L4 implementations

Shams shams at orcon.net.nz
Fri Jun 8 03:05:36 CEST 2007


1. Also is OKL4 the one and only commercially implementaed
and supported version of L4?

2. I believe OK is using gcc to build OKL4. However is this
a custom version of gcc or just the normal 4.x version thats
available for everyone else?



"Gernot Heiser" <gernot at nicta.com.au> wrote in message
news:20070604.192206.39162110.gernot at nicta.com.au...
>>>>>> On Mon, 4 Jun 2007 07:43:12 +1200, "Shams" <shams at orcon.net.nz> said:
> S> Thanks for the info.
> S> 1. After reading up on http://www.ok-labs.com/ I still couldn't find
> the
> S> following info.
> S> Does OKL4 only run on ERTOS or can it run on other architectures like
> S> L4.Pistachio
> S> eg. PowerPC, IA32, IA64, see: http://l4ka.org/projects/pistachio/?
> not sure what you mean with "only run on ERTOS".
> OKL4 presently is supported on x86, ARM and MIPS. Others will be
> released in the future.  Some Pistachio ports (like Alpha, Itanium)
> aren't presently maintained by anyone. In fact, I don't think anyone
> is really maintaining Pistachio on anything but x86 (but I could be
> mistaken).
> S> 2. Since OKL4 is evolving as a commercial project (and being a
> descendant of
> S> L4.Pistachio)
> S> how much contribution is OKL4 making back to the L4 community in
> particular
> S> L4.Pistachio
> S> in terms of API, ABI, Architecture, Documentation etc, I mean for
> S> significant commercial
> S> improvements to OKL4 are most/some of them integrated back into
> S> L4-V4/.Pistachio?
> Given that OKL4 has forked from L4Ka::Pistachio a couple years ago,
> there is a limit to what code can be contributed back. However, OKL4
> is distributed under a compatible license, so people are welcome to
> take stuff back into Pistachio.
> As far as API is concerned, I don't think that the KA Pistachio
> maintainers want to go the way OKL4 is going.
> S> 3. Also if L4-V4/L4.Pistachio evolves then doe the changes get followed
> S> through into
> S> OKL4.
> Maybe, maybe not. KA changes are motivated by different deployment
> scenarios, and the code and API has diverged significantly.
> S> 4. So OKL4 can be used commercially or in a research environment (free
> of
> S> charge) but if one
> S> wants commercial support/development then they have to pay for it,
> right?
> S> Sorry just getting my
> S> BSD license understanding clarified.
> OKL4 is presently licensed under a straight BSD license. You can do
> with it pretty much whatever you can do with Pistachio. In addition,
> you can get commercial support (services such as porting, system
> architecture, training etc). Also, OK has code which builds on OKL4
> that is under proprietary licenses.
> In addition, while the KA folks have always maintained very high
> standards of code quality, they are a research team and cannot
> possibly put as much effort into QA as Open Kernel does.
> Gernot

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