v1.10 release for Pi 4

Cleanup and bug fixes.


What’s inside this release?

Those last two fixed regressions seen on Windows 10 after some ACPI restructuring to properly describe DMA constraints on VideoCore-attached devices. The regressions affected Pi 3, but the fix should equally apply to Pi 4.

The matching release over in Pi 3 land is v1.23. But that release is interesting enough to deserve it’s own post :-).

As always, read the release notes and usual caveats. The notes have gotten a bit of a rinse, so have a look to clear out any old assumptions.

v1.9 release is out

This mostly updates the underlying TF-A firmware, bringing a few important improvements.


What’s inside this release?

  • Update to TF-A v2.3 [tianocore/edk2-non-osi@96ec764]
  • Fix an ASSERT being produced with the DEBUG version, related to TFTP functionality [tianocore/edk2-platforms@f09ea1a]

The TF-A changes are worth describing in greater detail.

TF-A is the Arm secure firmware, providing services such as platform power off/reset and secondary CPU manipulation. The improvements to UART detection mean that TF-A firmware, just like UEFI, will honor config.txt selection of the UART (e.g. via overlay, although it’s really done by the VPU firmware). This is more developer oriented, and means not losing logging/initialization messages. Unrelated to Pi 4 itself, it paves the way for proper (transparent) Pi 3 UEFI support for Compute Module variants and that 64-bit variant of the Pi 2 (rev 1.2).

As always, read the release notes and usual caveats. Note that we do not distribute DEBUG builds. The PSCI CPU_OFF implementation allow a host OS to de-initialize individual CPU cores. More concretely, this will allow more of the Arm Architecture Compliance Suite (ACS) to pass.

The matching Pi 3 UEFI release is v1.22.

v1.8 release out

This is a pretty small update, mostly as a checkpoint to some internal refactoring happening.


What’s inside this release?

The matching Pi 3 release is https://github.com/pftf/RPi3/releases/tag/v1.21

As always, read the release notes and usual caveats.

New Pi Foundation BCM2711 docs!

Thanks to a tip from user clever in our Discord channel (#rpi4-uefi-dev), I just found out one of the Pi Foundation engineers and forum moderators, jamesh, posted something cool:

Enjoy this extensive read during the current crisis! It’s a major update to the original 2835 datasheet, with a lot more information. If you find any problems, please comment on this thread.



This doc is for the SoC in the Pi 4B. I personally haven’t read through it yet, but glancing at the table of contents I see there are many goodies here. Hooray for not having to look at Pi 4B DTS (device tree) sources as documentation! 😇

Linaro Tech Days talk on Pi UEFI

Originally Samer and I were going to present the ongoing Raspberry Pi 4B UEFI work at Linaro Connect ’20 in Budapest. Of course, life had its own plans, but fortunately Linaro was gracious and accommodating to host a virtual event and invite us to be a part of it.


We briefly talked about ServerReady and standardization of the server parts, mentioned the difficulties seen with current non-server parts like the Pi, described the approach taken, provided a status update on where the UEFI/ACPI “ServerReady”-like firmware is today, and left the audience with a call to action to both join the community effort and help beyond the Pi with some other devices, like Rockchip and nVidia-based platforms. Had some good questions from the audience, too.

The full video presentation is available on Youtube, and slides are over at LTD20 207 Making Pi ServerReady.

Guide – Windows 10 ARM64 on Pi 4B

So you want to install Windows 10 on this ‘Berry. You better follow this guide closely.

All 5 usb ports work now. 1 type C and 4 type A however drivers for type c port requires 1GB RAM limitation.

Hardware needed

  • A PC with recent Windows 10 build installed.
  • USB mouse and keyboard.
  • USB storage device.
  • Raspberry Pi 4B,
  • Micro HDMI cable.
  • Power supply (5V 3A+).

or if you still want to use sdcard for boot then you should also get

  • A fast micro SD card – 16GB or higher – Class A1 or A2
  • Micro SD card reader


Download Windows 10 installation files for arm64 from https://uup.rg-adguard.net/.

  • Download ISO compiler in OneClick!
  • Run downloaded CMD-file (run creatingISO.cmd file).

Or, download via https://uupdump.ml/, using aria2 and convert, running aria2_download_windows.cmd after extracting it.

Either of those services will help you to generate a ISO file but we only need install.wim file from sources folder on the ISO. Any build that passes OOBE without issues will be fine.

WoR (windows on raspberry) -Download 2.0.1 from https://worproject.ml/downloads


Once you download all of the things above you can proceed.

Open WoR. Select Disk from the list which will be your microsd card reader or usb storage device and select Raspberry pi 4 as a device that you will use. Then select build of windows WoR should use by pointing to a correct install.wim file. Use the latest drivers that WoR server provides. Select the latest UEFI for Raspberry pi 4 in WoR. Use Advanced tab in WoR to limit memory to 1024MB for USB type-c and if you don’t need type-c port then RAM is still limited by UEFI by default to 3GB of RAM. Do edit boot options in WoR if you need to (I always overclock as my Pi has a fan and heatsink attached).

