HW video offload on Fedora Arm

There’s been the starting pieces of hardware video offload with the stateless engine support for some time and it now supports at least H264/HEVC/VP8/VP9/mepg2 decode offload depending on the hardware capabilities. The problem has been support for software/userspace has taken longer then the initial drivers but now that’s catching up now with gstreamer support landing in 2020 and with apps like clapper now using it. I’ve been meaning to play with this and work out how to make it work in Fedora as it’s useful for devices based on the AllWinner/Rockchip/NXP i.MX8 devices like the Pine64 laptops/phones plus a bunch of other devices, even NVIDIA Jetson devices should work before long.

You’ll need to ensure you have gstreamer1-plugins-bad-free installed and the video application I was testing with is clapper:

$ sudo dnf install -y gstreamer1-plugins-bad-free clapper

Seeing what hardware offload is supported:

$ gst-inspect-1.0 v4l2codecs
Plugin Details:
  Name                     v4l2codecs
  Description              V4L2 CODEC Accelerators plugin
  Filename                 /usr/lib64/gstreamer-1.0/libgstv4l2codecs.so
  Version                  1.20.0
  License                  LGPL
  Source module            gst-plugins-bad
  Source release date      2022-02-03
  Binary package           Fedora GStreamer-plugins-bad package
  Origin URL               http://download.fedoraproject.org

  v4l2slh264dec: V4L2 Stateless H.264 Video Decoder
  v4l2slmpeg2dec: V4L2 Stateless Mpeg2 Video Decoder
  v4l2slvp8alphadecodebin: VP8 Alpha Decoder
  v4l2slvp8dec: V4L2 Stateless VP8 Video Decoder
  v4l2slvp9alphadecodebin: VP9 Alpha Decoder
  v4l2slvp9dec: V4L2 Stateless VP9 Video Decoder

  6 features:
  +-- 6 elements

Finally in Clapper you need to enable playbin3 option, I also enabled Pipewire audio support:
Clapper Preferences

We will also be enabling decode support in Chromium and Chromium freeworld before long, there’s a little more work to do here, but as usual once it lands it’ll all just start to work in Chromium too!

Fedora on NVIDIA Jetson Xavier

The last two years or so I’ve been working with NVIDIA on general distro support including UEFI and ACPI for their Jetson Xavier platforms. Their Xavier platform, except a few quirks, are mostly SystemReady-ES compliant, so having a SBBR compliant firmware goes quite some way to having a widely available, relatively affordable, platform that “just works” for the arm ecosystem. I was very excited to finally have NVIDIA finally release the first version in March this year. This firmware is a standard UEFI firmware based on the open source TianoCore/EDK2 reference firmware, it allows booting in either ACPI or Device-Tree mode and supports all the basic things needed. The ACPI mode is not as fully featured as the Device-Tree mode as yet. In ACPI you get compute (cpu/memory/virt etc), PCIe, USB, network, which is just fine if you’re just looking for standard server or for testing a SystemReady system but there’s no display or accelerator support as yet. The Device-Tree mode is more feature full but both work pretty well with upstream kernels and NVIDIA are improving and upstreaming more things regularly.

For flashing with the latest Fedora releases you’ll want the Linux for Tegra (L4T) R32.6.1 release and the latest UEFI firmware (1.1.2 ATM). The R32.6.1 release fixes issues with python3.9 and later so you’ll need that for Fedora. The following will extract everything into a directory called Linux_for_Tegra. Note the release for Xavier is different to the L4T for the TX1/TX2 series of devices such as the nano.

$ tar xvf Jetson_Linux_R32.6.1_aarch64.tbz2
$ tar xvf nvidia-l4t-jetson-uefi-R32.6.1-20211119125725.tbz2
$ cd Linux_for_Tegra

To flash either the Xavier AGX or NX you need to put them into recovery mode and connect a USB cable, USB-C for AGX or micro-USB for NX. Once you’re in recovery mode you can flash them.

