9 files changed, 116 insertions, 143 deletions

diff --git a/sys/i386/apm/apm.c b/sys/i386/apm/apm.c
index c0813403ed50..268755916e14 100644
--- a/sys/i386/apm/apm.c
+++ b/sys/i386/apm/apm.c
@@ -13,19 +13,17 @@
  *
  * Sep, 1994	Implemented on FreeBSD 1.1.5.1R (Toshiba AVS001WD)
  *
- *	$Id: apm.c,v 1.22 1995/12/25 07:38:26 bde Exp $
+ *	$Id: apm.c,v 1.23 1995/12/27 16:16:02 bde Exp $
  */
 
 #include "apm.h"
 
 #include <sys/param.h>
-#include <conf.h>
 #include <sys/conf.h>
 #include <sys/kernel.h>
 #ifdef DEVFS
 #include <sys/devfsext.h>
 #endif /*DEVFS*/
-#include <sys/kernel.h>
 #include <sys/systm.h>
 #include <sys/malloc.h>
 #include <sys/ioctl.h>
diff --git a/sys/i386/apm/apm_init/apm_init.inc b/sys/i386/apm/apm_init/apm_init.inc
index 44fc01e743ee..82f476caacaf 100644
--- a/sys/i386/apm/apm_init/apm_init.inc
+++ b/sys/i386/apm/apm_init/apm_init.inc
@@ -2,55 +2,51 @@
 /* Original file is 'apm_init' */
 
