On 21/11/2014 6:31 pm, Sebastian Huber wrote:
On 21/11/14 06:10, Chris Johns wrote:
On 21/11/2014 12:53 am, Sebastian Huber wrote:
Module: rtems
Branch: master
Commit: 50440c065e247899ee739d56cb1392c259289031
Changeset:
http://git.rtems.org/rtems/commit/?id=50440c065e247899ee739d56cb1392c259289031
Author: Sebastian Huber <sebastian.hu...@embedded-brains.de>
Date: Wed Nov 19 15:30:24 2014 +0100
bsps/arm: Enable L2C for Cortex-A9 MPCore BSPs
---
+RTEMS_BSPOPTS_SET([BSP_DATA_CACHE_ENABLED],[*],[1])
+RTEMS_BSPOPTS_HELP([BSP_DATA_CACHE_ENABLED],[enable data cache])
+
+RTEMS_BSPOPTS_SET([BSP_INSTRUCTION_CACHE_ENABLED],[*],[1])
+RTEMS_BSPOPTS_HELP([BSP_INSTRUCTION_CACHE_ENABLED],[enable
instruction cache])
+
To disable I provide configure with:
BSP_DATA_CACHE_ENABLED=0 BSP_INSTRUCTION_CACHE_ENABLED=0
however this:
+#if defined(BSP_DATA_CACHE_ENABLED) ||
defined(BSP_INSTRUCTION_CACHE_ENABLED)
+ /* Enable unified L2 cache */
+ rtems_cache_enable_data();
+#endif
and this:
+#if !defined(RTEMS_SMP) \
+ && (defined(BSP_DATA_CACHE_ENABLED) \
+ || defined(BSP_INSTRUCTION_CACHE_ENABLED))
+ /* Enable unified L2 cache */
+ rtems_cache_enable_data();
+#endif
only check for defined and it is always defined. These should check
for the value only ie:
#if BSP_DATA_CACHE_ENABLED || BSP_INSTRUCTION_CACHE_ENABLED
?
You should use
BSP_DATA_CACHE_ENABLED= BSP_INSTRUCTION_CACHE_ENABLED=
for the configure.
Urrr <bletch> sure if I have to. This is the first I have ever heard of
doing this and it is confusing because the configure.ac code uses the
value '1' and for me that implied a value of '0' had the opposite
effect. I seem to remember other opts such as the reset one in the PC
BSP taking 1 or 0.
My preference these days is not to rely on 'defined()' tests. It avoids
this type of error and the code reads much better.
This is not the only case of BSPOPTS'less'ness we have in RTEMS but
this one is an issue for me. Have I told you recently how much I
dislike the BSPOPTS support.
Yes, I know, but what is the alternative? These defines are already
used for a lot of PowerPC BSPs and I don't think it is good to invent
yet another solution for the same problem on ARM.
I am not suggesting we change anything with this build system. I am
suggesting we need to address this issue in 5.0 and a new build system
and my concern is the mixed use of defined() and/or value testing in the
code base. We need one consistent method and BSPOPTS has no structure
and so the code has no formal approach and it is confusing to users
because you need to check all references to see what it actually means.
It is ok if you wrote the code but if you have not it is a slog to
figure it all out.
Chris
_______________________________________________
devel mailing list
devel@rtems.org
http://lists.rtems.org/mailman/listinfo/devel
