[Arm-netbook] systemd and kernel: 3.4, mainline [was: Re: Logging and journaling]

[Luke Kenneth Casson Leighton]

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crowd-funded eco-conscious hardware: https://www.crowdsupply.com/eoma68


On Sun, Feb 12, 2017 at 9:23 AM, Tzafrir Cohen <tzafrir at cohens.org.il> wrote:
> On Sat, Feb 11, 2017 at 12:39:46PM +0000, Luke Kenneth Casson Leighton wrote:
>
>> this is a decision that is easily justifiable based on the fact that
>> it's going to have to be distributed with the sunxi 3.4 kernel as
>> that's the only one which supports the full hardware.
>
> That's a proper technical argument, indeed. Anybody here managed to get
> the Jessie systemd running on the 3.4 sunxi kernel?
>
> Also: I figure that currently mainline kernel support for those is still
> not good enough for the image. But what are the chances for me to later
> have it running with mainline kernel and get a decent hardware support?

 you'll have to hunt for the patch that was somewhere around 4.7rc0 to
rc4 which causes the a20 cards to go unstable and crash arbitrarily
within 30 to 200 seconds.  i compiled about 100 versions of the linux
kernel source trying to track down exactly where it was, but the above
was as far as i could get.  i had to stop as it was simply absorbing
too much time right during the middle of the campaign.

 i documented this on the updates.

 [side-note directly to you tzafrir: btw i assume you'll be reading
this, and that you've seen my response about libselinux1.  i'm
mentioning it because i have a vague recollection of answering your
question multiple times, and each time you raising the exact same
question demonstrating that you haven't seen my response.
acknowledgement greatly appreciated so it doesn't keep on happening].

 there appeared to be some significant chances to devicetree around
that time and the cubieboard2 (which i was using as the basis for
testing) was not kept up-to-date around that time.

 once that bug which was introduced around that time has been found
and fixed use of mainline kernel support should be absolutely fine...

 but bear in mind that there is still a library needed to be written
(which must go into u-boot as well) which reads the EOMA68 EEPROM at
address 0x51 and loads the required "overlay" (devicetree fragment).

 i just mention this just in case you were considering upstreaming an
arbitrary devicetree file for the EOMA68-A20 - please don't, not
without consulting me first.

l.