diff --git a/sys/amd64/amd64/machdep.c b/sys/amd64/amd64/machdep.c
index a74c108c2a6..dfde63760a8 100644
--- a/sys/amd64/amd64/machdep.c
+++ b/sys/amd64/amd64/machdep.c
@@ -35,7 +35,7 @@
  * SUCH DAMAGE.
  *
  *	from: @(#)machdep.c	7.4 (Berkeley) 6/3/91
- *	$Id: machdep.c,v 1.357 1999/07/29 01:49:18 msmith Exp $
+ *	$Id: machdep.c,v 1.358 1999/08/09 10:34:43 phk Exp $
  */
 
 #include "apm.h"
@@ -995,7 +995,16 @@ struct soft_segment_descriptor gdt_segs[] = {
 	0, 0,
 	0,			/* default 32 vs 16 bit size */
 	0  			/* limit granularity (byte/page units)*/ },
-/* GPANIC_SEL	8 Panic Tss Descriptor */
+/* GBIOSLOWMEM_SEL 8 BIOS access to realmode segment 0x40, must be #8 in GDT */
+{	0x400,			/* segment base address */
+	0xfffff,		/* length */
+	SDT_MEMRWA,		/* segment type */
+	0,			/* segment descriptor priority level */
+	1,			/* segment descriptor present */
+	0, 0,
+	1,			/* default 32 vs 16 bit size */
+	1  			/* limit granularity (byte/page units)*/ },
+/* GPANIC_SEL	9 Panic Tss Descriptor */
 {	(int) &dblfault_tss,	/* segment base address  */
 	sizeof(struct i386tss)-1,/* length - all address space */
 	SDT_SYS386TSS,		/* segment type */
@@ -1004,16 +1013,7 @@ struct soft_segment_descriptor gdt_segs[] = {
 	0, 0,
 	0,			/* unused - default 32 vs 16 bit size */
 	0  			/* limit granularity (byte/page units)*/ },
-/* GBIOSCODE32_SEL 9 BIOS 32-bit interface (32bit Code) */
-{	0,			/* segment base address (overwritten)  */
-	0xfffff,		/* length */
-	SDT_MEMERA,		/* segment type */
-	0,			/* segment descriptor priority level */
-	1,			/* segment descriptor present */
-	0, 0,
-	1,			/* default 32 vs 16 bit size */
-	1  			/* limit granularity (byte/page units)*/ },
-/* GBIOSCODE16_SEL 10 BIOS 32-bit interface (16bit Code) */
+/* GBIOSCODE32_SEL 10 BIOS 32-bit interface (32bit Code) */
 {	0,			/* segment base address (overwritten)  */
 	0xfffff,		/* length */
 	SDT_MEMERA,		/* segment type */
@@ -1022,7 +1022,16 @@ struct soft_segment_descriptor gdt_segs[] = {
 	0, 0,
 	0,			/* default 32 vs 16 bit size */
 	1  			/* limit granularity (byte/page units)*/ },
-/* GBIOSDATA_SEL 11 BIOS 32-bit interface (Data) */
+/* GBIOSCODE16_SEL 11 BIOS 32-bit interface (16bit Code) */
+{	0,			/* segment base address (overwritten)  */
+	0xfffff,		/* length */
+	SDT_MEMERA,		/* segment type */
+	0,			/* segment descriptor priority level */
+	1,			/* segment descriptor present */
+	0, 0,
+	0,			/* default 32 vs 16 bit size */
+	1  			/* limit granularity (byte/page units)*/ },
+/* GBIOSDATA_SEL 12 BIOS 32-bit interface (Data) */
 {	0,			/* segment base address (overwritten) */
 	0xfffff,		/* length */
 	SDT_MEMRWA,		/* segment type */
@@ -1031,7 +1040,7 @@ struct soft_segment_descriptor gdt_segs[] = {
 	0, 0,
 	1,			/* default 32 vs 16 bit size */
 	1  			/* limit granularity (byte/page units)*/ },
-/* GBIOSUTIL_SEL 12 BIOS 16-bit interface (Utility) */
+/* GBIOSUTIL_SEL 13 BIOS 16-bit interface (Utility) */
 {	0,			/* segment base address (overwritten) */
 	0xfffff,		/* length */
 	SDT_MEMRWA,		/* segment type */
@@ -1040,7 +1049,7 @@ struct soft_segment_descriptor gdt_segs[] = {
 	0, 0,
 	0,			/* default 32 vs 16 bit size */
 	1  			/* limit granularity (byte/page units)*/ },
-/* GBIOSARGS_SEL 13 BIOS 16-bit interface (Arguments) */
+/* GBIOSARGS_SEL 14 BIOS 16-bit interface (Arguments) */
 {	0,			/* segment base address (overwritten) */
 	0xfffff,		/* length */
 	SDT_MEMRWA,		/* segment type */
diff --git a/sys/amd64/include/segments.h b/sys/amd64/include/segments.h
index 14afa570af7..1a6e20d91af 100644
--- a/sys/amd64/include/segments.h
+++ b/sys/amd64/include/segments.h
@@ -35,7 +35,7 @@
  * SUCH DAMAGE.
  *
  *	from: @(#)segments.h	7.1 (Berkeley) 5/9/91
- *	$Id: segments.h,v 1.20 1999/06/18 14:32:21 bde Exp $
+ *	$Id: segments.h,v 1.21 1999/07/29 01:49:19 msmith Exp $
  */
 
