sandbox: put stdin into raw mode

This allows us to act like a serial device: we get tab chars and CTRL+C
and respond appropriately.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Tested-by: Simon Glass <sjg@chromium.org>

arch/sandbox/cpu/os.c

@@ -21,6 +21,7 @@
 
 #include <fcntl.h>
 #include <stdlib.h>
+#include <termios.h>
 #include <unistd.h>
 #include <sys/types.h>
 #include <sys/stat.h>
@@ -53,3 +54,36 @@ void os_exit(int exit_code)
 {
 	exit(exit_code);
 }
+
+/* Restore tty state when we exit */
+static struct termios orig_term;
+
+static void os_fd_restore(void)
+{
+	tcsetattr(0, TCSANOW, &orig_term);
+}
+
+/* Put tty into raw mode so <tab> and <ctrl+c> work */
+void os_tty_raw(int fd)
+{
+	static int setup = 0;
+	struct termios term;
+
+	if (setup)
+		return;
+	setup = 1;
+
+	/* If not a tty, don't complain */
+	if (tcgetattr(fd, &orig_term))
+		return;
+
+	term = orig_term;
+	term.c_iflag = IGNBRK | IGNPAR;
+	term.c_oflag = OPOST | ONLCR;
+	term.c_cflag = CS8 | CREAD | CLOCAL;
+	term.c_lflag = 0;
+	if (tcsetattr(fd, TCSANOW, &term))
+		return;
+
+	atexit(os_fd_restore);
+}

drivers/serial/sandbox.c

@@ -30,6 +30,7 @@
 
 int serial_init(void)
 {
+	os_tty_raw(0);
 	return 0;
 }
 

include/os.h

@@ -71,3 +71,8 @@ int os_close(int fd);
  * @param exit_code	exit code for U-Boot
  */
 void os_exit(int exit_code);
+
+/**
+ * Put tty into raw mode to mimic serial console better
+ */
+void os_tty_raw(int fd);