Malloc alignment in libstand / loader(8)

[Ian Lepore]

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.

-- Ian