Am 19.10.21 um 16:48 schrieb Sebastian Huber:
On 18/10/2021 23:08, Chris Johns wrote:
On 18/10/21 8:37 pm, Sebastian Huber wrote:
On 18/10/2021 09:53, Chris Johns wrote:
On 18/10/21 4:50 pm, Sebastian Huber wrote:
On 18/10/2021 07:19,chr...@rtems.org wrote:
From: Chris Johns<chr...@rtems.org>
- Coherent cache memory is used in libbsd for things like descriptors
and it optionally clears the memory on allocation. Test is
works.
There is no guarantee that memset() and memcpy() work with cache
coherent
memory. Such memory areas may disallow misaligned access for example.
That seems reasonable however this change about testing the implicit
requirements we have that memset works. LibBSD requires memset works
...
https://git.rtems.org/rtems-libbsd/tree/rtemsbsd/rtems/rtems-kernel-bus-dma.c?h=6-freebsd-12#n260
Using memset() here could be a bug in libbsd.
Yes, I also think so.
But what is a suitable mechanism to make sure the arch or BSP handle it
correctly? Maybe a clear routine in libbsd using the bus space API? That
interface has to work or the drivers will not work.
I think we had similar issues on another BSP. Christian, do you remember
how we solved this?
I remember mainly problems with copying memory. I think the last time it
resulted in an ugly "copy_from/to_io" function on the atsam:
https://git.rtems.org/rtems/tree/bsps/arm/atsam/start/iocopy.c
The bus_space_* functions should work. Only problem is that a valid
bus_space_tag is missing in this context. I think x86 uses it. I think
for all other platforms it is unused.
Best regards
Christian
--
--------------------------------------------
embedded brains GmbH
Herr Christian MAUDERER
Dornierstr. 4
82178 Puchheim
Germany
email: christian.maude...@embedded-brains.de
phone: +49-89-18 94 741 - 18
fax: +49-89-18 94 741 - 08
Registergericht: Amtsgericht München
Registernummer: HRB 157899
Vertretungsberechtigte Geschäftsführer: Peter Rasmussen, Thomas Dörfler
Unsere Datenschutzerklärung finden Sie hier:
https://embedded-brains.de/datenschutzerklaerung/
_______________________________________________
devel mailing list
devel@rtems.org
http://lists.rtems.org/mailman/listinfo/devel
