Little-endian PowerPC [LWN.net]

Little-endian PowerPC

Posted Oct 7, 2010 5:50 UTC (Thu) by ikm (guest, #493)
Parent article: Little-endian PowerPC

> the fact that one obscure architecture - x86 - is little-endian

Not to mention ARM. Those together hold a lion share, such big that endian-correctness in programs isn't too big a deal anymore.

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Little-endian PowerPC

Posted Oct 7, 2010 8:55 UTC (Thu) by jond (subscriber, #37669) [Link] (3 responses)

ARM comes in both flavours. The Linksys NSLU2 is big-endian ARM, for example.

Little-endian PowerPC

Posted Oct 7, 2010 16:46 UTC (Thu) by linuxjacques (subscriber, #45768) [Link] (2 responses)

The NSLU2 (like most (all?)) ARMs can run either endian.

I've run my slugs both ways.

Little-endian PowerPC

Posted Oct 7, 2010 16:51 UTC (Thu) by linuxjacques (subscriber, #45768) [Link] (1 responses)

The NSLU2 SoC, an Intel IXP425 defaulted to BE because it's a
"network processor" and network byte order is BE.

There was a slight but measurable network throughput gain when
running in BE vs LE.

Little-endian PowerPC

Posted Oct 8, 2010 1:19 UTC (Fri) by busterb (subscriber, #560) [Link]

Also, the IXP425 has a proprietary firmware that runs on the microengines that drive the networking subsystem. These always run big-endian, so it makes sense to have the whole chip be big endian (the microengines are not byte-swappable like the ARM core is.)

I did a lot of coding for the IXP2855, which is the IXP425's discontinued big brother.