msdos/dosmem.c

   1 /*
   2  * DOS memory emulation
   3  *
   4  * Copyright 1995 Alexandre Julliard
   5  * Copyright 1996 Marcus Meissner
   6  */
   7
   8 #include <signal.h>
   9 #include <stdio.h>
  10 #include <stdlib.h>
  11 #include <string.h>
  12 #include "windows.h"
  13 #include "winbase.h"
  14 #include "global.h"
  15 #include "ldt.h"
  16 #include "miscemu.h"
  17 #include "module.h"
  18 #include "debug.h"
  19
  20
  21 HANDLE16 DOSMEM_BiosSeg;  /* BIOS data segment at 0x40:0 */
  22
  23
  24 #pragma pack(1)
  25
  26 typedef struct
  27 {
  28     WORD  Com1Addr;                  /* 00: COM1 I/O address */
  29     WORD  Com2Addr;                  /* 02: COM2 I/O address */
  30     WORD  Com3Addr;                  /* 04: COM3 I/O address */
  31     WORD  Com4Addr;                  /* 06: COM4 I/O address */
  32     WORD  Lpt1Addr;                  /* 08: LPT1 I/O address */
  33     WORD  Lpt2Addr;                  /* 0a: LPT2 I/O address */
  34     WORD  Lpt3Addr;                  /* 0c: LPT3 I/O address */
  35     WORD  Lpt4Addr;                  /* 0e: LPT4 I/O address */
  36     WORD  InstalledHardware;         /* 10: Installed hardware flags */
  37     BYTE  POSTstatus;                /* 12: Power-On Self Test status */
  38     WORD  MemSize WINE_PACKED;       /* 13: Base memory size in Kb */
  39     WORD  unused1 WINE_PACKED;       /* 15: Manufacturing test scratch pad */
  40     BYTE  KbdFlags1;                 /* 17: Keyboard flags 1 */
  41     BYTE  KbdFlags2;                 /* 18: Keyboard flags 2 */
  42     BYTE  unused2;                   /* 19: Keyboard driver workspace */
  43     WORD  NextKbdCharPtr;            /* 1a: Next character in kbd buffer */
  44     WORD  FirstKbdCharPtr;           /* 1c: First character in kbd buffer */
  45     WORD  KbdBuffer[16];             /* 1e: Keyboard buffer */
  46     BYTE  DisketteStatus1;           /* 3e: Diskette recalibrate status */
  47     BYTE  DisketteStatus2;           /* 3f: Diskette motor status */
  48     BYTE  DisketteStatus3;           /* 40: Diskette motor timeout */
  49     BYTE  DisketteStatus4;           /* 41: Diskette last operation status */
  50     BYTE  DiskStatus[7];             /* 42: Disk status/command bytes */
  51     BYTE  VideoMode;                 /* 49: Video mode */
  52     WORD  VideoColumns;              /* 4a: Number of columns */
  53     WORD  VideoPageSize;             /* 4c: Video page size in bytes */
  54     WORD  VideoPageStartAddr;        /* 4e: Video page start address */
  55     BYTE  VideoCursorPos[16];        /* 50: Cursor position for 8 pages */
  56     WORD  VideoCursorType;           /* 60: Video cursor type */
  57     BYTE  VideoCurPage;              /* 62: Video current page */
  58     WORD  VideoCtrlAddr WINE_PACKED; /* 63: Video controller address */
  59     BYTE  VideoReg1;                 /* 65: Video mode select register */
  60     BYTE  VideoReg2;                 /* 66: Video CGA palette register */
  61     DWORD ResetEntry WINE_PACKED;    /* 67: Warm reset entry point */
  62     BYTE  LastIRQ;                   /* 6b: Last unexpected interrupt */
  63     DWORD Ticks;                     /* 6c: Ticks since midnight */
  64     BYTE  TicksOverflow;             /* 70: Timer overflow if past midnight */
  65     BYTE  CtrlBreakFlag;             /* 71: Ctrl-Break flag */
  66     WORD  ResetFlag;                 /* 72: POST Reset flag */
  67     BYTE  DiskOpStatus;              /* 74: Last hard-disk operation status */
  68     BYTE  NbHardDisks;               /* 75: Number of hard disks */
  69     BYTE  DiskCtrlByte;              /* 76: Disk control byte */
  70     BYTE  DiskIOPort;                /* 77: Disk I/O port offset */
  71     BYTE  LptTimeout[4];             /* 78: Timeouts for parallel ports */
  72     BYTE  ComTimeout[4];             /* 7c: Timeouts for serial ports */
  73     WORD  KbdBufferStart;            /* 80: Keyboard buffer start */
  74     WORD  KbdBufferEnd;              /* 82: Keyboard buffer end */
  75 } BIOSDATA;
  76
  77 #pragma pack(4)
  78
  79
  80 static BIOSDATA *pBiosData = NULL;
  81 char    *DOSMEM_dosmem;
  82 struct dosmem_entry {
  83         struct  dosmem_entry    *next;
  84         BYTE                    isfree;
  85 };
  86
  87
  88 /***********************************************************************
  89  *           DOSMEM_InitCollateTable
  90  *
  91  * Initialises the collate table (character sorting, language dependend)
  92  */
  93 DWORD DOSMEM_CollateTable;
  94
  95 static void DOSMEM_InitCollateTable()
  96 {
  97         DWORD           x;
  98         unsigned char   *tbl;
  99         int             i;
 100
 101         x=GlobalDOSAlloc(258);
 102         DOSMEM_CollateTable=MAKELONG(0,(x>>16));
 103         tbl=DOSMEM_RealMode2Linear(DOSMEM_CollateTable);
 104         *(WORD*)tbl     = 0x100;
 105         tbl+=2;
 106         for (i=0;i<0x100;i++)
 107                 *tbl++=i;
 108 }
 109
 110
 111 /***********************************************************************
 112  *           DOSMEM_Init
 113  *
 114  * Create the dos memory segments, and store them into the KERNEL
 115  * exported values.