For the Xavier AGX:

$ lsusb | grep -i NV
Bus 001 Device 086: ID 0955:7019 NVIDIA Corp. APX
$ sudo ./flash.sh jetson-xavier-uefi-min external

For the Xavier NX:

$ lsusb | grep -i NV
Bus 001 Device 089: ID 0955:7e19 NVIDIA Corp. APX
$ sudo ./flash.sh jetson-xavier-nx-uefi-acpi internal

There will be a bunch of output and it will eventually return to the prompt and reset the device. You can now install Fedora on the device. You can use any of the pre-canned aarch64 image or traditional installer available from the fedora website. When running in ACPI mode you don’t get display output so you’ll need to use a serial console, in both ACPI and Device-Tree mode there’s not currently support for accelerated GPU graphics/AI/ML support. If you want to be able to easily switch between ACPI/Device-Tree modes you’ll want to install the dracut-config-generic package to have a generic initrd to make it easy to reboot between both modes.

SystemReady ES support for MacchiatoBin

I’ve had a MacchiatoBin Double Shot board for some time. It runs various services for my local network and generally just works. I run a TianoCore EDK2 firmware on it using ACPI. It’s purely a network device so I don’t bother with any form of graphics and in the very few occasions I need to access it locally I do so via the built in USB serial TTL.

Recently Solid Run announced the MacciatoBin is now SystemReady ES certified. Excellent news! I’ve worked with Arm for some time on both the SytemReady ES (Embedded Server) and SystemReady IR (IoT Ready) standards and recently the certification program has been finalised so it’s nice to start to see the fruits from all the hard work myself, and may others, have done over a number of years appear.

The EDK2 firmware I was running was coming up to two years old and there’s been a number of enhancements to the various components of the firmwares that make up a complete update so I decided to download the latest firmware and update it. Eventually I am sure Solid Run will have these published to LVFS to make the process even easier but I know that to get to this stage has been a LOT of effort so it’s still a great step forward.

The first step of updating a EDK2 firmware is to download it and put it on the EFI partition:

peter@macbin:~ $ wget https://github.com/Semihalf/edk2-platforms/wiki/releases/flash-image-a8k-mcbin.bin_r20210630
peter@macbin:~ $ sudo mv flash-image-a8k-mcbin.bin_r20210630 /boot/efi
peter@macbin:~ $ sudo reboot

On reboot you’re given a prompt to interrupt the boot process. From the menu select the option for the shell:

Shell> fs0:
FS0:\> ls
Directory of: FS0:\
04/06/2021  19:08          4,096  EFI
07/25/2021  17:01           2,855,040  flash-image-a8k-mcbin.bin_r20210630
          1 File(s)   2,855,040 bytes
          1 Dir(s)

FS0:\> fupdate flash-image-a8k-mcbin.bin_r20210630
Detected w25q32bv SPI NOR flash with page size 256 B, erase size 4 KB, total 4 MB
Updating, 99%
fupdate: Update 2855040 bytes at offset 0x0 succeeded!
FS0:\> reset

It then reboots and we’re done, you see a very similar output to previously with some updated versions of various firmware and before long you’re back through grub and running Fedora again. Painless!

I’m really happy to see this is such a straightforward process, and I’m looking forward to seeing more features, enhancements and fixes to the firmware including capsule updates and the associated LVFS/fwupdmgr support, and improvements around firmware security (fwupdmgr –force security). Top marks to the Solid Run team!

Fedora on the Pinebook Pro

First thing to note here is that this is not limited to the Pinebook Pro, I’m just using it as the example for 64 bit Rockchip devices with SPI flash on Fedora. This post is focused on devices with SPI but I’ll do a separate follow-up post for other devices including details for writing to eMMC over USB.

The story of Fedora on the Pinebook Pro, and other Rockchip devices, has been a sordid story of a lack of time, bugs, rabbit holes, more bugs and various other things. Not at all sordid at all really, mostly just a lack of time on my behalf, and nobody else stepping up to assist in a way to benefit all Fedora users, mostly they do one time hacks to sort themselves. Overall the support in Fedora for Rockchip devices has been quite solid for a number of releases. The problem has been with the early boot firmware, notable because without SPI flash it wants to splat itself across the first 8Mb of the disk, and if there was SPI flash it generally wasn’t overly stable/straight forward.

