no more 60k limit!

no more explicit real<-->prot switching!
fix 2.88 floppy drives.....
kbd fixes coming soon!
test it!

5 files changed, 224 insertions, 274 deletions

diff --git a/sys/arch/i386/stand/Makefile.inc b/sys/arch/i386/stand/Makefile.inc
index d94df93ebd7..dbeaa4bf257 100644
--- a/sys/arch/i386/stand/Makefile.inc
+++ b/sys/arch/i386/stand/Makefile.inc
@@ -1,11 +1,12 @@
-#	$OpenBSD: Makefile.inc,v 1.6 1997/04/11 19:07:07 weingart Exp $
+#	$OpenBSD: Makefile.inc,v 1.7 1997/04/18 01:28:00 mickey Exp $
 
 #CPPFLAGS+=-nostdinc -I/sys
 CPPFLAGS+=-Wall -Werror -I. -Imachine
-SACFLAGS+=-Wa,-R -fno-common -fpack-struct -fno-builtin -fomit-frame-pointer
+SACFLAGS+=-Wa,-R -fpack-struct -fno-builtin -fomit-frame-pointer
 CPPFLAGS+=-D_STANDALONE
-# CPPFLAGS+=-DSAVE_MEMORY	/* XXX - Does *NOT* work */
+# CPPFLAGS+=-DSAVE_MEMORY
 # CPPFLAGS+=-DDEBUG
+# CPPFLAGS+=-DGIDT_DEBUG
 # CPPFLAGS+=-DBIOS_DEBUG
 # CPPFLAGS+=-DEXEC_DEBUG
 # CPPFLAGS+=-DALLOC_TRACE
@@ -13,11 +14,10 @@ CPPFLAGS+=-D_STANDALONE
 # CPPFLAFS+=-DUNIX_DEBUG
 # CPPFLAFS+=-DBOOTP_DEBUG -DNETIF_DEBUG -DETHER_DEBUG
 # CPPFLAGS+=-DNFS_DEBUG -DRPC_DEBUG -DRARP_DEBUG
-START=0x1000
-HEAP_START=0x10000
-HEAP_LIMIT=0x40000
+START=0x10000
+HEAP_LIMIT=0x50000
 BOOTREL=0x3000
 BOOTMAGIC=0xdeadbeef
 
-NO_NET=no_net
+# NO_NET=no_net
 BINDIR=	/usr/mdec
diff --git a/sys/arch/i386/stand/libsa/Makefile b/sys/arch/i386/stand/libsa/Makefile
index 5e757fc4f5c..b2f03c14fe8 100644
--- a/sys/arch/i386/stand/libsa/Makefile
+++ b/sys/arch/i386/stand/libsa/Makefile
@@ -1,4 +1,4 @@
-#	$OpenBSD: Makefile,v 1.8 1997/04/15 20:01:55 mickey Exp $
+#	$OpenBSD: Makefile,v 1.9 1997/04/18 01:28:01 mickey Exp $
 
 
 LIB=	sa
@@ -8,14 +8,18 @@ DIR_SA=	$S/lib/libsa
 DIR_KERN=$S/lib/libkern
 
 CFLAGS+=$(SACFLAGS) -D__INTERNAL_LIBSA_CREAD
-CFLAGS+=-DHEAP_START=$(HEAP_START) -DHEAP_LIMIT=$(HEAP_LIMIT)
+CFLAGS+=-DSTART=$(START) -DHEAP_LIMIT=$(HEAP_LIMIT)
 CFLAGS+=${DEBUGFLAGS} -I${.CURDIR} -I${.CURDIR}/..
 CFLAGS+=-I$(S)/lib/libsa -I$(S)
 AS+=	-R
-#AS+=	-Wa,-a
+AS+=	-Wa,-a
+
+# i386 stuff (so, it will possibly load in the same 64k)
+SRCS=	unixsys.S bioscom.S biosdisk.S bioskbd.S biostime.S biosmem.S gidt.S \
+	debug_i386.S dev_i386.c exec_i386.c biosdev.c gateA20.c memprobe.c
 
