Index: sys/arm/s3c2xx0/uart_dev_s3c2410.c
===================================================================
--- sys/arm/s3c2xx0/uart_dev_s3c2410.c	(revision 260005)
+++ sys/arm/s3c2xx0/uart_dev_s3c2410.c	(working copy)
@@ -70,6 +70,8 @@
 static void s3c2410_putc(struct uart_bas *bas, int);
 static int s3c2410_rxready(struct uart_bas *bas);
 static int s3c2410_getc(struct uart_bas *bas, struct mtx *mtx);
+static void s3c2410_grab(struct uart_bas *bas);
+static void s3c2410_ungrab(struct uart_bas *bas);
 
 extern SLIST_HEAD(uart_devinfo_list, uart_devinfo) uart_sysdevs;
 
@@ -143,6 +145,8 @@
 	.putc = s3c2410_putc,
 	.rxready = s3c2410_rxready,
 	.getc = s3c2410_getc,
+	.grab = s3c2410_grab,
+	.ungrab = s3c2410_ungrab,
 };
 
 static int
@@ -204,6 +208,20 @@
 	return sscom_getc(bas->bst, bas->bsh);
 }
 
+static void
+s3c2410_grab(struct uart_bas *bas)
+{
+
+	arm_mask_irq(get_sub_irq(irq, RX_OFF));
+}
+
+static void
+s3c2410_ungrab(struct uart_bas *bas)
+{
+
+	arm_unmask_irq(get_sub_irq(irq, RX_OFF));
+}
+
 static int s3c2410_bus_probe(struct uart_softc *sc);
 static int s3c2410_bus_attach(struct uart_softc *sc);
 static int s3c2410_bus_flush(struct uart_softc *, int);
Index: sys/arm/sa11x0/uart_dev_sa1110.c
===================================================================
--- sys/arm/sa11x0/uart_dev_sa1110.c	(revision 260005)
+++ sys/arm/sa11x0/uart_dev_sa1110.c	(working copy)
@@ -54,6 +54,8 @@
 static void sa1110_putc(struct uart_bas *bas, int);
 static int sa1110_rxready(struct uart_bas *bas);
 static int sa1110_getc(struct uart_bas *bas, struct mtx *mtx);
+static void sa1110_grab(struct uart_bas *bas);
+static void sa1110_ungrab(struct uart_bas *bas);
 
 extern SLIST_HEAD(uart_devinfo_list, uart_devinfo) uart_sysdevs;
 
@@ -64,6 +66,8 @@
 	.putc = sa1110_putc,
 	.rxready = sa1110_rxready,
 	.getc = sa1110_getc,
+	.grab = sa1110_grab,
+	.ungrab = sa1110_ungrab,
 };
 
 static int
@@ -127,6 +131,22 @@
 	return (c);
 }
 
+static void
+sa1110_grab(struct uart_bas *bas)
+{
+
+	/* Turn off Rx interrupts */
+	uart_setreg(bas, SACOM_CR3, CR3_TXE | CR3_TIE);
+}
+
+static void
+sa1110_ungrab(struct uart_bas *bas)
+{
+
+	/* Turn on Rx interrupts */
+	uart_setreg(bas, SACOM_CR3, CR3_RXE | CR3_TXE | CR3_RIE | CR3_TIE);
+}
+
 static int sa1110_bus_probe(struct uart_softc *sc);
 static int sa1110_bus_attach(struct uart_softc *sc);
 static int sa1110_bus_flush(struct uart_softc *, int);
@@ -164,10 +184,10 @@
 static int
 sa1110_bus_attach(struct uart_softc *sc)
 {
-	 bcopy(&sc->sc_sysdev->bas, &sc->sc_bas, sizeof(sc->sc_bas));
+	bcopy(&sc->sc_sysdev->bas, &sc->sc_bas, sizeof(sc->sc_bas));
 
