xref: /netbsd-src/sys/arch/i386/stand/lib/getextmemx.c (revision 3b01aba77a7a698587faaae455bbfe740923c1f5)
1 /*	$NetBSD: getextmemx.c,v 1.2 1999/03/08 21:38:28 drochner Exp $	*/
2 
3 /*
4  * Copyright (c) 1997, 1999
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 /*
36  * Try 2 more fancy BIOS calls to get the size of extended
37  * memory besides the classical int15/88, take maximum.
38  * needs lowlevel parts from biosmemx.S and biosmem.S
39  */
40 
41 #include <lib/libsa/stand.h>
42 #include "libi386.h"
43 
44 extern int getextmem2 __P((int *));
45 extern int getmementry __P((int *, int *));
46 
47 int
48 getextmemx()
49 {
50 	int buf[5], i;
51 	int extmem = getextmem1();
52 
53 	if (!getextmem2(buf) && buf[0] <= 15 * 1024) {
54 		int help = buf[0];
55 		if (help == 15 * 1024)
56 			help += buf[1] * 64;
57 		if (extmem < help)
58 			extmem = help;
59 	}
60 
61 	i = 0;
62 	do {
63 		if (getmementry(&i, buf))
64 			break;
65 		if ((buf[4] == 1 && buf[0] == 0x100000)
66 		    && extmem < buf[2] / 1024)
67 			extmem = buf[2] / 1024;
68 	} while (i);
69 
70 	return (extmem);
71 }
72