 # stand routines
-SRCS=	alloc.c exit.c exec.c getfile.c gets.c globals.c strcmp.c strlen.c \
+SRCS+=	alloc.c exit.c exec.c getfile.c gets.c globals.c strcmp.c strlen.c \
 	strncmp.c memcmp.c memcpy.c memset.c printf.c strerror.c strncpy.c
 
 # math for cd9660
@@ -35,12 +39,7 @@ SRCS+=	bootp.c bootparam.c rarp.c
 SRCS+=	ufs.c nfs.c cd9660.c
 
 # debugger
-SRCS+=	debug.c debug_aout.c debug_i386.S
-
-# i386 stuff
-SRCS+=	asm.S bioscom.S biosdev.c biosdisk.S bioskbd.S biostime.S biosmem.S \
-	dev_i386.c gateA20.c memprobe.c real_prot.S unixsys.S exec_i386.c \
-	gidt.S
+SRCS+=	debug.c debug_aout.c
 
 NOPROFILE=noprofile
 NOPIC=nopic
diff --git a/sys/arch/i386/stand/libsa/biosdev.c b/sys/arch/i386/stand/libsa/biosdev.c
index 696a37611d8..e6ee0edd8c7 100644
--- a/sys/arch/i386/stand/libsa/biosdev.c
+++ b/sys/arch/i386/stand/libsa/biosdev.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: biosdev.c,v 1.8 1997/04/17 19:03:20 weingart Exp $	*/
+/*	$OpenBSD: biosdev.c,v 1.9 1997/04/18 01:28:01 mickey Exp $	*/
 
 /*
  * Copyright (c) 1996 Michael Shalayeff
@@ -263,7 +263,7 @@ biosstrategy(void *devdata, int rw,
 {
 	u_int8_t error = 0;
 	register struct biosdisk *bd = (struct biosdisk *)devdata;
-	register size_t i, nsect, n;
+	register size_t i, nsect, n, spt;
 	register const struct bd_error *p = bd_errors;
 
 	nsect = (size + DEV_BSIZE-1) / DEV_BSIZE;
@@ -278,15 +278,20 @@ biosstrategy(void *devdata, int rw,
 		       buf, rsize, bd->biosdev, bd->bsddev);
 #endif
 
+	/* handle floppies w/ different from drive geometry */
+	if (!(bd->biosdev & 0x80))
+		spt = bd->disklabel.d_nsectors;
+	else
+		spt = BIOSNSECTS(bd->dinfo);
+
 	for (i = 0; error == 0 && i < nsect;
 	     i += n, blk += n, buf += n * DEV_BSIZE) {
 		register int	cyl, hd, sect, j;
 		void *bb;
 
-		btochs(blk, cyl, hd, sect, 
-			BIOSNHEADS(bd->dinfo), BIOSNSECTS(bd->dinfo));
-		if ((sect + (nsect - i)) >= BIOSNSECTS(bd->dinfo))
-			n = BIOSNSECTS(bd->dinfo) - sect;
+		btochs(blk, cyl, hd, sect, BIOSNHEADS(bd->dinfo), spt);
+		if ((sect + (nsect - i)) >= spt)
+			n = spt - sect;
 		else
 			n = nsect - i;
 		
diff --git a/sys/arch/i386/stand/libsa/gidt.S b/sys/arch/i386/stand/libsa/gidt.S
index 1653a0d21d9..56fc268e84b 100644
--- a/sys/arch/i386/stand/libsa/gidt.S
+++ b/sys/arch/i386/stand/libsa/gidt.S
@@ -1,4 +1,4 @@
-/*	$OpenBSD: gidt.S,v 1.3 1997/04/09 08:39:37 mickey Exp $	*/
+/*	$OpenBSD: gidt.S,v 1.4 1997/04/18 01:28:02 mickey Exp $	*/
 
 /*
  * Copyright (c) 1997 Michael Shalayeff
@@ -31,6 +31,9 @@
  * SUCH DAMAGE.
  *
  */
+
+	.file "gidt.S"
+
 #include <machine/asm.h>
 #include <machine/psl.h>
 #define _LOCORE
@@ -45,7 +48,6 @@
 
