Hi Greg,
On Wed, Jun 6, 2012 at 8:31 AM, Greg Ungerer <gerg@xxxxxxxxxxxx> wrote:
Yes, looks like that should have a "|| defined(CONFIG_CPU32)".
(According to the CPU32 reference manual words and long words must
be aligned on word boundaries.)
I think something like CONFIG_CPU_HAS_NO_UNALIGNED makes sense.
OK, doing that now...
Then I saw arch/m68k/lib/memcpy.c.
commit f230e80b423f6cb002015ab4771c06a53d5a2287
("m68k: fix memcpy to unmatched/unaligned source and dest on 68000")
| The original 68000 processors cannot copy 16bit or larger quantities from
| odd addresses. All newer members of the 68k family (including ColdFire)
| can do this.
So all Coldfires can do unaligned _reads_, but not unaligned _writes_
(exceptions below)?
I also think that the Coldfire 5272 can do unaligned accesses, but I
cannot test that at the moment.
According to the MCF5272 User Manual, "it supports misaligned data
accesses ...". So it looks like it does.
Having a CONFIG_CPU_HAS_NO_UNALIGNED looks like a really good solution
then. We need to be able select it as required on individual CPU types.
For now, I just make COLDFIRE select it, but we can move it to the individual
CPU types later.
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
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