-	 sc->sc_hwiflow = 0;
-	 uart_setreg(&sc->sc_bas, SACOM_CR3, CR3_RXE | CR3_TXE | CR3_RIE | CR3_TIE);
+	sc->sc_hwiflow = 0;
+	uart_setreg(&sc->sc_bas, SACOM_CR3, CR3_RXE | CR3_TXE | CR3_RIE | CR3_TIE);
 	return (0);
 }
 static int
Index: sys/arm/xilinx/uart_dev_cdnc.c
===================================================================
--- sys/arm/xilinx/uart_dev_cdnc.c	(revision 260005)
+++ sys/arm/xilinx/uart_dev_cdnc.c	(working copy)
@@ -155,6 +155,8 @@
 static void cdnc_uart_putc(struct uart_bas *bas, int);
 static int cdnc_uart_rxready(struct uart_bas *bas);
 static int cdnc_uart_getc(struct uart_bas *bas, struct mtx *mtx);
+static void cdnc_uart_grab(struct uart_bas *bas);
+static void cdnc_uart_ungrab(struct uart_bas *bas);
 
 extern SLIST_HEAD(uart_devinfo_list, uart_devinfo) uart_sysdevs;
 
@@ -165,6 +167,8 @@
 	.putc = cdnc_uart_putc,
 	.rxready = cdnc_uart_rxready,
 	.getc = cdnc_uart_getc,
+	.grab = cdnc_uart_grab,
+	.ungrab = cdnc_uart_ungrab,
 };
 
 #define	SIGCHG(c, i, s, d)				\
@@ -383,6 +387,27 @@
 	return (c);
 }
 
+static void
+cdnc_uart_grab(struct uart_bas *bas)
+{
+
+	/* Enable interrupts. */
+	WR4(bas, CDNC_UART_IEN_REG,
+	    CDNC_UART_INT_TXOVR | CDNC_UART_INT_RXOVR |
+	    CDNC_UART_INT_DMSI);
+}
+
+static void
+cdnc_uart_ungrab(struct uart_bas *bas)
+{
+
+	/* Enable interrupts. */
+	WR4(bas, CDNC_UART_IEN_REG,
+	    CDNC_UART_INT_RXTRIG | CDNC_UART_INT_RXTMOUT |
+	    CDNC_UART_INT_TXOVR | CDNC_UART_INT_RXOVR |
+	    CDNC_UART_INT_DMSI);
+}
+
 /*****************************************************************************/
 /*
  * High-level UART interface.
Index: sys/dev/uart/uart_dev_imx.c
===================================================================
--- sys/dev/uart/uart_dev_imx.c	(revision 260005)
+++ sys/dev/uart/uart_dev_imx.c	(working copy)
@@ -56,6 +56,8 @@
 static void imx_uart_putc(struct uart_bas *bas, int);
 static int imx_uart_rxready(struct uart_bas *bas);
 static int imx_uart_getc(struct uart_bas *bas, struct mtx *);
+static void imx_uart_grab(struct uart_bas *bas);
+static void imx_uart_ungrab(struct uart_bas *bas);
 
 static struct uart_ops uart_imx_uart_ops = {
 	.probe = imx_uart_probe,
@@ -64,6 +66,8 @@
 	.putc = imx_uart_putc,
 	.rxready = imx_uart_rxready,
 	.getc = imx_uart_getc,
+	.grab = imx_uart_grab,
+	.ungrab = imx_uart_ungrab,
 };
 
 static int
@@ -122,6 +126,18 @@
 	return (c & 0xff);
 }
 
+static void
+imx_uart_grab(struct uart_bas *bas)
+{
+	DIS(bas, UCR4, DREN);
+}
+
+static void
+imx_uart_ungrab(struct uart_bas *bas)
+{
+	ENA(bas, UCR4, DREN);
+}
+
 /*
  * High-level UART interface.
  */
@@ -189,12 +205,7 @@
 
 	(void)imx_uart_bus_getsig(sc);
 
