Re: [Gnewsense-dev] Current Status (and Wiki Performance)

[Paul Boddie]

On Saturday 3. September 2016 00.02.47 Sam Geeraerts wrote:
> Op Thu, 1 Sep 2016 00:18:47 +0200
> 
> schreef Paul Boddie <address@hidden>:
> > So I guess there were gNewSense builds for mipsel at some point to
> > support the Lemote products, and that these worked with the various
> > kernels provided for the Ben NanoNote?
> 
> I don't remember if I used the gNewSense kernel or another one.

OK, but as I understand it, then, gNewSense must have been supporting mipsel 
instead of mips64el and thus the distribution worked on the Ben. (My 
impression is that mips64el is a fairly new thing in Debian.)

> > Fortunately/unfortunately, it was shown that the A20 card can most
> > likely be endorsed, thus eliminating any urgent need for the jz4775
> > card. But that would also mean that the A20 card could be used
> > instead (to support ARM systems, obviously).
> 
> Hm, considering the problems we've had with mipsel, I'm not keen on
> adding another architecture to the repo.

Well, this was more a personal experiment at present. I'm not advocating 
anything for the distribution itself.

> > The reference you provide [1] is somewhat confusing, partly because I
> > don't really know that much about the Yeeloong, but also because I
> > thought that it was a MIPS64 system. Maybe only the later
> > models/variants are MIPS64, but it then confuses me that this change
> > would seek to affect MIPS32 systems, too.
> 
> As I understand it, it can run 32 bit and 64 bit ABIs [1] and the "one
> size fits all" MIPS I o32 instruction set that Debian provided, but not
> the MIPS II instruction set to which they're switching now.

I think the Ingenic SoCs may support MIPS II, but I'm not entirely sure, and 
their datasheets probably intentionally do not indicate this because the 
"XBurst" architecture is based on presumably-unencumbered aspects of the MIPS 
architecture. They may have licensed the architecture from ImgTec 
subsequently, however.

> > Interestingly, Guix(SD) supports mips64el presumably for Yeeloong
> > compatibility, but I'm not too familiar with Guix at the moment, so I
> > don't know what architecture version restrictions that system imposes
> > in its build environment. I can always dig up some more information
> > about that.
> 
> It's good to know that there are other options that still support the
> Yeeloong.

Yes.

> > In addition, the jz4780 uses widely-disliked PowerVR technologies,
> > but maybe they are not mandatory for it to be used in a productive
> > way. And Imagination Technologies seem to have moved on to the CI40
> > (which is less suitable as a build host), and I don't see a
> > particularly large amount of obvious support for the CI20 any more.
> 
> So that's a dead end, then. So if I understand you correctly, then with
> regards to current and near-future hardware options, there's no real
> reason to continue mipsel support in gNewSense post-Yeeloong.

I don't know. The Ingenic SoCs have been used in a variety of devices, but I'm 
not sure how available those devices are now. The GCW-Zero is perhaps the most 
well-known, but it seems to suffer availability problems, although there does 
seem to be some kind of community around it and other devices.

> > Maybe it's some other kind of server issue. Anyway, if you need any
> > assistance then I'd be happy to take a look.
> 
> Ack.
> 
> [1]
> https://blogs.gentoo.org/blueness/2014/07/02/continued-support-for-the-lemo
> te-yeeloong-gentoo-mips-is-alive-and-well/

Thanks for the references!

Where should I start looking if I want to derive a gNewSense variant from 
Debian for the purposes of evaluating the feasibility of my little project? I 
did find this...

http://bzr.savannah.gnu.org/lh/gnewsense/

...but it seems to be down at present.

Paul