Add original unix v6

sys/dmr/sys.c

@@ -0,0 +1,54 @@
+#
+/*
+ */
+
+/*
+ *	indirect driver for controlling tty.
+ */
+#include "../param.h"
+#include "../conf.h"
+#include "../user.h"
+#include "../tty.h"
+#include "../proc.h"
+
+syopen(dev, flag)
+{
+	register *tp;
+
+	if(tp = syttyp())
+	(*cdevsw[tp->t_dev.d_major].d_open)(tp->t_dev, flag);
+}
+
+syread(dev)
+{
+	register *tp;
+
+	if(tp = syttyp())
+	(*cdevsw[tp->t_dev.d_major].d_read)(tp->t_dev);
+}
+
+sywrite(dev)
+{
+	register *tp;
+
+	if(tp = syttyp())
+	(*cdevsw[tp->t_dev.d_major].d_write)(tp->t_dev);
+}
+
+sysgtty(dev, flag)
+{
+	register *tp;
+
+	if(tp = syttyp())
+	(*cdevsw[tp->t_dev.d_major].d_sgtty)(tp->t_dev, flag);
+}
+
+syttyp()
+{
+	register tp;
+
+	tp = u.u_procp->p_ttyp;
+	if(tp == NULL)
+		u.u_error = ENXIO;
+	return(tp);
+}