-	/* XXX workaround to have working console on mount prompt */
-	if (sc->sc_sysdev != NULL && sc->sc_sysdev->type == UART_DEV_CONSOLE){
-		DIS(bas, UCR4, DREN);
-	} else {
-		ENA(bas, UCR4, DREN);
-	}
+	ENA(bas, UCR4, DREN);
 	DIS(bas, UCR1, RRDYEN);
 	DIS(bas, UCR1, IDEN);
 	DIS(bas, UCR3, RXDSEN);
@@ -402,13 +413,6 @@
 imx_uart_bus_setsig(struct uart_softc *sc, int sig)
 {
 
-	/* TODO: implement (?) */
-
-	/* XXX workaround to have working console on mount prompt */
-	/* Enable RX interrupt */
-	if (sc->sc_sysdev != NULL && sc->sc_sysdev->type == UART_DEV_CONSOLE)
-		if (!IS(&sc->sc_bas, UCR4, DREN))
-			ENA(&sc->sc_bas, UCR4, DREN);
 	return (0);
 }
 
Index: sys/dev/uart/uart_dev_lpc.c
===================================================================
--- sys/dev/uart/uart_dev_lpc.c	(revision 260005)
+++ sys/dev/uart/uart_dev_lpc.c	(working copy)
@@ -252,6 +252,8 @@
 static void lpc_ns8250_putc(struct uart_bas *bas, int);
 static int lpc_ns8250_rxready(struct uart_bas *bas);
 static int lpc_ns8250_getc(struct uart_bas *bas, struct mtx *);
+static void lpc_ns8250_grab(struct uart_bas *bas);
+static void lpc_ns8250_ungrab(struct uart_bas *bas);
 
 static struct uart_ops uart_lpc_ns8250_ops = {
 	.probe = lpc_ns8250_probe,
@@ -260,6 +262,8 @@
 	.putc = lpc_ns8250_putc,
 	.rxready = lpc_ns8250_rxready,
 	.getc = lpc_ns8250_getc,
+	.grab = lpc_ns8250_grab,
+	.ungrab = lpc_ns8250_ungrab,
 };
 
 static int
@@ -376,6 +380,27 @@
 	return (c);
 }
 
+static void
+lpc_ns8250_grab(struct uart_bas *bas)
+{
+	/* Should be using ns8250->fcr here, but can't access it via bas */
+	uint8_t fcr = FCR_ENABLE;
+
+	/* Switch to RX polling while grabbed */
+	uart_setreg(bas, REG_FCR, fcr);
+}
+
+static void
+lpc_ns8250_ungrab(struct uart_bas *bas)
+{
+	/* Should be using ns8250->fcr here, but can't access it via bas */
+	uint8_t fcr = FCR_ENABLE | FCR_RX_MEDH;
+
+	/* Switch to RX interrupts while not grabbed */
+	uart_setreg(bas, REG_FCR, fcr);
+}
+
+
 /*
  * High-level UART interface.
  */
Index: sys/dev/uart/uart_dev_ns8250.c
===================================================================
--- sys/dev/uart/uart_dev_ns8250.c	(revision 260005)
+++ sys/dev/uart/uart_dev_ns8250.c	(working copy)
@@ -239,6 +239,8 @@
 static void ns8250_putc(struct uart_bas *bas, int);
 static int ns8250_rxready(struct uart_bas *bas);
 static int ns8250_getc(struct uart_bas *bas, struct mtx *);
+static void ns8250_grab(struct uart_bas *bas);
+static void ns8250_ungrab(struct uart_bas *bas);
 
 struct uart_ops uart_ns8250_ops = {
 	.probe = ns8250_probe,
@@ -247,6 +249,8 @@
 	.putc = ns8250_putc,
 	.rxready = ns8250_rxready,
 	.getc = ns8250_getc,
+	.grab = ns8250_grab,
+	.ungrab = ns8250_ungrab,
 };
 
