The state of open source accelerated graphics on ARM devices

I’ve been meaning to write about the state of accelerated open source graphics options for a while now to give an update on a blog post I wrote over 5 years ago in January 2012, before the Raspberry Pi even existed! Reading back through that post it was pretty dark times for any form of GUI on ARM devices but with the massive changes in ARM devices and the massive change in SBCs (Single Board Computers) heralded by things like the Raspberry Pi have things improved at all? The answer is generally yes!

The bad

Looking back at that post the MALI situation is still just as dire with ARM still steadfastly refusing to budge. The the LIMA reverse engineering effort started with promise, but went up in smoke with a fairly public community break down, I don’t envision that situation improving any time soon although just recently there appears to be some forward movement happening finally after a long silence. This only covers the MALI-400 series and any newer GPU is a completely different architecture/IP. Even with sessions recently at Linaro Connect titled What’s happening with ARM Mali drivers I don’t see fast change here.

The Imagination Technologies PowerVR is still just as dire as situation as it was five years ago. The company’s incompetent management recently managed to avoid being bought by Apple which in turn, because they’ve screwed the open source community while milking the Apple cash cow, essentially means they’re screwed. I suspect they’ll either open source to try and remain a relevant contender or die in a tire fire. Only time will tell there, in the mean time any ARM SoC that has this IP on board is useless for anything graphical so I’d tend to avoid it, thankfully there seems to be less of them these days.

The good

Despite the two bad examples above there’s actually been a lot of good change in the last five years. We now have a number of options for fully accelerated 2D/3D graphics on ARM SoCs and I run GNOME Shell on Wayland, yes the full open source shiny, on a number of different devices regularly.

NVIDIA true to the rumours did open up all the graphics on the Tegra series of hardware. The new Tegra K/X series have GPUs similar to their x86 offerings with Kepler/Maxwell/Pascal GPU cores but NVIDIA supports these devices by contributing to the nouveau open driver rather than the closed x86 driver. The performance on 32 bit TK1 devices has been decent for a number of releases of Fedora and improves all the time, we’ll be supporting the X series (X1/X2) with their Maxwell/Pascal GPUs in Fedora 27.

In the old post I brushed past Vivante with a mere mention of Marvell and Freescale (now NXP). The Vivante GPUs ship in NXP i.MX6 and i.MX4, some Marvell chips and some TI chips. There was a reverse engineering effort called etnaviv that must have started not long after I wrote that post and after a number of years of development support landed upstream in the kernel late 2015, and in mesa in the 7.1 release allowing us to support fully accelerated Wayland in Fedora 26! Did anyone notice? I didn’t really yell about it as much as I should have! It supports fully accelerated 3D in mesa/wayland, is pretty stable and is improving all the time, well done to all the contributors to that effort!

Another I brushed past in the old post was the Qualcomm Snapdragon SoC. They ship with a Adreno GPU. This was previously closed source, with the SoC primarily used by phone/tablet manufacturers I suspect they didn’t care… until Rob Clark (and no doubt there were other contributors) decided to reverse engineer the driver with the open freedreno driver. This is now the default driver with even Qualcomm contributing to it. We’ll support this in Fedora 27, initially with the 96boards Dragonboard 410c using the freedreno driver, but I doubt it’ll be the last Qualcomm based device we support. The Snapdragon 835 SoC, the device in all the high end Android phones this year and the ARM Windows 10 laptops, is really nice with decent performance, I’d love to be able to support a device with that SoC!

Raspberry Pi, as I mentioned in the introduction, wasn’t even out in when I wrote the original post. When it fist launched there wasn’t an open driver but 5 years later there is, sponsored by Broadcom no less. We introduced initial support for the Raspberry Pi with the open vc4 driver by Eric Anholt in Fedora 25 and it’s improving regularly. It supports fully accelerated 3D in mesa/wayland, and 2D via glamor in mesa.

