Alignment Issues - TI OMAP and Marvell Kirkwood processors

[Chris Tyler]

I was experimenting Wednesday with two systems, one using a Marvell
Kirkwood processor (SheevaPlug) and the other using a TI OMAP
(BeagleBoard), testing the PHP 1/4 bug[0] and the effect of alignment
fixups[1], using the same binary F12 ARM packages.

Oddly, the OMAP system always calculated the right value regardless of
the fixups setting, while the Kirkwood needed fixups enabled to display
the right value. Why do the two processors act differently? Does the
OMAP processor have additional logic handle to handle non-aligned
access? (Or did I somehow accidentally provoke something that changed
the memory layout?)

-Chris

[0]
http://lists.fedoraproject.org/pipermail/arm/2009-December/000420.html

[1]
http://fedora-arm.blogspot.com/2009/11/fedora-arm-alignment-errors.html , 
http://lecs.cs.ucla.edu/wiki/index.php/XScale_alignment