On 2 July 2010 15:03, Chris Tyler <chris(a)tylers.info> wrote:
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? [snip]
Yes. The OMAP3530's Cortex-A8 supports unaligned memory accesses.
There will be an overhead for accessing what is actually two memory
locations and fixing the result, but it'll be nothing like the
overhead of causing an abort and handling it in the kernel.
See, for example:
http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.ddi0344k/Beih...
Hope that helps,
Matthew