[PATCH 1/2] LEON3: add dedicated SMP BSP config

Chris Johns chrisj at rtems.org
Fri Jul 4 03:39:19 UTC 2014

On 4/07/2014 3:24 am, Joel Sherrill wrote:
> On 7/3/2014 2:59 AM, Daniel Hellstrom wrote:
>> In order to support older toolchains and LEON3 v7 systems the
>> -mcpu=leon3 flag can not be used in the LEON3 BSP. The SMP
>> kernel however requires -mcpu=leon3 for the CAS support only
>> present in GCC-4.8 and GCC-4.9.
> I don't know if older tools is an issue with 4.11 or not. I lean to not.
> But if we end up with leon3smp as a BSP, doesn't that mean that
> the regular leon3 BSP isn't turning on the right compiler flags
> for the CAS instruction?
> What does having SMP on mean for the regular leon3 configuration?
> Does it work? fail to compile? The erc32 and leon2 BSPs still work
> when SMP is enabled even though they are uniprocessor.
> Just curious if making this distinction is (a) necessary and
> (b) doesn't introduce subtle breakage if you build leon3
> with --enable-smp.

We need to decide which direction we are heading in. It is either 
specific BSPs that enable SMP or it is the configure options.

Using a specific BSP removes the need for the configure option and this 
has the advantage of not needing to know which BSPs are SMP able and 
which are not. This should be viewed from the perspective of buildbot 
and how that is set up. The zynq zc702 bsp has had the SMP variants 
removed because of the configure option so there is confusion here.


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