So in conclusion we have improved by A LOT! We now have numerous different GPUs with open drivers to choose from in all price ranges that support fully accelerated 2D/3D desktops from four different vendors on both ARMv7 and aarch64. The media acceleration offload is also looking quite good, but that’s one for another post. The biggest holdout is MALI, and that would need two open drivers or ARM to come to the table, LIMA might work out for the 400 series, but that won’t work on the newer midguard series. With support in a number of drivers for the shiny new Wayland there’s an increasing number of devices people can use to enjoy the latest desktops fully accelerated!

Raspberry Pi improvements in Fedora 26

So since I landed support for the Raspberry Pi 2 and 3 just in time for Fedora 25 Beta it’s been a bit of a fun ride. The support for Raspberry Pi is mostly done in my spare time along side all the other responsibilities I have and it’s been interesting to see people’s feedback. Going into Fedora 25 I knew it wasn’t going to be perfect but the experience was going to be reasonable for newbies to get going without generally needing serial consoles and it met Fedora’s (and mine) exacting standards on free drivers. I think we achieved that quite well but I also learned a lot in the Fedora 25 cycle and what’s coming in Fedora 26 is quite a substantial jump forward.

Hardware for a good experience

So what have I learned about the first six months or so of Raspberry Pi in Fedora? Well there’s a couple of things that the user can do to ensure a decent starting experience themselves. The biggest FAQs I’ve dealt with on the various support forums are generally fixed by these three things:

  • A proper spec power supply. For the RPi2 this means at least 2 AMPs and for the RPi3 at least 2.5 AMPs. If you want to plug in USB WiFi dongle and a USB HDD you’ll likely want to add a little more! In most cases an old phone charger will not suffice.
  • A good quality Class 10 micro SD card. I generally use Samsung EVO or SanDisk Ultra cards.
  • A Raspberry Pi 2 or 3. Yes, it’s surprising how many people hope to run it on something else. SORRY (actually, I’m not!)!

What’s in Fedora 26 Final

So enough of what to do! Everyone wants to know what improvements arrived in the Fedora 26 Final with the 4.11.x kernels:

  • Pi3 WiFi: It’s been working in F-26 since Alpha and is surprisingly stable. There’s a file you need to grab to enable it. See details in the wiki here.
  • Performance: In the process of dealing with wifi I worked out one of the reasons we were seeing poor performance on the SD card. We’ve had some minor improvements in F-25 but this fix over doubles the performance for me on the SD card.
  • HDMI video: There’s been issues around certain monitors crashing the video (vc4) driver and people getting black screens during boot. While this isn’t perfect yet (ain’t hardware great!!) it’s greatly improved across numerous devices.
  • Composite video: We’ve had support for the composite video since 4.10 but I need people to help test this.
  • Sound: HDMI audio is supported, I’ve done minor testing with the one HDMI audio capable device I have. Analogue audio out isn’t upstream yet.
  • HAT support: We now have all the support needed to do overlays in the kernel/bootloader and dtc stack. I just need to test it some more, document it and work out how we can best distribute pre built overlays to ease consumption. There’s still no consensus on an Overlay Manager from upstream to auto load overlays based on EEPROM on the HATs. In a lot of cases you want to load the overlays from u-boot anyway for things like display. Look out for docs and blog posts on this soon!

What arrived with the 4.12 kernel rebase

  • Thermal support: so if the RPi runs too hot it’ll slow it down
  • More performance improvements and tweaks.

What’s coming in the 4.13 kernel rebase

  • Bluetooth support: upstream finally tracked down the issues here. It’s been a much requested features and I should have the bits in place soon!
  • More performance, stability and graphics improvements and tweaks.

What about Fedora 25?

