Last updated Jul 8th, 2018.

This is a port of 64-bit Tiano Core UEFI firmware for the RPi3/RPi3B+ platforms, based on Ard Bisheuvel's 64-bit and Microsoft's 32-bit implementations.

Initially, this was supposed to be an easy walk in the park, where the Microsoft drivers just sorta slide into Ard's UEFI implementation, and I call it a day. It turned out to be a bit more frustrating of an experience than that :-).

This is meant as a generally useful 64-bit UEFI implementation for the Pi3, good enough for most kinds of UEFI development and good enough for running real operating systems. It has been validated to install and boot Linux (SUSE, Ubuntu) and FreeBSD, and there is experimental Windows on Arm support as well.

• 2018 Jul 8th: switch to private MmcDxe, improve multiblock write robustness, power-off/halt in ATF
• 2018 Jun 26th: SdHostDxe error handling, early eMMC support for both SdHost and Arasan
• 2018 Jun 22nd: Arasan and SdHost multiblock, Arasan/SdHost/MMC tweaks/stability, uSD default routing is SdHost
• 2018 Jun 17th: SdHostDxe boot order fix, MMC tweaks menu, GCC5_DEBUG fix.
• 2018 Jun 16th: SdHostDxe support, HypDxe on by default.
• 2018 Jun 13th: Fix GCC5 compilation error for HypDxe.
• 2018 Jun 12th: Fix SMBIOS Type 0 BIOS date.
• 2018 Jun 7th: HypDxe can redirect WoA kernel messages to UART.
• 2018 May 27th: allow 640 x 480 and lower resolutions.
• 2018 May 24th: fix WoA regression reported with build 17134.
• 2018 May 22nd: can boot 64-bit Windows on Arm without WinDbg (and without hacky ATF).
• 2018 May 19th: Ax88772b USB NIC (not onboard SMSC95xx) PXE boot.
• 2018 May 18th: allow changing Arm frequency settings (do nothing, force 600MHz or max)
• 2018 May 14th: rebase to current edk2 upstream (still under verification, no bin release).
• 2018 May 13th: set maximum Arm frequency, better info/smbios, DisplayDxe fix.
• 2018 May 12th: updated May 9th build VC firmware to support RPi3.
• 2018 May 9th: pseudo-NVRAM, persisted RTC, Arasan controller ACPI description, USB fix.
• 2018 Apr 24th: SMP support in WoA.
• 2018 Apr 22nd: switched to MS-IoT ACPI, can boot 64-bit WoA WinPE with WinDbg.
• 2018 Apr 21st: improved booting experience, removed BGRT, WoA docs.
• 2018 Apr 5th: improved ACPI (FADT, GTDT, SPCR, BGRT, MADT), UEFI implementation comparison.
• 2018 Mar 31st: updated supported keyboard info.
• 2018 Mar 1st: updated ATF to fix Ubuntu poweroff crash and add directions.
• 2018 Feb 27th: updated ATF to fix overheat on SYSTEM_OFF.
• 2018 Feb 26th: improved USB driver and HS support.
• 2018 Feb 22nd: improved USB support for keyboards.
• 2018 Jan 13th: updated build instructions, information on keyboards supported, added prebuilts.
• 2017 Dec 26th: USB hotplug and keyboard support.
• 2017 Dec 15th: Initial release.

Here is a comparison table between different available EFI firmware implementations for the RPi3.

Note: If you want to use the pre-built UEFI images, you can skip this section.

1. Clone https://github.com/tianocore/edk2.git

This is the last known good edk2 commit:

commit 989f7a2cf0e27123fda5ca538b15832e115e0f4e
Author: cinnamon shia <cinnamon.shia@hpe.com>
Date:   Fri May 11 23:21:12 2018 +0800

You should rewind your edk2 tree to this commit. Here be dragons!

