started backporting the eradicate code

[dosdemo] / src / dos / timer.c

diff --git a/src/dos/timer.c b/src/dos/timer.c
index dcf790c..2440bd5 100644 (file)
--- a/src/dos/timer.c
+++ b/src/dos/timer.c
@@ -1,3 +1,8 @@
+/* for sound we use MIDAS, which takes over the PIT and we can't use it
+ * therefore only compile this file for NO_SOUND builds.
+ */
+#ifdef NO_SOUND
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <assert.h>
@@ -16,6 +21,7 @@
 
 #include "pit8254.h"
 #include "inttypes.h"
+#include "util.h"
 
 #define PIT_TIMER_INTR 8
 #define DOS_TIMER_INTR 0x1c
@@ -45,7 +51,7 @@ static _go32_dpmi_seginfo intr, prev_intr;
 
 static void INTERRUPT timer_irq();
 
-static unsigned long ticks;
+static volatile unsigned long ticks;
 static unsigned long tick_interval, ticks_per_dos_intr;
 static int inum;
 
@@ -123,6 +129,16 @@ unsigned long get_msec(void)
        return ticks * tick_interval;
 }
 
+void sleep_msec(unsigned long msec)
+{
+       unsigned long wakeup_time = ticks + msec / tick_interval;
+       while(ticks < wakeup_time) {
+#ifdef USE_HLT
+               halt();
+#endif
+       }
+}
+
 static void set_timer_reload(int reload_val)
 {
        outp(PORT_CMD, CMD_CHAN0 | CMD_ACCESS_BOTH | CMD_OP_SQWAVE);
@@ -163,3 +179,5 @@ static void INTERRUPT timer_irq()
        /* send EOI to the PIC */
        outp(PIC1_CMD, OCW2_EOI);
 }
+
+#endif /* NO_SOUND */