Some of the above pieces will be coming to Fedora 25 with the 4.12 rebase. The focus of my spare time is Fedora 27 mostly now, with the above coming to F-26. Some components are a lot harder to back port without issues or a complex series of package updates to ensure smooth upgrade. The WiFi and performance improvements were the hardest as part of that change moves around the use of hardware blocks and drivers. I managed to stop both the RPi2 and RPi3 booting numerous times in testing before I properly realised the implications of the change. Getting these changes for users back into a stable release without issues is hard and time consuming to do across all the various use cases. I tried this with some fixes in 4.9 and ended up making the RPi3 very unstable. This cost me a lot of time to debug and fix and I don’t really want a repeat of that!!

Graphics device

One of the surprising side effects was the discovery of a device that is five years old is that Fedora suffered from early adopters issues. We were one of the first distributions to adopt a fully upstream open kernel and graphics stack and with that came a number of issues around monitor detection, especially older/cheaper models that aren’t 1920/1080 “Full HD” or via HDMI to VGA adapters. We’re still working through these with upstream and have improved the situation quite a bit in Fedora 26 overall but it takes time and reproducible use cases which with random hardware isn’t easy or quick! πŸ™

Next up?

I’ll leave Fedora 27 features and functionality for another, this post has been sitting in my drafts folder since June so it’s time to get it out and like my development move on to Fedora 27!

Getting started with Zephyr on Fedora

So while Fedora is great for a lot of IoT use cases it can’t be used everywhere, such as on tiny micro controllers such as an ARM Cortex-M series or Intel Quark micro controllers, but that doesn’t mean that Fedora doesn’t make a fantastic developer platform for working with these devices.

I have a handful of Zephyr capable devices (BBC Micro:bit, NXP FRDM-K64F, 96Boards Carbon, TI CC3200 LaunchPad) so how can you get a build environment up and running quickly so you can start doing real development as quickly as possible.

In testing this I used a Digital Ocean cloud instance for a build host. Wherever you choose to build it make sure you have at least 2GB of RAM available as from my experience you need at least 2GB for building a Zephyr image.

From there we diverge a little from the upstream notes by installing the Fedora ARM cross compiler (only tested with ARM, not sure of state of other targets) and developer tools:

sudo dnf install git-core gcc gcc-arm-linux-gnu glibc-static libstdc++-static make dfu-util dtc python3-PyYAML

Next up we clone the upstream Zephyr git repository:

git clone https://gerrit.zephyrproject.org/r/zephyr zephyr-project

If we want to use a particular stable branch we now switch to the chosen branch. I’m using the latest stable release branch:

cd zephyr-project; git checkout v1.7-branch

Set up the cross compiler variables:

export GCCARMEMB_TOOLCHAIN_PATH="/usr"
source zephyr-env.sh
cd $ZEPHYR_BASE/samples/hello_world

Select and build our target:

make CROSS_COMPILE="/usr/bin/arm-linux-gnu-" DTC=/usr/bin/dtc BOARD=96b_carbon

If we’re developing this on our local machine we can now just directly flash the new build straight to the device. To do this we connect a micro USB cable to the USB OTG port on the Carbon and to your computer. The board should power on. Force the board into DFU mode by keeping the BOOT0 switch pressed while pressing and releasing the RST switch.

Confirm DFU can see the device:

$ sudo dfu-util -l
dfu-util 0.9

Copyright 2005-2009 Weston Schmidt, Harald Welte and OpenMoko Inc.
Copyright 2010-2016 Tormod Volden and Stefan Schmidt
This program is Free Software and has ABSOLUTELY NO WARRANTY
Please report bugs to http://sourceforge.net/p/dfu-util/tickets/

