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 #define NONAMELESSUNION
  24
  25 #include "windef.h"
  26 #include "winbase.h"
  27 #include "wine/winbase16.h"
  28 #include "wine/winuser16.h"
  29 #include "wownt32.h"
  30 #include "winternl.h"
  31 #include "wine/debug.h"
  32
  33 WINE_DEFAULT_DEBUG_CHANNEL(system);
  34
  35 typedef struct
  36 {
  37     FARPROC16       callback16;
  38     INT             rate;
  39     INT             ticks;
  40 } SYSTEM_TIMER;
  41
  42 #define NB_SYS_TIMERS   8
  43 #define SYS_TIMER_RATE  54925
  44
  45 static SYSTEM_TIMER SYS_Timers[NB_SYS_TIMERS];
  46 static int SYS_NbTimers = 0;
  47 static HANDLE SYS_timer;
  48 static HANDLE SYS_thread;
  49 static BOOL SYS_timers_disabled;
  50
  51
  52 /***********************************************************************
  53  *           SYSTEM_TimerTick
  54  */
  55 static void CALLBACK SYSTEM_TimerTick( LPVOID arg, DWORD low, DWORD high )
  56 {
  57     int i;
  58
  59     if (SYS_timers_disabled) return;
  60     for (i = 0; i < NB_SYS_TIMERS; i++)
  61     {
  62         if (!SYS_Timers[i].callback16) continue;
  63         if ((SYS_Timers[i].ticks -= SYS_TIMER_RATE) <= 0)
  64         {
  65             FARPROC16 proc = SYS_Timers[i].callback16;
  66             CONTEXT context;
  67
  68             SYS_Timers[i].ticks += SYS_Timers[i].rate;
  69
  70             memset( &context, 0, sizeof(context) );
  71             context.SegCs = SELECTOROF( proc );
  72             context.Eip   = OFFSETOF( proc );
  73             context.Ebp   = CURRENT_SP + FIELD_OFFSET(STACK16FRAME, bp);
  74             context.Eax   = i + 1;
  75
  76             WOWCallback16Ex( 0, WCB16_REGS, 0, NULL, (DWORD *)&context );
  77         }
  78     }
  79 }
  80
  81
  82 /***********************************************************************
  83  *           SYSTEM_TimerThread
  84  */
  85 static DWORD CALLBACK SYSTEM_TimerThread( void *dummy )
  86 {
  87     LARGE_INTEGER when;
  88
  89     if (!(SYS_timer = CreateWaitableTimerA( NULL, FALSE, NULL ))) return 0;
  90
  91     when.u.LowPart = when.u.HighPart = 0;
  92     SetWaitableTimer( SYS_timer, &when, (SYS_TIMER_RATE+500)/1000, SYSTEM_TimerTick, 0, FALSE );
  93     for (;;) SleepEx( INFINITE, TRUE );
  94 }
  95
  96
  97 /**********************************************************************
  98  *           SYSTEM_StartTicks
  99  *
 100  * Start the system tick timer.
 101  */
 102 static void SYSTEM_StartTicks(void)
 103 {
 104     if (!SYS_thread) SYS_thread = CreateThread( NULL, 0, SYSTEM_TimerThread, NULL, 0, NULL );
 105 }
 106
 107
 108 /**********************************************************************
 109  *           SYSTEM_StopTicks
 110  *
 111  * Stop the system tick timer.
 112  */
 113 static void SYSTEM_StopTicks(void)
 114 {
 115     if (SYS_thread)
 116     {
 117         CancelWaitableTimer( SYS_timer );
 118         TerminateThread( SYS_thread, 0 );
 119         CloseHandle( SYS_thread );
 120         CloseHandle( SYS_timer );
 121         SYS_thread = 0;
 122     }
 123 }
 124
 125
 126 /***********************************************************************
 127  *           InquireSystem   (SYSTEM.1)
 128  *
 129  * Note: the function always takes 2 WORD arguments, contrary to what
 130  *       "Undocumented Windows" says.
