Malloc alignment in libstand / loader(8)

[John Baldwin]

On Wednesday, February 05, 2014 01:07:09 PM Ian Lepore wrote:
> On Wed, 2014-02-05 at 08:29 -0500, John Baldwin wrote:
> > On Tuesday, February 04, 2014 09:55:34 PM Ian Lepore wrote:
> > > On newer ARM chips, the device drivers used by loader(8) require that
> > > I/O buffers be aligned on cache line sized boundaries.  The drivers are
> > > part of u-boot which serves as a sort of load-time bios.
> > > 
> > > Attached is a patch that sets the malloc alignment in libstand to 64
> > > bytes when compiled on ARM, and leaves it at 16 bytes for all other
> > > platforms.  If there are no objections I'd like to commit this soon.
> > > 
> > > I've tested this on ARM, but have no way to test it on other platforms.
> > > The changes should be a no-op on other platforms.
> > 
> > I think this looks fine, but perhaps use CTASSERT() instead of rolling
> > your
> > own?  (I would say to use _Static_assert(), but I don't think that works
> > with our old GCC)
> 
> I wasn't sure if it's a good idea to #include <systm.h> in the libstand
> environment, since it has declarations for a lot of stuff.  I looked at
> what's in systm.h and then hand-replicated what seemed like the most
> generic of the choices.

That's fair.

-- 
John Baldwin