, it has included the relicensing of header files and some restructuring to permit simple rebuilding of the binary modules for new FDK releases.

So this new port comes with some blobs - BUT it does bring source code for ACPI, SMBIOS, (non-PCIe) SATA controller, Hardware RNG and overall platform initialization. And of course it reuses some existing open source drivers available in EDK2. From a personal perspective, this means I can now with a quick turnaround test new EDK2 core changes on my Overdrive.

This being a platform with all of its RAM > 4GB, it has also helped flush out some incorrect assumptions in core EDK2 code (and a Linux driver or two).


We actually got most of the way towards a port for the D02 platform back in December - enough for me to agree to post it as a public branch on the main OpenPlatformPkg repository. But I still had a fair amount of things I wanted improved style wise, and the Hisilicon engineers were under pressure to provide a port for the newer D03 platform as well, so spent a few months getting this up and running.

But contrary to the story we have seen many times (with many different vendors) in the mobile space, once they completed this they came back. and put a big effort responding to review feedback to ensure both platforms could be merged simultaneously during our reference platform sprint in Cambridge (UK) last week.


Well, Tianocore has now obtained a more standardised (and public) change process, and there is currently a proposal underway for how to support platforms in official repositories: http://thread.gmane.org/gmane.comp.bios.edk2.devel/11624 With a bit of luck and some hard work OpenPlatformPkg can become redundant the year after it was introduced!

I have also had a few more contacts from people looking to provide ports for upcoming (and existing) platforms, so there should be some more to show later in the year.

posted at: 16:54 | path: /uefi | permanent link to this entry