1 files changed, 65 insertions, 0 deletions
diff --git a/kernel.soso/timer.c b/kernel.soso/timer.c
new file mode 100644
index 00000000..443afa05
--- /dev/null
+++ b/kernel.soso/timer.c
@@ -0,0 +1,65 @@
+#include "timer.h"
+#include "isr.h"
+#include "screen.h"
+#include "process.h"
+#include "common.h"
+
+#define TIMER_FREQ 1000
+
+uint32 gSystemTickCount = 0;
+
+BOOL gSchedulerEnabled = FALSE;
+
+//called from assembly
+void handleTimerIRQ(TimerInt_Registers registers)
+{
+    gSystemTickCount++;
+
+    if (/*gSystemTickCount % 10 == 0 &&*/ gSchedulerEnabled == TRUE)
+    {
+        schedule(&registers);
+    }
+}
+
+uint32 getSystemTickCount()
+{
+    return gSystemTickCount;
+}
+
+uint32 getUptimeSeconds()
+{
+    return gSystemTickCount / TIMER_FREQ;
+}
+
+uint32 getUptimeMilliseconds()
+{
+    return gSystemTickCount;
+}
+
+void enableScheduler()
+{
+    gSchedulerEnabled = TRUE;
+}
+
+void disableScheduler()
+{
+    gSchedulerEnabled = FALSE;
+}
+
+static void initTimer(uint32 frequency)
+{
+    uint32 divisor = 1193180 / frequency;
+
+    outb(0x43, 0x36);
+
+    uint8 l = (uint8)(divisor & 0xFF);
+    uint8 h = (uint8)( (divisor>>8) & 0xFF );
+
+    outb(0x40, l);
+    outb(0x40, h);
+}
+
+void initializeTimer()
+{
+    initTimer(TIMER_FREQ);
+}