Re: [Reproducible-builds] Raspi 3 suitable for arm64?
On Sun, Mar 06, 2016 at 08:34:23AM -0800, Vagrant Cascadian wrote:
> Cc'ed correct debian-arm address...
>
> On 2016-03-06, Holger Levsen wrote:
> > On Sonntag, 6. März 2016, Axel Beckert wrote:
> >> I now wonder if a bunch of Raspberry Pi 3 -- since they have 64-bit
> >> CPUs (IIRC an Allwinner A53T) -- would make us able to check
> >> reproducible-builds for Debian arm64, too.
>
> I got the impression it was another broadcom chip, maybe with a
> cortex-a53? Gotta love ARM's confusing namespace.
The Raspberry Pi 3 is based on the Broadcom BCM2837 SoC, which
uses ARM Cortex A53 cores. The problem with the BCM2837 is that
there is currently no mainline kernel support at all and there is
AFAICS not even a publicly available SoC manual, which makes
working on mainline support kind of difficult.
The Raspberry Pi foundation currently doesn't support running the
Raspberry Pi 3 in arm64 mode and it is unclear whether that will
change in the future. For the time being, the Pi 3 is therefore
effectively armhf-only.
> > as far as I know, yes. Though I would want to use some other arm64 boards as
> > well, to have hardware variety right from the start. for example:
> > http://www.heise.de/newsticker/meldung/RasPi-Angreifer-Odroid-C2-Schneller-
> > etwas-teurer-aber-ohne-WLAN-3123182.html also has an arm64 cpu, but twice
> > as much ram (2gb) as the raspi3 and 2 ghz cores instead of 1.2 ghz ones on the
> > raspi3. *buntu also has a new arm64 developer/reference board. There will be
> > more in 3 months too.
>
> I've definitely been thinking about some of these new arm64 capable
> boards. The Odroid-C2, Pine64 and LeMaker HiKey have 2GB RAM options, at
> least. I do worry a bit about sufficient mainline support, as a few of
> the boards I've tried (odroid-c1+, cubieboard4) didnt really work out
> with vendor kernels and the mainline support wasn't close enough to be
> useable.
Mainline support for the Pine64 (which is based on the Allwinner
A64 SoC) is early work-in-progress. The current state of affairs
is roughly as follows:
- There are patches against linux-next with which one can boot
mainline on the Pine64 (serial console, rootfs in initramfs).
- MMC is kind-of-working with the sunxi-mmc driver for older
Allwinner SoCs, but proper MMC support on the A64 needs some
further work because the MMC clock handling on the A64 is
different from the older SoCs.
- Ethernet is currently unsupported. The MAC block in the A64
seems to be the same as in the H3 and there is somebody working
on H3 ethernet support, so there is a chance that ethernet
might work with mainline in the near future.
- USB is currently unsupported. The SoC has an EHCI-compatible
USB host controller, so the host controller itself would be
supported in mainline, but USB support depends on a proper
regulator driver which is not yet available.
One big hurdle for supporting the Pine64 in mainline is proper
u-boot support. The vendor u-boot for the Pine64 is largely
unsuitable for mainline use - it is technically possible to boot
a mainline kernel with it, but that requires jumping through a
bunch of hoops and is nothing I would want to do for any kind of
production environment. Mainline u-boot support is
work-in-progress, but it depends on Allwinner making information
about initializing the DRAM controller available. There have
recently been talks with Allwinner about the topic and Allwinner
has indicated willingness to address the issue, but no DRAM init
sourcecode or documentation have been released yet.
All in all, having proper mainline support for the Pine64 will
still take some time.
For the Odroid-C2 there is AFAICS no mainline support at all.
For the HiKey, some patches for basic mainline support have been
posted on the u-boot and on the linux-arm-kernel development
lists during the last weeks, but AFAICS it is unclear whether
they will make it into the next merge window.
Regards,
Karsten
--
Gem. Par. 28 Abs. 4 Bundesdatenschutzgesetz widerspreche ich der Nutzung
sowie der Weitergabe meiner personenbezogenen Daten für Zwecke der
Werbung sowie der Markt- oder Meinungsforschung.
Reply to: