Re: Why is __cpu_simple_lock_t an unsigned char?

[Heikki Krogerus <krohei%gmail.com@localhost>]

Matt Thomas wrote:
> 
> On Nov 5, 2008, at 11:21 PM, Heikki Krogerus wrote:
> 
>> This probably is a silly quistion, I know, but how should the
>> ldrex/strex be
>> handled in the future? Our ARM1136JF-S does not seem to support
>> ldrexb/strexb
>> instructions.
>>
>> Thumb does not support the swp instruction.
> 
> because armv4 and later have swpb (swap byte).
> 

but the ARM architecture reference manual mentions that "From ARMv6, use of SWP
and SWPB instructions is deprecated" and from the comments in
sys/arch/arm/include/mutex.h I figured that ldrex/strex will be added 
eventually.