Index: macppc/conf/std.macppc
===================================================================
RCS file: /cvsroot/src/sys/arch/macppc/conf/std.macppc,v
retrieving revision 1.24
diff -u -u -r1.24 std.macppc
--- macppc/conf/std.macppc	9 Jun 2018 02:25:52 -0000	1.24
+++ macppc/conf/std.macppc	22 Jun 2018 01:21:46 -0000
@@ -7,6 +7,7 @@
 
 # standard ("mandatory") kernel options.
 options 	PPC_OEA		# OEA class PowerPC chips
+options		PPC_OFW		# OpenFirmware
 makeoptions	PPCDIR="oea"	# Tell Makefile.powerpc what dir to use
 makeoptions     PPC_ARCH_MODE="ppc32"
 
Index: powerpc/conf/files.powerpc
===================================================================
RCS file: /cvsroot/src/sys/arch/powerpc/conf/files.powerpc,v
retrieving revision 1.90
diff -u -u -r1.90 files.powerpc
--- powerpc/conf/files.powerpc	1 Jun 2018 18:06:58 -0000	1.90
+++ powerpc/conf/files.powerpc	22 Jun 2018 01:21:46 -0000
@@ -3,7 +3,7 @@
 defflag	opt_altivec.h	ALTIVEC K_ALTIVEC PPC_HAVE_SPE
 defflag	opt_openpic.h	OPENPIC_DISTRIBUTE
 defparam opt_ppcparam.h	L2CR_CONFIG L3CR_CONFIG INTSTK CLOCKBASE VERBOSE_INITPPC
-defflag	opt_ppcarch.h	PPC_OEA PPC_OEA601 PPC_OEA64 PPC_OEA64_BRIDGE PPC_MPC8XX PPC_IBM4XX PPC_IBM403 PPC_BOOKE
+defflag	opt_ppcarch.h	PPC_OEA PPC_OEA601 PPC_OEA64 PPC_OEA64_BRIDGE PPC_MPC8XX PPC_IBM4XX PPC_IBM403 PPC_BOOKE PPC_OFW
 defflag opt_ppccache.h	CACHE_PROTO_MEI
 defflag opt_pmap.h	PMAPDEBUG PMAPCHECK PMAPCOUNTERS PMAP_MINIMALTLB
 defparam opt_pmap.h	PTEGCOUNT PMAP_MEMLIMIT
Index: powerpc/powerpc/db_interface.c
===================================================================
RCS file: /cvsroot/src/sys/arch/powerpc/powerpc/db_interface.c,v
retrieving revision 1.53
diff -u -u -r1.53 db_interface.c
--- powerpc/powerpc/db_interface.c	23 Jan 2015 07:27:05 -0000	1.53
+++ powerpc/powerpc/db_interface.c	22 Jun 2018 01:21:46 -0000
@@ -59,7 +59,10 @@
 #define db_printf printf
 #endif
 
+#ifdef PPC_OFW
 #include <dev/ofw/openfirm.h>
+static void db_prom_cmd(db_expr_t, bool, db_expr_t, const char *);
+#endif
 
 #define NOCPU   ~0
 volatile u_int ddb_cpu = NOCPU;
@@ -101,7 +104,11 @@
 
 #ifdef DDB
 const struct db_command db_machine_command_table[] = {
-#if defined (PPC_OEA) || defined(PPC_OEA64) || defined (PPC_OEA64_BRIDGE)
+#if defined(PPC_OFW)
+	{ DDB_ADD_CMD("prom",	db_prom_cmd,	0,
+	  "Enter the OpenFirmware PROM monitor.",NULL,NULL) },
+#endif
+#if defined(PPC_OEA) || defined(PPC_OEA64) || defined (PPC_OEA64_BRIDGE)
 	{ DDB_ADD_CMD("bat",	db_show_bat,		0,
 	  "Print BAT register translations", NULL,NULL) },
 	{ DDB_ADD_CMD("mmu",	db_show_mmu,		0,
@@ -461,6 +468,16 @@
 	}
 }
 
+
+#ifdef PPC_OFW
+static void
+db_prom_cmd(db_expr_t addr, bool have_addr, db_expr_t count, const char *modif)
+{
+
+	OF_enter();
+}
+#endif
+
 static void
 db_show_mmu(db_expr_t addr, bool have_addr, db_expr_t count, const char *modif)
 {