 	.byte	0xfa, 0x55, 0x66, 0x8c, 0xd8, 0x66, 0x8e, 0xe0
-	.byte	0x66, 0xb8, 0xf0, 0x00, 0x66, 0x8e, 0xd8, 0x66
-	.byte	0x8e, 0xc0, 0x66, 0x8e, 0xd0, 0x89, 0x25, 0x94
+	.byte	0x66, 0xb8, 0xe8, 0x00, 0x66, 0x8e, 0xd8, 0x66
+	.byte	0x8e, 0xc0, 0x66, 0x8e, 0xd0, 0x89, 0x25, 0x74
 	.byte	0x01, 0x00, 0x00, 0xbc, 0x00, 0x00, 0x01, 0x00
-	.byte	0x0f, 0x01, 0x0d, 0xb0, 0x01, 0x00, 0x00, 0xe8
-	.byte	0x24, 0x01, 0x00, 0x00, 0xb4, 0x53, 0xb0, 0x00
+	.byte	0x0f, 0x01, 0x0d, 0x90, 0x01, 0x00, 0x00, 0xe8
+	.byte	0x14, 0x01, 0x00, 0x00, 0xb4, 0x53, 0xb0, 0x00
 	.byte	0x66, 0xbb, 0x00, 0x00, 0x00, 0x00, 0xfb, 0xcd
 	.byte	0x15, 0xfa, 0x73, 0x15, 0x66, 0xe8, 0xde, 0x00
-	.byte	0x00, 0x00, 0xc7, 0x05, 0x98, 0x01, 0x00, 0x00
+	.byte	0x00, 0x00, 0xc7, 0x05, 0x78, 0x01, 0x00, 0x00
 	.byte	0xff, 0xff, 0xff, 0xff, 0xe9, 0x92, 0x00, 0x00
 	.byte	0x00, 0x89, 0xc2, 0x66, 0xe8, 0xc7, 0x00, 0x00
 	.byte	0x00, 0x80, 0xff, 0x50, 0x75, 0x05, 0x80, 0xfb
-	.byte	0x4d, 0x74, 0x0c, 0xc7, 0x05, 0x98, 0x01, 0x00
+	.byte	0x4d, 0x74, 0x0c, 0xc7, 0x05, 0x78, 0x01, 0x00
 	.byte	0x00, 0xff, 0xff, 0xff, 0xff, 0xeb, 0x74, 0xf7
 	.byte	0xc1, 0x02, 0x00, 0x00, 0x00, 0x75, 0x0c, 0xc7
-	.byte	0x05, 0x98, 0x01, 0x00, 0x00, 0xfe, 0xff, 0xff
+	.byte	0x05, 0x78, 0x01, 0x00, 0x00, 0xfe, 0xff, 0xff
 	.byte	0xff, 0xeb, 0x60, 0x81, 0xe2, 0xff, 0xff, 0x00
-	.byte	0x00, 0x89, 0x15, 0x98, 0x01, 0x00, 0x00, 0x81
-	.byte	0xe1, 0xff, 0xff, 0x00, 0x00, 0x89, 0x0d, 0x9c
-	.byte	0x01, 0x00, 0x00, 0xe8, 0xb0, 0x00, 0x00, 0x00
+	.byte	0x00, 0x89, 0x15, 0x78, 0x01, 0x00, 0x00, 0x81
+	.byte	0xe1, 0xff, 0xff, 0x00, 0x00, 0x89, 0x0d, 0x7c
+	.byte	0x01, 0x00, 0x00, 0xe8, 0xa0, 0x00, 0x00, 0x00
 	.byte	0xb4, 0x53, 0xb0, 0x03, 0x66, 0xbb, 0x00, 0x00
 	.byte	0x00, 0x00, 0xfb, 0xcd, 0x15, 0xfa, 0x73, 0x12
 	.byte	0x66, 0xe8, 0x6a, 0x00, 0x00, 0x00, 0xc7, 0x05
-	.byte	0x98, 0x01, 0x00, 0x00, 0xfd, 0xff, 0xff, 0xff
+	.byte	0x78, 0x01, 0x00, 0x00, 0xfd, 0xff, 0xff, 0xff
 	.byte	0xeb, 0x21, 0x89, 0xc5, 0x66, 0xe8, 0x56, 0x00
 	.byte	0x00, 0x00, 0xb8, 0xff, 0xff, 0x00, 0x00, 0x21
 	.byte	0xc5, 0x21, 0xc1, 0x21, 0xc2, 0x21, 0xc6, 0x21
 	.byte	0xc7, 0xc1, 0xe5, 0x10, 0x09, 0xe9, 0xc1, 0xe7
-	.byte	0x10, 0x09, 0xfe, 0xfa, 0x0f, 0x01, 0x1d, 0xb0
-	.byte	0x01, 0x00, 0x00, 0x8b, 0x25, 0x94, 0x01, 0x00
-	.byte	0x00, 0x8b, 0x2d, 0x98, 0x01, 0x00, 0x00, 0x8b
-	.byte	0x3d, 0x9c, 0x01, 0x00, 0x00, 0x66, 0x8c, 0xe0
+	.byte	0x10, 0x09, 0xfe, 0xfa, 0x0f, 0x01, 0x1d, 0x90
+	.byte	0x01, 0x00, 0x00, 0x8b, 0x25, 0x74, 0x01, 0x00
+	.byte	0x00, 0x8b, 0x2d, 0x78, 0x01, 0x00, 0x00, 0x8b
+	.byte	0x3d, 0x7c, 0x01, 0x00, 0x00, 0x66, 0x8c, 0xe0
 	.byte	0x66, 0x8e, 0xd0, 0x66, 0x8e, 0xc0, 0x66, 0x8e
 	.byte	0xd8, 0x31, 0xc0, 0x66, 0x8e, 0xe0, 0x89, 0xe8
 	.byte	0x5d, 0xcb, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
 	.byte	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
 	.byte	0xfa, 0x0f, 0x20, 0xc0, 0x66, 0x83, 0xc8, 0x01
 	.byte	0x0f, 0x22, 0xc0, 0x66, 0xea, 0x33, 0x01, 0x00
-	.byte	0x00, 0xe8, 0x00, 0xb8, 0xf0, 0x00, 0x00, 0x00
-	.byte	0x66, 0x8e, 0xd8, 0x66, 0x8e, 0xd0, 0x66, 0x8e
-	.byte	0xc0, 0x0f, 0x01, 0x1d, 0xb0, 0x01, 0x00, 0x00
-	.byte	0xc3, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
-	.byte	0xa1, 0x90, 0x01, 0x00, 0x00, 0xc1, 0xf8, 0x04
-	.byte	0x66, 0x50, 0x66, 0xb8, 0x72, 0x01, 0x66, 0x50
-	.byte	0xea, 0x67, 0x01, 0x00, 0x00, 0xf8, 0x00, 0x0f
-	.byte	0x20, 0xc0, 0x66, 0x83, 0xe0, 0xfe, 0x0f, 0x22
-	.byte	0xc0, 0xcb, 0x66, 0x8c, 0xc8, 0x66, 0x8e, 0xd8
-	.byte	0x66, 0x8e, 0xd0, 0x66, 0x8e, 0xc0, 0x67, 0x66
-	.byte	0x0f, 0x01, 0x1d, 0xb6, 0x01, 0x00, 0x00, 0x66
-	.byte	0xc3, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
+	.byte	0x00, 0xe0, 0x00, 0x66, 0xb8, 0xe8, 0x00, 0x8e
+	.byte	0xd8, 0x8e, 0xd0, 0x8e, 0xc0, 0xc3, 0x00, 0x00
+	.byte	0x66, 0xb8, 0xf8, 0x00, 0xea, 0x4b, 0x01, 0x00
+	.byte	0x00, 0xf0, 0x00, 0x8e, 0xd8, 0x8e, 0xd0, 0x8e
+	.byte	0xc0, 0x0f, 0x20, 0xc0, 0x66, 0x83, 0xe0, 0xfe
+	.byte	0x0f, 0x22, 0xc0, 0x66, 0xea, 0x63, 0x01, 0x00
+	.byte	0x00, 0x00, 0x80, 0x8c, 0xc8, 0x8e, 0xd8, 0x8e
+	.byte	0xd0, 0x8e, 0xc0, 0x66, 0xc3, 0x00, 0x00, 0x00
 	.byte	0x00, 0x00, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00
 	.byte	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
 	.byte	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
@@ -58,4 +54,4 @@
 	.byte	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xff, 0x03
 	.byte	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
 
