Don't check ICSR.RETTOBASE outside an exception handler

The ICSR.RETTOBASE bit value is UNKNOWN when not inside an
exception handler, so don't try to test it in that situation.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 1 insertions, 0 deletions

diff --git a/armv7m.h b/armv7m.h
index 3d1c1ae..36955f8 100644
--- a/armv7m.h
+++ b/armv7m.h
@@ -31,6 +31,7 @@
 #define PRIGROUP_BITS 3
 #define PRIO_MASK (((1<<3)-1)<<(8-PRIGROUP_BITS))
 
+#define ICSR_RETTOBASE (1 << 11)
 
 typedef void (*vectfn)(void);