system.h

一个微型操作系统源码

/*
 * OSV
 * Copyright (C) 2002 Ciprian DOSOFTEI <[e-mail]>
 * All rights reserved.
 * 
 * http://backster.free.fr/osv
 *
 * This file is part of the OSV project. OSV is free software, also known as
 * "open source"; you can redistribute it and/or modify it under the terms 
 * of the GNU General Public License (GPL), version 2, as published by the Free
 * Software Foundation (FSF). To explore alternate licensing terms, contact 
 * the author at [e-mail] or [phone].
 * 
 * OSV is distributed in the hope that it will be useful, but WITHOUT ANY
 * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE.  See the GPL for more details.  You should have
 * received a copy of the GPL along with OSV; see the file COPYING.  If
 * not, write to the FSF, 59 Temple Place #330, Boston, MA 02111-1307, USA.
 */

#ifndef ASMSYSTEM
#define ASMSYSTEM

#include <asm/types.h>

#define __save_flags(x)		__asm__ __volatile__("pushfl ; popl %0":"=g" (x): /* no input */)
#define __restore_flags(x) 	__asm__ __volatile__("pushl %0 ; popfl": /* no output */ :"g" (x):"memory")
#define __cli() 		__asm__ __volatile__("cli": : :"memory")
#define __sti()			__asm__ __volatile__("sti": : :"memory")
#define safe_halt()		__asm__ __volatile__("sti; hlt": : :"memory")

#define local_irq_save(x)	__asm__ __volatile__("pushfl ; popl %0 ; cli":"=g" (x): /* no input */ :"memory")
#define local_irq_restore(x)	__restore_flags(x)
#define local_irq_disable()	__cli()
#define local_irq_enable()	__sti()

#define nop() __asm__ __volatile__ ("nop")
#define cli() __cli()
#define sti() __sti()
#define save_flags(x) __save_flags(x)
#define restore_flags(x) __restore_flags(x)
#define get_flags(x) __save_flags(x)
#define set_flags(x) __restore_flags(x)

extern inline dword get_CR0 (void)
{
    register dword x;
    __asm__ __volatile__ ("movl %%cr0,%0" : "=r" (x));
    return (x);
}

extern inline dword get_CR2 (void)
{
    register dword x;
    __asm__ __volatile__ ("movl %%cr2,%0" : "=r" (x));
    return (x);
}

extern inline dword get_CR3 (void)
{
    register dword x;
    __asm__ __volatile__ ("movl %%cr3,%0" : "=r" (x));
    return (x);
}

#define set_CR0(c)  __asm__ __volatile__ ("movl %%eax, %%cr0"::"a" (c))
#define set_CR3(c)  __asm__ __volatile__ ("movl %%eax, %%cr3"::"a" (c))

extern inline void flush_tlb(void) { set_CR3(get_CR3()); }

extern inline void rep_nop(void) { __asm__ __volatile__("rep;nop"); }

#endif