Found DFU: [0483:df11] ver=2200, devnum=8, cfg=1, intf=0, path="2-1", alt=3, name="@Device Feature/0xFFFF0000/01*004 e", serial="123456789"
Found DFU: [0483:df11] ver=2200, devnum=8, cfg=1, intf=0, path="2-1", alt=2, name="@OTP Memory /0x1FFF7800/01*512 e,01*016 e", serial="123456789"
Found DFU: [0483:df11] ver=2200, devnum=8, cfg=1, intf=0, path="2-1", alt=1, name="@Option Bytes  /0x1FFFC000/01*016 e", serial="123456789"
Found DFU: [0483:df11] ver=2200, devnum=8, cfg=1, intf=0, path="2-1", alt=0, name="@Internal Flash  /0x08000000/04*016Kg,01*064Kg,03*128Kg", serial="123456789"

Flash our build onto the device:

sudo dfu-util -d [0483:df11] -a 0 -D outdir/96b_carbon/zephyr.bin -s 0x08000000

Now connect another micro USB cable to the UART port and run a console:

sudo screen /dev/ttyUSB0 115200

Hit the reset button and you should see the following output:

***** BOOTING ZEPHYR OS v1.7.1 - BUILD: Jun  6 2017 14:07:24 *****
Hello World! arm

Now we have a basic development environment setup, know we can build, flash and run a release on the 96boards Carbon next time we can do something more advanced πŸ˜‰

Update (2017-06-13): Minor updates to dependency installs and make command

WiFi on Raspberry Pi 3 for Fedora 26 Alpha

So I managed to land just about everything needed for the WiFi on the Raspberry Pi 3 for Fedora 26 Alpha (around 4.11 rc3). There’s one thing missing, because we can’t currently redistribute it, but it’s straight forward for the end user to do themselves once they’ve done the initial setup:

sudo curl https://raw.githubusercontent.com/RPi-Distro/firmware-nonfree/master/brcm80211/brcm/brcmfmac43430-sdio.txt -o /lib/firmware/brcm/brcmfmac43430-sdio.txt

Or you can also do it when you’re flashing the image if you mount the root filesystem but the above is likely easier. It’s been surprisingly stable in my testing.

Before you all ask, at the moment I don’t plan on pushing this to earlier Fedora releases, as the upgrade path is not trivial. I will also soon publish more details of some of the other new features coming for the Raspberry Pi to Fedora 26 but I thought you’d all like the WiFi details now. The wiki has also been updated to reflect the status of the WiFi.

PS: No this is not an April Fool’s joke (it’s well past midday in UK).

Updating Raspberry Pi firmware on Fedora

The upstream Raspberry Pi firmware/bootloader gets regular updates and improvements. In Fedora we ship that firmware in a package called bcm283x-firmware. I regularly follow the git repo of the upstream firmware and on occasion when I believe there’s reasonable changes that benefit Fedora I’ll prepare a new version, do some brief testing on my devices to make sure it boots and basic functionality hasn’t regressed at which point I’ll update the package and send it out to supported releases as an update.

Once the new bcm283x-firmware lands on your Raspberry Pi it doesn’t automatically update the firmware though. Why is that you ask? I don’t like to spring surprises on people where they end up with a device that might not boot or it might regress things they care about.

So how do you upgrade the firmware for the Raspberry Pi on Fedora? It’s simple! You simply run the command rpi-firmware-update and it’ll update the firmware and the u-boot to the latest one that’s shipped as a Fedora package. Then you just need to reboot to make it active.

The easiest way to work out which firmware you’re currently running is “dmesg | grep raspberrypi-firmware”

I tend to try and push out a new firmware update every month or so but if I see something that’s of interest or that fixes known issues I do it as needed.

Fedora 24 released on all architectures simultaneously!!

So for the first time ever we’ve released Fedora 24 across both primary and alternate architectures pretty much simultaneously! That’s the three primary architectures, x86_64, ARMv7 and i686, plus the alternate architectures of aarch64, ppc64, ppc64le and s390x. This is the first time we’ve ever released SEVEN architectures on the same day!

