msdos/int1a.c

   1 /*
   2  * BIOS interrupt 1ah handler
   3  */
   4
   5 #include <time.h>
   6 #include <sys/time.h>
   7 #include <stdlib.h>
   8 #include "options.h"
   9 #include "miscemu.h"
  10 #include "debug.h"
  11
  12 #define BCD_TO_BIN(x) ((x&15) + (x>>4)*10)
  13 #define BIN_TO_BCD(x) ((x%10) + ((x/10)<<4))
  14
  15
  16 /**********************************************************************
  17  *          INT1A_GetTicksSinceMidnight
  18  *
  19  * Return number of clock ticks since midnight.
  20  */
  21 DWORD INT1A_GetTicksSinceMidnight(void)
  22 {
  23     struct tm *bdtime;
  24     struct timeval tvs;
  25     time_t seconds;
  26
  27     /* This should give us the (approximately) correct
  28      * 18.206 clock ticks per second since midnight.
  29      */
  30     gettimeofday( &tvs, NULL );
  31     seconds = tvs.tv_sec;
  32     bdtime = localtime( &seconds );
  33     return (((bdtime->tm_hour * 3600 + bdtime->tm_min * 60 +
  34               bdtime->tm_sec) * 18206) / 1000) +
  35                   (tvs.tv_usec / 54927);
  36 }
  37
  38
  39 /**********************************************************************
  40  *          INT_Int1aHandler
  41  *
  42  * Handler for int 1ah (date and time).
  43  */
  44 void WINAPI INT_Int1aHandler( CONTEXT *context )
  45 {
  46     time_t ltime;
  47     DWORD ticks;
  48     struct tm *bdtime;
  49
  50     switch(AH_reg(context))
  51     {
  52         case 0:
  53             ticks = INT1A_GetTicksSinceMidnight();
  54             CX_reg(context) = HIWORD(ticks);
  55             DX_reg(context) = LOWORD(ticks);
  56             AX_reg(context) = 0;  /* No midnight rollover */
  57             TRACE(int,"int1a: AH=00 -- ticks=%ld\n", ticks);
  58             break;
  59
  60         case 2:
  61                 ltime = time(NULL);
  62                 bdtime = localtime(&ltime);
  63
  64                 CX_reg(context) = (BIN_TO_BCD(bdtime->tm_hour)<<8) |
  65                                    BIN_TO_BCD(bdtime->tm_min);
  66                 DX_reg(context) = (BIN_TO_BCD(bdtime->tm_sec)<<8);
  67
  68         case 4:
  69                 ltime = time(NULL);
  70                 bdtime = localtime(&ltime);
  71                 CX_reg(context) = (BIN_TO_BCD(bdtime->tm_year/100)<<8) |
  72                                    BIN_TO_BCD((bdtime->tm_year-1900)%100);
  73                 DX_reg(context) = (BIN_TO_BCD(bdtime->tm_mon)<<8) |
  74                                    BIN_TO_BCD(bdtime->tm_mday);
  75                 break;
  76
  77                 /* setting the time,date or RTC is not allow -EB */
  78         case 1:
  79                 /* set system time */
  80         case 3:
  81                 /* set RTC time */
  82         case 5:
  83                 /* set RTC date */
  84         case 6:
  85                 /* set ALARM */
  86         case 7:
  87                 /* cancel ALARM */
  88                 break;
  89
  90         default:
  91                 INT_BARF( context, 0x1a );
  92     }
  93 }