dlls/krnl386.exe16/dosvm.c

   1 /*
   2  * DOS Virtual Machine
   3  *
   4  * Copyright 1998 Ove Kåven
   5  * Copyright 2002 Jukka Heinonen
   6  *
   7  * This library is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * This library is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with this library; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  20  *
  21  * Note: This code hasn't been completely cleaned up yet.
  22  */
  23
  24 #include "config.h"
  25 #include "wine/port.h"
  26
  27 #include <stdarg.h>
  28 #include <stdio.h>
  29 #include <stdlib.h>
  30 #include <string.h>
  31 #include <errno.h>
  32 #include <fcntl.h>
  33 #include <signal.h>
  34 #ifdef HAVE_UNISTD_H
  35 # include <unistd.h>
  36 #endif
  37 #ifdef HAVE_SYS_TIME_H
  38 # include <sys/time.h>
  39 #endif
  40 #include <sys/types.h>
  41
  42 #include "wine/winbase16.h"
  43 #include "wine/exception.h"
  44 #include "windef.h"
  45 #include "winbase.h"
  46 #include "winternl.h"
  47 #include "wingdi.h"
  48 #include "winuser.h"
  49 #include "wownt32.h"
  50 #include "winnt.h"
  51 #include "wincon.h"
  52
  53 #include "dosexe.h"
  54 #include "wine/debug.h"
  55 #include "excpt.h"
  56
  57 WINE_DEFAULT_DEBUG_CHANNEL(int);
  58
  59 WORD DOSVM_psp = 0;
  60 WORD DOSVM_retval = 0;
  61
  62 /*
  63  * Wine DOS memory layout above 640k:
  64  *
  65  *   a0000 - affff : VGA graphics         (vga.c)
  66  *   b0000 - bffff : Monochrome text      (unused)
  67  *   b8000 - bffff : VGA text             (vga.c)
  68  *   c0000 - cffff : EMS frame            (int67.c)
  69  *   d0000 - effff : Free memory for UMBs (himem.c)
  70  *   f0000 - fffff : BIOS stuff           (msdos/dosmem.c)
  71  *  100000 -10ffff : High memory area     (unused)
  72  */
  73
  74 /*
  75  * Table of real mode segments and protected mode selectors
  76  * for code stubs and other miscellaneous storage.
  77  */
  78 struct DPMI_segments *DOSVM_dpmi_segments = NULL;
  79
  80 /*
  81  * First and last address available for upper memory blocks.
  82  */
  83 #define DOSVM_UMB_BOTTOM 0xd0000
  84 #define DOSVM_UMB_TOP    0xeffff
  85
  86 /*
  87  * First free address for upper memory blocks.
  88  */
  89 static DWORD DOSVM_umb_free = DOSVM_UMB_BOTTOM;
  90
  91
  92 /**********************************************************************
  93  *          DOSVM_Exit
  94  */
  95 void DOSVM_Exit( WORD retval )
  96 {
  97     DWORD count;
  98
  99     ReleaseThunkLock( &count );
 100     ExitThread( retval );
 101 }
 102
 103 /***********************************************************************
 104  *           DOSVM_AllocUMB
 105  *
 106  * Allocate upper memory block (UMB) from upper memory.
 107  * Returned pointer is aligned to 16-byte (paragraph) boundary.
 108  *
 109  * This routine is only for allocating static storage for
 110  * Wine internal uses. Allocated memory can be accessed from
 111  * real mode, memory is taken from area already mapped and reserved
 112  * by Wine and the allocation has very little memory and speed
 113  * overhead. Use of this routine also preserves precious DOS
 114  * conventional memory.
 115  */
 116 static LPVOID DOSVM_AllocUMB( DWORD size )
 117 {
 118   LPVOID ptr = (LPVOID)DOSVM_umb_free;
 119
 120   size = ((size + 15) >> 4) << 4;
 121
 122   if(DOSVM_umb_free + size - 1 > DOSVM_UMB_TOP) {
 123     ERR("Out of upper memory area.\n");
 124     return 0;
 125   }
 126
 127   DOSVM_umb_free += size;
 128   return ptr;
 129 }
 130
 131
 132 /**********************************************************************
 133  *          alloc_selector
 134  *
 135  * Allocate a selector corresponding to a real mode address.
 136  * size must be < 64k.