 	.data
 	.globl	_Gdtr
-	.globl	_codeseg
 
 	.align	3
 gdt:
@@ -67,17 +69,23 @@ gdt:
 	.byte	0			# hibase
 		/* 0x18 : 16 bit code */
 	.word	0xFFFF			# lolimit
-	.word	0			# lobase
-	.byte	0			# midbase
+	.word	(START & 0xffff)	# lobase
+	.byte	(START >> 16) & 0xff	# midbase
 	.byte	SDT_MEMERA | 0 | 0x80	# RXAC, dpl = 0, present
-	.byte	0x0 | 0 | 0 | 0		# hilimit, xx, 16bit, byte granularity
-	.byte	0			# hibase
+	.byte	0xf | 0 | 0 | 0		# hilimit, xx, 16bit, byte granularity
+	.byte	(START >> 20) & 0xff	# hibase
+		/* 0x20 : 16 bit data */
+	.word	0xFFFF			# lolimit
+	.word	(START & 0xffff)	# lobase
+	.byte	(START >> 16) & 0xff	# midbase
+	.byte	SDT_MEMRWA | 0 | 0x80	# RXAC, dpl = 0, present
+	.byte	0xf | 0 | 0 | 0		# hilimit, xx, 16bit, byte granularity
+	.byte	(START >> 20) & 0xff	# hibase
+
 _Gdtr:	.word	. - gdt - 1
 	.long	gdt
 	.word	0
 
-_codeseg:	.long	0
-
 	.globl	_Idtr_real
 	.align 3
 _Idtr_real:
@@ -92,59 +100,58 @@ _Idtr_reset:
 
 	.globl	_Idtr_prot
 	.align 3
-idt:	/*
-	 * We beleive that all the boot code fits into
-	 * 64k, so no need for high 16 bit of procedure address (;
-	 *
-	 */
-#define IPROC(n)	X/**/n
-#define IDTENTRY(proc) \
-	.word	IPROC(proc)		/* lo offset handler */ ; \
-	.word	0x8			/* handler %cs */ ; \
-	.byte	0			/* reserved */ ; \
-	.byte	0x80 | SDT_SYS386TGT /* present, dpl=0, 32bit trap gate */ ; \
-	.word	0			/* hi offset handler */
-
-	IDTENTRY(de)	/* #DE divide by zero */
-	IDTENTRY(db)	/* #DB debug */
-	IDTENTRY(nmi)	/* NMI */
-	IDTENTRY(bp)	/* #BP breakpoint */
-	IDTENTRY(of)	/* #OF overflow */
-	IDTENTRY(br)	/* #BR BOUND range exceeded */
-	IDTENTRY(ud)	/* #UD invalid opcode */
-	IDTENTRY(nm)	/* #NM device not available */
-	IDTENTRY(df)	/* #DF double fault */
-	IDTENTRY(fo)	/* #FO coprocessor segment overrun */
-	IDTENTRY(ts)	/* #TS innvalid TSS */
-	IDTENTRY(np)	/* #NP segmant not present */
-	IDTENTRY(ss)	/* #SS stack fault */
-	IDTENTRY(gp)	/* #GP general protection */
-	IDTENTRY(pf)	/* #PF page fault */
-	IDTENTRY(xx)	/*	Intel reserved */
-	IDTENTRY(mf)	/* #MF floating point error */
-	IDTENTRY(ac)	/* #AC alignment check */
-	IDTENTRY(mc)	/* #MC machine check */
-			/*	Intel reserved (19-31) */
-	IDTENTRY(xx); IDTENTRY(xx); IDTENTRY(xx); IDTENTRY(xx)
-	IDTENTRY(xx); IDTENTRY(xx); IDTENTRY(xx); IDTENTRY(xx)
-	IDTENTRY(xx); IDTENTRY(xx); IDTENTRY(xx); IDTENTRY(xx)
-	IDTENTRY(xx)
-			/*	Maskable interrupts(32-255) */
-			/*	BIOS entry points (32-63) */
-#define IBIOS(n)	IPROC(bios/**/n)
-#define IDTBIOS(n)	IDTENTRY(bios/**/n)
-	IDTBIOS(0);  IDTBIOS(1);  IDTBIOS(2);  IDTBIOS(3);  IDTBIOS(4)
-	IDTBIOS(5);  IDTBIOS(6);  IDTBIOS(7);  IDTBIOS(8);  IDTBIOS(9)
-	IDTBIOS(10); IDTBIOS(11); IDTBIOS(12); IDTBIOS(13); IDTBIOS(14)
-	IDTBIOS(15); IDTBIOS(16); IDTBIOS(17); IDTBIOS(18); IDTBIOS(19)
-	IDTBIOS(20); IDTBIOS(21); IDTBIOS(22); IDTBIOS(23)
-			/*	DOS entry points */
+idt:
+	.space 32*8, 0	/* internal (0-31) */
+			/*	Maskable interrupts (32-255) */
+	.space 32*8, 0	/* BIOS entry points (32-63) */
+	.space 16*8, 0	/* DOS entry points (64-80) */
 
