Re: Big endian in debian ARM
On Fri, May 27, 2005 at 03:35:41PM +0200, Marco Canini wrote:
> I've an IXP2400 based PCI card.
> Inside the IXP2400 there's an Intel XScale processor.
> I would like to run Debian ARM on it, but as far as I understand Debian ARM is
> little endian. Is there a way to get a big endian version of Debian ARM?
> My need for big endian is because the IXP2400 is a multi-core processor which
> has 8 processors called Microengine running in big endian.
I thought the arm procesors (and the xscale) were only little endian
Even if the arm can do big endian, it certainly isn't something
currently supported and probably won't be.
I know the PPC can do both ways and the kernel developers have been very
clear they have no intension of ever doing the other option on the PPC.
Do the microengine processors run arm instructions? I rather doubt it,
in which case as long as you convert the data when exchanging between
the xscale and the microengines you should be fine. One of the two
probably even has instructions to do so efficiently, unless the chip was
badly designed (I doubt that somewhat).
The arm wants little endian, so that's what you should run. Whatever
programs you load into the microengines is different since they aren't
linux programs and they aren't arm programs (as far as I can tell) so
their endianess doesn't matter. Trying to change the endianess of a cpu
and its OS just to avoid a few byte swaps does not make sense at all.