Holger Bettag wrote:
Mark Salisbury [off-list ref] writes:
[... linux in ppc little endian mode ...]
quoted
well, this is in the context of a multi-CPU type (x86/ppc, sparc/ppc,
ppc/ppc, mips/ppc) shared memory multicomputer.
when dealing w/ direct mapped, shared memory, uniformity of endian-ness
makes many multicomputer problems easier to solve.(not to mention easier
for the customer to program...)
You are aware that a PPC in little endian mode is merely tricking with the
low order address bits, but does not actually lay out its data in a little
endian fashion in physical memory?
not according to section 3.1 of the motorola ppc "green book"
according to that it is a sort of munged le representation,
which thanks to a "one trick pony" PCI bridge looks like standard LE to
the PCI based x86 host.
understand please that what I am proposing is a config option. as a
sub-architecture port. it would not affect any code that it didn't
absolutely need to, and would only be compiled if sombody selected that
particular config.
I am _NOT_ suggesting running pmacs in LE mode.
as in:
ppc---
|-- PREP
|-- CHRP
|-- MAC
|-- MERCURY ---
|-- Big Endian
|-- Little Endian
--
/*------------------------------------------------**
** Mark Salisbury | Mercury Computer Systems **
** mbs@mc.com | System OS - Kernel Team **
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** Infinite Justice is niether. **
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