Fedora 24 from a Release Engineering perspective has been fairly momentous, we’ve made the single biggest change to our tooling that composes the release since Fedora Core and Fedora Extras was merged in Fedora 7! The plans for this change had been long discussed and first started to move back in the Fedora 21 cycle with the hope it could be implemented in Fedora 22…. boy were we wrong! But on the flip slide, while it’s still not perfect, it has massively improved the process for the releases. We now FINALLY have a full compose every single night! No more Test Composes! It now means QA can automate tests against any bit of the compose output, it means the installer team can see the results of their changes the next day. For the average user this has no material visible impact, for those much closer into the process it has a hugely positive impact!

From the alternate “secondary” architecture perspective I’ve ticked of a massive amount of “goal check boxes” that I made for myself when I joined this role almost two years ago.

My big ticket item was “make the release process like primary”. Our release process was a lot more manual than “primary” but we had also a lot less “features”. Well with this release neither are now true. We’re not 100% of the primary process, but the difference is tiny. We have a full nightly compose now, like primary, where previously we basically had a “newRepo” process we now have a full installer stack with network and iso installs produced. This in itself is a massive improvement! To this we add docker to aarch64 and Power64, cloud to aarch64 (and more automation of cloud to Power64), and initial “tech preview” disk images to aarch64 for Single Board Computers (I’m sorry I really did want to nail down this feature but even I have to sleep!) like the Pine64.

Some of the “smaller” tick box improvements to non primary arches is that we’re now fully 100% ansible run for the aarch64 and Power64 infrastructure, and only have a few minor bits to work out for s390x. This means from the back end everything is 100% like primary and orchestrated as such, the hubs all looks the same and the experience is consistent. Changes are deployed simultaneously and hence consistently. YAY automation! We’ve also simplified the way the secondary content gets to the mirrors so it’s more consistent and faster!

On the not x86 architecture front we’ve got a whole bunch more exciting features planned, and improvements to make, for the Fedora 25 cycle and beyond, some of which will begin happening very soon. Watch this space, the second half of the year looks to me to be just as frantic as the first!!

Fedora 24 Alpha for aarch64 and POWER

So Fedora 24 Alpha is out for aarch64 and POWER. Keen followers will note that we were a couple of days behind the primary architecture’s Alpha release, which hasn’t been the case for the last few Fedora cycles where we’ve generally released on the same day.

The primary reason for the delay was the Pungi Refactor. While the pungi 4 change has been massive for primary architectures for the secondary architectures it’s the single biggest change to our release process EVER! Basically we’ve thrown the lot out and started again. When I started in release engineering over 18 months ago the number one goal that was set for me can be summarised as “Be more like primary. Make the whole secondary architecture as close to primary as possible!” and we’ve been continuously moving, albeit not as fast as I would have liked, in that general direction. With the arrival of pungi 4 for Fedora 24 we’re almost at that end goal in terms of the current way we do secondary architectures.

With Fedora 24 we’re also adding a lot more release engineering focused features and functionality to the secondary architectures. We have now have full nightly composes on rawhide and branched whereas previously we’d just produce a “Everything” repo. This allows ongoing continual testing on things so it’s easier to know when things regress. On PowerPC we’ve produced qcow2 cloud images to some degree since Fedora 22 but it was a bit of a manual process. These are now fully integrated into the pungi/koji process and, like on primary produced nightly, similarly they’ll be coming to aarch64 very shortly too. In Fedora 24 we’ve added Docker base images, they’re produced nighly on branched and rawhide for PowerPC now, and will be nightly for aarch64 at the same time the qcow2 cloud images arrive. Finally aarch64 will also soon have disk images like ARMv7 on primary to enable us to easily support the new shiny aarch64 Single Board Computers (SBCs) that are _FINALLY_ becoming available for the architecture, for Fedora 24 it’ll be a bit of a hack, but with Fedora 25 both ARMv7 and aarch64 will be able to move to koji based live-media-creator image build process but I’ll outline more of that in another post.

