initial version

Book-Lite/linux-0.12/kernel/chr_drv/pty.c

@@ -0,0 +1,63 @@
+/*
+ *  linux/kernel/chr_drv/pty.c
+ *
+ *  (C) 1991  Linus Torvalds
+ */
+
+/*
+ *	pty.c
+ *
+ * This module implements the pty functions
+ *	void mpty_write(struct tty_struct * queue);
+ *	void spty_write(struct tty_struct * queue);
+ */
+
+#include <linux/tty.h>
+#include <linux/sched.h>
+#include <asm/system.h>
+#include <asm/io.h>
+
+static inline void pty_copy(struct tty_struct * from, struct tty_struct * to)
+{
+	char c;
+
+	while (!from->stopped && !EMPTY(from->write_q)) {
+		if (FULL(to->read_q)) {
+			if (FULL(to->secondary))
+				break;
+			copy_to_cooked(to);
+			continue;
+		}
+		GETCH(from->write_q,c);
+		PUTCH(c,to->read_q);
+		if (current->signal & ~current->blocked)
+			break;
+	}
+	copy_to_cooked(to);
+	wake_up(&from->write_q->proc_list);
+}
+
+/*
+ * This routine gets called when tty_write has put something into
+ * the write_queue. It copies the input to the output-queue of it's
+ * slave.
+ */
+void mpty_write(struct tty_struct * tty)
+{
+	int nr = tty - tty_table;
+
+	if ((nr >> 6) != 2)
+		printk("bad mpty\n\r");
+	else
+		pty_copy(tty,tty+64);
+}
+
+void spty_write(struct tty_struct * tty)
+{
+	int nr = tty - tty_table;
+
+	if ((nr >> 6) != 3)
+		printk("bad spty\n\r");
+	else
+		pty_copy(tty,tty-64);
+}