diff --git a/sys/boot/i386/boot2/Makefile b/sys/boot/i386/boot2/Makefile
index d0d5fefae2a8..b7823bf427bd 100644
--- a/sys/boot/i386/boot2/Makefile
+++ b/sys/boot/i386/boot2/Makefile
@@ -1,4 +1,4 @@
-#	$Id: Makefile,v 1.7 1998/10/15 22:08:13 rnordier Exp $
+#	$Id: Makefile,v 1.8 1998/10/20 20:20:48 rnordier Exp $
 
 PROG=		boot2
 NOMAN=
@@ -11,6 +11,7 @@ CLEANFILES+=	boot1 boot1.out boot1.o \
 
 M4?=	m4
 
+B1INT13X?=	0
 B2SIOPRT?=	0x3f8
 B2SIOFMT?=	0x3
 B2SIODIV?=	0xc
@@ -41,7 +42,7 @@ boot1.out: boot1.o
 	${LD} ${LDFLAGS} -e start -Ttext ${ORG1} -o ${.TARGET} boot1.o
 
 boot1.o: boot1.m4 boot1.s
-	(cd ${.CURDIR}; ${M4} boot1.m4 boot1.s) | \
+	(cd ${.CURDIR}; ${M4} -DFLAGS=${B1INT13X} boot1.m4 boot1.s) | \
 		${AS} ${AFLAGS} -o ${.TARGET}
 
 boot2: boot2.ldr boot2.bin
diff --git a/sys/boot/i386/boot2/boot1.S b/sys/boot/i386/boot2/boot1.S
index a919d2ecdfcd..99397a394a56 100644
--- a/sys/boot/i386/boot2/boot1.S
+++ b/sys/boot/i386/boot2/boot1.S
@@ -13,7 +13,7 @@
 # purpose.
 #
 
-#	$Id: boot1.s,v 1.2 1998/10/13 21:35:42 rnordier Exp $
+#	$Id: boot1.s,v 1.3 1998/10/27 20:19:24 rnordier Exp $
 
 		.set MEM_REL,0x600		# Relocation address
 		.set MEM_ARG,0x800		# Arguments
@@ -156,7 +156,9 @@ return: 	ret				# Generic return
 
 # Read from disk
 
-read:		testb %dh,%dh			# Try for extensions?
+read:		tstbim(0x80,MEM_REL+flags-start)# Extensions enabled?
+		jz read.3			# No
+		testb %dh,%dh			# Try for extensions?
 		jz read.3			# No
 		movwir(0x55aa,_bx)		# Magic
 		pushl %edx			# Save
@@ -239,6 +241,8 @@ msg_read:	.asciz "Read error"
 msg_part:	.asciz "No bootable partition"
 msg_boot:	.asciz "\r\nHit return to reboot: "
 
+flags:		.byte FLAGS			# Flags
+
 		.org PRT_OFF,0x90
 
 # Partition table
diff --git a/sys/boot/i386/boot2/boot1.m4 b/sys/boot/i386/boot2/boot1.m4
index fc221a1854c1..b16de41babeb 100644
--- a/sys/boot/i386/boot2/boot1.m4
+++ b/sys/boot/i386/boot2/boot1.m4
@@ -13,7 +13,7 @@
 # purpose.
 #
 
-#	$Id:$
+#	$Id: boot1.m4,v 1.1.1.1 1998/10/12 21:16:26 rnordier Exp $
 
 define(_al,0x0)dnl
 define(_cl,0x1)dnl
@@ -60,3 +60,4 @@ define(movbi1,`.byte 0xc6; .byte 0x40 | $3; .byte $2; .byte $1')dnl
 define(callwi,`.byte 0xe8; .word $1 - . - 0x2')dnl
 define(jmpnwi,`.byte 0xe9; .word $1 - . - 0x2')dnl
 define(tstbi0,`.byte 0xf6; .byte $2; .byte $1')dnl
+define(tstbim,`.byte 0xf6; .byte 0x6; .word $2; .byte $1')dnl
diff --git a/sys/boot/i386/boot2/boot1.s b/sys/boot/i386/boot2/boot1.s
index a919d2ecdfcd..99397a394a56 100644
--- a/sys/boot/i386/boot2/boot1.s
+++ b/sys/boot/i386/boot2/boot1.s
@@ -13,7 +13,7 @@
 # purpose.
 #
 
-#	$Id: boot1.s,v 1.2 1998/10/13 21:35:42 rnordier Exp $
+#	$Id: boot1.s,v 1.3 1998/10/27 20:19:24 rnordier Exp $
 
 		.set MEM_REL,0x600		# Relocation address
 		.set MEM_ARG,0x800		# Arguments
@@ -156,7 +156,9 @@ return: 	ret				# Generic return
 
 # Read from disk
 
-read:		testb %dh,%dh			# Try for extensions?
+read:		tstbim(0x80,MEM_REL+flags-start)# Extensions enabled?
+		jz read.3			# No
+		testb %dh,%dh			# Try for extensions?
 		jz read.3			# No
 		movwir(0x55aa,_bx)		# Magic
 		pushl %edx			# Save
@@ -239,6 +241,8 @@ msg_read:	.asciz "Read error"
 msg_part:	.asciz "No bootable partition"
 msg_boot:	.asciz "\r\nHit return to reboot: "
 
+flags:		.byte FLAGS			# Flags
+
 		.org PRT_OFF,0x90
 
 # Partition table
diff --git a/sys/boot/i386/gptboot/Makefile b/sys/boot/i386/gptboot/Makefile
index d0d5fefae2a8..b7823bf427bd 100644
--- a/sys/boot/i386/gptboot/Makefile
+++ b/sys/boot/i386/gptboot/Makefile
@@ -1,4 +1,4 @@
-#	$Id: Makefile,v 1.7 1998/10/15 22:08:13 rnordier Exp $
+#	$Id: Makefile,v 1.8 1998/10/20 20:20:48 rnordier Exp $
 
 PROG=		boot2
 NOMAN=
@@ -11,6 +11,7 @@ CLEANFILES+=	boot1 boot1.out boot1.o \
 
 M4?=	m4
 
+B1INT13X?=	0
 B2SIOPRT?=	0x3f8
 B2SIOFMT?=	0x3
 B2SIODIV?=	0xc
@@ -41,7 +42,7 @@ boot1.out: boot1.o
 	${LD} ${LDFLAGS} -e start -Ttext ${ORG1} -o ${.TARGET} boot1.o
 
 boot1.o: boot1.m4 boot1.s
-	(cd ${.CURDIR}; ${M4} boot1.m4 boot1.s) | \
+	(cd ${.CURDIR}; ${M4} -DFLAGS=${B1INT13X} boot1.m4 boot1.s) | \
 		${AS} ${AFLAGS} -o ${.TARGET}
 
 boot2: boot2.ldr boot2.bin