2. Clone this repo.

3. Apply the various patches against the edk2 tree. Yes, it sucks to have to do this, but this is a clearer way forward than forking every single Tiano driver that has a bug in it, or worse - carrying around an entire private fork of edk2. You're welcome to upstream these patches!

To avoid issues, apply using --ignore-whitespace. E.g.:

$ git am --ignore-whitespace ../RaspberryPiPkg/edk2Patches/*.patch

4. Use one of the provided templates for your build script. If you use a different GCC version, change accordingly, and adjust the compiler prefix to match your system - i.e. set GCC49_AARCH64_PREFIX if you're passing -t GCC49 to build.

If you want to build your own ATF, instead of using the checked-in binaries, follow the additional directions under Binary/atf/readme.md.

UEFI boot media can be a uSD card or USB mass storage, if you've enabled USB booting previously in the OTP (i.e. via program_usb_boot_mode=1).

UEFI boot media must be MBR partitioned and FAT32 formatted.

As a starting point, take one of the latest RELEASE prebuilt image directories and copy contents to empty boot media. If you've built your own UEFI from source (e.g. $WORKSPACE/Build/RaspberryPiPkg-AARCH64/RELEASE_GCC5/FV/RPI_EFI.fd) you can simply now copy over and overwrite RPI_EFI.fd.

Note: You may not have a kernel.img (or kernelX.img, where X is a digit) in the root catalogue of the boot media. It will not boot.

The most basic config.txt contents are:

arm_control=0x200
enable_uart=1
armstub=RPI_EFI.fd
disable_commandline_tags=1

This will boot UEFI and expose an RPi3 device tree that is compatible with openSUSE Leap 42.2/42.3, although it was found to work with Ubuntu 18.04 (Bionic Beaver) as well.

Of course use the debug variant (e.g. $WORKSPACE/Build/RaspberryPiPkg-AARCH64/DEBUG_GCC5/FV/RPI_EFI.fd) if necessary, but it will boot a lot slower due to the verbose spew.

HDMI and the mini-UART serial port can be used for output devices. Output is mirrored. USB keyboards and the mini-UART serial port can be used as input.

USB keyboard support has been validated with a few keyboards:

• Logitech K750 (wireless)
• Dell SK-8125 keyboard (with built-in hub)
• Microsoft Natural Ergonomic Keyboard 4000
• An Apple keyboard (chicklet, USB2 hub)

The boot order is hardcoded to first be the USB ports and then the uSD card. If there are no bootable media, you should be looking at the UEFI Shell. ESC enters setup. F1 always boots the UEFI Shell.

Note: you cannot boot 32-bit OSes like Raspbian with this firmware. Aw, shucks, right?

Most likely, if you boot an OS other than openSUSE Leap 42.3, you will need to pass your own distro- and kernel- specific device tree. This will need to be extracted from the distributed media or from a running system (e.g that was booted via U-Boot).

This involves a few changes to the above config.txt:

...
disable_commandline_tags=2
device_tree_address=0x8000
device_tree_end=0x10000
device_tree=my_fdt.dtb

Note: the address range must be [0x8000:0x10000). dtoverlay and dtparam parameters are also supported.

This firmware will honor the command line passed by the GPU via cmdline.txt.

Note, that the ultimate contents of /chosen/bootargs are a combination of several pieces:

• Original /chosen/bootargs if using the internal DTB. Seems to be completely discarded by GPU when booting with a custom device tree.
• GPU-passed hardware configuration. This one is always present.
• Additional boot options passed via cmdline.txt.

Untested with the Pi 3 B+. You may need to get the latest device tree and follow the instructions.

Download the Leap 42.3 RPi image first, from http://download.opensuse.org/ports/aarch64/distribution/leap/42.3/appliances/ (e.g. openSUSE-Leap42.3-ARM-XFCE-raspberrypi3.aarch64-2017.07.26-Build1.1 was good).

