cortexm: Add target option to inhibit assersion of SRST.

src/cortexm.c

@@ -418,8 +418,10 @@ static void cortexm_pc_write(target *t, const uint32_t val)
  * using the core debug registers in the NVIC. */
 static void cortexm_reset(target *t)
 {
-	jtagtap_srst(true);
-	jtagtap_srst(false);
+	if ((t->target_options & CORTEXM_TOPT_INHIBIT_SRST) == 0) {
+		jtagtap_srst(true);
+		jtagtap_srst(false);
+	}
 
 	/* Read DHCSR here to clear S_RESET_ST bit before reset */
 	target_mem_read32(t, CORTEXM_DHCSR);

src/include/cortexm.h

@@ -153,6 +153,8 @@
 
 #define ARM_THUMB_BREAKPOINT 0xBE00
 
+#define	CORTEXM_TOPT_INHIBIT_SRST (1 << 2)
+
 bool cortexm_attach(target *t);
 void cortexm_detach(target *t);
 void cortexm_halt_resume(target *t, bool step);

src/lpc43xx.c

@@ -110,6 +110,7 @@ bool lpc43xx_probe(target *t)
 				                  0x1B010000, 0x70000, 0x10000);
 				target_add_commands(t, lpc43xx_cmd_list, "LPC43xx");
 				target_add_ram(t, 0x1B080000, 0xE4F80000UL);
+				t->target_options |= CORTEXM_TOPT_INHIBIT_SRST;
 			}
 			break;
 		case 0x4100C200: