sprintf.c

操作系统试验！通过这个试验

/*
 * sprintf.c
 * Modified for use in 15-410 at CMU
 * Zachary Anderson(zra)
 */

/*
 * Copyright (c) 1994-1996 University of Utah and the Flux Group.
 * All rights reserved.
 * 
 * This file is part of the Flux OSKit.  The OSKit 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 University of Utah at [e-mail] or [phone].
 * 
 * The OSKit 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 the OSKit; see the file COPYING.  If
 * not, write to the FSF, 59 Temple Place #330, Boston, MA 02111-1307, USA.
 */
/* 
 * Mach Operating System
 * Copyright (c) 1991,1990,1989 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  [e-mail]
 *  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 <stdarg.h>
#include "doprnt.h"

#define SPRINTF_UNLIMITED -1
struct sprintf_state {
      char *buf;
      unsigned int len;
      unsigned int max;
};

static void
savechar(char *arg, int c)
{
	struct sprintf_state *state = (struct sprintf_state *)arg;
	
	if (state->max != SPRINTF_UNLIMITED)
	{
		if (state->len == state->max)
			return;
	}

	state->len++;
	*state->buf = c;
	state->buf++;
}

int vsprintf(char *s, const char *fmt, va_list args)
{
	struct sprintf_state state;
	state.max = SPRINTF_UNLIMITED;
	state.len = 0;
	state.buf = s;

	_doprnt(fmt, args, 0, (void (*)()) savechar, (char *) &state);
	*(state.buf) = '\0';

	return state.len;
}

int vsnprintf(char *s, int size, const char *fmt, va_list args)
{
	struct sprintf_state state;
	state.max = size;
	state.len = 0;
	state.buf = s;

	_doprnt(fmt, args, 0, (void (*)()) savechar, (char *) &state);
	*(state.buf) = '\0';

	return state.len;
}

int sprintf(char *s, const char *fmt, ...)
{
	va_list	args;
	int err;

	va_start(args, fmt);
	err = vsprintf(s, fmt, args);
	va_end(args);

	return err;
}

int snprintf(char *s, int size, const char *fmt, ...)
{
	va_list	args;
	int err;

	va_start(args, fmt);
	err = vsnprintf(s, size, fmt, args);
	va_end(args);

	return err;
}


/* this is assembly code for passing str up to simics */
static void simicsPrint (char *str)
{
  asm volatile("pushl %%eax;\
                pushl %%ebx;\
                movl %0, %%eax;\
                movl $0x1badd00d, %%ebx;\
                xchg %%bx,%%bx;\
                popl %%ebx;\
                popl %%eax" : : "m"(str) : "%eax", "%ebx");
}

void lprintf_kern(char *fmt, ...)
{
  char str[256];
  va_list ap;

  va_start(ap, fmt);
  vsnprintf (str, 255, fmt, ap);
  va_end(ap);

  simicsPrint(str);
}

void lprintf(char* fmt, ...)
{
  char str[256];
  va_list ap;

  va_start(ap, fmt);
  vsnprintf (str, 255, fmt, ap);
  va_end(ap);

  simicsPrint(str);
}