• dd image to media.
• If booting UEFI from same media:
  • In the EFI partition, delete everything but the EFI folder.
  • Follow the basic steps for booting UEFI.

Login is root/linux. There is also a login available on the serial port.

Note: if your media is USB, after first boot you must follow these steps, or you will have an unbootable system after first reboot:

• Edit the file /etc/dracut.conf.d/raspberrypi_modules.conf to include as its first line: add_drivers+=" bcm2835-sdhost bcm2835_dma sdhci_bcm2835 dwc2 usbnet uas usb_storage usbcore usb_common "
• mkinitrd

You may choose to remove enable_uart=1 from config.txt to get your RPi3 to run at full speed.

If you wish to use virtualization (e.g. KVM), you must configure UEFI to boot in EL2 mode. In UEFI setup screen:

• go to Device Manager
• go to Raspberry Pi Configuration
• go to HypDxe Configuration
• configure System Boot Mode as Boot in EL2
• after saving, Pi will reset itself.

Untested with the Pi 3 B+. You may need to get the latest device tree and follow the instructions.

• Download http://ports.ubuntu.com/ubuntu-ports/dists/bionic/main/installer-arm64/current/images/netboot/mini.iso and write out to a USB stick.
• Boot installer.
• Install to another USB stick (uSD slot is not available).
• Enjoy. uSD slot will be available as mmcblk0.

There is a device tree blob under http://ports.ubuntu.com/ubuntu-ports/dists/bionic/main/installer-arm64/current/images/device-tree/bcm2837-rpi-3-b.dtb, which you will need to use to if you want Wi-Fi and Bluetooth, but otherwise things seem to work just fine with the bundled openSUSE Leap 42.2 device tree.

Note: don't use DEBUG builds of ATF (e.g. DEBUG builds of UEFI) with Ubuntu, as the latter disables the mini-UART port, which the ATF relies on for logging. If you want to use a DEBUG build of UEFI, you must use a release version of ATF. Follow the directions under Binary/atf/readme.md.

For Wi-Fi and BT there are a few more steps, as certain firmware files appear to be missing from the installation:

• cd /lib/firmware/brcm/
• wget https://raw.githubusercontent.com/RPi-Distro/firmware-nonfree/master/brcm/brcmfmac43430-sdio.txt
• wget https://github.com/OpenELEC/misc-firmware/raw/master/firmware/brcm/BCM43430A1.hcd
• apt-get install wireless-regdb

If you wish to use virtualization (e.g. KVM), you must configure UEFI to boot in EL2 mode. In UEFI setup screen:

• go to Device Manager
• go to Raspberry Pi Configuration
• go to HypDxe Configuration
• configure System Boot Mode as Boot in EL2
• after saving, Pi will reset itself.

Untested with the Pi 3 B+. You may need to get the latest device tree and follow the instructions.

• Download http://ftp.freebsd.org/pub/FreeBSD/snapshots/ISO-IMAGES/12.0/FreeBSD-12.0-CURRENT-arm64-aarch64-RPI3-20171206-r326622.img.xz
• Uncompress and dd to media.
• If booting UEFI from same media:
  • Delete everything from the MSDOSBOOT partition, except:
    • EFI
    • overlays
    • bcm2710-rpi-3-b.dtb
  • Follow the basic steps for booting UEFI to boot from media.
• If not booting UEFI from same media:
  • Follow the basic steps for booting UEFI to boot from media.
  • Copy bcm2710-rpi-3-b.dtb and overlays to the UEFI boot media.

Now replace config.txt in the UEFI boot media with:

arm_control=0x200
armstub=RPI_EFI.fd
enable_uart=1
disable_commandline_tags=2
dtoverlay=mmc
dtparam=audio=on,i2c_arm=on,spi=on
device_tree_address=0x8000
device_tree_end=0x10000
device_tree=bcm2710-rpi-3-b.dtb

For a different (newer) release, you will need to look at the original config.txt.