So the pungi refactor has been big for the secondary architectures. It’s required big changes in our infrastructure which is now mostly complete, there’s a few infrastructure cleanups and final changes that are in process, these will be done in the next few weeks in the lead up to Beta. We have a single host left to migrate to ansible (YAY!!) and some final moving around of resources. We’ll be changing the way we sync content out to mirrors too which will close out one of the final deltas of the rel-eng secondary process. Overall the last few weeks have been challenging getting all the bits in place, but by the time we hit Beta it’ll all be complete! The new processes lay the foundations for the secondary architectures to add functionality quicker than ever before, and by being almost identical to primary the “onboarding” of new people to use that process, or end users be able to consume the output of the rel-eng process is easier than ever before and that makes me happy! πŸ™‚

Lipstick on a Pig AKA the Raspberry Pi 3

So while waiting for local scratch kernel builds for much more interesting devices I started looking around to see if I could find details of the kernel sources for the new BCM2837 SoC that is centre stage in the Raspberry Pi 3.

The problem is I couldn’t. What I did find is the hack the Raspberry Pi Foundation uses to boot the RPi3 on github.

So there is no source code release for the new BCM2837 SoC, just a device tree file. Someone said to me “They’re violating the GPL” and before people get out their pitch forks… they’re NOT because this is the code they ship, they are meeting their obligations there.

So for the lay person (yes, I know there’s a lot of deep level tech details I’m glossing over deep ARM architecturey people!!) basically what they are doing is booting this device as a ARMv7 device, and because the code isn’t built for ARMv8 (32 or 64 bit) they really just get the speed bump of a ARMv7 device running a bit faster, and possibly some better memory speeds and other general improvements.

So what does this mean for other distributions that wish to actually to support the Raspberry Pi 3 as a aarch64 device? You currently can NOT do so!. Why? Basically it boils down to two things:

  • Source code release for the kernel: To be honest I don’t think this should be large. People with low level knowledge of ARMv7 and the BCM283x could probably hack this up
  • Firmware support: I suspect there will need to be a new firmware that supports booting this as a aarch64 device. I obviously don’t know for sure but I’m guessing the firmware will need changes to actually properly boot this as a aarch64 device. I’ve little doubt there’s a bunch of hackery going on in there!

Of the above two, if my theory is correct, the firmware is the problematic one because it relies on the Raspberry Pi Foundation to do the work. This work for something that they feel, at the moment, gives them no particular gain but only confusion about multiple OSes. They are of course correct for their use case, basically like old school enterprise where you buy a bigger server to scale vertically because your app won’t scale horizontally, but this is another kick in the guts of the Open Source community they so heavily rely on! Oh well, it’s about as much as I expected from the Raspberry Pi Foundation as after all their devices are only just now becoming usable with upstream kernels and open userspace GPU drivers…. after a mere four years.

So what does this mean for Fedora? Basically the only way we’ll be able to support it in the short, possibly medium, term is like it’s sibling the Raspberry Pi 2 as an ARMv7 device but with added shitty wifi. Really, this device isn’t a cheap aarch64 device, it’s just like lipstick on a pig! If a cheap aarch64 device is what you want one of those go and buy a PINE64.

On the plus side the work needed to support it as a ARMv7 device at the same time as it’s sibling should just be some minor u-boot and kernel device tree patches on top of what I previously documented . Note I’ve not looked closely at this as yet, I’m still waiting for mine to arrive (YAY day 3 of 1 day shipping)! Frankly I’d sooner support it this way, an aarch64 device with terrible USB2 IO and 1GB of RAM won’t provide much, if any, of a perf bump over ARMv7, and then have the Raspberry Pi Foundation spend their time working with Broadcom on fixing the wifi and enabling distribution of the wifi firmware in linux-firmware as proper opensource broadcom wifi support would have a wider impact on the Open Source community the Foundation relies upon!

