Re: X32 psABI status

From: Petr Baudis
Date: Sun Feb 13 2011 - 11:46:29 EST


On Sun, Feb 13, 2011 at 07:13:57AM -0800, H.J. Lu wrote:
> On Sun, Feb 13, 2011 at 7:07 AM, Florian Weimer <fw@xxxxxxxxxxxxx> wrote:
> > * H. J. Lu:
> >
> >>> Actually, I'm wondering if you can do the translation in user space.
> >>> There already are 32-on-64 implementations in existence, without
> >>> kernel changes (recent Hotspot, LuaJIT, and probably some more).
> >>
> >> Please check out the x32 kernel source and provide feedback.
> >
> > I still don't understand why you need a separate syscall table.  You
> > should really be able to run on an unmodified amd64 kernel, in 64 bit
>
> That is done on purpose. x32 is designed for environments where the
> current ia32 API is sufficient. You can think it as ia32 with register
> extended to 64bit plus 8 more registers. Everything else is still 32bit.

I think it would be great if you could add some text like this plus some
rationale (AIUI, this is geared mainly at new Atoms and other x86_64
embedded platforms) to the document.

(BTW, it is not really convincing to me that such a niche is worth all
the trouble this is going to bring.)

--
Petr "Pasky" Baudis
Computer science education cannot make an expert programmer any more
than studying brushes and pigment can make an expert painter. --esr
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