Index: head/sys/arm/arm/machdep.c
===================================================================
--- head/sys/arm/arm/machdep.c
+++ head/sys/arm/arm/machdep.c
@@ -66,6 +66,7 @@
 #include <sys/kernel.h>
 #include <sys/linker.h>
 #include <sys/msgbuf.h>
+#include <sys/reboot.h>
 #include <sys/rwlock.h>
 #include <sys/sched.h>
 #include <sys/syscallsubr.h>
@@ -785,7 +786,17 @@
 }
 #endif
 
+static void
+arm_kdb_init(void)
+{
 
+	kdb_init();
+#ifdef KDB
+	if (boothowto & RB_KDB)
+		kdb_enter(KDB_WHY_BOOTFLAGS, "Boot flags requested debugger");
+#endif
+}
+
 #ifdef FDT
 #if __ARM_ARCH < 6
 void *
@@ -1054,7 +1065,7 @@
 
 	init_param2(physmem);
 	dbg_monitor_init();
-	kdb_init();
+	arm_kdb_init();
 
 	return ((void *)(kernelstack.pv_va + USPACE_SVC_STACK_TOP -
 	    sizeof(struct pcb)));
@@ -1263,7 +1274,7 @@
 	/* Init message buffer. */
 	msgbufinit(msgbufp, msgbufsize);
 	dbg_monitor_init();
-	kdb_init();
+	arm_kdb_init();
 	/* Apply possible BP hardening. */
 	cpuinfo_init_bp_hardening();
 	return ((void *)STACKALIGN(thread0.td_pcb));
Index: head/sys/arm/arm/machdep_boot.c
===================================================================
--- head/sys/arm/arm/machdep_boot.c
+++ head/sys/arm/arm/machdep_boot.c
@@ -27,6 +27,7 @@
  */
 
 #include "opt_platform.h"
+#include "opt_ddb.h"
 
 #include <sys/cdefs.h>
 __FBSDID("$FreeBSD$");
@@ -55,6 +56,10 @@
 
 #ifdef EFI
 #include <sys/efi.h>
+#endif
+
+#ifdef DDB
+#include <ddb/ddb.h>
 #endif
 
 #ifdef DEBUG