-/* Total size = 0x01c0 */
+/* Total size = 0x01a0 */
diff --git a/sys/i386/apm/apm_init/real_prot.S b/sys/i386/apm/apm_init/real_prot.S
index d61a394bb763..cf1514affd1d 100644
--- a/sys/i386/apm/apm_init/real_prot.S
+++ b/sys/i386/apm/apm_init/real_prot.S
@@ -24,7 +24,7 @@
  * the rights to redistribute these changes.
  *
  *	from: Mach, Revision 2.2  92/04/04  11:34:13  rpd
- *	$Id: asm.S,v 1.2 1993/10/16 19:11:27 rgrimes Exp $
+ *	$Id: real_prot.S,v 1.1 1994/10/01 02:55:51 davidg Exp $
  */
 
 
@@ -69,18 +69,19 @@ WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 /*
  * Modified for APM BIOS initializer by HOSOKAWA Tatsumi
  *
- * See also locore.s. It supports these functions works correctly.
+ * See also locore.s.
+ * (This file is based directly on /sys/i386/boot/biosboot/asm.S)
  */
 
 	.file "real_prot.S"
 
 #include "real_prot.h"
 #include "apm_segments.h"
+#include "apm_bios.h"
 
 CR0_PE_ON	=	0x1
 CR0_PE_OFF	=	0xfffffffe
 
-.globl	_ouraddr
 	.text
 
 /*
@@ -117,19 +118,21 @@ ENTRY(real_to_prot)
 	 */
 	data32
 	ljmp	$(APM_INIT_CS_SEL), $xprot
-
 xprot:
+
 	/*
 	 * we are in USE32 mode now
 	 * set up the protected mode segment registers : DS, SS, ES
 	 */
-	mov	$(APM_INIT_DS_SEL), %eax
-	movw	%ax, %ds
-	movw	%ax, %ss
-	movw	%ax, %es
+	movw	$(APM_INIT_DS_SEL), %ax		/* data segment */
+	mov	%ax, %ds	/* gas would waste a prefix byte for movw */
+	mov	%ax, %ss
+	mov	%ax, %es
 
+#ifdef BDE_DEBUGGER
 	/* load idtr so we can debug */
 	lidt	EXT(Idtr_prot)
+#endif
 
 	ret
 
@@ -142,17 +145,17 @@ xprot:
 
 ENTRY(prot_to_real)
 
-	/* set up a dummy stack frame for the second seg change. */
-	movl 	_ouraddr, %eax
-	sarl	$4, %eax
-	pushw	%ax
-	movw	$xreal, %ax	/* gas botches pushw $xreal - extra bytes 0, 0*/
-	pushw	%ax		/* decode to add %al, (%eax) (%al usually 0) */
+	/* Prepare %ax while we're still in a mode that gas understands. */
+	movw	$(APM_INIT_DS16_SEL), %ax
 
 	/* Change to use16 mode. */
 	ljmp	$(APM_INIT_CS16_SEL), $x16
-
 x16:
+
+	mov	%ax, %ds
+	mov	%ax, %ss
+	mov	%ax, %es
+
 	/* clear the PE bit of CR0 */
 	mov	%cr0, %eax
 	data32
@@ -161,25 +164,27 @@ x16:
 
