Bootable 64-bit RPi3 Gentoo image (OpenRC/Xfce/VC4) UPDATED

Sakaki · Guru Joined: 21 May 2014 Posts: 409

Hello

Do you own a Raspberry Pi 3 Model B single board computer, and would like to try running Gentoo on it in 64-bit mode?

If so, you may be interested to know that I've just released a bootable (~arm64) Gentoo image for the RPi3 on GitHub (available here).

Update 18 June 2019: a new 1.4.2 release of the image is available; please see this post for more details.

You can burn the image (~675MiB compressed) to a microSD card (>=8GB), then boot your RPi3 from it directly (the root partition will be automatically resized to fill the card on first boot). Full instructions for download and use are provided on the project's GitHub page.

The image contains a complete (OpenRC-based) Gentoo system (including a full Portage tree, up-to-date as of 28 Jan 2017) - so you can run emerge operations immediately - and has a reasonably populated userland (Xfce v4.12, Firefox v50.1.0, Claws Mail v3.14.1, VLC v2.2.4, AbiWord v3.0.2 etc.) so that you can get productive without having to compile anything first (unless you wish to do so, of course ^-^).

WiFi and Bluetooth both work, as does sound (via onboard headphone jack, and over HDMI). VC4 acceleration is supported via the mixed-mode vc4-fkms-v3d device-tree overlay / kernel module / Mesa driver, and performance seems reasonable (glxgears 400-750fps, real-time video playback). The kernel on the image is 4.10.0-rc5-v8 from raspberrypi/linux, in pure bcmrpi3_defconfig form.

Additional instructions are provided on the project's wiki about setting up an RPi3-compatible crossdev (and distccd) on your Gentoo PC, should you wish to do that to speed up builds (not necessary simply to play around with the image of course). A Portage binhost for the project is also available here.

If you get a chance to try it out, please let me know how you get on ^-^

PS I'd like to acknowledge NeddySeagoon's work getting Gentoo to run in 64-bit mode on the RPi3 (see particularly this thread, which was a really useful reference when putting this project together).

PPS To quote the Gentoo wiki: "Rpi3 in 64-bit mode has issues. It remains unstable and is not recommended. [...] Proceeding down the 64-bit path may enter a world of pain." Well... it's maybe not quite that bad, but you have been warned ^-^
_________________
Regards,

sakaki

NeddySeagoon · Posted: Mon Jan 30, 2017 12:06 pm Post subject:

Sakaki,

First off, well done! Its downloading as I write.
I've been working on keywording mostly. I can add icedtea, libreoffice and a few other things to the mix. Like you, I can't get thunderbird to work either.
It segfaults a few minutes after startup, exactly like older Firefox.

icedtea is keyworded ~arm64 as of a few days ago.

-- edit --

Also works from Sakakis image. :)
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

will_flint · n00b Joined: 30 Jan 2017 Posts: 1 Location: UK

Awesome work guys , were currently toying with the idea of a 64bit build of Flint OS (chromium OS fork) for the Pi3.

Are you seeing any performance improvements?

I will download and test the Gentoo build and let you know if I find anything interesting.

Again awesome work there arn't many decent 64bit Pi OS out there at the moment.

Sakaki · Guru Joined: 21 May 2014 Posts: 409

NeddySeagoon · Posted: Mon Jan 30, 2017 10:04 pm Post subject:

Sakaki,

I've added /etc/local.d/ondemand_freq_scaling.start and emerged xfce-extra/xfce4-cpufreq-plugin. That all looks good.
Firefox appears to start faster.

The SD card still runs at 22Mb/sec for sequential reads according to

Sakaki · Guru Joined: 21 May 2014 Posts: 409

NeddySeagoon · Posted: Tue Jan 31, 2017 1:27 pm Post subject:

Sakaki,

I started out using the keywording suggested by portage, which is =. I need to go back and fix that to be <9999 so I get updates.