Anyway we’re now in a place where devices with SPI flash should mostly work just fine, those devices without it will work with a little manual intervention, and while the support isn’t complete, and will need more polish, they’re all details we can polish with little interruption to users by standard package updates. By default users will have accelerated graphics and from my testing on GNOME 40 it’s by all accounts a pretty decent experience!

Setting up the firmware

First step is to get the firmware written to SPI flash. This is a two step process, the first is to write out a micro SD card from another device, the second is to boot that mSD card on the Pinebook Pro, or another device like the Rockpro64, and write the firmware to the SPI flash.

There’s some nuances to this process, and the way the early boot firmware works, if another version of U-Boot takes precedence that is likely OK as it should still be able to work, the fall back is to use the internal switch to turn off the eMMC temporarily. I also have no idea if the Pine64 shipped U-Boot has any display output, the Fedora build does, if not you’ll need to use the option to disable eMMC or use a serial console cable. Anyway on to the steps:

Set up the mSD card
Use a mSD card that has no data you wish to keep, this process will wipe it out. You want at least U-Boot build 2021.04-3.fc34, you can adjust the umount to be more specific, and you need to substitute XXX for the media, otherwise it’s a relatively quick and straightforward process:

sudo dnf install --enablerepo=updates-testing -y arm-image-installer uboot-images-armv8
sudo umount /run/media//*
sudo spi-flashing-disk --target=pinebook-pro-rk3399 --media=/dev/XXX

Write the firmware to flash
Now remove the mSD card from your host and put it into the Pinebook Pro. Press the power button, from experience you likely need to press and momentarily hold and in a second or two the display will light up with text output. Interrupt the boot by pressing space. Next up we write out the flash:

Hit any key to stop autoboot:  0 
=> ls mmc 1:1
   167509   idbloader.img
   335872   idbloader.spi
   975872   u-boot.itb
  9331712   u-boot-rockchip.bin

4 file(s), 0 dir(s)

=> sf probe
SF: Detected gd25q128 with page size 256 Bytes, erase size 4 KiB, total 16 MiB

=> load mmc 1:1 ${fdt_addr_r} idbloader.spi
335872 bytes read in 39 ms (8.2 MiB/s)

=> sf update ${fdt_addr_r} 0 ${filesize}
device 0 offset 0x0, size 0x52000
61440 bytes written, 274432 bytes skipped in 0.803s, speed 427777 B/s

=> load mmc 1:1 ${fdt_addr_r} u-boot.itb
975872 bytes read in 107 ms (8.7 MiB/s)

=> sf update ${fdt_addr_r} 60000 ${filesize}
device 0 offset 0x60000, size 0xee400
914432 bytes written, 61440 bytes skipped in 9.415s, speed 106127 B/s

Once the last command above has completed eject the mSD card and type reset at the => prompt and the device should reboot and you should see output similar to before but running from the SPI flash!

If you had to turn off the eMMC you can now turn it back on.

Installing Fedora

The nice thing with the firmware on SPI flash it should now work mostly like any other laptop and you can use either the pre canned desktop images (Workstation, KDE, XFCE, Sugar), the Workstation LiveCD iso or the standard everything network installer.

To run the arm Workstation image off a micro SD card or USB stick you can do the following:

arm-image-installer --media=/dev/XXX --resizefs --target=none --image=Fedora-Workstation-34-1.2.aarch64.raw.xz

Note ATM you’ll need to use the USB port on the right hand side, I need to investigate the USB/USB-C port on the left as it appears not to currently work in firmware, but works fine once Fedora is running.

Next steps and improvements

The two biggest issues remaining for the Pinebook Pro is enabling PCIe support and the lack of the brcmfmac firmware, both WiFi and bluetooth, being upstream. For the later issue if there’s anyone from Synaptics that can assist in resolving that problem please reach out to me! A interim WiFi firmware to use is here.

