Re: Proposed roadmap to 1.0

[Isaac <idunham@lavabit.com>]

On Sun, Jun 30, 2013 at 01:34:09AM -0400, Rich Felker wrote:
> On Sat, Jun 29, 2013 at 10:20:45PM -0700, Isaac wrote:
> > > 1.0.0
> > > Projected release: Early fall
> > > Key targets:
> > > - Polished documentation.
> > > - Organized and coordinated publicity plan.
> > > - At least one new exciting addition to make the release noteworthy,
> > >   but which has no chance of breaking things that work. Best candidate
> > >   would be one or more new ports, labeled experimental.
> > 
> > How about s390 and ia64? ;-)
> 
> s390 looks like a maybe. I'm not sufficiently familiar with it to call
> it a no, and Rob seemed interested in supporting it at one time.
> 
> ia64 is nothing but gratuitous incompatibility and arch-specific code
> where it doesn't belong, all for an arch that was dead before it was
> launched. I think it's officially dead now even, or maybe that's just
> wishful thinking.
 
> > All joking aside, I'd say +1. 

I mentioned those as the two worst candidates I could think of (hence the 
"all joking aside"). s390 is a 31-bit (yes, really) architecture; to be 
precise, it's the discontinued IBM System/390 architecture, which has been 
replaced with a 64-bit cpu.
All along it has been a mainframe platform.

> > And for ports, arm64, mips64 or mips n32, x32, and/or sh seem like
> > interesting targets. 
> 
> Agreed, all of those look interesting. Super H might be another
> candidate; IIRC it was used on some game consoles and automotive
> control computers.

Super H == sh for short. I'm using Debian's port names.

> > While sparc is not "dead", basically leon is the only sparc cpu that is 
> > alive and likely to provide an interested audience.
> > And that's sparc32.
> 
> I don't really know much about sparc except that the register windows
> system looks ugly.
> 
> > m68k/coldfire are 32-bit only, slow, and largely obsolete with little 
> > prospect of new development (Freescale is working on ppc and arm systems),
> > but there is some use of them in the embedded market, so I could imagine a
> > port being useful to someone.
> 
> m68k is in some ways an arch I'd like to avoid, but if it's
> interesting to people we could do it.

I'm mentioning it as potentially making sense in terms of the usage.

> > Do we currently support 64-bit ppc?
> 
> No, but 32-bit apps can run on 64-bit kernel as far as I know. I was
> just looking at the 64-bit ABI earlier today and it's rather
> gratuitously ugly, but probably not too hard to support.

Apparently, it's also slower on some CPUs:
http://www.yellowdog-board.com/viewtopic.php?p=23037#p23037

> Is hppa the same as pa-risc? If so, it's one I'd definitely like to
> omit. It's the only machine with a stack that grows upward, so it's a
Yes.

> > m32r is live, but I'm not aware of much interest.
> > tilera and epiphany (the Parallela coprocessor) sound interesting,
> > but are likely to be limited in availability.
> 
> Not familiar with them, but my guess would be they're interesting. In

Tilera Tile:
http://www.tilera.com/products/processors
In brief, it's a 64-bit processor that comes with up to 100 cores per cpu
(last I checked), topping out around 1.6 GHz. Linux is the only OS.

Epiphany:
http://www.adapteva.com/introduction/
Used in this project:
http://www.kickstarter.com/projects/adapteva/parallella-a-supercomputer-for-everyone/
In short, a multicore 32-bit risc cpu currently only used as a coprocessor.
Not really a candidate for a port, but if it ever does get a full Linux,
it might be interesting.

> embedded, everything has niche uses. On the high-end server side, on
> the other hand, anything but x86_64 (for straight power) or ARM (for
> cutting the primary cost of a data center: electricity) is madness. In
> other words, I think there's a lot more value in supporting diversity
> on the embedded side than on the enterprise side.

Power has a bit of the enterprise, too; it's got lower power usage (vs 
x86, no comparisons with ARM I'm aware of), and currently holds the 
highest clock speed of any stock cpu.
But I'd somehow expect embedded to be more open to a new libc than 
enterprise; for the latter, we'd need either a big vendor using musl
or a distro (Debian/RHEL/SLES) using it...most likely in place of 
klibc / newlib / dietlibc, for static rescue tools or for the initrd.

Which reminds me...
I've been in contact with someone working on a musl package for Debian:
https://github.com/wermut/musl/
He's currently looking for a sponsor/mentor, and has packaging that is 
co-installable with libc6.

Isaac Dunham