xref: /netbsd-src/sys/arch/i386/stand/lib/getextmemx.c (revision 2a399c6883d870daece976daec6ffa7bb7f934ce)
1 /*	$NetBSD: getextmemx.c,v 1.1 1997/08/14 15:22:00 drochner Exp $	*/
2 
3 /*
4  * Copyright (c) 1997
5  *	Matthias Drochner.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *	This product includes software developed for the NetBSD Project
18  *	by Matthias Drochner.
19  * 4. The name of the author may not be used to endorse or promote products
20  *    derived from this software without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
23  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
24  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
25  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
26  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
27  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
31  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32  *
33  */
34 
35 /* Try 2 more fancy BIOS calls to get the size of extended
36  memory besides the classical int15/88, take maximum.
37  needs lowlevel parts from biosmemx.S and biosmem.S
38  */
39 
40 #include <lib/libsa/stand.h>
41 #include "libi386.h"
42 
43 extern int getextmem2 __P((int*));
44 extern int getmementry __P((int, int*));
45 
46 int getextmemx()
47 {
48 	int buf[5], i;
49 	int extmem = getextmem1();
50 
51 	if(!getextmem2(buf) && buf[0] <= 15 * 1024) {
52 		int help = buf[0];
53 		if(help == 15 * 1024)
54 			help += buf[1] * 64;
55 		if(extmem < help)
56 			extmem = help;
57 	}
58 
59 	for(i = 0; (i = getmementry(i, buf)) != 0;) {
60 		if((buf[4] == 1 && buf[0] == 0x100000)
61 		   && extmem < buf[2] / 1024)
62 			extmem = buf[2] / 1024;
63 	}
64 
65 	return(extmem);
66 }
67