 static int
@@ -353,6 +357,26 @@
 	return (c);
 }
 
+static void
+ns8250_grab(struct uart_bas *bas)
+{
+	/* Should be using ns8250->fcr here, but can't access it via bas */
+	uint8_t fcr = FCR_ENABLE;
+
+	/* Switch to RX polling while grabbed */
+	uart_setreg(bas, REG_FCR, fcr);
+}
+
+static void
+ns8250_ungrab(struct uart_bas *bas)
+{
+	/* Should be using ns8250->fcr here, but can't access it via bas */
+	uint8_t fcr = FCR_ENABLE | FCR_RX_MEDH;
+
+	/* Switch to RX interrupts while not grabbed */
+	uart_setreg(bas, REG_FCR, fcr);
+}
+
 static kobj_method_t ns8250_methods[] = {
 	KOBJMETHOD(uart_attach,		ns8250_bus_attach),
 	KOBJMETHOD(uart_detach,		ns8250_bus_detach),
Index: sys/dev/uart/uart_dev_pl011.c
===================================================================
--- sys/dev/uart/uart_dev_pl011.c	(revision 260005)
+++ sys/dev/uart/uart_dev_pl011.c	(working copy)
@@ -102,6 +102,8 @@
 static void uart_pl011_putc(struct uart_bas *bas, int);
 static int uart_pl011_rxready(struct uart_bas *bas);
 static int uart_pl011_getc(struct uart_bas *bas, struct mtx *);
+static void uart_pl011_grab(struct uart_bas *bas);
+static void uart_pl011_ungrab(struct uart_bas *bas);
 
 static struct uart_ops uart_pl011_ops = {
 	.probe = uart_pl011_probe,
@@ -110,6 +112,8 @@
 	.putc = uart_pl011_putc,
 	.rxready = uart_pl011_rxready,
 	.getc = uart_pl011_getc,
+	.grab = uart_pl011_grab,
+	.ungrab = uart_pl011_ungrab,
 };
 
 static int
@@ -218,6 +222,24 @@
 	return (c);
 }
 
+static void
+uart_pl011_grab(struct uart_bas *bas)
+{
+
+	/* Switch to RX polling while grabbed */
+	__uart_setreg(bas, UART_IMSC,
+	    ~UART_RXREADY & __uart_getreg(bas, UART_IMSC));
+}
+
+static void
+uart_pl011_ungrab(struct uart_bas *bas)
+{
+
+	/* Switch to RX interrupts while not grabbed */
+	__uart_setreg(bas, UART_IMSC,
+	    UART_RXREADY | __uart_getreg(bas, UART_IMSC));
+}
+
 /*
  * High-level UART interface.
  */
Index: sys/dev/uart/uart_dev_quicc.c
===================================================================
--- sys/dev/uart/uart_dev_quicc.c	(revision 260005)
+++ sys/dev/uart/uart_dev_quicc.c	(working copy)
@@ -148,6 +148,8 @@
 static void quicc_putc(struct uart_bas *bas, int);
 static int quicc_rxready(struct uart_bas *bas);
 static int quicc_getc(struct uart_bas *bas, struct mtx *);
+static void quicc_grab(struct uart_bas *bas);
+static void quicc_ungrab(struct uart_bas *bas);
 
 static struct uart_ops uart_quicc_ops = {
 	.probe = quicc_probe,
@@ -156,6 +158,8 @@
 	.putc = quicc_putc,
 	.rxready = quicc_rxready,
 	.getc = quicc_getc,
+	.grab = quicc_grab,
+	.ungrab = quicc_ungrab,
 };
 