 _Idtr_prot:
 	.word	. - idt - 1
 	.long	idt
 
 	.text
+#define IPROC(n)	X/**/n
+#define IBIOS(n)	IPROC(bios/**/n)
+#define IDOS(n)		IPROC(dos/**/n)
+
+	.globl	idt_init
+idt_init:
+	pushl	%edi
+
+	movl	$idt, %edi
+
+#define	fixe(p)								\
+	movl	$ IPROC(p), %eax;					\
+	stosw; 					/* lo offset handler */	\
+	movw	$0x8, (%edi);			/* handler %cs */	\
+	incl %edi; incl %edi;						\
+	incl %edi;				/* reserved */		\
+	movb	$(0x80|SDT_SYS386TGT), (%edi);	/* 32bit trap gate */	\
+	incl %edi;							\
+	shrl	$16, %eax;						\
+	stosw;					/* hi offset handler */
+
+	fixe(de); fixe(db); fixe(nmi); fixe(bp); fixe(of); fixe(br)
+	fixe(ud); fixe(nm); fixe(df);  fixe(fo); fixe(ts); fixe(np)
+	fixe(ss); fixe(gp); fixe(pf);  fixe(xx); fixe(mf); fixe(ac)
+	fixe(mc)
+	fixe(xx); fixe(xx); fixe(xx);  fixe(xx); fixe(xx); fixe(xx)
+	fixe(xx); fixe(xx); fixe(xx);  fixe(xx); fixe(xx); fixe(xx)
+	fixe(xx) 
+
+#define fixb(b) fixe(bios/**/b)
+	fixb(0);  fixb(1);  fixb(2);  fixb(3);  fixb(4);  fixb(5)
+	fixb(6);  fixb(7);  fixb(8);  fixb(9);  fixb(10); fixb(11)
+	fixb(12); fixb(13); fixb(14); fixb(15); fixb(16); fixb(17)
+	fixb(18); fixb(19); fixb(20); fixb(21); fixb(22); fixb(23)
+	fixb(24); fixb(25); fixb(26); fixb(27); fixb(28); fixb(29)
+	fixb(30); fixb(31)
+
+#define fixd(d) fixe(dos/**/b)
+
+	popl	%edi
+	ret
 
