+ /* if no bkpt instruction is found at pc then we can perform
+ * a normal step, otherwise we have to manually step over the bkpt
+ * instruction - as such simulate a step */
+ if (bkpt_inst_found == false)
+ {
+ /* Automatic ISR masking mode off: Just step over the next instruction */
+ if ((cortex_m3->isrmasking_mode != CORTEX_M3_ISRMASK_AUTO))
+ {
+ cortex_m3_write_debug_halt_mask(target, C_STEP, C_HALT);
+ }
+ else
+ {
+ /* Process interrupts during stepping in a way they don't interfere
+ * debugging.
+ *
+ * Principle:
+ *
+ * Set a temporary break point at the current pc and let the core run
+ * with interrupts enabled. Pending interrupts get served and we run
+ * into the breakpoint again afterwards. Then we step over the next
+ * instruction with interrupts disabled.
+ *
+ * If the pending interrupts don't complete within time, we leave the
+ * core running. This may happen if the interrupts trigger faster
+ * than the core can process them or the handler doesn't return.
+ *
+ * If no more breakpoints are available we simply do a step with
+ * interrupts enabled.
+ *
+ */
+
+ /* Set a temporary break point */
+ retval = breakpoint_add(target, pc_value , 2, BKPT_TYPE_BY_ADDR(pc_value));
+ bool tmp_bp_set = (retval == ERROR_OK);
+
+ /* No more breakpoints left, just do a step */
+ if (!tmp_bp_set)
+ {
+ cortex_m3_write_debug_halt_mask(target, C_STEP, C_HALT);
+ }
+ else
+ {
+ /* Start the core */
+ LOG_DEBUG("Starting core to serve pending interrupts");
+ int64_t t_start = timeval_ms();
+ cortex_m3_write_debug_halt_mask(target, 0, C_HALT | C_STEP);
+
+ /* Wait for pending handlers to complete or timeout */
+ do {
+ retval = mem_ap_read_atomic_u32(swjdp, DCB_DHCSR, &cortex_m3->dcb_dhcsr);
+ if (retval != ERROR_OK)
+ {
+ target->state = TARGET_UNKNOWN;
+ return retval;
+ }
+ isr_timed_out = ((timeval_ms() - t_start) > 500);
+ } while (!((cortex_m3->dcb_dhcsr & S_HALT) || isr_timed_out));
+
+ /* Remove the temporary breakpoint */
+ breakpoint_remove(target, pc_value);
+
+ if (isr_timed_out)
+ {
+ LOG_DEBUG("Interrupt handlers didn't complete within time, "
+ "leaving target running");
+ }
+ else
+ {
+ /* Step over next instruction with interrupts disabled */
+ cortex_m3_write_debug_halt_mask(target, C_HALT | C_MASKINTS, 0);
+ cortex_m3_write_debug_halt_mask(target, C_STEP, C_HALT);
+ /* Re-enable interrupts */
+ cortex_m3_write_debug_halt_mask(target, C_HALT, C_MASKINTS);
+ }
+ }
+ }
+ }
+
+ retval = mem_ap_read_atomic_u32(swjdp, DCB_DHCSR, &cortex_m3->dcb_dhcsr);
+ if (retval != ERROR_OK)
+ return retval;