Supporting Fedora 24 on the Raspberry Pi 2

So I get asked the question dozens of times a day so I thought I’d outline the answer to the question “When is Fedora going to support the Raspberry Pi 2?” and “The kernel support is upstream in the 4.5 kernel, why isn’t it enabled in Fedora 24?”

Ultimately support in the kernel is great, it’s obviously a core blocker, and the first steps to supporting a new piece of hardware in Fedora. The thing is that when people say kernel support is easy they are partially right but it’s only a very small part of what’s needed to support a complex device such has an ARMv7 Single Board Computer for the average user, especially one as popular as the Raspberry Pi! To make the device work with Fedora we could just enable the kernel bits but it doesn’t make for a good user experience OOTB (Out Of The Box).

With a lot of ARMv7 devices these days a new device comes out and it just works with Fedora. It’s awesome when I read a report, or someone tells me “I tried device X with Fedora and it just worked”. That’s because of a lot of work Fedora, and others, have done to ensure upstream boot loaders and boot process just works with new devices. It’s taken a long time to get us to this point. The Raspberry Pi is sadly not like all the other ARMv7 or aarch64 devices. It doesn’t have a standard boot process, doesn’t use u-boot or uEFI, needs vFAT partitions, firmware, text config files and other things that none of our other supported devices need. All of these differences need to be taken into account.

So in terms of the support being upstream in 4.5 the answer to that is it’s “mostly” upstream, there’s still a bunch of patches we’d need to pull in to ensure a nice OOTB experience. This isn’t a blocker in my opinion, it’s something that’s relatively straight foward with most of the bits already headed upstream into 4.6 so it’s a short term issue.

For the rest of the bits what do I consider a nice out of the box experience? This:

  • A single image to support the Raspberry Pi and all out devices (more on that below)
  • Graphics and USB support from boot to login
  • Most basic peripherals working, at a minimum USB (inc keyboard/mouse), HDMI, wired ethernet, a decent selection of wireless USB dongles, storage (MMC and USB) and preferably sound (analog, digital HDMI, mic)
  • A means of easily creating a bootable SD card from at least the Fedora command line, and probably Windows or MacOSX
  • Good documentation, FAQ etc

Single Image:
We currently produce a lot of different images for ARMv7 like Workstation, Server, Minimal and various desktops. If we had to double the amount of images we make to add vFAT that would double the work needed by QA, rel-eng and also lead to confusion by end users as to which image is needed. I have no intention of doubling anyone’s work, or adding confusion for end users, there needs to be a proper engineering solution to this problem!

Serial Console
A number of people have said to me “just enable it and tell them to use the serial console” but having been working on ARMv7 for over 6 years now I know from experience that this leads to vast amounts of confusion by end users as to why “it’s not working” and it leads to a lot of time “providing support” to end users. With a device such as the Raspberry Pi this will become an order of magnitude worse which won’t provide users a good Fedora experience, and likely drive the people who are trying to support the device a even more nuts than normal!

Basic peripheral support
I feel that network, storage, display, input and sound, although I’m still on the fence about sound, are the minimum viable supported peripherals needed for a good OOTB experience for users.

I know that initially we won’t support HATs very well, you can already copy around device tree overlays in the /sys filesystem for basic support, but upstream still hasn’t finalised what a good experience will look like in this regard. I think we can live with this. This won’t stop the use of I2C or SPI devices connected to the 40 pin header, most of these should work just fine.

Image to card creation
Closely related to the single image and basic peripheral support I think the ability to easily create an image to use is important. I’m not sure we’re going to be able to easily solve the Windows/OSX problem, although to be honest I’ve not looked at what’s out there and we might be able to extend LiveUSBCreator here.