 	/*
 	 * make intersegment jmp to flush the processor pipeline
-	 * using the fake stack frame set up earlier
 	 * and reload CS register
 	 */
-	lret
-
+	data32
+	ljmp	$(APM_OURADDR>>4), $xreal
 xreal:
+
 	/*
 	 * we are in real mode now
 	 * set up the real mode segment registers : DS, SS, ES
 	 */
-	movw	%cs, %ax
-	movw	%ax, %ds
-	movw	%ax, %ss
-	movw	%ax, %es
+	mov	%cs, %ax
+	mov	%ax, %ds
+	mov	%ax, %ss
+	mov	%ax, %es
 
+#ifdef BDE_DEBUGGER
 	/* load idtr so we can debug */
 	addr32
 	data32
 	lidt	EXT(Idtr_real)
+#endif
 
 	data32
 	ret
diff --git a/sys/i386/apm/apm_setup.s b/sys/i386/apm/apm_setup.s
index b3ae77d26a56..e33260f59f1e 100644
--- a/sys/i386/apm/apm_setup.s
+++ b/sys/i386/apm/apm_setup.s
@@ -12,30 +12,20 @@
  *
  * Sep., 1994	Implemented on FreeBSD 1.1.5.1R (Toshiba AVS001WD)
  *
- *	$Id: apm_setup.s,v 1.4 1994/10/10 01:14:03 phk Exp $
+ *	$Id: apm_setup.s,v 1.5 1995/02/17 02:22:23 phk Exp $
  */
 
 #include "apm.h"
   
 #if NAPM > 0
 
-#ifdef __FreeBSD__
 #define ASSEMBLER
 #include "assym.s"                    /* system definitions */
 #include <machine/asmacros.h>         /* miscellaneous asm macros */
 #include <machine/apm_bios.h>
 #include <machine/apm_segments.h>
 #define PADDR(addr)        addr-KERNBASE
-#endif /* __FreeBSD__ */
   
-#ifdef MACH_KERNEL
-#define ASSEMBLER
-#include "assym.s"
-#include "i386at/apm_bios.h"
-#include "i386at/apm_segments.h"
-#define PADDR(addr)        addr-KERNELBASE
-#endif /* MACH_KERNEL */
-
 	.file	"apm_setup.s"
 
 	.data
@@ -43,12 +33,7 @@ _apm_init_image:
 	.globl	_apm_init_image
 
 1:
-#ifdef __FreeBSD__
 #include "i386/apm/apm_init/apm_init.inc"
-#endif /* __FreeBSD__ */
-#ifdef MACH_KERNEL
-#include "i386at/apm_init/apm_init.inc"
-#endif /* MACH_KERNEL */
 2:
 
 _apm_init_image_size:
@@ -168,6 +153,7 @@ _apm_setup:
 	APM_SETUP_GDT(APM_INIT_CS_INDEX  , CS32_ATTRIB)
 	APM_SETUP_GDT(APM_INIT_DS_INDEX  , DS32_ATTRIB)
 	APM_SETUP_GDT(APM_INIT_CS16_INDEX, CS16_ATTRIB)
+	APM_SETUP_GDT(APM_INIT_DS16_INDEX, DS16_ATTRIB)
 
 	/*
 	 * Call the initializer:
diff --git a/sys/i386/bios/apm.c b/sys/i386/bios/apm.c
index c0813403ed50..268755916e14 100644
--- a/sys/i386/bios/apm.c
+++ b/sys/i386/bios/apm.c
@@ -13,19 +13,17 @@
  *
  * Sep, 1994	Implemented on FreeBSD 1.1.5.1R (Toshiba AVS001WD)
  *
- *	$Id: apm.c,v 1.22 1995/12/25 07:38:26 bde Exp $
+ *	$Id: apm.c,v 1.23 1995/12/27 16:16:02 bde Exp $
  */
 
 #include "apm.h"
 
 #include <sys/param.h>
-#include <conf.h>
 #include <sys/conf.h>
 #include <sys/kernel.h>
 #ifdef DEVFS
 #include <sys/devfsext.h>
 #endif /*DEVFS*/
-#include <sys/kernel.h>
 #include <sys/systm.h>
 #include <sys/malloc.h>
 #include <sys/ioctl.h>
diff --git a/sys/i386/bios/apm_init/apm_init.inc b/sys/i386/bios/apm_init/apm_init.inc
index 44fc01e743ee..82f476caacaf 100644
--- a/sys/i386/bios/apm_init/apm_init.inc
+++ b/sys/i386/bios/apm_init/apm_init.inc
@@ -2,55 +2,51 @@
 /* Original file is 'apm_init' */
 
