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/*
* Copyright (c) 1995-1994 The University of Utah and
* the Computer Systems Laboratory at the University of Utah (CSL).
* All rights reserved.
*
* Permission to use, copy, modify and distribute this software is hereby
* granted provided that (1) source code retains these copyright, permission,
* and disclaimer notices, and (2) redistributions including binaries
* reproduce the notices in supporting documentation, and (3) all advertising
* materials mentioning features or use of this software display the following
* acknowledgement: ``This product includes software developed by the
* Computer Systems Laboratory at the University of Utah.''
*
* THE UNIVERSITY OF UTAH AND CSL ALLOW FREE USE OF THIS SOFTWARE IN ITS "AS
* IS" CONDITION. THE UNIVERSITY OF UTAH AND CSL DISCLAIM ANY LIABILITY OF
* ANY KIND FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
*
* CSL requests users of this software to return to csl-dist@cs.utah.edu any
* improvements that they make and grant CSL redistribution rights.
*
* Author: Bryan Ford, University of Utah CSL
*/
#ifndef _I386_I16_
#define _I386_I16_
#include <mach/machine/code16.h>
#include "gdt.h"
/* Macros to switch between 16-bit and 32-bit code
in the middle of a C function.
Be careful with these! */
#define i16_switch_to_32bit() asm volatile("
ljmp %0,$1f
.code32
1:
" : : "i" (KERNEL_CS));
#define switch_to_16bit() asm volatile("
ljmp %0,$1f
.code16
1:
" : : "i" (KERNEL_16_CS));
/* From within one type of code, execute 'stmt' in the other.
These are safer and harder to screw up with than the above macros. */
#define i16_do_32bit(stmt) \
({ i16_switch_to_32bit(); \
{ stmt; } \
switch_to_16bit(); })
#define do_16bit(stmt) \
({ switch_to_16bit(); \
{ stmt; } \
i16_switch_to_32bit(); })
#endif _I386_I16_
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