This should boot to login prompt on HDMI with USB HID as the input. Login is root/root.

Note: you must remove dtoverlay=pi3-disable-bt, if present, from config.txt, as both ATF and UEFI rely on the mini-UART being initialized.

PL011 serial console in FreeBSD is not supported, yet.

Builds 17125-17134, 17672 are known to work.

Validated with a Pi3B+ as well.

To try:

• Get a Windows 10 host.
• Download the Windows ADK Insider Preview (matching one of the builds above).
• Install ADK (Deployment Tools and Windows Preinstallation Environment).
• If your Windows 10 host is arm64, you will need to patch the DandISetEnv.bat script to SET PROCESSOR_ARCHITECTURE=x86 to get the Deployment and Imaging Tools environment working to run the next few commands.
• copype arm64 C:\WinPE_arm64
• MakeWinPEMedia /ufd C:\WinPE_arm64 <usb drive letter:>
• Follow the basic steps for booting UEFI.

System should boot to a single cmd.exe window.

Note: there are no built-in drivers for anything.

Note: if HypDxe is configured to Boot in EL2, Windows on Arm will not boot. The remaining HypDxe configuration options are developer-oriented.

andreiw#12 for related discussion.

The UEFI HDMI video support relies on the VC (that's the GPU) firmware to correctly detect and configure the attached screen. Some screens are slow, and this detection may not occur fast enough. Finally, you may wish to be able to boot your Pi headless, yet be able to attach a display to it later for debugging.

To accomodate these issues, the following extra lines are recommended for your config.txt:

• hdmi_force_hotplug=1 to allow plugging in video after system is booted.
• hdmi_group=1 and hdmi_mode=4 to force a specific mode, both to accomodate late-plugged screens or buggy/slow screens. See official documentation to make sense of these parameters (example above sets up 720p 60Hz).

The Raspberry Pi has no NVRAM.

NVRAM is emulated, with the non-volatile store backed by the UEFI image itself. This means that any changes made in UEFI proper will be persisted, but changes made in HLOS will not. It would be nice to implement ATF-assisted warm reboot, to allow persisting HLOS NVRAM changes.

The Rasberry Pi has no RTC.

RtcEpochSeconds NVRAM variable is used to store the boot time This should allow you to set whatever date/time you want using the Shell date and time commands. While in UEFI or HLOS, the time will tick forward. RtcEpochSeconds is not updated on reboots.

UEFI supports both the Arasan SDHCI and the Broadcom SDHost controllers to access the uSD slot. You can use either. The other controller gets routed to the SDIO card. The choice made will impact ACPI OSes booted (e.g. Windows 10). Arasan, being an SDIO controller, is usually used with the WiFi adapter where available. SDHost cannot be used with SDIO. In UEFI setup screen:

• go to Device Manager
• go to Raspberry Pi Configuration
• go to Chipset
• configure Boot uSD Routing

Known issues:

• Arasan HS/4bit support is missing.
• No 8 bit mode support for (e)MMC (irrelevant for the Pi 3).
• Hacky (e)MMC support (no HS).
• No card removal/replacement detection, tons of timeouts and slow down during boot without an uSD card present.

• USB1 BBB mass storage devices untested (USB2 and USB3 devices are fine).
• USB1 CBI mass storage devices don't work (e.g. HP FD-05PUB floppy).

More-or-less matches MS-IoT ones. Good enough to boot WinPE, but unclear how functional all of it is, given current state of WoA on RPi3. Both Arasan and SDHost SD controllers are exposed.

• Network booting via onboard NIC.
• Ability to switch UART use to PL011.

All of the code is BSD licensed, with the exception of:

1. DwUsbHostDxe, which I've documented as being GPL 2.0 licensed, since it appears to be directly related to the U-Boot driver.

Andrey Warkentin andrey.warkentin@gmail.com

Btw, feel free to upstream, if so inclined.