Raspberry Pi 3
So when will we support this? Well the kernel support hasn’t been released yet, at least that I could find at the time of writing this. That being said I don’t think it’ll be a particularly evasive or large patch set, the hardware around the Cortex-A53 is the same, so it’ll be just some glue and a pinctrl driver to make all the bits work together, likely not too dissimilar to other recent SoCs that have gained ARMv8 support. This won’t land in 4.6 as the major changes are already queued to land in that, so likely 4.7 will be the earliest upstream kernel. The wireless on the other hand could be more interesting.

So basically the work needed for support of the Raspberry Pi 3, with a proper 64 bit OS πŸ˜‰ , shouldn’t be too hard once the kernel bits are upstream.

Firmwares
The other issue we had was the legal ability to redistribute the “GPU boot loader firmware” thankfully that problem was resolved about a year ago, although it did take us over 2 years to do so!

The other firmware issue which will cause problems with Raspberry Pi 3 support is that the Broadcom wireless is notoriously terrible, as any Linux running Mac user will contest to, and their wireless firmware isn’t re-distributable in the standard process of being included in the upstream linux-firmware. With luck this is something that the Raspberry Pi Foundation could assist Broadcom in improving!

Summary
So we’re well on the way to adding support. Assistance in the issues above would be very welcome, whether for supporting a single image or adding support for writing images for the Pi, to help us get the bits done sooner rather than later. Feel free to reach out to me on IRC (pbrobinson on FreeNode) or some other means.

My ARM grab bag device list

They say the first step of coming to terms with addiction is admitting you have a problem… I have a problem with collecting ARM devices… there I said it! How big is this problem you ask? How about I list them out and let you decide!

I’ll break the list down into categories as I believe it’s big enough to do so :-/

The aarch64 set of devices currently stands at:

  • 2x Applied Mustang (different x-gene SoC revs)
  • AMD Seattle
  • 96boards HiKey (hi6220)

The ARMv7 boards list is currently:

  • Compulabs Trimslice (tegra-2)
  • Toshiba AC100 (tegra-2)
  • nVidia Jetson TK1 (tegra-124)
  • Acer Chromebook (tegra-124)
  • BeagleBoard xM (omap3)
  • Nokia n900 (omap3)
  • Nokia n950 prototype (omap3)
  • BeagleBone (am33xx)
  • BeagleBone Black (am33xx) x3
  • BeagleBone Green (am33xx)
  • PandaBoard ES Prototype (omap4)
  • PandaBoard ES B2 (omap4)
  • CubieBoard (allwinner-a10)
  • CubieTruck (allwinner-a20)
  • Banana Pi (allwinner-a20)
  • C.H.I.P. Alpha x2 (allwinner-r8)
  • Snowball (u8500)
  • Compulabs Utilite (imx6q)
  • WandBoard Quad revb (imx6q)
  • novena board (imx6q)
  • RIoTboard (imx6s)
  • UDOO Neo (imx6sx)
  • Origen (exynos-4)
  • OLPC XO 1.75 – a number of variants (mmp2) xNumerous
  • OLPC XO-4 including XO-Touch (mmp3) xNumerous
  • Linksys WRT1900AC (armada-xp)
  • Mirabox (armada-370)
  • ifc6410 (qcom)
  • Parallella Board (zynq7000)
  • Raspberry Pi 2 x3

The Cortex-M series for IoT sensors is currently:

  • TI SensorTag 2015
  • ARM mBed IoT starter kit
  • BeeWi SmartClim

Other random related bits:

  • BeagleBone Breadboard Prototyping Cape x2
  • BeagleBone CryptoCape
  • Original 256Mb Raspberry Pi model B
  • Grove starter kit for BeagleBone Green
  • Explorer HAT
  • PiGlo HAT
  • TI CC2531 802.15.4 USB dongle x3
  • numerous random sensors

So the list above is the devices that I use for hacking on. I count 41 without listing out the dozen or so ARM based XOs I have (various prototypes and models). I also don’t have in that list phones, tablets and two drones as I don’t really hack on those as it’s not like with the list above I don’t already have enough toys! So do I have a problem?