setjmp.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.
 */

typedef struct {
    ulong eip;
    ulong edi;
    ulong esi;
    ulong ebp;
    ulong esp;
    ulong ebx;
    ulong edx;
    ulong ecx;
    ulong eax;
} jmp_buf[1];

inline static int setjmp(jmp_buf regs) {
    register int retcode;
    
    __asm__ __volatile__ (
    	"movl $1f,(%%edi)\n\t"
	"movl %%esi,8(%%edi)\n\t"
	"movl %%esp,%%eax\n\t"
	"movl %%ebp,12(%%edi)\n\t"
	"subl $4,%%eax\n\t"
	"movl %%eax,16(%%edi)\n\t"
	"xorl %%eax,%%eax\n\t"
	"movl %%ebx,20(%%edi)\n\t"
	"movl %%edx,24(%%edi)\n\t"
	"movl %%ecx,28(%%edi)\n"
	"1:\n\t"
	: "=a" (retcode)
	: "D" (regs));
    return(retcode);
}

inline static void longjmp(jmp_buf regs, int retval) {
    __asm__ __volatile__ (
	"movl 16(%%edi),%%esp\n\t"
	"movl 12(%%edi),%%ebp\n\t"
	"movl 8(%%edi),%%esi\n\t"
	"movl (%%edi),%%edx\n\t"
	"movl %%edx,(%%esp)\n\t"
	"movl 20(%%edi),%%ebx\n\t"
	"movl 24(%%edi),%%edx\n\t"
	"movl 28(%%edi),%%ecx\n\t"
	"ret\n\t"
	: /* No output */
	: "D" (regs), "a" (retval));
}