Some things at the Fedora level I’ve not really tested and will do so more, and likely polish with OS updates, in the coming weeks include sound, USB-C port (charging and display output). On the firmware level there’s still some more improvements to be done, tweaks to improve the USB support, turning on the power LED as early as possible to give an indicator, improvements to the EFI framebuffer to ensure consistent early boot output, support for UEFI BGRT to enable smooth boot etc.

For support please email the Fedora Arm mailing list or reach out on IRC via #fedora-arm on Libera.Chat.

Installing Fedora on the NVIDIA Jetson nano

Updated – Aug 2021
You now used the latest R32.6.1 release and it now works with the latest Python releases. Some minor edits below.

Overview
Nvidia launched the Jetson Nano Developer Kit in March 2019, since there there’s been a few minor refreshes including a just announced cheaper 2Gb model. I received the original 4Gb rev A device shortly after they were launched.

Over the last year or so as part of my role at Red Hat I started working with some of the NVidia Tegra team to improve support for the Jetson devices. This work has been wide ranging and though it’s taken awhile, with Fedora 33 we’re starting to see the fruits of that collaboration. The first is improved support for the Jetson Nano. The official L4T (Linux 4 Tegra) Jetson Nano images look a lot like an Android phone with numerous partitions across the mSD card. This makes it harder to support a generic Linux distribution like Fedora as there are assumptions by distributions of control they can have over the storage, so while it was certainly possible to get Fedora to run on these devices it generally wasn’t for the faint of heart. As of the recent L4T releases, you definitely want R32.4.4, it’s now a supported option to flash all the firmware to the onboard SPI flash enabling the use of the entire mSD card for the OS of your choice, which as we all know will be Fedora 😉 but the instructions here should be adaptable to work for any distribution.

Before we begin
We do it in two stages, first is to flash the new firmware to the SPI over the micro USB port, second we’ll prepare the Fedora OS for the mSD card. For the first stage you’ll need the latest L4T Release R32.6.1 and the Fedora U-Boot builds installed locally.

Before we get started you’ll need the following:

  • A USB-A to micro USB cable for flashing
  • A HDMI monitor and a USB keyboard
  • A jumper, a jumper wire or something to close the connection on the FRC pins for recovery mode
  • A 3.3v USB Serial TTY (optional)
  • An appropriate 5v barrel PSU (optional)

If you wish to use a serial TTY there’s a good guide here for connecting it to the RevA nano, the RevB has two camera connectors so they’ve moved the serial console headers to near the mSD card slot. The command to see serial output is:

screen /dev/ttyUSB0 115200

Flashing the Jetson Nano
So let’s get started with flashing the firmware. This step with the firmware on the SPI doesn’t have to be done often. First we’ll extract the L4T release and get all the bits installed that we need to flash the firmware:

sudo dnf install -y usbutils uboot-images-armv8 arm-image-installer
tar xvf ~/Downloads/Jetson-210_Linux_R32.6.1_aarch64.tbz2
cd Linux_for_Tegra
cp /usr/share/uboot/p3450-0000/u-boot.bin bootloader/t210ref/p3450-0000/

Next, based on instructions from the NVidia Jetson Nano Quick Start Guide, we need to put the Jetson Nano into Force Recovery Mode (FRC) to prepare for flashing the firmware:

  1. Ensure that your Jetson Nano Developer Kit is powered off. There’s no need for a mSD card ATM, we’re just writing to the SPI flash.
  2. Connect the Micro-USB OTG cable to the Micro USB port on the Nano. Don’t plug it into the host computer just yet.
  3. Enable Force Recovery mode by placing a jumper across the FRC pins of the Button Header on the carrier board.
    a. For carrier board revision A02, these are pins 3 and 4 of Button Header (J40) which is located near the camera header.
    b. For carrier board revision B01, these are pins 9 and 10 of Button Header (J50), which is located on the edge of the carrier board under the Jetson module.
  4. Only if you wish to use a separate PSU place a jumper across J48 to enable use of a DC power adapter.
  5. Connect a DC power adapter to J25. The developer kit powers on automatically and enters Force Recovery mode. Note it may be possible to do this with USB power but I’ve not tested it.
  6. Remove the jumper from the FRC pins of the Button Header.
  7. See if you can see the Jetson Nano is in recovery mode by running:
    lsusb | grep -i nvidia

