dlls/system.drv16/system.c

   1 /*
   2  * SYSTEM DLL routines
   3  *
   4  * Copyright 1996 Alexandre Julliard
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  19  */
  20
  21 #include <stdarg.h>
  22
  23 #include "windef.h"
  24 #include "winbase.h"
  25 #include "wine/winbase16.h"
  26 #include "wine/winuser16.h"
  27 #include "wownt32.h"
  28 #include "winternl.h"
  29 #include "wine/debug.h"
  30
  31 WINE_DEFAULT_DEBUG_CHANNEL(system);
  32
  33 typedef struct
  34 {
  35     FARPROC16       callback16;
  36     INT             rate;
  37     INT             ticks;
  38 } SYSTEM_TIMER;
  39
  40 #define NB_SYS_TIMERS   8
  41 #define SYS_TIMER_RATE  54925
  42
  43 static SYSTEM_TIMER SYS_Timers[NB_SYS_TIMERS];
  44 static int SYS_NbTimers = 0;
  45 static HANDLE SYS_timer;
  46 static HANDLE SYS_thread;
  47 static BOOL SYS_timers_disabled;
  48
  49
  50 /***********************************************************************
  51  *           SYSTEM_TimerTick
  52  */
  53 static void CALLBACK SYSTEM_TimerTick( LPVOID arg, DWORD low, DWORD high )
  54 {
  55     int i;
  56
  57     if (SYS_timers_disabled) return;
  58     for (i = 0; i < NB_SYS_TIMERS; i++)
  59     {
  60         if (!SYS_Timers[i].callback16) continue;
  61         if ((SYS_Timers[i].ticks -= SYS_TIMER_RATE) <= 0)
  62         {
  63             FARPROC16 proc = SYS_Timers[i].callback16;
  64             CONTEXT context;
  65
  66             SYS_Timers[i].ticks += SYS_Timers[i].rate;
  67
  68             memset( &context, 0, sizeof(context) );
  69             context.SegCs = SELECTOROF( proc );
  70             context.Eip   = OFFSETOF( proc );
  71             context.Ebp   = CURRENT_SP + FIELD_OFFSET(STACK16FRAME, bp);
  72             context.Eax   = i + 1;
  73
  74             WOWCallback16Ex( 0, WCB16_REGS, 0, NULL, (DWORD *)&context );
  75         }
  76     }
  77 }
  78
  79
  80 /***********************************************************************
  81  *           SYSTEM_TimerThread
  82  */
  83 static DWORD CALLBACK SYSTEM_TimerThread( void *dummy )
  84 {
  85     LARGE_INTEGER when;
  86
  87     if (!(SYS_timer = CreateWaitableTimerA( NULL, FALSE, NULL ))) return 0;
  88
  89     when.u.LowPart = when.u.HighPart = 0;
  90     SetWaitableTimer( SYS_timer, &when, (SYS_TIMER_RATE+500)/1000, SYSTEM_TimerTick, 0, FALSE );
  91     for (;;) SleepEx( INFINITE, TRUE );
  92 }
  93
  94
  95 /**********************************************************************
  96  *           SYSTEM_StartTicks
  97  *
  98  * Start the system tick timer.
  99  */
 100 static void SYSTEM_StartTicks(void)
 101 {
 102     if (!SYS_thread) SYS_thread = CreateThread( NULL, 0, SYSTEM_TimerThread, NULL, 0, NULL );
 103 }
 104
 105
 106 /**********************************************************************
 107  *           SYSTEM_StopTicks
 108  *
 109  * Stop the system tick timer.
 110  */
 111 static void SYSTEM_StopTicks(void)
 112 {
 113     if (SYS_thread)
 114     {
 115         CancelWaitableTimer( SYS_timer );
 116         TerminateThread( SYS_thread, 0 );
 117         CloseHandle( SYS_thread );
 118         CloseHandle( SYS_timer );
 119         SYS_thread = 0;
 120     }
 121 }
 122
 123
 124 /***********************************************************************
 125  *           InquireSystem   (SYSTEM.1)
 126  *
 127  * Note: the function always takes 2 WORD arguments, contrary to what
 128  *       "Undocumented Windows" says.