 #define IENTRY(name,type) \
 IPROC(name): \
@@ -158,33 +165,33 @@ IPROC(name): \
 
 IPROC(xx):
 	pushl	$1
-	pushl	$256
+	pushl	$T_RESERVED
 	jmp	1f
 
-IENTRY_ERR(de,0,T_DIVIDE)
-IENTRY_ERR(db,0,T_TRCTRAP)
-IENTRY_ERR(nmi,0,T_NMI)
-IENTRY_ERR(bp,0,T_BPTFLT)
-IENTRY_ERR(of,0,T_OFLOW)
-IENTRY_ERR(br,0,T_BOUND)
-IENTRY_ERR(ud,0,T_PRIVINFLT)
-IENTRY_ERR(nm,0,T_DNA)
-IENTRY(df,T_DOUBLEFLT)
-IENTRY_ERR(fo,0,T_FPOPFLT)
-IENTRY(ts,T_TSSFLT)
-IENTRY(np,T_SEGNPFLT)
-IENTRY(ss,T_STKFLT)
-IENTRY(gp,T_PROTFLT)
-IENTRY(pf,T_PAGEFLT)
-IENTRY_ERR(mf,0,T_ARITHTRAP)
-IENTRY(ac,T_ALIGNFLT)
-IENTRY(mc,T_MACHK)
+IENTRY_ERR(de,0,T_DIVIDE)	/* #DE divide by zero */
+IENTRY_ERR(db,0,T_TRCTRAP)	/* #DB debug */
+IENTRY_ERR(nmi,0,T_NMI)		/* NMI */
+IENTRY_ERR(bp,0,T_BPTFLT)	/* #BP breakpoint */
+IENTRY_ERR(of,0,T_OFLOW)	/* #OF overflow */
+IENTRY_ERR(br,0,T_BOUND)	/* #BR BOUND range exceeded */
+IENTRY_ERR(ud,0,T_PRIVINFLT)	/* #UD invalid opcode */
+IENTRY_ERR(nm,0,T_DNA)		/* #NM device not available */
+IENTRY(df,T_DOUBLEFLT)		/* #DF double fault */
+IENTRY_ERR(fo,0,T_FPOPFLT)	/* #FO coprocessor segment overrun */
+IENTRY(ts,T_TSSFLT)		/* #TS innvalid TSS */
+IENTRY(np,T_SEGNPFLT)		/* #NP segmant not present */
+IENTRY(ss,T_STKFLT)		/* #SS stack fault */
+IENTRY(gp,T_PROTFLT)		/* #GP general protection */
+IENTRY(pf,T_PAGEFLT)		/* #PF page fault */
+IENTRY_ERR(mf,0,T_ARITHTRAP)	/* #MF floating point error */
+IENTRY(ac,T_ALIGNFLT)		/* #AC alignment check */
+IENTRY(mc,T_MACHK)		/* #MC machine check */
 
 	.globl	alltraps
 1:	/* save on jumps */
 	jmp	alltraps
 
-#define	IBIOSENT(n)	IBIOS(n): pushl %eax; movb $n, %al ; jmp 1f
+#define	IBIOSENT(n)	IBIOS(n): pushl $n; jmp BIOSh
 
 IBIOSENT(0);  IBIOSENT(1);  IBIOSENT(2);  IBIOSENT(3)
 IBIOSENT(4);  IBIOSENT(5);  IBIOSENT(6);  IBIOSENT(7)
@@ -192,38 +199,143 @@ IBIOSENT(8);  IBIOSENT(9);  IBIOSENT(10); IBIOSENT(11)
 IBIOSENT(12); IBIOSENT(13); IBIOSENT(14); IBIOSENT(15)
 IBIOSENT(16); IBIOSENT(17); IBIOSENT(18); IBIOSENT(19)
 IBIOSENT(20); IBIOSENT(21); IBIOSENT(22); IBIOSENT(23)
+IBIOSENT(24); IBIOSENT(25); IBIOSENT(26); IBIOSENT(27)
+IBIOSENT(28); IBIOSENT(29); IBIOSENT(30); IBIOSENT(31)
 
-	.text
-	.globl	_real_to_prot, _prot_to_real
-1:
-	movb	%al, intno
-	popl	%eax
+/*
+ * entry point for BIOS real-mode interface
+ * all the magic for real-prot mode switching is here
+ *
+ * Call:	%eax, %ecx, %edx, %ebx, %ebp, %esi, %ds, %di==real mode %es
+ * Return:	%eax, %edx, %ecx, %eflags (as returned from BIOS)
+ *
+ */
+	.globl	BIOSh
+BIOSh:
 	pushal
 	pushl	%ds
 	pushl	%es
 
-	call	_prot_to_real
+	/* save %eax */
+	movl	%eax, 2f
+
+	/* save BIOS int vector */
+	movb	10*4(%esp), %al
+	movb	%al, intno
+
+	/* setup 16bit labels in ljmps */
 