Now we can actually flash the firmware (make sure you’re still in the Linux_for_Tegra directory):

sudo ./flash.sh p3448-0000-max-spi external

You will see a lot of output as the command runs, and if you have a serial TTY you’ll see some output there but eventually you’ll be returned to the command prompt and the system will reset. If you have a HDMI monitor attached you’ll see the NVidia logo pop up, if you have a serial console you’ll see a bunch of output and eventually the output of U-Boot and the associated U-Boot prompt.

Jetson TX1 and TX2
You can basically follow the same instructions above for the older TX1/TX2 devices except for two things. For the TX1 you can use the same L4T release, for the TX2 you need to download a different L4T release.

For the U-Boot copy there’s a different U-Boot for each device which needs to be copied to a different location. For the firmware copy I treat the eMMC as if it was the SPI flash, and run the OS off a SD card, it’s not the most efficient but it keeps things more straight forward:

TX1:

cp /usr/share/uboot/p2371-2180/u-boot* bootloader/t210ref/p2371-2180/
sudo ./flash.sh jetson-tx1 mmcblk0p1

TX2:

cp /usr/share/uboot/p2771-0000-500/* bootloader/t186ref/p2771-0000/500/
sudo ./flash.sh jetson-tx2 mmcblk0p1

Getting Fedora running
Now we have the firmware flashed we can prepare Fedora for the mSD card. Download the Fedora Workstation for aarch64 raw image. You can of course also use XFCE, Minimal or Server images. Put the mSD card in reader and after unmounting any filesystem run the following command (look at the help for other options around users/ssh-keys):

sudo arm-image-installer --media=/dev/XXX --resizefs --target=none --image=~/Downloads/Fedora-Workstation-33-1.3.aarch64.raw.xz

Note you need to replace XXX with the right device, and you don’t need a target option as we’re not writing the firmware to the mSD card.

Once that completes you should be able to pop the mSD card into your Jetson Nano and reset the device and see it boot. You will see all the output if you have a serial console attached. If you’re using HDMI it may take a little while once the NVidia logo disappears for the GNOME first user setup to appear.

Also note that while a lot of things work on this device, like the nouveau driver for display, it’s not perfect yet and we’re actively working to fix and improve the support for the Jetson Nano, most of these will come via the standard Fedora update mechanism. If you have queries please engage in the usual ways via the mailing list or #fedora-arm on Libera.Chat.

Documenting my various arm and IoT devices: quick overview

It’s been around ten years since I got my first arm single board computer, a Beagle-xM, which started me down the route of playing with Fedora on ARM and ultimately to my role in device edge/IoT at Red Hat. Shortly after that time I also moved into my current flat, almost ten years later I finally made the decision to move to a new place.

In the process of unpacking the contents of boxes from the flat into my new home office I thought I would document all my devices. This is mostly for my own reference, but I have little doubt others are interested from previous conversations. I’ve broken the list down into a few broad categories, mostly so the blog post isn’t unwieldy, there’s certainly cross overs between the categories, like some generations of the Raspberry Pi can run in either 32 or 64 bit mode, some Arm SBCs also have an integrated micro controller etc. For simplicity I’m putting those cross over devices in a single list, that of which they’re most capable, I’m also not putting devices on the list that aren’t easily able to run an open source OS such as Linux or Zephyr RTOS as I have numerous micro controllers/phones etc I can’t be bothered with and hence they’re not seen as useful for this list.

The lists, I will update with links as I post them, are going to be as follows:

  • Part one: Arm 64 bit devices (aarch64)
  • Part two: Arm 32 bit devices (ARMv7)
  • Part three: Micro controllers
  • Part four: x86 and other devices

Three ways to speed up dnf on arm devices

I have a large bunch of Arm Single Board Computers I use for testing a lot. Most of the testing ends up being pretty basic stuff like firmware, kernels, and the various bits of hardware peripherals that people use like storage, network, display and sound output, plus things like sensors and HAT support.