 129   */
 130 DWORD WINAPI InquireSystem16( WORD code, WORD arg )
 131 {
 132     WORD drivetype;
 133     WCHAR root[3];
 134
 135     switch(code)
 136     {
 137     case 0:  /* Get timer resolution */
 138         return SYS_TIMER_RATE;
 139
 140     case 1:  /* Get drive type */
 141         root[0] = 'A' + arg;
 142         root[1] = ':';
 143         root[2] = 0;
 144         drivetype = GetDriveTypeW( root );
 145         if (drivetype == DRIVE_CDROM) drivetype = DRIVE_REMOTE;
 146         else if (drivetype == DRIVE_NO_ROOT_DIR) drivetype = DRIVE_UNKNOWN;
 147         return MAKELONG( drivetype, drivetype );
 148
 149     case 2:  /* Enable one-drive logic */
 150         FIXME("Case %d: set single-drive %d not supported\n", code, arg );
 151         return 0;
 152     }
 153     WARN("Unknown code %d\n", code );
 154     return 0;
 155 }
 156
 157
 158 /***********************************************************************
 159  *           CreateSystemTimer   (SYSTEM.2)
 160  */
 161 WORD WINAPI CreateSystemTimer16( WORD rate, FARPROC16 proc )
 162 {
 163     int i;
 164     for (i = 0; i < NB_SYS_TIMERS; i++)
 165         if (!SYS_Timers[i].callback16)  /* Found one */
 166         {
 167             SYS_Timers[i].rate = (UINT)rate * 1000;
 168             if (SYS_Timers[i].rate < SYS_TIMER_RATE)
 169                 SYS_Timers[i].rate = SYS_TIMER_RATE;
 170             SYS_Timers[i].ticks = SYS_Timers[i].rate;
 171             SYS_Timers[i].callback16 = proc;
 172             if (++SYS_NbTimers == 1) SYSTEM_StartTicks();
 173             return i + 1;  /* 0 means error */
 174         }
 175     return 0;
 176 }
 177
 178
 179 /***********************************************************************
 180  *           KillSystemTimer   (SYSTEM.3)
 181  *
 182  * Note: do not confuse this function with USER.182
 183  */
 184 WORD WINAPI SYSTEM_KillSystemTimer( WORD timer )
 185 {
 186     if ( !timer || timer > NB_SYS_TIMERS || !SYS_Timers[timer-1].callback16 )
 187         return timer;  /* Error */
 188     SYS_Timers[timer-1].callback16 = 0;
 189     if (!--SYS_NbTimers) SYSTEM_StopTicks();
 190     return 0;
 191 }
 192
 193
 194 /***********************************************************************
 195  *           EnableSystemTimers   (SYSTEM.4)
 196  */
 197 void WINAPI EnableSystemTimers16(void)
 198 {
 199     SYS_timers_disabled = FALSE;
 200 }
 201
 202
 203 /***********************************************************************
 204  *           DisableSystemTimers   (SYSTEM.5)
 205  */
 206 void WINAPI DisableSystemTimers16(void)
 207 {
 208     SYS_timers_disabled = TRUE;
 209 }
 210
 211
 212 /***********************************************************************
 213  *           GetSystemMSecCount (SYSTEM.6)
 214  */
 215 DWORD WINAPI GetSystemMSecCount16(void)
 216 {
 217     return GetTickCount();
 218 }
 219
 220
 221 /***********************************************************************
 222  *           Get80x87SaveSize   (SYSTEM.7)
 223  */
 224 WORD WINAPI Get80x87SaveSize16(void)
 225 {
 226     return 94;
 227 }
 228
 229
 230 /***********************************************************************
 231  *           Save80x87State   (SYSTEM.8)
 232  */
 233 void WINAPI Save80x87State16( char *ptr )
 234 {
 235 #ifdef __i386__
 236     __asm__(".byte 0x66; fsave %0; fwait" : "=m" (ptr) );
 237 #endif
 238 }
 239
 240
 241 /***********************************************************************
 242  *           Restore80x87State   (SYSTEM.9)
 243  */
 244 void WINAPI Restore80x87State16( const char *ptr )
 245 {
 246 #ifdef __i386__
 247     __asm__(".byte 0x66; frstor %0" : : "m" (ptr) );
 248 #endif
 249 }
 250
 251
 252 /***********************************************************************
 253  *           A20_Proc  (SYSTEM.20)
 254  */
 255 void WINAPI A20_Proc16( WORD unused )
 256 {
 257     /* this is also a NOP in Windows */
 258 }