1 /* $NetBSD: getextmemx.c,v 1.12 2024/08/24 20:23:11 riastradh 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 int
getextmemx(void)39 getextmemx(void)
40 {
41 /*
42 * Allocate 6 words, not 5, to work around buggy firmware --
43 * see comment on getmementry in biosmemx.S.
44 */
45 int buf[6], 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