The problem is that these devices often aren’t the fastest in the world for various reasons so I want to be able to apply updates to the basic system as quickly as possible to find out the results. Over time I’ve worked out that these three things speed up dnf quite a bit for the sort of testing I wish to do are as follows:

  1. Disable modularity:
    sed -i 's/enabled=1/enabled=0/' /etc/yum.repos.d/fe*mod*
  2. Don’t install weak dependencies:
    echo "install_weak_deps=False" >> /etc/dnf/dnf.conf
  3. Disable dnf makecache. It never seems to be up to date when you need it anyway:
    systemctl disable dnf-makecache; systemctl mask dnf-makecache

You may need to re-do some of these each major update as they seem to want to force you to have them every time.

The state of open source GPU drivers on Arm in 2019

I first blogged about the state of open source drivers for Arm GPUs 7 years ago, in January 2012, and then again in September 2017. I’ve had a few requests since then to provide an update but I’ve not bothered because there’s really been no real change in the last few years, that is until now!

The good news

So the big positive change is that there’s two new open drivers om the scene with the panfrost and lima drivers. Panfrost is a reverse engineered driver for the newer Midguard and Bitfrost series of Mali GPUs designed/licensed by Arm, whereas Lima is aimed at the older Utguard series Mali 4xx series of devices. Panfrost, started by Alyssa Rosenzweig, and now has quite a large contributor base, has over the last few months has been coming along leaps and bounds and by the time Mesa 19.2 is out I suspect it should be able to run gnome-shell on an initial set of devices. I’m less certain the state of Lima. The drivers landed in the kernel in the 5.2 development cycle, which Linus just released. On the userspace side they landed in the mesa 19.1 development cycle, but they’ve greatly improving in mesa 19.2 cycle. Of course they’re all enabled in Fedora rawhide, although I don’t expect them to be really testable until later in the 19.2 cycle, but it makes it easy for early adopters who know they’re doing to be able to start to play.

A decent open source driver for the MALI GPUs from Arm had been the last biggest hold out from the Arm ecosystem we’ve been waiting for and it covers a lot of the cheaper end of the SBC market with a lot of AllWinner and some Rockchip SoCs having the MALI 4xx series of hardware, which will use the Lima driver and other lower to midrange hardware shipping with the newer Mali midguard GPUs like in the Rockchip 3399 SoC.

Other general updates

Since I last wrote the freedreno (QCom Ardreno) and etnaviv (Vivante GCxxx series) have continued to improve and add support for newer hardware. The vc4 open drivers for the Raspberry Pi 0-3 generations have seen gradual improvement over time, and there’s a new open v3d driver for the Raspberry Pi 4 which they use from the outset.

The last driver is one that seems to have transitioned to be in limbo is the driver for the Nvidia Tegra Arm platform. While it has an open driver for the display controller, and the GPU mostly works with the nouveau driver, at least on the 32 bit TegraK1 (the upstream state of the Tegra X-series is definitely for another post) they appear to have yet another driver, not their closer x86 driver, but another one (not the latest rev, which is 4.9 based, but the only linkable version I could find) which is needed to do anything fun from an CUDA/AI/ML point of view, I wonder how it will fit with their commitment to support Arm64 for their HPC stack or will that only be interesting to them for PCIe/fabric attached discrete cards for HPC super computer deals?

That brings me to OpenCL and Vulkan for all the drivers above, for the vast majority of the open drivers support for either is basically non existent or in the very early stages of development so for the time being I’m going to leave that for another follow up in this long winded series, probably when there’s something of note to report. The other thing that is looking quite good, but one for another post, is video acceleration offload, there’s been quite a bit of recent movement there too.

Raspberry Pi improvements in Fedora 29

So Fedora 29 is probably going to account for the largest single improvement to support on the Raspberry Pi support in Fedora since we added initial support in Fedora 25. It certainly wasn’t without issue, but after quite a bit of debug we’ve got the post release issues with the WiFi back to being stable!

