Little-endian PowerPC [LWN.net]

Little-endian PowerPC

Posted Oct 7, 2010 16:46 UTC (Thu) by linuxjacques (subscriber, #45768)
In reply to: Little-endian PowerPC by jond
Parent article: Little-endian PowerPC

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

I've run my slugs both ways.

to post comments

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.