Malloc alignment in libstand / loader(8)

[Warner Losh]

On Feb 5, 2014, at 6:29 AM, 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'd enable it for mips and powerpc, the other two platforms that have uboot callback support.

Other than that, the change looks good to me.

Warner