 131   */
 132 DWORD WINAPI InquireSystem16( WORD code, WORD arg )
 133 {
 134     WORD drivetype;
 135     WCHAR root[3];
 136
 137     switch(code)
 138     {
 139     case 0:  /* Get timer resolution */
 140         return SYS_TIMER_RATE;
 141
 142     case 1:  /* Get drive type */
 143         root[0] = 'A' + arg;
 144         root[1] = ':';
 145         root[2] = 0;
 146         drivetype = GetDriveTypeW( root );
 147         if (drivetype == DRIVE_CDROM) drivetype = DRIVE_REMOTE;
 148         else if (drivetype == DRIVE_NO_ROOT_DIR) drivetype = DRIVE_UNKNOWN;
 149         return MAKELONG( drivetype, drivetype );
 150
 151     case 2:  /* Enable one-drive logic */
 152         FIXME("Case %d: set single-drive %d not supported\n", code, arg );
 153         return 0;
 154     }
 155     WARN("Unknown code %d\n", code );
 156     return 0;
 157 }
 158
 159
 160 /***********************************************************************
 161  *           CreateSystemTimer   (SYSTEM.2)
 162  */
 163 WORD WINAPI CreateSystemTimer16( WORD rate, FARPROC16 proc )
 164 {
 165     int i;
 166     for (i = 0; i < NB_SYS_TIMERS; i++)
 167         if (!SYS_Timers[i].callback16)  /* Found one */
 168         {
 169             SYS_Timers[i].rate = (UINT)rate * 1000;
 170             if (SYS_Timers[i].rate < SYS_TIMER_RATE)
 171                 SYS_Timers[i].rate = SYS_TIMER_RATE;
 172             SYS_Timers[i].ticks = SYS_Timers[i].rate;
 173             SYS_Timers[i].callback16 = proc;
 174             if (++SYS_NbTimers == 1) SYSTEM_StartTicks();
 175             return i + 1;  /* 0 means error */
 176         }
 177     return 0;
 178 }
 179
 180
 181 /***********************************************************************
 182  *           KillSystemTimer   (SYSTEM.3)
 183  *
 184  * Note: do not confuse this function with USER.182
 185  */
 186 WORD WINAPI SYSTEM_KillSystemTimer( WORD timer )
 187 {
 188     if ( !timer || timer > NB_SYS_TIMERS || !SYS_Timers[timer-1].callback16 )
 189         return timer;  /* Error */
 190     SYS_Timers[timer-1].callback16 = 0;
 191     if (!--SYS_NbTimers) SYSTEM_StopTicks();
 192     return 0;
 193 }
 194
 195
 196 /***********************************************************************
 197  *           EnableSystemTimers   (SYSTEM.4)
 198  */
 199 void WINAPI EnableSystemTimers16(void)
 200 {
 201     SYS_timers_disabled = FALSE;
 202 }
 203
 204
 205 /***********************************************************************
 206  *           DisableSystemTimers   (SYSTEM.5)
 207  */
 208 void WINAPI DisableSystemTimers16(void)
 209 {
 210     SYS_timers_disabled = TRUE;
 211 }
 212
 213
 214 /***********************************************************************
 215  *           GetSystemMSecCount (SYSTEM.6)
 216  */
 217 DWORD WINAPI GetSystemMSecCount16(void)
 218 {
 219     return GetTickCount();
 220 }
 221
 222
 223 /***********************************************************************
 224  *           Get80x87SaveSize   (SYSTEM.7)
 225  */
 226 WORD WINAPI Get80x87SaveSize16(void)
 227 {
 228     return 94;
 229 }
 230
 231
 232 /***********************************************************************
 233  *           Save80x87State   (SYSTEM.8)
 234  */
 235 void WINAPI Save80x87State16( char *ptr )
 236 {
 237 #ifdef __i386__
 238     __asm__(".byte 0x66; fsave %0; fwait" : "=m" (ptr) );
 239 #endif
 240 }
 241
 242
 243 /***********************************************************************
 244  *           Restore80x87State   (SYSTEM.9)
 245  */
 246 void WINAPI Restore80x87State16( const char *ptr )
 247 {
 248 #ifdef __i386__
 249     __asm__(".byte 0x66; frstor %0" : : "m" (ptr) );
 250 #endif
 251 }
 252
 253
 254 /***********************************************************************
 255  *           A20_Proc  (SYSTEM.20)
 256  */
 257 void WINAPI A20_Proc16( WORD unused )
 258 {
 259     /* this is also a NOP in Windows */
 260 }