 #ifndef _MACHINE_SEGMENTS_H_
@@ -214,17 +214,18 @@ struct region_descriptor {
 #define	GLDT_SEL	5	/* LDT - eventually one per process */
 #define	GUSERLDT_SEL	6	/* User LDT */
 #define	GTGATE_SEL	7	/* Process task switch gate */
-#define	GPANIC_SEL	8	/* Task state to consider panic from */
-#define GBIOSCODE32_SEL	9	/* BIOS interface (32bit Code) */
-#define GBIOSCODE16_SEL	10	/* BIOS interface (16bit Code) */
-#define GBIOSDATA_SEL	11	/* BIOS interface (Data) */
-#define GBIOSUTIL_SEL	12	/* BIOS interface (Utility) */
-#define GBIOSARGS_SEL	13	/* BIOS interface (Arguments) */
+#define	GBIOSLOWMEM_SEL	8	/* BIOS low memory access (must be entry 8) */
+#define	GPANIC_SEL	9	/* Task state to consider panic from */
+#define GBIOSCODE32_SEL	10	/* BIOS interface (32bit Code) */
+#define GBIOSCODE16_SEL	11	/* BIOS interface (16bit Code) */
+#define GBIOSDATA_SEL	12	/* BIOS interface (Data) */
+#define GBIOSUTIL_SEL	13	/* BIOS interface (Utility) */
+#define GBIOSARGS_SEL	14	/* BIOS interface (Arguments) */
 
 #ifdef BDE_DEBUGGER
 #define	NGDT		18	/* some of 11-17 are reserved for debugger */
 #else
-#define NGDT 		14
+#define NGDT 		15
 #endif
 
 /*
diff --git a/sys/i386/i386/machdep.c b/sys/i386/i386/machdep.c
index a74c108c2a6..dfde63760a8 100644
--- a/sys/i386/i386/machdep.c
+++ b/sys/i386/i386/machdep.c
@@ -35,7 +35,7 @@
  * SUCH DAMAGE.
  *
  *	from: @(#)machdep.c	7.4 (Berkeley) 6/3/91
- *	$Id: machdep.c,v 1.357 1999/07/29 01:49:18 msmith Exp $
+ *	$Id: machdep.c,v 1.358 1999/08/09 10:34:43 phk Exp $
  */
 