 static int
@@ -227,6 +231,28 @@
 	return (c);
 }
 
+static void
+quicc_grab(struct uart_bas *bas)
+{
+	uint16_t st, rb;
+
+	/* Disable interrupts on the receive buffer. */
+	rb = quicc_read2(bas, QUICC_PRAM_SCC_RBASE(bas->chan - 1));
+	st = quicc_read2(bas, rb);
+	quicc_write2(bas, rb, st & ~0x9000);
+}
+
+static void
+quicc_ungrab(struct uart_bas *bas)
+{
+	uint16_t st, rb;
+
+	/* Enable interrupts on the receive buffer. */
+	rb = quicc_read2(bas, QUICC_PRAM_SCC_RBASE(bas->chan - 1));
+	st = quicc_read2(bas, rb);
+	quicc_write2(bas, rb, st | 0x9000);
+}
+
 /*
  * High-level UART interface.
  */
Index: sys/dev/uart/uart_dev_sab82532.c
===================================================================
--- sys/dev/uart/uart_dev_sab82532.c	(revision 260005)
+++ sys/dev/uart/uart_dev_sab82532.c	(working copy)
@@ -175,6 +175,8 @@
 static void sab82532_putc(struct uart_bas *bas, int);
 static int sab82532_rxready(struct uart_bas *bas);
 static int sab82532_getc(struct uart_bas *bas, struct mtx *);
+static void sab82532_grab(struct uart_bas *bas);
+static void sab82532_ungrab(struct uart_bas *bas);
 
 static struct uart_ops uart_sab82532_ops = {
 	.probe = sab82532_probe,
@@ -183,6 +185,8 @@
 	.putc = sab82532_putc,
 	.rxready = sab82532_rxready,
 	.getc = sab82532_getc,
+	.grab = sab82532_grab,
+	.ungrab = sab82532_ungrab,
 };
 
 static int
@@ -347,6 +351,27 @@
 	return (c);
 }
 
+static void
+sab82532_grab(struct uart_bas *bas)
+{
+	uint8_t imr0;
+
+	imr0 = SAB_IMR0_TIME|SAB_IMR0_CDSC|SAB_IMR0_RFO; /* No TCD or RPF */
+	uart_setreg(bas, SAB_IMR0, 0xff & ~imr0);
+	uart_barrier(bas);
+}
+
+static void
+sab82532_ungrab(struct uart_bas *bas)
+{
+	uint8_t imr0;
+
+	imr0 = SAB_IMR0_TCD|SAB_IMR0_TIME|SAB_IMR0_CDSC|SAB_IMR0_RFO|
+	    SAB_IMR0_RPF;
+	uart_setreg(bas, SAB_IMR0, 0xff & ~imr0);
+	uart_barrier(bas);
+}
+
 /*
  * High-level UART interface.
  */
Index: sys/dev/uart/uart_dev_z8530.c
===================================================================
--- sys/dev/uart/uart_dev_z8530.c	(revision 260005)
+++ sys/dev/uart/uart_dev_z8530.c	(working copy)
@@ -194,6 +194,8 @@
 static void z8530_putc(struct uart_bas *bas, int);
 static int z8530_rxready(struct uart_bas *bas);
 static int z8530_getc(struct uart_bas *bas, struct mtx *);
+static void z8530_grab(struct uart_bas *bas);
+static void z8530_ungrab(struct uart_bas *bas);
 
 static struct uart_ops uart_z8530_ops = {
 	.probe = z8530_probe,
@@ -202,6 +204,8 @@
 	.putc = z8530_putc,
 	.rxready = z8530_rxready,
 	.getc = z8530_getc,
+	.grab = z8530_grab,
+	.ungrab = z8530_ungrab,
 };
 
