Memcpy() on MPC5200B

[Jon Smirl]

On Mon, Sep 22, 2008 at 4:07 PM, Wright, Chuck
<Charles.A.Wright at snapon.com> wrote:
> I've found a case where memcpy() is failing on copies longer that 4
> bytes.
>
> Closer investigation found that the destination pointer is not pointing
> to a word aligned address.
>
> The problem comes from the JFFS2 driver where there is a struct that is
> being used to create the destination pointer for the memcpy() function.

There is a thread about this problem here:
http://thread.gmane.org/gmane.linux.drivers.mtd/21521

I don't believe it has been resolved yet.


>
> If I insert my own padding into the struct, my memcpy() problems go
> away!
> I'm concerned that this problem may be lurking in other areas of code.
> (I get no warnings during compile)
>
> On the MPC5200B processor, is that the assumed behavior for an unaligned
> memcpy()??
> Is there a gcc option to force word alignment??
>
> I'm using a MontaVista supplied kernel and compiler. (not my choice!)
> Unfortunately, six weeks later, MontaVista is still confused.
>
> Thanks for any help you can offer,
>
> Chuck Wright
>
>
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-- 
Jon Smirl
jonsmirl at gmail.com