diff --git a/common/stdio.c b/common/stdio.c
index 8232815..68c595d 100644
--- a/common/stdio.c
+++ b/common/stdio.c
@@ -39,39 +39,39 @@
 #endif
 
 #ifdef CONFIG_SYS_DEVICE_NULLDEV
-void nulldev_putc(struct stdio_dev *dev, const char c)
+static void nulldev_putc(struct stdio_dev *dev, const char c)
 {
 	/* nulldev is empty! */
 }
 
-void nulldev_puts(struct stdio_dev *dev, const char *s)
+static void nulldev_puts(struct stdio_dev *dev, const char *s)
 {
 	/* nulldev is empty! */
 }
 
-int nulldev_input(struct stdio_dev *dev)
+static int nulldev_input(struct stdio_dev *dev)
 {
 	/* nulldev is empty! */
 	return 0;
 }
 #endif
 
-void stdio_serial_putc(struct stdio_dev *dev, const char c)
+static void stdio_serial_putc(struct stdio_dev *dev, const char c)
 {
 	serial_putc(c);
 }
 
-void stdio_serial_puts(struct stdio_dev *dev, const char *s)
+static void stdio_serial_puts(struct stdio_dev *dev, const char *s)
 {
 	serial_puts(s);
 }
 
-int stdio_serial_getc(struct stdio_dev *dev)
+static int stdio_serial_getc(struct stdio_dev *dev)
 {
 	return serial_getc();
 }
 
-int stdio_serial_tstc(struct stdio_dev *dev)
+static int stdio_serial_tstc(struct stdio_dev *dev)
 {
 	return serial_tstc();
 }
diff --git a/drivers/serial/serial.c b/drivers/serial/serial.c
index 82fbbd9..71cb97d 100644
--- a/drivers/serial/serial.c
+++ b/drivers/serial/serial.c
@@ -256,28 +256,28 @@
 	serial_assign(default_serial_console()->name);
 }
 
-int serial_stub_start(struct stdio_dev *sdev)
+static int serial_stub_start(struct stdio_dev *sdev)
 {
 	struct serial_device *dev = sdev->priv;
 
 	return dev->start();
 }
 
-int serial_stub_stop(struct stdio_dev *sdev)
+static int serial_stub_stop(struct stdio_dev *sdev)
 {
 	struct serial_device *dev = sdev->priv;
 
 	return dev->stop();
 }
 
-void serial_stub_putc(struct stdio_dev *sdev, const char ch)
+static void serial_stub_putc(struct stdio_dev *sdev, const char ch)
 {
 	struct serial_device *dev = sdev->priv;
 
 	dev->putc(ch);
 }
 
-void serial_stub_puts(struct stdio_dev *sdev, const char *str)
+static void serial_stub_puts(struct stdio_dev *sdev, const char *str)
 {
 	struct serial_device *dev = sdev->priv;
 
diff --git a/drivers/serial/serial_sh.c b/drivers/serial/serial_sh.c
index 144a925..7c1f271 100644
--- a/drivers/serial/serial_sh.c
+++ b/drivers/serial/serial_sh.c
@@ -122,7 +122,7 @@
 	sci_out(&sh_sci, SCLSR, 0x00);
 }
 
-void serial_raw_putc(const char c)
+static void serial_raw_putc(const char c)
 {
 	while (1) {
 		/* Tx fifo is empty */
@@ -152,7 +152,7 @@
 }
 
 
-int serial_getc_check(void)
+static int serial_getc_check(void)
 {
 	unsigned short status;
 
diff --git a/drivers/video/cfb_console.c b/drivers/video/cfb_console.c
index 8567231..6aa50cb 100644
--- a/drivers/video/cfb_console.c
+++ b/drivers/video/cfb_console.c
@@ -944,7 +944,7 @@
 		CURSOR_SET;
 }
 
-void video_putc(struct stdio_dev *dev, const char c)
+static void video_putc(struct stdio_dev *dev, const char c)
 {
 #ifdef CONFIG_CFB_CONSOLE_ANSI
 	int i;
@@ -1158,7 +1158,7 @@
 		flush_cache(VIDEO_FB_ADRS, VIDEO_SIZE);
 }
 
-void video_puts(struct stdio_dev *dev, const char *s)
+static void video_puts(struct stdio_dev *dev, const char *s)
 {
 	int count = strlen(s);