WiFi improvements
The support for upstream NVRAM files and the ability to add those files to linux-firmware means we get WiFi support for the Raspberry Pi 3 Series of devices out of the box! No need to grab anything, it just works! Well mostly, we had some issues with WiFi being very intermittent, as well as a missed bug around aarch64 but now with the 4.19.10 kernel everything appears to be working and stable. This makes me very happy and it took longer than I had hoped but we’re there. This device specific NVRAM driver support will also help another bunch of cheap Arm and x86 based devices that ship with Broadcom/Cyprus based WiFi support moving forward.

ZRAM enabled by default
By supporting and enabling ZRAM swap by default we get a more responsive device and less wear on the MicroSD storage. Over all we’ve seen reasonable performance improvements and to no date no major issues.

GNOME performance improvements
In May 2018 the Raspberry Pi Foundation kindly hosted a GNOME Performance Hackfest in the lovely Cambridge. Over a couple of days we managed to fix a number of issues seen, review and document a number of issues and work on a number of ways of reducing the memory usage of GNOME. Of course this improvement is primarily seen constrained devices like the Raspberry Pi but ultimately less memory utilisation by GNOME even helps devices with decent amounts of RAM and CPUs too. The fixes didn’t arrive in time for Fedora 28, but a bunch have landed in Fedora 29 providing noticeable improvements, and the GNOME team is by no means done and there will be more coming in Fedora 30 and beyond! It was an excellent start and I expect there will be ongoing enhancements here into the future especially with devices like the Purism Phone which will have similar constraints.

Initial CPU frequency support
Another of the largest issues around the Raspberry Pi is complaints it was slow, part of the issue here is that there’s no upstream CPU Frequency driver which means all models of the Raspberry Pi run at a glacial, but safe, 600Mhz out of the box compared to the highest speed, which on the 3B+ is 1400Mhz. With Fedora 29 we’ve landed an experimental cpufreq driver which allows us to run the Raspberry Pi 3-Series at much closer to optimal speeds. While this is experimental it might not stay around if we find out it causes issues or ends up being a maintenance burden but to date it hasn’t yet appeared to have caused any issues.

HWmon Voltage Sensor
There’s a new driver that reports when the voltage supplied by the PSU drops below the required voltage. It can be a bit noisy in dmesg but one of the biggest support problems we have with the Raspberry Pis is people using a power supply that’s not powerful enough, this issue is more of a problem with Fedora 29 because with the support for running at faster frequencies due to the cpufreq driver it means we also draw more power and some PSUs that were previously fine now cause issues because they can’t supply enough current.

Enhanced support for config.txt
A lot of the hardware addons are supported in Raspbian are done by enabling things in the config.txt file, this in turn does things like loading DT overlays and merging them with the base DT to enable extra hardware like HAT support. We have enhanced the way Fedora works with this which enables us to be much closer to the way Raspbian handles these things. The advantage this has is that the documentation that’s written for Raspbian is then usable by Fedora in the wider Raspberry Pi ecosystem which in turn makes it easier for end users to get HW up and running due to less differences in process. There’s further enhancements to make here but every step closer is easier for everyone to enable and use their favourite HATs.

Improved bcm283x firmware support
In preparation for grub2 support we enhanced how we deal with the firmware that the Raspberry Pi uses for booting. This deals with the early startup. We never use to upgrade it by default to ensure things didn’t break, but it also meant most users also didn’t by default get the fixes and enhancements. Now we do. The config.txt is also handled directly which means if you never edit the file you now automatically get any changes we make, because rpm handles the file as a config file, if we change it you get a .rpmnew file so you won’t lose your changes.

Camera support
This wasn’t available in the Fedora 29 4.18 kernels, but with the rebase to the 4.19 kernel the support for the camera on the Raspberry Pi CSI Camera interface improved enough we could enable this in Fedora. The early 4.19 kernels don’t automatically detect and load support if the camera module is attached. There’s some patches in 4.20 in rawhide for this, and we’ll bring some of this to 4.19 soon, and we’re working with upstream to further improve the camera support. You’ll also want the latest bcm283x firmware which tweaks some of the config.txt and updates to a firmware with ISP fixes.