 	.byte	0xfa, 0x55, 0x66, 0x8c, 0xd8, 0x66, 0x8e, 0xe0
-	.byte	0x66, 0xb8, 0xf0, 0x00, 0x66, 0x8e, 0xd8, 0x66
-	.byte	0x8e, 0xc0, 0x66, 0x8e, 0xd0, 0x89, 0x25, 0x94
+	.byte	0x66, 0xb8, 0xe8, 0x00, 0x66, 0x8e, 0xd8, 0x66
+	.byte	0x8e, 0xc0, 0x66, 0x8e, 0xd0, 0x89, 0x25, 0x74
 	.byte	0x01, 0x00, 0x00, 0xbc, 0x00, 0x00, 0x01, 0x00
-	.byte	0x0f, 0x01, 0x0d, 0xb0, 0x01, 0x00, 0x00, 0xe8
-	.byte	0x24, 0x01, 0x00, 0x00, 0xb4, 0x53, 0xb0, 0x00
+	.byte	0x0f, 0x01, 0x0d, 0x90, 0x01, 0x00, 0x00, 0xe8
+	.byte	0x14, 0x01, 0x00, 0x00, 0xb4, 0x53, 0xb0, 0x00
 	.byte	0x66, 0xbb, 0x00, 0x00, 0x00, 0x00, 0xfb, 0xcd
 	.byte	0x15, 0xfa, 0x73, 0x15, 0x66, 0xe8, 0xde, 0x00
-	.byte	0x00, 0x00, 0xc7, 0x05, 0x98, 0x01, 0x00, 0x00
+	.byte	0x00, 0x00, 0xc7, 0x05, 0x78, 0x01, 0x00, 0x00
 	.byte	0xff, 0xff, 0xff, 0xff, 0xe9, 0x92, 0x00, 0x00
 	.byte	0x00, 0x89, 0xc2, 0x66, 0xe8, 0xc7, 0x00, 0x00
 	.byte	0x00, 0x80, 0xff, 0x50, 0x75, 0x05, 0x80, 0xfb
-	.byte	0x4d, 0x74, 0x0c, 0xc7, 0x05, 0x98, 0x01, 0x00
+	.byte	0x4d, 0x74, 0x0c, 0xc7, 0x05, 0x78, 0x01, 0x00
 	.byte	0x00, 0xff, 0xff, 0xff, 0xff, 0xeb, 0x74, 0xf7
 	.byte	0xc1, 0x02, 0x00, 0x00, 0x00, 0x75, 0x0c, 0xc7
-	.byte	0x05, 0x98, 0x01, 0x00, 0x00, 0xfe, 0xff, 0xff
+	.byte	0x05, 0x78, 0x01, 0x00, 0x00, 0xfe, 0xff, 0xff
 	.byte	0xff, 0xeb, 0x60, 0x81, 0xe2, 0xff, 0xff, 0x00
-	.byte	0x00, 0x89, 0x15, 0x98, 0x01, 0x00, 0x00, 0x81
-	.byte	0xe1, 0xff, 0xff, 0x00, 0x00, 0x89, 0x0d, 0x9c
-	.byte	0x01, 0x00, 0x00, 0xe8, 0xb0, 0x00, 0x00, 0x00
+	.byte	0x00, 0x89, 0x15, 0x78, 0x01, 0x00, 0x00, 0x81
+	.byte	0xe1, 0xff, 0xff, 0x00, 0x00, 0x89, 0x0d, 0x7c
+	.byte	0x01, 0x00, 0x00, 0xe8, 0xa0, 0x00, 0x00, 0x00
 	.byte	0xb4, 0x53, 0xb0, 0x03, 0x66, 0xbb, 0x00, 0x00
 	.byte	0x00, 0x00, 0xfb, 0xcd, 0x15, 0xfa, 0x73, 0x12
 	.byte	0x66, 0xe8, 0x6a, 0x00, 0x00, 0x00, 0xc7, 0x05
-	.byte	0x98, 0x01, 0x00, 0x00, 0xfd, 0xff, 0xff, 0xff
+	.byte	0x78, 0x01, 0x00, 0x00, 0xfd, 0xff, 0xff, 0xff
 	.byte	0xeb, 0x21, 0x89, 0xc5, 0x66, 0xe8, 0x56, 0x00
 	.byte	0x00, 0x00, 0xb8, 0xff, 0xff, 0x00, 0x00, 0x21
 	.byte	0xc5, 0x21, 0xc1, 0x21, 0xc2, 0x21, 0xc6, 0x21
 	.byte	0xc7, 0xc1, 0xe5, 0x10, 0x09, 0xe9, 0xc1, 0xe7
-	.byte	0x10, 0x09, 0xfe, 0xfa, 0x0f, 0x01, 0x1d, 0xb0
