target/cortex_m: restore C_MASKINTS after reset

The cortex_m maskisr user-facing setting is not changed across a target
reset. However, the in-core C_MASKINTS bit was always cleared as part of
reset processing, meaning that a cortex_m maskisr on setting would not
be respected after a reset. Set C_MASKINTS based on the user-facing
setting value rather than always clearing it after reset.

Change-Id: I5aa5b9dfde04a0fb9c6816fa55b5ef1faf39f8de
Signed-off-by: Christopher Head <chead@zaber.com>
Reviewed-on: http://openocd.zylin.com/4605
Tested-by: jenkins
Reviewed-by: Tomas Vanek <vanekt@fbl.cz>

diff --git a/src/target/cortex_m.c b/src/target/cortex_m.c
index f186946722609dd51b55c2743f25e1b9984fbdd4..ca3dbec78dbc61b924d54230c66468b8db3f00c5 100644 (file)
--- a/src/target/cortex_m.c
+++ b/src/target/cortex_m.c
@@ -237,8 +237,11 @@ static int cortex_m_endreset_event(struct target *target)
                        return retval;
        }
 
-       /* clear any interrupt masking */
-       cortex_m_write_debug_halt_mask(target, 0, C_MASKINTS);
+       /* Restore proper interrupt masking setting. */
+       if (cortex_m->isrmasking_mode == CORTEX_M_ISRMASK_ON)
+               cortex_m_write_debug_halt_mask(target, C_MASKINTS, 0);
+       else
+               cortex_m_write_debug_halt_mask(target, 0, C_MASKINTS);
 
        /* Enable features controlled by ITM and DWT blocks, and catch only
         * the vectors we were told to pay attention to.