Another improvements
There was also a number of general Arm improvements which sped up crypto on the Raspberry Pi, improved the USB, fixed up some issues with the wired ethernet on the 3B+, power and a number of other fixes. As always there’s more coming. The 4.20 kernel rebase should also bring with it analog sound support early in the new year.

Conclusion
Overall I was pleased with the work that landed in Fedora over 2018 for the Raspberry Pi. The WiFi regression was disappointing, but now with that fixed in 4.19.10 we have WiFi support out of the box without users needing to download anything which moving forward will make things a lot more straight forward. The initial support for the camera makes it much more useful in numerous use cases and we’ll really polish up the HAT support in Fedora 30 which for me is the last remaining big ticket item for Raspberry Pi support. There’s still some annoying bits around the EDID detection in the display, but there’s work to improve that upstream, and also there’s work to land the media decode offloading upstream too which will also one of the few remaining bits.

The Raspberry Pi 3 B+ in Fedora

So I’m sure none of you are surprised to hear that I’ve been asked a bunch about support for the Raspberry Pi 3 B+ in Fedora. Well the good news is that it’ll be supported in Fedora 28. Most of the bits were there for the official Fedora 28 beta, it just needed a minor work around, but nightly images since Beta have had all the bits integrated so the upcoming Fedora 28 GA release will support the Raspberry Pi 3 B+ to the same levels as the original 3 B on both ARMv7 and aarch64. The Fedora Raspberry Pi FAQ has now been updated with all the details of both the RPi3+ and Fedora 28.

WiFi

As with the original 3 there’s files with the firmware we can’t redistribute. The details are documented in the Fedora Raspberry Pi FAQ.

You can grab the files like for the 3 although there’s now an extra one, which you don’t really need, but it gives you all the 802.11a frequencies:

$ sudo curl https://fedora.roving-it.com/brcmfmac43455-sdio.txt -o /lib/firmware/brcm/brcmfmac43455-sdio.txt
$ sudo curl https://fedora.roving-it.com/brcmfmac43455-sdio.clm_blob -o /lib/firmware/brcm/brcmfmac43455-sdio.clm_blob

I’ve also done a rpm of the files for both editions of the RPi3 (plus a few other brcm adapters used on ARM boards). You can either just grab the rpm or setup the repo if you want to get the latest if I update it:

$ sudo curl https://fedora.roving-it.com/wireless.repo -o /etc/yum.repos.d//wireless.repo
$ sudo dnf install brcm-firmware

Issues

Like all new things there’s often a few teething problems. Over all the support for the new RPi 3 B+ is relatively solid but like all new devices there’s some bits still bedding down, and the combination of a new device and new OS there’s been a few minor issues that have been seen in some circumstances. We pulled in the latest firmware just before GA to fix some issues but no doubt as it gets wider testing both in Fedora and in the wider Raspberry Pi community more issues may well come up.

The ones we’re aware of are:

  • The new USB hub and gigbit ethernet interface have seen a few issues in some cases. We’ve pulled in quite a few patches to help stabilise the NIC in Linux and it now mostly works in the vast majority of use cases.
  • The USB hub in u-boot, uEFI and grub on aarch64 can cause some issues. If there’s too many USB devices connected it sometimes won’t boot or will do so really slowly. The work around for the moment is to disconnect all the USB devices until Fedora has started to boot and then plug them in.

In Fedora we’ll deliver updates and fixes by the usual updates, in particular as fixes land upstream we’ll review and land them where useful into Fedora, more than likely via a kernel update. If you see a uboot-tools or a bcm283x-firmware update you’ll want to run the rpi-firmware-update command to update the firmware and then reboot for it to take effect.

Older releases

We won’t be supported the new device in the older releases. Why I hear you say? Well it’s possible but it needs update to the firmware, U-Boot and kernel to work. The Raspberry Pi foundation respun Raspbian to support it and basically it’s not straight forward. Much better to have a new shiny Fedora for a new shiny device!