Jeremy O'Donoghue jeremy.odonoghue at
Fri May 26 09:49:46 CEST 2006

Espen Skoglund <esk <at>> writes:
> [Jeremy ]
> > Espen Skoglund <esk <at>> writes:
> >> [Jeremy ]
> >>> Sigma0 has disappeared from the latest Pistachio kernels as well,
> >>> so even the information above is version dependent.
> >> 
> >> What?!?  Sigma0 has always come with the kernels and will always
> >> do.  How else are the applications supposed to get access to
> >> memory?
> > I'm currently working with a prerelease of Pistachio based on the N2
> > embedded architecture. This is not yet available for general use,
> > and does contain changes over X.2 (as, to a more limited extent,
> > does N1).
> It's not really fair to be talking about a specification (and
> implementation) which has not yet been released is it?  Anyhow, when
> you said Pistachio I was assuming that you were referring to
> L4Ka::Pistachio, not NICTA::Pisctachio-embedded.

Apologies for slow response: GMANE was down yesterday.

My major mistake was that I didn't appreciate fully the distinction between 
Pistachio::L4Ka and Pistachio::NICTA-embedded before answering. I certainly 
apologise for any confusion which that caused.

Given where I started, (i.e. assuming NICTA-embedded), I don't think it's 
entirely unreasonable to mention an API change which is arriving imminently on 
that platform (after careful checking, public download version is 1.1; my 
version is 1.1.1).


> > This depends on what you are trying to do. If running L4 on a
> > hardware platform for which a BSP exists, I would agree with you (at
> > least to a point). The API is well defined and clear pre and post
> > conditions are specified.
> BSP?

Board Support Package. It's a pretty commonly used acronym. The BSP is the set 
of customizations which make it possible to at least boot a kernel on some 
hardware. It's basically the code which lives under the platform directory, so 
the code in platform/pleb2 is the BSP for the Pleb2 board.

> > I'm not sure that I'd use the word 'hack' to describe the NICTA
> > N-series Pistachio APIs, but I would agree that these are (of
> > necessity) changing faster than X.2
> Sure.  You definitely should be more specific about the API you're
> talking about in the future, though.  When one says "Pistachio" most
> people consider it to mean L4Ka::Pistachio and the Version X.2 API.

I will take care to be clear when I am talking about the embedded kernel API, 
rather than X.2 in future.


More information about the l4-hackers mailing list