-	.byte	0x01, 0x00, 0x00, 0x8b, 0x25, 0x94, 0x01, 0x00
-	.byte	0x00, 0x8b, 0x2d, 0x98, 0x01, 0x00, 0x00, 0x8b
-	.byte	0x3d, 0x9c, 0x01, 0x00, 0x00, 0x66, 0x8c, 0xe0
+	.byte	0x10, 0x09, 0xfe, 0xfa, 0x0f, 0x01, 0x1d, 0x90
+	.byte	0x01, 0x00, 0x00, 0x8b, 0x25, 0x74, 0x01, 0x00
+	.byte	0x00, 0x8b, 0x2d, 0x78, 0x01, 0x00, 0x00, 0x8b
+	.byte	0x3d, 0x7c, 0x01, 0x00, 0x00, 0x66, 0x8c, 0xe0
 	.byte	0x66, 0x8e, 0xd0, 0x66, 0x8e, 0xc0, 0x66, 0x8e
 	.byte	0xd8, 0x31, 0xc0, 0x66, 0x8e, 0xe0, 0x89, 0xe8
 	.byte	0x5d, 0xcb, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
 	.byte	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
 	.byte	0xfa, 0x0f, 0x20, 0xc0, 0x66, 0x83, 0xc8, 0x01
 	.byte	0x0f, 0x22, 0xc0, 0x66, 0xea, 0x33, 0x01, 0x00
-	.byte	0x00, 0xe8, 0x00, 0xb8, 0xf0, 0x00, 0x00, 0x00
-	.byte	0x66, 0x8e, 0xd8, 0x66, 0x8e, 0xd0, 0x66, 0x8e
-	.byte	0xc0, 0x0f, 0x01, 0x1d, 0xb0, 0x01, 0x00, 0x00
-	.byte	0xc3, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
-	.byte	0xa1, 0x90, 0x01, 0x00, 0x00, 0xc1, 0xf8, 0x04
-	.byte	0x66, 0x50, 0x66, 0xb8, 0x72, 0x01, 0x66, 0x50
-	.byte	0xea, 0x67, 0x01, 0x00, 0x00, 0xf8, 0x00, 0x0f
-	.byte	0x20, 0xc0, 0x66, 0x83, 0xe0, 0xfe, 0x0f, 0x22
-	.byte	0xc0, 0xcb, 0x66, 0x8c, 0xc8, 0x66, 0x8e, 0xd8
-	.byte	0x66, 0x8e, 0xd0, 0x66, 0x8e, 0xc0, 0x67, 0x66
-	.byte	0x0f, 0x01, 0x1d, 0xb6, 0x01, 0x00, 0x00, 0x66
-	.byte	0xc3, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
+	.byte	0x00, 0xe0, 0x00, 0x66, 0xb8, 0xe8, 0x00, 0x8e
+	.byte	0xd8, 0x8e, 0xd0, 0x8e, 0xc0, 0xc3, 0x00, 0x00
+	.byte	0x66, 0xb8, 0xf8, 0x00, 0xea, 0x4b, 0x01, 0x00
+	.byte	0x00, 0xf0, 0x00, 0x8e, 0xd8, 0x8e, 0xd0, 0x8e
+	.byte	0xc0, 0x0f, 0x20, 0xc0, 0x66, 0x83, 0xe0, 0xfe
+	.byte	0x0f, 0x22, 0xc0, 0x66, 0xea, 0x63, 0x01, 0x00
+	.byte	0x00, 0x00, 0x80, 0x8c, 0xc8, 0x8e, 0xd8, 0x8e
+	.byte	0xd0, 0x8e, 0xc0, 0x66, 0xc3, 0x00, 0x00, 0x00
 	.byte	0x00, 0x00, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00
 	.byte	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
 	.byte	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
@@ -58,4 +54,4 @@
 	.byte	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xff, 0x03
 	.byte	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
 