+#ifdef	GIDT_DEBUG
+	movl	$0xb8000, %eax
+	movl	$0x47314730, (%eax)
+#endif
+	movl	$0x20, %eax
+
+	# ljmp	$0x18, $2f
+	.byte	0xea		/* Change to 16bit mode */
+	.long	1f - START
+	.word	0x18
+1:
+	movl	%ax, %ds
+#ifdef	GIDT_DEBUG
+	data32
+	movl	$(0xb8000 - START), %eax
+	data32
+	addr32
+	movl	$0x4f314f30, (%eax)
+#endif
+	movl	%cr0, %eax	/* disable prot mode memory management */
+	data32
+	andl 	$~CR0_PE, %eax
+	movl	%eax, %cr0
+
+	# ljmp	(START >> 16), $4f
+	.byte	0xea		/* load real mode cs:ip */
+	.word	1f
+	.word	(START >> 4)
+1:
+	xorl	%eax, %eax	/* setup: %ds, %es, %ss */
+	movl	%ax, %ds
+	movl	%ax, %ss
 	movl	%di, %es
+#ifdef	GIDT_DEBUG
+	data32
+	movl	$0xb8004, %eax
+	data32
+	addr32
+	movl	$0x47334732, (%eax)
+#endif
+
+	addr32
+	data32
+	lidt	_Idtr_real	/* load idtr for DOS/BIOS operations */
+
+	data32
+	# movl	Leax, %eax
+	.byte	0xb8
+2:	.long	0x90909090	/* restore %eax */
+
+	sti
 
 	int	$0
-intno = . - 1
+intno	= . - 1
 
-	movb	%ah, %bh
+	movb	%ah, %bh	/* save flags to return to caller */
 	lahf
 	xchgb	%ah, %bh
 
+	cli			/* no maskable interrupts in prot mode */
+
+	addr32
+	data32
+	movl	%eax, 2f	/* save %eax */
+
+#ifdef	GIDT_DEBUG
+	data32
+	movl	$0xb8004, %eax
+	data32
+	addr32
+	movl	$0x4f334f32, (%eax)
+#endif
+
+	addr32
+	data32
+	lgdt	_C_LABEL(Gdtr)	/* load the gdtr */
+
+	movl	%cr0, %eax	/* enable prot mode memory management */
+	data32
+	orl	$CR0_PE, %eax
+	movl	%eax, %cr0 
+
 	data32
-	call	_real_to_prot
+	ljmp	$0x08, $1f	/* reload %cs, and flush pipeline */
+1:
+	/* reload 32bit %ds, %ss, %es */
+	movl	$0x10, %eax
+	movl	%ax, %ds
+	movl	%ax, %ss
+
+#ifdef	GIDT_DEBUG
+	movl	$0xb8008, %eax
+	movl	$0x47344733, (%eax)
+#endif
+
+	/* load idtr for debugger and DOS/BIOS iface */
+	lidt	_Idtr_prot
+
+	# movl	Leax, %eax
+	.byte	0xb8
+2:	.long	0x90909090	/* eax */
 
 	/* pass BIOS return values back to caller */
 	movl	%eax, 0x9*4(%esp)
 	movl	%ecx, 0x8*4(%esp)
 	movl	%edx, 0x7*4(%esp)
-	movb	%bh , 0xc*4(%esp)
+	movb	%bh , 0xd*4(%esp)
 
