xref: /netbsd-src/sys/arch/i386/stand/lib/getextmemx.c (revision b1c86f5f087524e68db12794ee9c3e3da1ab17a0)
1 /*	$NetBSD: getextmemx.c,v 1.9 2008/12/14 17:03:43 christos 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  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26  *
27  */
28 
29 /*
30  * Try 2 more fancy BIOS calls to get the size of extended
31  * memory besides the classical int15/88, take maximum.
32  * needs lowlevel parts from biosmemx.S and biosmem.S
33  */
34 
35 #include <lib/libsa/stand.h>
36 #include "libi386.h"
37 
38 extern int getextmem2(int *);
39 extern int getmementry(int *, int *);
40 extern int getextmemps2(void *);
41 
42 int
43 getextmemx(void)
44 {
45 	int buf[5], i;
46 	int extmem = getextmem1();
47 #ifdef SUPPORT_PS2
48 	struct {
49 		uint16_t len;
50 		uint32_t dta[8];
51 		/* pad to 64 bytes - without this, machine would reset */
52 		uint8_t __pad[30];
53 	} __packed bufps2;
54 #endif
55 
56 #ifdef DEBUG_MEMSIZE
57 	printf("extmem1: %xk\n", extmem);
58 #endif
59 	if (!getextmem2(buf)) {
60 #ifdef DEBUG_MEMSIZE
61 		printf("extmem2: %xk + %xk\n", buf[0], buf[1] * 64);
62 #endif
63 		if (buf[0] <= 15 * 1024) {
64 			int help = buf[0];
65 			if (help == 15 * 1024)
66 				help += buf[1] * 64;
67 			if (extmem < help)
68 				extmem = help;
69 		}
70 	}
71 
72 	i = 0;
73 	do {
74 		if (getmementry(&i, buf))
75 			break;
76 #ifdef DEBUG_MEMSIZE
77 		printf("mementry: (%d) %x %x %x %x %x\n",
78 			i, buf[0], buf[1], buf[2], buf[3], buf[4]);
79 #endif
80 		if ((buf[4] == 1 && buf[0] == 0x100000)
81 		    && extmem < buf[2] / 1024)
82 			extmem = buf[2] / 1024;
83 	} while (i);
84 
85 #ifdef SUPPORT_PS2
86 	/* use local memory information from RETURN MEMORY-MAP INFORMATION */
87 	if (!getextmemps2((void *) &bufps2)) {
88 		int help = bufps2.dta[0];
89 		if (help == 15 * 1024)
90 			help += bufps2.dta[1];
91 		if (extmem < help)
92 			extmem = help;
93 	}
94 #endif
95 
96 	return extmem;
97 }
98