Re: Linux/IA-64 byte order

Taral (taral@cyberjunkie.com)
Mon, 8 Mar 1999 21:46:27 -0600


On Mon, 08 Mar 1999, Richard Gooch wrote:
>I'd like to start a discussion and see if we can reach some reasonable
>consensus on whether big-endian is acceptable to the community. I
>think this is an important issue, as a little-endian Linux/IA-64 is
>going to make it a second choice for a significant number of
>people. This reason for this follows (from my orginal message to
>David):

To tell you the truth, big-endian is generally preferred in many systems, due
to the fact that groupings don't change the ordering of bytes. In other words:

12 34 56 78 9A BC DE F0
1234 5678 9ABC DEF0
12345678 9ABCDEF0

Are all the same data, just shown as bytes/shorts/longs, respectively. This
makes viewing data *much* easier, since you're not constantly byte-swapping.

As far as compatability goes, it *can* and *will* break programs, but only
those which had dependencies on endianness -- a generally agreed Bad Thing(tm).
_Properly_ written programs shouldn't even blink at the change, except to
perhaps switch #defines around in configuration.

Since programs and the kernel can all easily cope with endianness changes, I
don't think the Linux community can really care either way, except either as a
backwards-compatability thing (which isn't really valid when one considers that
POSIX, etc. exist so that code can be ported rapidly and easily between
disparate architectures) or as an aesthetic thing (see above).

Taral

P.S. I assume by your post that IA64 processors will have selectable
endianness, like the ARM processor (iirc). Is this correct?

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.rutgers.edu
Please read the FAQ at http://www.tux.org/lkml/