[PATCH 1/4] bsp/leon3: Invalidate L1 caches during startup

[Daniel Hellstrom]

On 02/18/2014 02:58 PM, Sebastian Huber wrote:
> On 2014-02-18 14:49, Daniel Hellstrom wrote:
>>
>> Is this needed for CPU0 also?
>
> I don't know.  In which state are the caches after a power-on-reset?

It is the boot loaders job to initialize hardware and to load RTEMS into RAM before jumping into it. Since single-core version seems to be working as it is I see no reason why the behaviour have 
changed with SMP. The bootloader initializes also the secondary CPUs and RTEMS is waiting in a loop for the secondary CPU (not modifying anything) to wake up, so I guess it shouldn't be needed there 
either.

>
>> Otherwise I think it would be enough to
>> invalidate the caches when the other cache parameters to save one instruction,
>> they are modified in leon3_secondary_cpu_initialize():
>>
>> - sparc_leon3_set_cctrl( 0x80000F );
>> + sparc_leon3_set_cctrl( 0xE0000F );
>
> I don't know if this cache flush is required at all.  In case it is required, then no read from memory must happen before the start of the flush operation. The easiest way to ensure this is to do it 
> right at the start before the first C function is called.
>