sys/msdos/ovlinit.c

   1 /* aNetHack 0.0.1       ovlinit.c       $ANH-Date: 1432512792 2015/05/25 00:13:12 $  $ANH-Branch: master $:$ANH-Revision: 1.8 $ */
   2 /* Copyright (c) aNetHack PC Development Team 1995                 */
   3 /* aNetHack may be freely redistributed.  See license for details. */
   4
   5 #include "hack.h"
   6 #include <dos.h>
   7 #include <stdio.h>
   8
   9 #ifdef _MSC_VER
  10
  11 #define RESERVED_PARAGRAPHS 5120 /* leave 80K for malloc and inits */
  12                                  /* subject to change before release */
  13
  14 /*
  15  * memavail() Returns the amount of RAM available (in paragraphs which are 16
  16  *  bytes) - the amount to be reserved for heap allocations.
  17  *
  18  */
  19 unsigned
  20 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 aNetHack (%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
  71 void
  72 _resizeOvrBuffer()
  73 {
  74     mem_top = (unsigned far *) MK_FP(_psp, 0x02);
  75     total = *mem_top - _psp;
  76
  77     ProgramSize = *(unsigned far *) MK_FP(_psp - 1, 0x03);
  78     tmpbuffer = total - ProgramSize - RSRVD_TOTAL / 16;
  79     memAlloc = min(MAX_OVRBUF / 16, tmpbuffer);
  80     if (tmpbuffer >= MIN_OVRBUF / 16)
  81         _ovrbuffer = memAlloc;
  82     else {
  83         _ovrbuffer = 1;
  84         appFail = 1;
  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 #pragma startup _resizeOvrBuffer 0 /* Put function in table */
  97
  98 void
  99 startup()
 100 {
 101     if (appFail) {
 102         printf("aNetHack fits in memory, but it cannot allocate memory");
 103         printf(" for the overlay buffer\nand the runtime functions.  ");
 104         printf("Please free up just %ld more bytes.",
 105                (long) (MIN_OVRBUF - tmpbuffer * 16L));
 106         exit(-1);
 107     } else {
 108         /* Now try to use expanded memory for the overlay manager */
 109         /* If that doesn't work, we revert to extended memory */
 110
 111         emsstatus = _OvrInitEms(0, 0, 0);
 112 #ifdef RECOGNIZE_XMS
 113         xmsstatus = (emsstatus) ? _OvrInitExt(0, 0) : -1;
 114 #endif
 115     }
 116 }
 117
 118 void
 119 show_borlandc_stats(win)
 120 winid win;
 121 {
 122     char buf[BUFSZ];
 123
 124     putstr(win, 0, "");
 125     putstr(win, 0, "");
 126     putstr(win, 0, "Memory usage stats");
 127     putstr(win, 0, "");
 128     putstr(win, 0, "");
 129     Sprintf(buf, "Overlay buffer memory allocation: %ld bytes.",
 130             memAlloc * 16L);
 131     putstr(win, 0, buf);
 132     Sprintf(buf, "_ovrbuffer = %u.", _ovrbuffer);
 133     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)
 140         Sprintf(buf, "EMS search failed (%d).", emsstatus);
 141     else
 142         Sprintf(buf, "EMS search successful.");
 143     putstr(win, 0, buf);
 144 #ifdef RECOGNIZE_XMS
 145     if (xmsstatus)
 146         Sprintf(buf, "XMS search failed (%d).", xmsstatus);
 147     else
 148         Sprintf(buf, "XMS search successful.");
 149     putstr(win, 0, buf);
 150 #endif
 151 }
 152
 153 #endif /* #ifdef RESIZE_OVL */
 154 #endif /* #ifdef __BORLANDC__ */
 155
 156 /*ovlinit.c*/