xnu-344.23.tar.gz

[apple/xnu.git] / osfmk / i386 / AT386 / mp / slave_boot.s

/*
 * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 * 
 * The contents of this file constitute Original Code as defined in and
 * are subject to the Apple Public Source License Version 1.1 (the
 * "License").  You may not use this file except in compliance with the
 * License.  Please obtain a copy of the License at
 * http://www.apple.com/publicsource and read it before using this file.
 * 
 * This Original Code and all software distributed under the License are
 * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
 * License for the specific language governing rights and limitations
 * under the License.
 * 
 * @APPLE_LICENSE_HEADER_END@
 */
/*
 * @OSF_COPYRIGHT@
 */

/* 
 * Mach Operating System
 * Copyright (c) 1991,1990 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.
 */


#include "i386/asm.h"
#include "i386/AT386/mp/boot.h"

#define CR0_PE_ON	0x1
#define CR0_PE_OFF	0xfffffffe

	.file	"slave_boot.s"

	.text	

#define	LJMP(segment,address)	\
	.byte	0xea		;\
	.long	address-EXT(slave_boot_base)		;\
	.word	segment

#define	LGDT(address)	\
	.word	0x010f ;\
	.byte	0x15 ;\
	.long	address-EXT(slave_boot_base)

ENTRY(slave_boot_base)
	/* code is loaded at 0x0:0x1000 */
	/* ljmp to the next instruction to set up %cs */
	data16
	LJMP(MP_BOOTSEG, EXT(slave_pstart))

ENTRY(slave_pstart)
	/* set up %ds */
	mov	%cs, %ax
	mov	%ax, %ds

	/* set up %ss and %esp */
	data16
	mov	$MP_BOOTSEG, %eax
	mov	%ax, %ss
	data16
	mov	$MP_BOOTSTACK, %esp

	/*set up %es */
	mov	%ax, %es

	/* change to protected mode */
	data16
	call	EXT(real_to_prot)

	push	MP_MACH_START
	call	EXT(startprog)

/*
 real_to_prot()
 	transfer from real mode to protected mode.
*/

ENTRY(real_to_prot)
	/* guarantee that interrupt is disabled when in prot mode */
	cli

	/* load the gdtr */
	addr16
	data16
	LGDT(EXT(gdtr))

	/* set the PE bit of CR0 */
	mov	%cr0, %eax

	data16
	or	$CR0_PE_ON, %eax
	mov	%eax, %cr0 

	/* make intrasegment jump to flush the processor pipeline and */
	/* reload CS register */
	data16
	LJMP(0x08, xprot)

xprot:
	/* we are in USE32 mode now */
	/* set up the protective mode segment registers : DS, SS, ES */
	mov	$0x10, %eax
	movw	%ax, %ds
	movw	%ax, %ss
	movw	%ax, %es

	ret

/*
 startprog(phyaddr)
	start the program on protected mode where phyaddr is the entry point
*/

ENTRY(startprog)
	push	%ebp
	mov	%esp, %ebp
	
	mov	0x8(%ebp), %ecx		/* entry offset  */
	mov	$0x28, %ebx		/* segment */
	push	%ebx
	push	%ecx

	/* set up %ds and %es */
	mov	$0x20, %ebx
	movw	%bx, %ds
	movw	%bx, %es

	lret


	. = MP_GDT-MP_BOOT	/* GDT location */
ENTRY(Gdt)

/*  Segment Descriptor
 *
 * 31          24         19   16                 7           0
 * ------------------------------------------------------------
 * |             | |B| |A|       | |   |1|0|E|W|A|            |
 * | BASE 31..24 |G|/|0|V| LIMIT |P|DPL|  TYPE   | BASE 23:16 |
 * |             | |D| |L| 19..16| |   |1|1|C|R|A|            |
 * ------------------------------------------------------------
 * |                             |                            |
 * |        BASE 15..0           |       LIMIT 15..0          |
 * |                             |                            |
 * ------------------------------------------------------------
 */
	.word	0,0		/* 0x0 : null */
	.byte	0,0,0,0

	.word	0xffff,MP_BOOT	/* 0x8 : boot code */
	.byte	0,0x9e,0x40,0

	.word	0xffff,MP_BOOT	/* 0x10 : boot data */
	.byte	0,0x92,0x40,0

	.word	0xffff,MP_BOOT	/* 0x18 : boot code, 16 bits */
	.byte	0,0x9e,0x0,0

	.word	0xffff,0	/* 0x20 : init data */
	.byte	0,0x92,0xcf,0

	.word	0xffff,0	/* 0x28 : init code */
	.byte	0,0x9e,0xcf,0

ENTRY(gdtr)
	.short	48		/* limit (8*6 segs) */
	.short	MP_GDT		/* base low */
	.short	0		/* base high */

ENTRY(slave_boot_end)