Re: [Jack-Devel] Jack on a Nexus 7

On Sunday 21 July 2013 16:43:44 Chris Caudle wrote:
> On Sun, July 21, 2013 8:45 am, Christian Schoenebeck wrote:
> > I doubt that the crash you got is caused by packed data structures.
> > Disabling the packed attributes most probably just moved the symptoms.
> 
> Non-aligned memory access is not supported on ARM.  This was discussed
> fairly extensively on the list a few months  back, should be in the
> archives.  I think currently Jack2 does not pack structs on ARM to solve
> that problem.

Well, the Nexus 7 provides an ARMv7 CPU with hardware supported non-aligned 
access. But on the other hand, I just figured that there are still 
instructions like double word (64 bit) access which raise an alignment fault 
(section A3.2.1 in the ARM Architecture Reference Manual). So far I thought 
those alignment faults would be caught & processed correctly by the OS 
(similar like software implemented unaligned simple loads/saves on ARMv6 
systems), but I must admit I am not sure if that's always the case.

CU
Christian

1374427310.19349_0.ltw:2,a <201307211923.04576.schoenebeck at crudebyte dot com>