1 files changed, 71 insertions, 0 deletions
diff --git a/os/boot/mpc/clock.c b/os/boot/mpc/clock.c
new file mode 100644
index 00000000..4d2d6bfd
--- /dev/null
+++ b/os/boot/mpc/clock.c
@@ -0,0 +1,71 @@
+#include	"u.h"
+#include	"lib.h"
+#include	"mem.h"
+#include	"dat.h"
+#include	"fns.h"
+#include	"io.h"
+#include	"ureg.h"
+
+enum {
+	Timebase = 4,	/* system clock cycles per time base cycle */
+};
+
+void	(*archclocktick)(void);	/* set by arch*.c when desired */
+
+static	ulong	clkreload;
+
+void
+delay(int l)
+{
+	ulong i, j;
+
+	j = m->delayloop;
+	while(l-- > 0)
+		for(i=0; i < j; i++)
+			;
+}
+
+void
+microdelay(int l)
+{
+	ulong i;
+
+	l *= m->delayloop;
+	l /= 1000;
+	if(l <= 0)
+		l = 1;
+	for(i = 0; i < l; i++)
+		;
+}
+
+void
+clockintr(Ureg*, void*)
+{
+	putdec(clkreload);
+	m->ticks++;
+	checkalarms();
+	if(archclocktick != nil)
+		archclocktick();
+}
+
+void
+clockinit(void)
+{
+	long x;
+
+	m->delayloop = m->cpuhz/1000;	/* initial estimate */
+	do {
+		x = gettbl();
+		delay(10);
+		x = gettbl() - x;
+	} while(x < 0);
+
+	/*
+	 *  fix count
+	 */
+	m->delayloop = ((vlong)m->delayloop*(10*m->clockgen/1000))/(x*Timebase);
+	if(m->delayloop == 0)
+		m->delayloop = 1;
+	clkreload = (m->clockgen/Timebase)/HZ-1;
+	putdec(clkreload);
+}