1 /* SCCS Id: @(#)ovlinit.c 3.4 1994/03/20 */
2 /* Copyright (c) NetHack PC Development Team 1995 */
3 /* NetHack may be freely redistributed. See license for details. */
4
5 #include "hack.h"
6 #include <dos.h>
7 #include <stdio.h>
8
9
10 #ifdef _MSC_VER
11
12 #define RESERVED_PARAGRAPHS 5120 /* leave 80K for malloc and inits */
13 /* subject to change before release */
14
15 /*
16 * memavail() Returns the amount of RAM available (in paragraphs which are 16
17 * bytes) - the amount to be reserved for heap allocations.
18 *
19 */
memavail(minovl)20 unsigned memavail(minovl)
21 unsigned minovl; /* minimum size of overlay heap */
22 {
23 unsigned available;
24
25 unsigned farparaavail;
26 unsigned tmp;
27
28 /*
29 * _dos_allocmem will return the maximum block size available.
30 * It uses DOS (int 21h) service 0x48.
31 */
32
33 _dos_allocmem(0xFFFF, &farparaavail);
34 available = farparaavail - RESERVED_PARAGRAPHS;
35 tmp = RESERVED_PARAGRAPHS + minovl;
36 if (farparaavail < tmp) {
37 panic("Not enough free RAM to begin a game of NetHack (%ld bytes)",
38 (long)((long)tmp * 16L));
39 }
40 return available;
41 }
42 #endif /*_MSC_VER*/
43
44 #ifdef __BORLANDC__
45
46 #define RSRVD_MALLOC 65 * 1024L /* malloc() calls use about 65K */
47 #define RSRVD_CRTL 50 * 1024L /* C runtime library uses 50K */
48 #define RSRVD_TOTAL 115 * 1024L /* reserved for use in malloc() */
49 /* as well as by C runtime library */
50 /* routines which allocate memory */
51 /* after this routine runs. */
52 #define MIN_OVRBUF 30 * 1024L /* Overlay buffer gets minimum of */
53 #define MAX_OVRBUF 200 * 1024L /* 30K and maximum of 200K. */
54
55 #define RESIZE_OVL
56 #ifdef RESIZE_OVL
57
58 extern unsigned _ovrbuffer = 0; /* Use default size initially */
59 unsigned appFail = 0; /* Fail flag if not enough RAM */
60 unsigned memAlloc = 0;
61 unsigned long ProgramSize;
62 unsigned long runAlloc;
63 unsigned far *mem_top;
64 unsigned total;
65 signed long tmpbuffer;
66 int emsstatus;
67 int xmsstatus;
68
69 void NDECL(_resizeOvrBuffer);
70
_resizeOvrBuffer()71 void _resizeOvrBuffer()
72 {
73 mem_top = (unsigned far *) MK_FP( _psp, 0x02 );
74 total = *mem_top - _psp;
75
76 ProgramSize = * (unsigned far *) MK_FP( _psp - 1, 0x03 );
77 tmpbuffer = total - ProgramSize - RSRVD_TOTAL / 16;
78 memAlloc = min (MAX_OVRBUF / 16, tmpbuffer);
79 if (tmpbuffer >= MIN_OVRBUF / 16)
80 _ovrbuffer = memAlloc;
81 else {
82 _ovrbuffer = 1;
83 appFail = 1;
84 };
85
86
87 /*
88 * Remember, when inside this code, nothing has been setup on
89 * the system, so do NOT call any RTL functions for I/O or
90 * anything else that might rely on a startup function. This
91 * includes accessing any global objects as their constructors
92 * have not been called yet.
93 */
94
95 }
96
97 #pragma startup _resizeOvrBuffer 0 /* Put function in table */
98
99 void
startup()100 startup ()
101 {
102 if (appFail) {
103 printf ("NetHack fits in memory, but it cannot allocate memory");
104 printf (" for the overlay buffer\nand the runtime functions. ");
105 printf ("Please free up just %ld more bytes.",
106 (long)(MIN_OVRBUF - tmpbuffer * 16L));
107 exit (-1);
108 } else {
109
110 /* Now try to use expanded memory for the overlay manager */
111 /* If that doesn't work, we revert to extended memory */
112
113 emsstatus = _OvrInitEms (0, 0, 0);
114 #ifdef RECOGNIZE_XMS
115 xmsstatus = (emsstatus) ? _OvrInitExt (0, 0) : -1;
116 #endif
117
118 }
119 }
120
121 void
show_borlandc_stats(win)122 show_borlandc_stats(win)
123 winid win;
124 {
125 char buf[BUFSZ];
126
127 putstr(win, 0, "");
128 putstr(win, 0, "");
129 putstr(win, 0, "Memory usage stats"); putstr(win, 0, "");
130 putstr(win, 0, "");
131 Sprintf (buf, "Overlay buffer memory allocation: %ld bytes.",
132 memAlloc * 16L); putstr(win, 0, buf);
133 Sprintf (buf, "_ovrbuffer = %u.", _ovrbuffer); putstr(win, 0, buf);
134 Sprintf (buf, "Startup memory usage: 0x%X", ProgramSize);
135 putstr(win, 0, buf);
136 runAlloc = * (unsigned far *) MK_FP( _psp - 1, 0x03);
137 Sprintf (buf, "Current memory usage: 0x%X", runAlloc);
138 putstr(win, 0, buf);
139 if (emsstatus) Sprintf (buf, "EMS search failed (%d).", emsstatus);
140 else Sprintf (buf, "EMS search successful.");
141 putstr(win, 0, buf);
142 #ifdef RECOGNIZE_XMS
143 if (xmsstatus) Sprintf (buf, "XMS search failed (%d).", xmsstatus);
144 else Sprintf (buf, "XMS search successful.");
145 putstr(win, 0, buf);
146 #endif
147
148
149 }
150
151 #endif /* #ifdef RESIZE_OVL */
152 #endif /* #ifdef __BORLANDC__ */
153
154 /*ovlinit.c*/
155