 	popl	%es
 	popl	%ds
 	popal
+	incl %esp; incl %esp; incl %esp; incl %esp
 	iret
 
diff --git a/sys/arch/i386/stand/libsa/real_prot.S b/sys/arch/i386/stand/libsa/real_prot.S
deleted file mode 100644
index b04d5545335..00000000000
--- a/sys/arch/i386/stand/libsa/real_prot.S
+++ /dev/null
@@ -1,166 +0,0 @@
-/*	$OpenBSD: real_prot.S,v 1.5 1997/04/09 08:39:42 mickey Exp $	*/
-
-/*
- * Mach Operating System
- * Copyright (c) 1992, 1991 Carnegie Mellon University
- * All Rights Reserved.
- * 
- * Permission to use, copy, modify and distribute this software and its
- * documentation is hereby granted, provided that both the copyright
- * notice and this permission notice appear in all copies of the
- * software, derivative works or modified versions, and any portions
- * thereof, and that both notices appear in supporting documentation.
- * 
- * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
- * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
- * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
- * 
- * Carnegie Mellon requests users of this software to return to
- * 
- *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
- *  School of Computer Science
- *  Carnegie Mellon University
- *  Pittsburgh PA 15213-3890
- * 
- * any improvements or extensions that they make and grant Carnegie Mellon
- * the rights to redistribute these changes.
- *
- *	from: Mach, Revision 2.2  92/04/04  11:34:13  rpd
- */
-
-
-/*
-  Copyright 1988, 1989, 1990, 1991, 1992 
-   by Intel Corporation, Santa Clara, California.
-
-                All Rights Reserved
-
-Permission to use, copy, modify, and distribute this software and
-its documentation for any purpose and without fee is hereby
-granted, provided that the above copyright notice appears in all
-copies and that both the copyright notice and this permission notice
-appear in supporting documentation, and that the name of Intel
-not be used in advertising or publicity pertaining to distribution
-of the software without specific, written prior permission.
-
-INTEL DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE
-INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS,
-IN NO EVENT SHALL INTEL BE LIABLE FOR ANY SPECIAL, INDIRECT, OR
-CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
-LOSS OF USE, DATA OR PROFITS, WHETHER IN ACTION OF CONTRACT,
-NEGLIGENCE, OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
-WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
-*/
-	.file "real_prot.S"
-
-#include <machine/asm.h>
-#include <machine/specialreg.h>
-
-#define addr32  .byte 0x67
-#define data32  .byte 0x66
-
-	.data
-
-	.globl	_codeseg
-	.globl	_Gdtr
-	.globl	_Idtr_prot
-	.globl	_Idtr_real
-
-	.text
-
-/*
- *
- * real_to_prot()
- * 	transfer from real mode to protected mode.
- */
-
-ENTRY(real_to_prot)
-	/* guarantee that interrupts are disabled when in prot mode */
-	cli
-	addr32
-	data32
-	movl	%eax, 2f
-
-	/* load the gdtr */
-	addr32
-	data32
-	lgdt	_C_LABEL(Gdtr)
-
-	/* set the PE bit of CR0 */
-	movl	%cr0, %eax
-	data32
-	orl	$CR0_PE, %eax
-	movl	%eax, %cr0 
-
-	/*
-	 * make intrasegment jump to flush the processor pipeline and
-	 * reload CS register
-	 */
-	data32
-	ljmp	$0x08, $1f
-
-1:	/*
-	 * we are in USE32 mode now
-	 * set up the protected mode segment registers : DS, SS, ES
-	 */
-	movl	$0x10, %eax
-	movl	%ax, %ds
-	movl	%ax, %ss
-	movl	%ax, %es
-
-	/* load idtr for debugger and BIOS iface */
-	lidt	_Idtr_prot
-	# movl	Leax, %eax
-	.byte	0xb8
-2:	.long	0	/* eax */
-	ret
-
-/*
- *
- * prot_to_real()
- *	transfer from protected mode to real mode
- * 
- */
-
-ENTRY(prot_to_real)
-
-	movl	%eax, 4f
-	movl 	_codeseg, %eax
-	movw	%ax, 2f
-
-	/* Change to use16 mode. */
-	ljmp	$0x18, $1f
-1:
-	/* clear the PE bit of CR0 */
-	movl	%cr0, %eax
-	data32
-	andl 	$~CR0_PE, %eax
-	movl	%eax, %cr0
-
-	data32
-	# ljmp	_codeseg, $2f
-	.byte	0xea
-	.long	3f
-2:	.word	0
-3:	
-	/* setup: %ds, %es, %ss */
-	movl	%cs, %ax
-	movl	%ax, %ds
-	movl	%ax, %ss
-	movl	%ax, %es
-
-	/* load idtr for BIOS operations */
-	addr32
-	data32
-	lidt	_Idtr_real
-
-	addr32
-	data32
-	# movl	Leax, %eax
-	.byte	0xb8
-4:	.long	0	/* %eax */
-
-	sti
-	data32
-	ret
-