Sakaki · Guru Joined: 21 May 2014 Posts: 409

NeddySeagoon · Posted: Wed Feb 01, 2017 8:18 pm Post subject:

Team,

Buried in the benchmarks cited by Sakaki is this wee gem.

celerrime · n00b Joined: 04 Feb 2017 Posts: 1

Thanks for all your work on this and the detailed info!

Currently running the latest RPi3 optimized builds from funtoo on my original microsd (workstation profile). Still taking a while to get it updated.

Looking forward to trying this out and taking notes.
_________________
real newb. excuse any stupid questions and kindly point me to a resource. loving gentoo.

NeddySeagoon · Posted: Sat Feb 04, 2017 12:16 pm Post subject:

Sakaki,

I've been able to reproduce your 64 bit VC4 success following your pointers. Thank you.
The hard bit was getting sound over HDMI to work. I had installed bluealsa and set up audio over bluetooth as the system default and forgotten how to disable it.
Anyway, its all good now.

The Pi just fails to play DVD .vob files (mpeg2) at 1920x1080 at 60Hz using Kodi.
VLC works for audio but makes Xorg segfault with mpeg2
My test is the opening sequence of "The Good, The Bad and The Ugly" where the dog walks across the screen. If its smooth, alls good but it makes dropped frames stand out.

sdlmame setup is usable. It wasn't under framebuffer-turbo. I need to install some ROMs to test further.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

Sakaki · Guru Joined: 21 May 2014 Posts: 409

NeddySeagoon · Posted: Sat Feb 04, 2017 12:42 pm Post subject:

Sakaki,

Being Old SKool, I still have an xorg.conf.
Turning off XVideo stopped the crash.

Thank you.

If you file too many PRs, you might get recruited, so you can commit your own work.
Keep it up.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

Sakaki · Guru Joined: 21 May 2014 Posts: 409

64-bit vs 32-bit performance

I sent Roy Longbottom a link to the 64-bit image and preliminary benchmark results a few days ago. He has now tried his own 64-bit variants of the benchmarks (compiled on GCC 6) on both this image and OpenSUSE 64-bit for Raspberry Pi. The results are here ff.

These seem to bear out the results reported above, for the most part. Looks like 64-bit is faster, quite a bit faster, at least for certain workloads...
_________________
Regards,

sakaki

roylongbottom · n00b Joined: 13 Feb 2017 Posts: 64 Location: Essex, UK

64 Bit Benchmarks

Confirming Sakaki’s report, I have compiled and run the first set of 64 bit benchmarks. Full details and results are in the following, with benchmarks and source codes in the tar.gz file:

http://www.roylongbottom.org.uk/Raspberry%20Pi%20Benchmarks.htm
http://www.roylongbottom.org.uk/Rpi3-64-Bit-Benchmarks.tar.gz

The Classic Benchmarks are the first programs that set standards of performance for computers in the 1970s and 1980s. They are Whetstone, Dhrystone, Linpack and Livermore Loops. Improvements indicated relate to comparisons of gcc-6 64 bit versions and 32 bit compilations from gcc 4.8 via Raspbian.

Whetstone - This includes simple test loops that do not benefit from advanced instructions. There was a 40% improvement in overall performance. This was due to limited but dominant tests using such as COS and EXP functions.

Dhrystone - rated in VAX MIPS AKA DMIPS produced a 43% improvement, but this benchmark is susceptible to over optimisation.

Linpack - double and single precision versions (DP and SP), with results reported in MFLOPS. Speed improvements, over the 32 bit version, were around 1.9 times DP and 2.5 times SP. There is also a version that uses NEON intrinsic functions where, at 32 bits and 64 bits, are compiled as different varieties of vector instructions, with only a 10% improvement.

Livermore Loops - has 24 test kernels, where 64 bit performance increased between 1.02 and 2.88 times. The official average was 34% faster, at 279 MFLOPS. This is 21 times faster than the Cray 1 supercomputer, where this benchmark confirmed the original selection.