WoR will deploy windows to the selected micro sd card or usb storage device which will take from 10 minutes to 3 hours depending on speed of your micro SD card or USB storage device .

Safely remove micro SD card or usb storage device and move it into the Raspberry Pi.


This guide will be most likely updated if anything changes. First boot will take between 6 minutes to 2 hours depending on speed of your micro SD card or usb storage device . If there are issues during OOBE setup pressing shift + F10 then typing

%windir%\System32\Sysprep\sysprep.exe /oobe /reboot 

might help. If it doesn’t, you will need to test a different build of Windows 10 arm64. Good luck!


Currently a lot of drivers are missing and not a lot of development is happening. We are missing drivers for audio jack, bluetooth ,wifi and gpu. Development of audio jack drivers is most likely to happen soon. Ethernet driver only loads on 19041 build of Windows 10. Ethernet for newer builds can be found here.


I freqently check comments under this post but for a bit faster response you can join Discord server and ask for help there as most people in that server will be able to answer your question. You might find there customised windows10 build (smaller and lighter).

v1.7 – yes, only a day after v1.6.

I hadn’t even finished writing up the 1.6 related artifacts when Pete pushed the button on the new release. Huge thanks both to Pete for getting this out there so soon and to Ard Biesheuvel for reviewing and approving the edk2-platforms fixes.


What’s inside this release?

The ACPI fixes will mean improved hardware support in OSes, although today that mostly means improved NetBSD support. We definitely need some volunteers to help with enabling Pi 4 support with ACPI in upstream Linux – see the issue tracker.

Big shout-out to Jeremy Linton for the PPTT implementation (Processor Properties Topology Table) – a new ACPI 6.3 table describing the relation between CPUs and caches. Yes, that’s not a typo – our PPTT is the 2nd revision variant introduced in ACPI 6.3, whereas PPTT was first introduced in 6.2.

Note: the matching Pi 3 UEFI release (v1.19) combines the fixes for the Pi 4 v1.6 and v1.7 releases.

As always, read the release notes and usual caveats.

v1.6 out

A few more goodies…


What’s inside this release?

Biggest change here is that your Pi will now boot at the default (Pi Foundation-recommended) frequency, instead of the 600MHz minimum. One less configuration option to change on every upgrade!

IMPORTANT: HTTP(S) boot, like PXE and iSCSI, will not currently work with the internal network card, because the GENET driver has not been upstreamed yet. This means you need a supported USB interface (Ax88772b) to use this feature.

As always, read the release notes and usual caveats.

More GENET work

Our UEFI firmware already supports certain USB-based network adapters for network booting (or other purposes), but that requires an additional adapter, which becomes even more awkward if you want to use a PoE HAT. NetBSD Arm platform guru Jared McNeill has been working on something, that Pi 4 UEFI users are going to find pretty cool. Dongle-less PXE and iSCSI is coming to a Pi 4 near you, because we’re getting native support for GENET networking soon! 😍🔥

This is being implemented as a Simple Network Protocol driver, so it will be usable by any UEFI driver or application.

v1.5 release available

A quick follow-up to v1.4, this release brings some important fixes.

Don’t stop me now (’cause I’m having a good time)
Don’t stop me now (yes, I’m havin’ a good time)
I don’t want to stop at all

Queen – Jazz


What’s inside this release?

This release mostly improves on the logic added to v1.4 release for switching between 3GB/4GB modes on the 4GB Pi 4.

Now, when you have 3GiB mode selected (which is the default), you will see 3GiB being reflected in the UEFI setup screen.

The fix for external .dtb is worth diving into. Many of our readers will know, that Raspberries traditionally boot operating systems with Device Tree, instead of ACPI. A dated overview can be found on the official Pi site. Long story short, if you want to boot an 64-bit Linux, NetBSD or FreeBSD today on the Pi with full I/O support, you still need the Device Tree that the VPU firmware prepares based on your config.txt settings (dtparams, overlays, etc).

The Pi 4 support for Device Tree is exactly like the Pi 3 support. At the time, UEFI relied on the Device Tree being placed in RAM after the UEFI image itself, basically overlaying itself on a section of the UEFI image. Recently, new VideoCore firmware broke this approach (which I really shouldn’t have come up with in the first place!) by switching the load ordering – now the Device Tree was loaded before the UEFI image, and since the two images overlapped, the Device Tree blob was getting overwritten. You can read more about it here and here. Anyway, it’s fixed now. The same fix needs to be made to the Pi 3 build. That’s still TBD.

If you want to boot an OS using Device Tree, don’t forget to enable it. By default the Pi 4 will boot in ACPI mode.

Be mindful that the fix involved changing the load address for the Device Tree in a way that wouldn’t overlap the UEFI image. The new values are:

  • device_tree_address=0x1f0000
  • device_tree_end=0x200000

While looking at the above regression, we were also able to regain 2MiB of memory, as the Trusted Firmware footprint for Pi 4 is much smaller than on the Pi 3.

As always, read the release notes and usual caveats.