Index: head/sys/boot/i386/zfsboot/Makefile
===================================================================
--- head/sys/boot/i386/zfsboot/Makefile	(revision 219701)
+++ head/sys/boot/i386/zfsboot/Makefile	(working copy)
@@ -17,6 +17,11 @@ REL1=	0x700
 ORG1=	0x7c00
 ORG2=	0x2000
 
+.if defined(USE_XREAD)
+XREAD_FLAGS=	-DUSE_XREAD
+XREAD_FILE=	xreadorg.h
+.endif
+
 CFLAGS=	-DBOOTPROG=\"zfsboot\" \
 	-Os -g \
 	-fno-guess-branch-probability \
@@ -24,7 +29,7 @@ CFLAGS=	-DBOOTPROG=\"zfsboot\" \
 	-fno-unit-at-a-time \
 	-mno-align-long-strings \
 	-mrtd \
-	-DBOOT2 \
+	-DBOOT2 ${XREAD_FLAGS} \
 	-DFLAGS=${BOOT_BOOT1_FLAGS} \
 	-DSIOPRT=${BOOT_COMCONSOLE_PORT} \
 	-DSIOFMT=${B2SIOFMT} \
@@ -64,9 +69,9 @@ zfsldr.out: zfsldr.o
 	${LD} ${LDFLAGS} -e start -Ttext ${ORG1} -o ${.TARGET} zfsldr.o
 
 CLEANFILES+=	zfsboot2 zfsboot.ld zfsboot.ldr zfsboot.bin zfsboot.out \
-		zfsboot.o zfsboot.s zfsboot.s.tmp xreadorg.h sio.o
+		zfsboot.o zfsboot.s zfsboot.s.tmp sio.o ${XREAD_FILE}
 
-# We currently allow 32768 bytes for zfsboot - in practice it could be
+# We currently allow 65536 bytes for zfsboot - in practice it could be
 # any size up to 3.5Mb but keeping it fixed size simplifies zfsldr.
 # 
 BOOT2SIZE=	65536
@@ -76,6 +81,8 @@ zfsboot2: zfsboot.ld
 	    echo "$$x bytes available"; test $$x -ge 0
 	dd if=zfsboot.ld of=${.TARGET} obs=${BOOT2SIZE} conv=osync
 
+CLEANFILES+=	util.o cons.o drv.o
+
 zfsboot.ld: zfsboot.ldr zfsboot.bin ${BTXKERN}
 	btxld -v -E ${ORG2} -f bin -b ${BTXKERN} -l zfsboot.ldr \
 	    -o ${.TARGET} -P 1 zfsboot.bin
@@ -91,9 +98,9 @@ zfsboot.out: ${BTXCRT} zfsboot.o sio.o drv.o cons.
 
 zfsboot.o: zfsboot.s
 
-SRCS=	zfsboot.c xreadorg.h
+SRCS=	zfsboot.c ${XREAD_FILE}
 
-zfsboot.s: zfsboot.c xreadorg.h ${.CURDIR}/../../zfs/zfsimpl.c
+zfsboot.s: zfsboot.c ${XREAD_FILE} ${.CURDIR}/../../zfs/zfsimpl.c
 	${CC} ${CFLAGS} -S -o zfsboot.s.tmp ${.CURDIR}/zfsboot.c
 	sed -e '/align/d' -e '/nop/d' < zfsboot.s.tmp > zfsboot.s
 	rm -f zfsboot.s.tmp
Index: head/sys/boot/i386/common/cons.c
===================================================================
--- head/sys/boot/i386/common/cons.c	(revision 219701)
+++ head/sys/boot/i386/common/cons.c	(working copy)
@@ -37,6 +37,7 @@ void
 putc(int c)
 {
 
+	v86.ctl = V86_FLAGS;
 	v86.addr = 0x10;
 	v86.eax = 0xe00 | (c & 0xff);
 	v86.ebx = 0x7;
Index: head/sys/boot/i386/common/drv.c
===================================================================
--- head/sys/boot/i386/common/drv.c	(revision 219701)
+++ head/sys/boot/i386/common/drv.c	(working copy)
@@ -26,7 +26,7 @@ __FBSDID("$FreeBSD$");
 #include "rbx.h"
 #include "util.h"
 #include "drv.h"
-#ifndef GPT
+#ifdef USE_XREAD
 #include "xreadorg.h"
 #endif
 
@@ -58,7 +58,7 @@ drvsize(struct dsk *dskp)
 }
 #endif	/* GPT */
 
-#ifdef GPT
+#ifndef USE_XREAD
 static struct {
 	uint16_t	len;
 	uint16_t	count;
@@ -66,7 +66,7 @@ static struct {
 	uint16_t	seg;
 	uint64_t	lba;
 } packet;
-#endif	/* GPT */
+#endif	/* !USE_XREAD */
 
 int
 drvread(struct dsk *dskp, void *buf, daddr_t lba, unsigned nblk)
@@ -75,7 +75,8 @@ drvread(struct dsk *dskp, void *buf, daddr_t lba,
 
 	if (!OPT_CHECK(RBX_QUIET))
 		printf("%c\b", c = c << 8 | c >> 24);
-#ifdef GPT
+
+#ifndef USE_XREAD
 	packet.len = 0x10;
 	packet.count = nblk;
 	packet.off = VTOPOFF(buf);
@@ -87,7 +88,7 @@ drvread(struct dsk *dskp, void *buf, daddr_t lba,
 	v86.edx = dskp->drive;
 	v86.ds = VTOPSEG(&packet);
 	v86.esi = VTOPOFF(&packet);
-#else	/* !GPT */
+#else	/* USE_XREAD */
 	v86.ctl = V86_ADDR | V86_CALLF | V86_FLAGS;
 	v86.addr = XREADORG;		/* call to xread in boot1 */
 	v86.es = VTOPSEG(buf);
@@ -95,7 +96,7 @@ drvread(struct dsk *dskp, void *buf, daddr_t lba,
 	v86.ebx = VTOPOFF(buf);
 	v86.ecx = lba >> 32;
 	v86.edx = nblk << 8 | dskp->drive;
-#endif	/* !GPT */
+#endif	/* USE_XREAD */
 	v86int();
 	if (V86_CY(v86.efl)) {
 		printf("%s: error %u lba %u\n",