Memory tests - These measure cache and RAM speeds with results in MB/second. As could be expected, RAM speeds were generally quite similar for particular test functions.

MemSpeed - Nine tests measure speeds using floating point (FP) and integer calculations. Cache based improvements were 1.64 to 2.60 DPFP, 1.17 to 1.55 SPFP and 1.03 to 1.23 integer.

BusSpeed - this reads data via loops with 64 AND instructions, attempting to measure maximum data transfer speeds. It includes variable address increments to identify burst reading and to provide a means of estimating bus speeds. Main differences were on using L1 cache data, where average bursts speeds were 38% faster but reading all data was slower. This is surprising as the 64 bit disassembly indicate that far more registers were used, with fewer load instructions, and the same type of AND instructions.

NeonSpeed - All floating point data is single precision. The source code carries out the same calculations using normal arithmetic and more complicated NEON intrinsic functions, the latter being compiled as different types of vector instructions, with no real average 64 bit improvement. The normal SP calculations were slightly faster.
_________________
Regards

Roy

Zucca · Posted: Wed Feb 15, 2017 12:29 pm Post subject:

Nice work!

I have few questions:

I assume this image has glibc. Is it possible to use musl µlibc?
What hardware parts/functions do not work yet? I have long planned to buy the offical RPi 7" touchscreen. I do remember It needed some extra software to work...

_________________
..: Zucca :..

roylongbottom · n00b Joined: 13 Feb 2017 Posts: 64 Location: Essex, UK

NeddySeagoon · Posted: Wed Feb 15, 2017 5:20 pm Post subject:

roylongbottom,

Thank you for the benchmarks and for joining the forums to comment.

All the onboard hardware works. Some is easier to get to go than others.
Bluez-5 needs some patches that have been unstreamed but were not in Gentoo at the end of 2016
I made a bluetooth keyboard work but bluetooth audio is harder, I've not got a satisfactory result there.

I don't have a camera or dsi device, so that's not tested.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

Sakaki · Guru Joined: 21 May 2014 Posts: 409

Ormaaj · Guru Joined: 28 Jan 2008 Posts: 319

Is this using AArch64 with ILP32 ABI or full LLP64? Is the former possible? Or multilib? I just glanced at the gcc manual and notice -mabi=ilp32 as an option and would think that would be the obvious choice given we only have 1G RAM to play with.

Coincidentally my pi is arriving tomorrow so I haven't done much research yet.

R0b0t1 · Apprentice Joined: 05 Jun 2008 Posts: 264

Hello,

Sakaki, the default config.txt is incompatible with some monitors - unfortunately I don't know precisely which (besides mine). Commenting hdmi_drive=2 solves it but gives a very low resolution screen. Moving or deleting the file gives a better boot environment. I'll do some testing of the best configuration options later, maybe after I get my own system going. I decided to use yours when I ran into a wall just so I could see it boot all the way up. Cheers!

Sakaki · Guru Joined: 21 May 2014 Posts: 409

R0b0t1 · Apprentice Joined: 05 Jun 2008 Posts: 264

R0b0t1 · Apprentice Joined: 05 Jun 2008 Posts: 264

I apologize for the double post, but having just re-imaged the SD card I am using it does not seem like video acceleration is used. Moving the mouse around the screen lags. Unlike the previous monitor I was using, however, (which is FullHD but nearly 10 years old) the display resolution is detected properly.

NeddySeagoon · Posted: Thu Feb 16, 2017 9:05 pm Post subject:

R0b0t1,

You can boot the Pi with a 64 bit kernel and 32 bit userland. If you try that, don't forget to put your 64 bit kernel modules into /lib/modules. [fixed in an edit /usr/lib was incorrect]

Video acceleration depends on loading a device tree overlay. That's done by config.txt.