 static int
@@ -261,6 +265,20 @@
 	return (c);
 }
 
+static void
+z8530_grab(struct uart_bas *bas)
+{
+	uart_setmreg(bas, WR_IDT, IDT_XIE | IDT_TIE);
+	uart_barrier(bas);
+}
+
+static void
+z8530_ungrab(struct uart_bas *bas)
+{
+	uart_setmreg(bas, WR_IDT, IDT_XIE | IDT_TIE | IDT_RIA);
+	uart_barrier(bas);
+}
+
 /*
  * High-level UART interface.
  */
Index: sys/mips/adm5120/uart_dev_adm5120.c
===================================================================
--- sys/mips/adm5120/uart_dev_adm5120.c	(revision 260005)
+++ sys/mips/adm5120/uart_dev_adm5120.c	(working copy)
@@ -58,6 +58,8 @@
 static void adm5120_uart_putc(struct uart_bas *bas, int);
 static int adm5120_uart_rxready(struct uart_bas *bas);
 static int adm5120_uart_getc(struct uart_bas *bas, struct mtx *);
+static void adm5120_uart_grab(struct uart_bas *bas);
+static void adm5120_uart_ungrab(struct uart_bas *bas);
 
 static struct uart_ops uart_adm5120_uart_ops = {
 	.probe = adm5120_uart_probe,
@@ -66,6 +68,8 @@
 	.putc = adm5120_uart_putc,
 	.rxready = adm5120_uart_rxready,
 	.getc = adm5120_uart_getc,
+	.grab = adm5120_uart_grab,
+	.ungrab = adm5120_uart_ungrab,
 };
 
 static int
@@ -131,6 +135,25 @@
 	return (c);
 }
 
+static void
+adm5120_uart_grab(struct uart_bas *bas)
+{
+
+	/* Enable interrupts - no RX_INT or RX_TIMEOUT */
+	uart_setreg(bas, UART_CR_REG,
+	    UART_CR_PORT_EN | UART_CR_MODEM_STATUS_INT_EN);
+}
+
+static void
+adm5120_uart_ungrab(struct uart_bas *bas)
+{
+
+	/* Enable interrupts */
+	uart_setreg(bas, UART_CR_REG,
+	    UART_CR_PORT_EN|UART_CR_RX_INT_EN|UART_CR_RX_TIMEOUT_INT_EN|
+	    UART_CR_MODEM_STATUS_INT_EN);
+}
+
 /*
  * High-level UART interface.
  */
Index: sys/mips/atheros/uart_dev_ar933x.c
===================================================================
--- sys/mips/atheros/uart_dev_ar933x.c	(revision 260005)
+++ sys/mips/atheros/uart_dev_ar933x.c	(working copy)
@@ -201,6 +201,8 @@
 static void ar933x_putc(struct uart_bas *bas, int);
 static int ar933x_rxready(struct uart_bas *bas);
 static int ar933x_getc(struct uart_bas *bas, struct mtx *);
+static void ar933x_grab(struct uart_bas *bas);
+static void ar933x_ungrab(struct uart_bas *bas);
 
 static struct uart_ops uart_ar933x_ops = {
 	.probe = ar933x_probe,
@@ -209,6 +211,8 @@
 	.putc = ar933x_putc,
 	.rxready = ar933x_rxready,
 	.getc = ar933x_getc,
+	.grab = ar933x_grab,
+	.ungrab = ar933x_ungrab,
 };
 
 static int
@@ -305,6 +309,26 @@
 	return (c);
 }
 
+static void
+ar933x_grab(struct uart_bas *bas)
+{
+
+	/* Disable the host interrupt now */
+	reg = ar933x_getreg(bas, AR933X_UART_CS_REG);
+	reg &= ~AR933X_UART_CS_HOST_INT_EN;
+	ar933x_setreg(bas, AR933X_UART_CS_REG, reg);
+}
+
+static void
+ar933x_ungrab(struct uart_bas *bas)
+{
+
+	/* Enable the host interrupt now */
+	reg = ar933x_getreg(bas, AR933X_UART_CS_REG);
+	reg |= AR933X_UART_CS_HOST_INT_EN;
+	ar933x_setreg(bas, AR933X_UART_CS_REG, reg);
+}
+
 /*
  * High-level UART interface.
  */
Index: sys/mips/cavium/uart_dev_oct16550.c
===================================================================
--- sys/mips/cavium/uart_dev_oct16550.c	(revision 260005)
+++ sys/mips/cavium/uart_dev_oct16550.c	(working copy)
@@ -266,6 +266,8 @@
 static void oct16550_putc(struct uart_bas *bas, int);
 static int oct16550_rxready(struct uart_bas *bas);
 static int oct16550_getc(struct uart_bas *bas, struct mtx *);
+static void oct16550_grab(struct uart_bas *bas);
+static void oct16550_ungrab(struct uart_bas *bas);
 