 #include "apm.h"
@@ -995,7 +995,16 @@ struct soft_segment_descriptor gdt_segs[] = {
 	0, 0,
 	0,			/* default 32 vs 16 bit size */
 	0  			/* limit granularity (byte/page units)*/ },
-/* GPANIC_SEL	8 Panic Tss Descriptor */
+/* GBIOSLOWMEM_SEL 8 BIOS access to realmode segment 0x40, must be #8 in GDT */
+{	0x400,			/* segment base address */
+	0xfffff,		/* length */
+	SDT_MEMRWA,		/* segment type */
+	0,			/* segment descriptor priority level */
+	1,			/* segment descriptor present */
+	0, 0,
+	1,			/* default 32 vs 16 bit size */
+	1  			/* limit granularity (byte/page units)*/ },
+/* GPANIC_SEL	9 Panic Tss Descriptor */
 {	(int) &dblfault_tss,	/* segment base address  */
 	sizeof(struct i386tss)-1,/* length - all address space */
 	SDT_SYS386TSS,		/* segment type */
@@ -1004,16 +1013,7 @@ struct soft_segment_descriptor gdt_segs[] = {
 	0, 0,
 	0,			/* unused - default 32 vs 16 bit size */
 	0  			/* limit granularity (byte/page units)*/ },
-/* GBIOSCODE32_SEL 9 BIOS 32-bit interface (32bit Code) */
-{	0,			/* segment base address (overwritten)  */
-	0xfffff,		/* length */
-	SDT_MEMERA,		/* segment type */
-	0,			/* segment descriptor priority level */
-	1,			/* segment descriptor present */
-	0, 0,
-	1,			/* default 32 vs 16 bit size */
-	1  			/* limit granularity (byte/page units)*/ },
-/* GBIOSCODE16_SEL 10 BIOS 32-bit interface (16bit Code) */
+/* GBIOSCODE32_SEL 10 BIOS 32-bit interface (32bit Code) */
 {	0,			/* segment base address (overwritten)  */
 	0xfffff,		/* length */
 	SDT_MEMERA,		/* segment type */
@@ -1022,7 +1022,16 @@ struct soft_segment_descriptor gdt_segs[] = {
 	0, 0,
 	0,			/* default 32 vs 16 bit size */
 	1  			/* limit granularity (byte/page units)*/ },
-/* GBIOSDATA_SEL 11 BIOS 32-bit interface (Data) */
+/* GBIOSCODE16_SEL 11 BIOS 32-bit interface (16bit Code) */
+{	0,			/* segment base address (overwritten)  */
+	0xfffff,		/* length */
+	SDT_MEMERA,		/* segment type */
+	0,			/* segment descriptor priority level */
+	1,			/* segment descriptor present */
+	0, 0,
+	0,			/* default 32 vs 16 bit size */
+	1  			/* limit granularity (byte/page units)*/ },
+/* GBIOSDATA_SEL 12 BIOS 32-bit interface (Data) */
 {	0,			/* segment base address (overwritten) */
 	0xfffff,		/* length */
 	SDT_MEMRWA,		/* segment type */
@@ -1031,7 +1040,7 @@ struct soft_segment_descriptor gdt_segs[] = {
 	0, 0,
 	1,			/* default 32 vs 16 bit size */
 	1  			/* limit granularity (byte/page units)*/ },
-/* GBIOSUTIL_SEL 12 BIOS 16-bit interface (Utility) */
+/* GBIOSUTIL_SEL 13 BIOS 16-bit interface (Utility) */
 {	0,			/* segment base address (overwritten) */
 	0xfffff,		/* length */
 	SDT_MEMRWA,		/* segment type */
@@ -1040,7 +1049,7 @@ struct soft_segment_descriptor gdt_segs[] = {
 	0, 0,
 	0,			/* default 32 vs 16 bit size */
 	1  			/* limit granularity (byte/page units)*/ },
-/* GBIOSARGS_SEL 13 BIOS 16-bit interface (Arguments) */
+/* GBIOSARGS_SEL 14 BIOS 16-bit interface (Arguments) */
 {	0,			/* segment base address (overwritten) */
 	0xfffff,		/* length */
 	SDT_MEMRWA,		/* segment type */
diff --git a/sys/i386/include/segments.h b/sys/i386/include/segments.h
index 14afa570af7..1a6e20d91af 100644
--- a/sys/i386/include/segments.h
+++ b/sys/i386/include/segments.h
@@ -35,7 +35,7 @@
  * SUCH DAMAGE.
  *
  *	from: @(#)segments.h	7.1 (Berkeley) 5/9/91
- *	$Id: segments.h,v 1.20 1999/06/18 14:32:21 bde Exp $
+ *	$Id: segments.h,v 1.21 1999/07/29 01:49:19 msmith Exp $
  */
 
 #ifndef _MACHINE_SEGMENTS_H_
@@ -214,17 +214,18 @@ struct region_descriptor {
 #define	GLDT_SEL	5	/* LDT - eventually one per process */
 #define	GUSERLDT_SEL	6	/* User LDT */
 #define	GTGATE_SEL	7	/* Process task switch gate */
-#define	GPANIC_SEL	8	/* Task state to consider panic from */
-#define GBIOSCODE32_SEL	9	/* BIOS interface (32bit Code) */
-#define GBIOSCODE16_SEL	10	/* BIOS interface (16bit Code) */
-#define GBIOSDATA_SEL	11	/* BIOS interface (Data) */
-#define GBIOSUTIL_SEL	12	/* BIOS interface (Utility) */
-#define GBIOSARGS_SEL	13	/* BIOS interface (Arguments) */
+#define	GBIOSLOWMEM_SEL	8	/* BIOS low memory access (must be entry 8) */
+#define	GPANIC_SEL	9	/* Task state to consider panic from */
+#define GBIOSCODE32_SEL	10	/* BIOS interface (32bit Code) */
+#define GBIOSCODE16_SEL	11	/* BIOS interface (16bit Code) */
+#define GBIOSDATA_SEL	12	/* BIOS interface (Data) */
+#define GBIOSUTIL_SEL	13	/* BIOS interface (Utility) */
+#define GBIOSARGS_SEL	14	/* BIOS interface (Arguments) */
 
 #ifdef BDE_DEBUGGER
 #define	NGDT		18	/* some of 11-17 are reserved for debugger */
 #else
-#define NGDT 		14
+#define NGDT 		15
 #endif
 
 /*