 137  */
 138 static WORD alloc_selector( void *base, DWORD size, unsigned char flags )
 139 {
 140     WORD sel = wine_ldt_alloc_entries( 1 );
 141
 142     if (sel)
 143     {
 144         LDT_ENTRY entry;
 145         wine_ldt_set_base( &entry, base );
 146         wine_ldt_set_limit( &entry, size - 1 );
 147         wine_ldt_set_flags( &entry, flags );
 148         wine_ldt_set_entry( sel, &entry );
 149     }
 150     return sel;
 151 }
 152
 153
 154 /***********************************************************************
 155  *           DOSVM_AllocCodeUMB
 156  *
 157  * Allocate upper memory block for storing code stubs.
 158  * Initializes real mode segment and 16-bit protected mode selector
 159  * for the allocated code block.
 160  *
 161  * FIXME: should allocate a single PM selector for the whole UMB range.
 162  */
 163 static LPVOID DOSVM_AllocCodeUMB( DWORD size, WORD *selector )
 164 {
 165     LPVOID ptr = DOSVM_AllocUMB( size );
 166     *selector = alloc_selector( ptr, size, WINE_LDT_FLAGS_CODE );
 167     return ptr;
 168 }
 169
 170
 171 /***********************************************************************
 172  *           DOSVM_AllocDataUMB
 173  *
 174  * Allocate upper memory block for storing data.
 175  * Initializes real mode segment and 16-bit protected mode selector
 176  * for the allocated data block.
 177  */
 178 LPVOID DOSVM_AllocDataUMB( DWORD size, WORD *selector )
 179 {
 180     LPVOID ptr = DOSVM_AllocUMB( size );
 181     *selector = alloc_selector( ptr, size, WINE_LDT_FLAGS_DATA );
 182     return ptr;
 183 }
 184
 185
 186 /***********************************************************************
 187  *           DOSVM_InitSegments
 188  *
 189  * Initializes DOSVM_dpmi_segments. Allocates required memory and
 190  * sets up segments and selectors for accessing the memory.
 191  */
 192 void DOSVM_InitSegments(void)
 193 {
 194     DWORD old_prot;
 195     LPSTR ptr;
 196     int   i;
 197
 198     static const char relay[]=
 199     {
 200         0xca, 0x04, 0x00, /* 16-bit far return and pop 4 bytes (relay void* arg) */
 201         0xcd, 0x31,       /* int 31 */
 202         0xfb, 0x66, 0xcb  /* sti and 32-bit far return */
 203     };
 204
 205     /*
 206      * Allocate pointer array.
 207      */
 208     DOSVM_dpmi_segments = DOSVM_AllocUMB( sizeof(struct DPMI_segments) );
 209
 210     /*
 211      * PM / offset N*5: Interrupt N in 16-bit protected mode.
 212      */
 213     ptr = DOSVM_AllocCodeUMB( 5 * 256, &DOSVM_dpmi_segments->int16_sel );
 214     for(i=0; i<256; i++) {
 215         /*
 216          * Each 16-bit interrupt handler is 5 bytes:
 217          * 0xCD,<i>       = int <i> (interrupt)
 218          * 0xCA,0x02,0x00 = ret 2   (16-bit far return and pop 2 bytes / eflags)
 219          */
 220         ptr[i * 5 + 0] = 0xCD;
 221         ptr[i * 5 + 1] = i;
 222         ptr[i * 5 + 2] = 0xCA;
 223         ptr[i * 5 + 3] = 0x02;
 224         ptr[i * 5 + 4] = 0x00;
 225     }
 226
 227     /*
 228      * PM / offset 0: Stub where __wine_call_from_16_regs returns.
 229      * PM / offset 3: Stub which swaps back to 32-bit application code/stack.
 230      * PM / offset 5: Stub which enables interrupts
 231      */
 232     ptr = DOSVM_AllocCodeUMB( sizeof(relay), &DOSVM_dpmi_segments->relay_code_sel);
 233     memcpy( ptr, relay, sizeof(relay) );
 234
 235     /*
 236      * Space for 16-bit stack used by relay code.
 237      */
 238     ptr = DOSVM_AllocDataUMB( DOSVM_RELAY_DATA_SIZE, &DOSVM_dpmi_segments->relay_data_sel);
 239     memset( ptr, 0, DOSVM_RELAY_DATA_SIZE );
 240
 241     /*
 242      * As we store code in UMB we should make sure it is executable
 243      */
 244     VirtualProtect((void *)DOSVM_UMB_BOTTOM, DOSVM_UMB_TOP - DOSVM_UMB_BOTTOM, PAGE_EXECUTE_READWRITE, &old_prot);
 245 }