[PATCH rtems 2/2] cpu/armv7m: Fix initialization of MPU regions

[Christian Mauderer]

The write to RBAR didn't have the valid flag set. Therefore the write to
RASR had an influence on the previously set region. That means for
example that if Region 0 had been enabled but 1 should be disabled due
to a size of 0, the previous code would have disabled region 0 instead.

This patch fixes that behaviour.

Close #4450
---
 cpukit/score/cpu/arm/include/rtems/score/armv7m.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/cpukit/score/cpu/arm/include/rtems/score/armv7m.h b/cpukit/score/cpu/arm/include/rtems/score/armv7m.h
index a5eaaef418..1803c8d8ca 100644
--- a/cpukit/score/cpu/arm/include/rtems/score/armv7m.h
+++ b/cpukit/score/cpu/arm/include/rtems/score/armv7m.h
@@ -660,7 +660,7 @@ static inline void _ARMV7M_MPU_Set_region(
     rbar = (uintptr_t) begin | region | ARMV7M_MPU_RBAR_VALID;
     rasr |= _ARMV7M_MPU_Get_region_size(size);
   } else {
-    rbar = region;
+    rbar = ARMV7M_MPU_RBAR_VALID | region;
     rasr = 0;
   }
 
-- 
2.26.2