-/* Total size = 0x01c0 */
+/* Total size = 0x01a0 */
diff --git a/sys/i386/bios/apm_init/real_prot.S b/sys/i386/bios/apm_init/real_prot.S
index d61a394bb763..cf1514affd1d 100644
--- a/sys/i386/bios/apm_init/real_prot.S
+++ b/sys/i386/bios/apm_init/real_prot.S
@@ -24,7 +24,7 @@
  * the rights to redistribute these changes.
  *
  *	from: Mach, Revision 2.2  92/04/04  11:34:13  rpd
- *	$Id: asm.S,v 1.2 1993/10/16 19:11:27 rgrimes Exp $
+ *	$Id: real_prot.S,v 1.1 1994/10/01 02:55:51 davidg Exp $
  */
 
 
@@ -69,18 +69,19 @@ WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 /*
  * Modified for APM BIOS initializer by HOSOKAWA Tatsumi
  *
- * See also locore.s. It supports these functions works correctly.
+ * See also locore.s.
+ * (This file is based directly on /sys/i386/boot/biosboot/asm.S)
  */
 
 	.file "real_prot.S"
 
 #include "real_prot.h"
 #include "apm_segments.h"
+#include "apm_bios.h"
 
 CR0_PE_ON	=	0x1
 CR0_PE_OFF	=	0xfffffffe
 
-.globl	_ouraddr
 	.text
 
 /*
@@ -117,19 +118,21 @@ ENTRY(real_to_prot)
 	 */
 	data32
 	ljmp	$(APM_INIT_CS_SEL), $xprot
-
 xprot:
+
 	/*
 	 * we are in USE32 mode now
 	 * set up the protected mode segment registers : DS, SS, ES
 	 */
-	mov	$(APM_INIT_DS_SEL), %eax
-	movw	%ax, %ds
-	movw	%ax, %ss
-	movw	%ax, %es
+	movw	$(APM_INIT_DS_SEL), %ax		/* data segment */
+	mov	%ax, %ds	/* gas would waste a prefix byte for movw */
+	mov	%ax, %ss
+	mov	%ax, %es
 
+#ifdef BDE_DEBUGGER
 	/* load idtr so we can debug */
 	lidt	EXT(Idtr_prot)
+#endif
 
 	ret
 
@@ -142,17 +145,17 @@ xprot:
 
 ENTRY(prot_to_real)
 
-	/* set up a dummy stack frame for the second seg change. */
-	movl 	_ouraddr, %eax
-	sarl	$4, %eax
-	pushw	%ax
-	movw	$xreal, %ax	/* gas botches pushw $xreal - extra bytes 0, 0*/
-	pushw	%ax		/* decode to add %al, (%eax) (%al usually 0) */
+	/* Prepare %ax while we're still in a mode that gas understands. */
+	movw	$(APM_INIT_DS16_SEL), %ax
 
 	/* Change to use16 mode. */
 	ljmp	$(APM_INIT_CS16_SEL), $x16
-
 x16:
+
+	mov	%ax, %ds
+	mov	%ax, %ss
+	mov	%ax, %es
+
 	/* clear the PE bit of CR0 */
 	mov	%cr0, %eax
 	data32
@@ -161,25 +164,27 @@ x16:
 
 	/*
 	 * make intersegment jmp to flush the processor pipeline
-	 * using the fake stack frame set up earlier
 	 * and reload CS register
 	 */
-	lret
-
+	data32
+	ljmp	$(APM_OURADDR>>4), $xreal
 xreal:
+
 	/*
 	 * we are in real mode now
 	 * set up the real mode segment registers : DS, SS, ES
 	 */
-	movw	%cs, %ax
-	movw	%ax, %ds
-	movw	%ax, %ss
-	movw	%ax, %es
+	mov	%cs, %ax
+	mov	%ax, %ds
+	mov	%ax, %ss
+	mov	%ax, %es
 