 struct uart_ops uart_oct16550_ops = {
 	.probe = oct16550_probe,
@@ -274,6 +276,8 @@
 	.putc = oct16550_putc,
 	.rxready = oct16550_rxready,
 	.getc = oct16550_getc,
+	.grab = oct16550_grab,
+	.ungrab = oct16550_ungrab,
 };
 
 static int
@@ -377,6 +381,25 @@
 	return (c);
 }
 
+static void
+oct16550_grab(struct uart_bas *bas)
+{
+
+	/* Should use oct16550->fcr here, but can't access it from here */
+	uart_setreg(bas, REG_FCR, FCR_ENABLE);
+	uart_barrier(bas);
+}
+
+static void
+oct16550_ungrab(struct uart_bas *bas)
+{
+
+	/* Should use oct16550->fcr here, but can't access it from here */
+	uart_setreg(bas, REG_FCR, FCR_ENABLE | FCR_RX_HIGH);
+	uart_barrier(bas);
+}
+
+
 /*
  * High-level UART interface.
  */
Index: sys/mips/rt305x/uart_dev_rt305x.c
===================================================================
--- sys/mips/rt305x/uart_dev_rt305x.c	(revision 260005)
+++ sys/mips/rt305x/uart_dev_rt305x.c	(working copy)
@@ -62,6 +62,8 @@
 static void rt305x_uart_putc(struct uart_bas *bas, int);
 static int rt305x_uart_rxready(struct uart_bas *bas);
 static int rt305x_uart_getc(struct uart_bas *bas, struct mtx *);
+static void rt305x_uart_grab(struct uart_bas *bas);
+static void rt305x_uart_ungrab(struct uart_bas *bas);
 
 static struct uart_ops uart_rt305x_uart_ops = {
 	.probe = rt305x_uart_probe,
@@ -70,6 +72,8 @@
 	.putc = rt305x_uart_putc,
 	.rxready = rt305x_uart_rxready,
 	.getc = rt305x_uart_getc,
+	.grab = rt305x_uart_grab,
+	.ungrab = rt305x_uart_ungrab,
 };
 
 static int	uart_output = 1;
@@ -177,6 +181,25 @@
 	return (c);
 }
 
+static void
+rt305x_uart_grab(struct uart_bas *bas)
+{
+
+	/* disable interrupts -- XXX not sure which one is RX, so kill them all */
+	uart_setreg(bas, UART_IER_REG, 0);
+	uart_barrier(bas);
+}
+
+static void
+rt305x_uart_ungrab(struct uart_bas *bas)
+{
+
+	/* Enable interrupts */
+	uart_setreg(bas, UART_IER_REG,
+	    UART_IER_EDSSI | UART_IER_ELSI | UART_IER_ERBFI);
+	uart_barrier(bas);
+}
+
 /*
  * High-level UART interface.
  */
@@ -278,7 +301,7 @@
 	uart_setreg(bas, UART_FCR_REG, 
 	    uart_getreg(bas, UART_FCR_REG) | 
 	    UART_FCR_FIFOEN | UART_FCR_TXTGR_1 | UART_FCR_RXTGR_1);
-	uart_barrier(bas);
+ 	uart_barrier(bas);
 	/* Enable interrupts */
 	uart_setreg(bas, UART_IER_REG,
 	    UART_IER_EDSSI | UART_IER_ELSI | UART_IER_ERBFI);