 116  */
 117 BOOL32 DOSMEM_Init(void)
 118 {
 119     /* Allocate 1 MB dosmemory */
 120     /* Yes, allocating 1 MB of memory, which is usually not even used, is a
 121      * waste of memory. But I (MM) don't see any easy method to use
 122      * GlobalDOS{Alloc,Free} within an area of memory, with protected mode
 123      * selectors pointing into it, and the possibilty, that the userprogram
 124      * calls SetSelectorBase(,physical_address_in_DOSMEM); that includes
 125      * dynamical enlarging (reallocing) the dosmem area.
 126      * Yes, one could walk the ldt_copy on every realloc() on DOSMEM, but
 127      * this feels more like a hack to me than this current implementation is.
 128      * If you find another, better, method, just change it. -Marcus Meissner
 129      */
 130     DOSMEM_dosmem = VirtualAlloc(NULL,0x100000,MEM_COMMIT,PAGE_EXECUTE_READWRITE);
 131     if (!DOSMEM_dosmem)
 132     {
 133         fprintf( stderr, "Could not allocate DOS memory.\n" );
 134         return FALSE;
 135     }
 136     DOSMEM_BiosSeg = GLOBAL_CreateBlock(GMEM_FIXED,DOSMEM_dosmem+0x400,0x100,
 137                                         0, FALSE, FALSE, FALSE, NULL );
 138     DOSMEM_FillBiosSegment();
 139     DOSMEM_InitMemoryHandling();
 140     DOSMEM_InitCollateTable();
 141     return TRUE;
 142 }
 143
 144 /***********************************************************************
 145  *           DOSMEM_InitMemoryHandling
 146  *
 147  * Initialises the DOS Memory structures.
 148  */
 149 void
 150 DOSMEM_InitMemoryHandling()
 151 {
 152     struct      dosmem_entry    *dm;
 153
 154     dm = (struct dosmem_entry*)(DOSMEM_dosmem+0x10000);
 155     dm->isfree  =  1;
 156     dm->next    =  (struct dosmem_entry*)(DOSMEM_dosmem+0x9FFF0);
 157     dm          =  dm->next;
 158     dm->isfree  = 0;
 159     dm->next    = NULL;
 160 }
 161
 162 /***********************************************************************
 163  *           DOSMEM_Tick
 164  *
 165  * Increment the BIOS tick counter. Called by timer signal handler.
 166  */
 167 void DOSMEM_Tick(void)
 168 {
 169     if (pBiosData) pBiosData->Ticks++;
 170 }
 171
 172
 173 /***********************************************************************
 174  *           DOSMEM_FillBiosSegment
 175  *
 176  * Fill the BIOS data segment with dummy values.
 177  */
 178 void DOSMEM_FillBiosSegment(void)
 179 {
 180     pBiosData = (BIOSDATA *)GlobalLock16( DOSMEM_BiosSeg );
 181
 182       /* Clear all unused values */
 183     memset( pBiosData, 0, sizeof(*pBiosData) );
 184
 185     /* FIXME: should check the number of configured drives and ports */
 186
 187     pBiosData->Com1Addr             = 0x3e8;
 188     pBiosData->Com2Addr             = 0x2e8;
 189     pBiosData->Lpt1Addr             = 0x378;
 190     pBiosData->Lpt2Addr             = 0x278;
 191     pBiosData->InstalledHardware    = 0x8443;
 192     pBiosData->MemSize              = 640;
 193     pBiosData->NextKbdCharPtr       = 0x1e;
 194     pBiosData->FirstKbdCharPtr      = 0x1e;
 195     pBiosData->VideoMode            = 0;
 196     pBiosData->VideoColumns         = 80;
 197     pBiosData->VideoPageSize        = 80 * 25 * 2;
 198     pBiosData->VideoPageStartAddr   = 0xb800;
 199     pBiosData->VideoCtrlAddr        = 0x3d4;
 200     pBiosData->Ticks                = INT1A_GetTicksSinceMidnight();
 201     pBiosData->NbHardDisks          = 2;
 202     pBiosData->KbdBufferStart       = 0x1e;
 203     pBiosData->KbdBufferEnd         = 0x3e;
 204 }
 205
 206 /***********************************************************************
 207  *           GlobalDOSAlloc     (KERNEL.184)
 208  *
 209  * Allocates a piece of DOS Memory, in the first 1 MB physical memory.