+#ifdef BDE_DEBUGGER
 	/* load idtr so we can debug */
 	addr32
 	data32
 	lidt	EXT(Idtr_real)
+#endif
 
 	data32
 	ret
diff --git a/sys/i386/bios/apm_setup.s b/sys/i386/bios/apm_setup.s
index b3ae77d26a56..e33260f59f1e 100644
--- a/sys/i386/bios/apm_setup.s
+++ b/sys/i386/bios/apm_setup.s
@@ -12,30 +12,20 @@
  *
  * Sep., 1994	Implemented on FreeBSD 1.1.5.1R (Toshiba AVS001WD)
  *
- *	$Id: apm_setup.s,v 1.4 1994/10/10 01:14:03 phk Exp $
+ *	$Id: apm_setup.s,v 1.5 1995/02/17 02:22:23 phk Exp $
  */
 
 #include "apm.h"
   
 #if NAPM > 0
 
-#ifdef __FreeBSD__
 #define ASSEMBLER
 #include "assym.s"                    /* system definitions */
 #include <machine/asmacros.h>         /* miscellaneous asm macros */
 #include <machine/apm_bios.h>
 #include <machine/apm_segments.h>
 #define PADDR(addr)        addr-KERNBASE
-#endif /* __FreeBSD__ */
   
-#ifdef MACH_KERNEL
-#define ASSEMBLER
-#include "assym.s"
-#include "i386at/apm_bios.h"
-#include "i386at/apm_segments.h"
-#define PADDR(addr)        addr-KERNELBASE
-#endif /* MACH_KERNEL */
-
 	.file	"apm_setup.s"
 
 	.data
@@ -43,12 +33,7 @@ _apm_init_image:
 	.globl	_apm_init_image
 
 1:
-#ifdef __FreeBSD__
 #include "i386/apm/apm_init/apm_init.inc"
-#endif /* __FreeBSD__ */
-#ifdef MACH_KERNEL
-#include "i386at/apm_init/apm_init.inc"
-#endif /* MACH_KERNEL */
 2:
 
 _apm_init_image_size:
@@ -168,6 +153,7 @@ _apm_setup:
 	APM_SETUP_GDT(APM_INIT_CS_INDEX  , CS32_ATTRIB)
 	APM_SETUP_GDT(APM_INIT_DS_INDEX  , DS32_ATTRIB)
 	APM_SETUP_GDT(APM_INIT_CS16_INDEX, CS16_ATTRIB)
+	APM_SETUP_GDT(APM_INIT_DS16_INDEX, DS16_ATTRIB)
 
 	/*
 	 * Call the initializer:
diff --git a/sys/i386/include/apm_segments.h b/sys/i386/include/apm_segments.h
index c76df0787fad..ff966ccc36af 100644
--- a/sys/i386/include/apm_segments.h
+++ b/sys/i386/include/apm_segments.h
@@ -12,7 +12,7 @@
  *
  * Sep., 1994	Implemented on FreeBSD 1.1.5.1R (Toshiba AVS001WD)
  *
- *	$Id: apm_segments.h,v 1.3 1995/02/17 02:22:46 phk Exp $
+ *	$Id: apm_segments.h,v 1.4 1995/05/30 08:00:25 rgrimes Exp $
  */
 
 #ifndef _MACHINE_APM_SEGMENTS_H
@@ -21,15 +21,18 @@
 #define SIZEOF_GDT		8
 #define BOOTSTRAP_GDT_NUM	32
 
-#define APM_INIT_CS_INDEX	(BOOTSTRAP_GDT_NUM - 3)
-#define APM_INIT_DS_INDEX	(BOOTSTRAP_GDT_NUM - 2)
-#define APM_INIT_CS16_INDEX	(BOOTSTRAP_GDT_NUM - 1)
+#define APM_INIT_CS_INDEX	(BOOTSTRAP_GDT_NUM - 4)
+#define APM_INIT_DS_INDEX	(BOOTSTRAP_GDT_NUM - 3)
+#define APM_INIT_CS16_INDEX	(BOOTSTRAP_GDT_NUM - 2)
+#define APM_INIT_DS16_INDEX	(BOOTSTRAP_GDT_NUM - 1)
 #define APM_INIT_CS_SEL		(APM_INIT_CS_INDEX << 3)
 #define APM_INIT_DS_SEL		(APM_INIT_DS_INDEX << 3)
 #define APM_INIT_CS16_SEL	(APM_INIT_CS16_INDEX << 3)
+#define APM_INIT_DS16_SEL	(APM_INIT_DS16_INDEX << 3)
 
 #define CS32_ATTRIB		0x409e
-#define CS16_ATTRIB		0x009e
 #define DS32_ATTRIB		0x4092
+#define CS16_ATTRIB		0x009e
+#define DS16_ATTRIB		0x0092
 
 #endif