 210  *
 211  * operates on the preallocated DOSMEM_dosmem (1MB). The useable area
 212  * starts at 1000:0000 and ends at 9FFF:FFEF
 213  * Memory allocation strategy is First Fit. (FIXME: Yes,I know that First Fit
 214  * is a rather bad strategy. But since those functions are rather seldom
 215  * called, it's easyness fits the purpose well.)
 216  *
 217  */
 218
 219 DWORD GlobalDOSAlloc(DWORD size)
 220 {
 221         struct  dosmem_entry    *dm,*ndm;
 222         DWORD   start,blocksize;
 223         WORD    sel;
 224         HMODULE16 hModule=GetModuleHandle("KERNEL");
 225
 226
 227         start   = 0;
 228         dm      = (struct dosmem_entry*)(DOSMEM_dosmem+0x10000);
 229         size    = (size+0xf)&~0xf;
 230         while (dm && dm->next) {
 231                 blocksize = ((char*)dm->next-(char*)dm)-16;
 232                 if ((dm->isfree) && (blocksize>=size)) {
 233                         dm->isfree = 0;
 234                         start = ((((char*)dm)-DOSMEM_dosmem)+0x10)& ~0xf;
 235                         if ((blocksize-size) >= 0x20) {
 236                                 /* if enough memory is left for a new block
 237                                  * split this area into two blocks
 238                                  */
 239                                 ndm=(struct dosmem_entry*)((char*)dm+0x10+size);
 240                                 ndm->isfree     = 1;
 241                                 ndm->next       = dm->next;
 242                                 dm->next        = ndm;
 243                         }
 244                         break;
 245                 }
 246                 dm=dm->next;
 247         }
 248         if (!start)
 249                 return 0;
 250         sel=GLOBAL_CreateBlock(
 251                 GMEM_FIXED,DOSMEM_dosmem+start,size,
 252                 hModule,FALSE,FALSE,FALSE,NULL
 253         );
 254         return MAKELONG(sel,start>>4);
 255 }
 256
 257 /***********************************************************************
 258  *           GlobalDOSFree      (KERNEL.185)
 259  *
 260  * Frees allocated dosmemory and corresponding selector.
 261  */
 262
 263 WORD
 264 GlobalDOSFree(WORD sel)
 265 {
 266         DWORD   base;
 267         struct  dosmem_entry    *dm;
 268
 269         base = GetSelectorBase(sel);
 270         /* base has already been conversed to a physical address */
 271         if (base>=0x100000)
 272                 return sel;
 273         dm      = (struct dosmem_entry*)(DOSMEM_dosmem+base-0x10);
 274         if (dm->isfree) {
 275                 fprintf(stderr,"Freeing already freed DOSMEM.\n");
 276                 return 0;
 277         }
 278         dm->isfree = 1;
 279
 280         /* collapse adjunct free blocks into one */
 281         dm = (struct dosmem_entry*)(DOSMEM_dosmem+0x10000);
 282         while (dm && dm->next) {
 283                 if (dm->isfree && dm->next->isfree)
 284                         dm->next = dm->next->next;
 285                 dm = dm->next;
 286         }
 287         GLOBAL_FreeBlock(sel);
 288         return 0;
 289 }
 290
 291 /***********************************************************************
 292  *           DOSMEM_RealMode2Linear
 293  *
 294  * Converts a realmode segment:offset address into a linear pointer
 295  */
 296 LPVOID DOSMEM_RealMode2Linear(DWORD x)
 297 {
 298         LPVOID  lin;
 299
 300         lin=DOSMEM_dosmem+(x&0xffff)+(((x&0xffff0000)>>16)*16);
 301         dprintf_selector(stddeb,"DOSMEM_RealMode2Linear(0x%08lx) returns 0x%p.\n",
 302                 x,lin
 303         );
 304         return lin;
 305 }
 306
 307 /***********************************************************************
 308  *           DOSMEM_AllocSelector
 309  *
 310  * Allocates a protected mode selector for a realmode segment.
 311  */
 312 WORD DOSMEM_AllocSelector(WORD realsel)
 313 {
 314         HMODULE16 hModule=GetModuleHandle("KERNEL");
 315         WORD    sel;
 316
 317         sel=GLOBAL_CreateBlock(
 318                 GMEM_FIXED,DOSMEM_dosmem+realsel*16,0x10000,
 319                 hModule,FALSE,FALSE,FALSE,NULL
 320         );
 321         dprintf_selector(stddeb,"DOSMEM_AllocSelector(0x%04x) returns 0x%04x.\n",
 322                 realsel,sel
 323         );
 324         return sel;
 325 }