diff --git a/sys/boot/arm/at91/boot0/at91rm9200_lowlevel.c b/sys/boot/arm/at91/boot0/at91rm9200_lowlevel.c
index ab3ae24e77c8..d0f10a181b80 100644
--- a/sys/boot/arm/at91/boot0/at91rm9200_lowlevel.c
+++ b/sys/boot/arm/at91/boot0/at91rm9200_lowlevel.c
@@ -44,7 +44,6 @@ _init(void)
 {
 	AT91PS_USART pUSART = (AT91PS_USART)AT91C_BASE_DBGU;
 	AT91PS_PDC pPDC = (AT91PS_PDC)&(pUSART->US_RPR);
-	AT91PS_PIO pPio = AT91C_BASE_PIOA;
 
 	register unsigned	value;
 	int i;
@@ -152,10 +151,14 @@ _init(void)
 	AT91C_BASE_SDRC->SDRC_MR = SDRAM_WIDTH | AT91C_SDRC_MODE_NORMAL_CMD;
 	*p = 0;
 
+#if	SDRAM_WIDTH == AT91C_SDRC_DBW_32_BITS
+	// Turn on the upper 16 bits on the SDRAM bus.
+	AT91C_BASE_PIOC->PIO_ASR = 0xffff0000;
+	AT91C_BASE_PIOC->PIO_PDR = 0xffff0000;
+#endif
 	// Configure DBGU -use local routine optimized for space
-	pPio->PIO_ASR = AT91C_PA31_DTXD | AT91C_PA30_DRXD;
-	pPio->PIO_BSR = 0;
-	pPio->PIO_PDR = AT91C_PA31_DTXD | AT91C_PA30_DRXD;
+	AT91C_BASE_PIOA->PIO_ASR = AT91C_PA31_DTXD | AT91C_PA30_DRXD;
+	AT91C_BASE_PIOA->PIO_PDR = AT91C_PA31_DTXD | AT91C_PA30_DRXD;
 	pUSART->US_IDR = (unsigned int) -1;
 	pUSART->US_CR =
 		AT91C_US_RSTRX | AT91C_US_RSTTX | AT91C_US_RXDIS | AT91C_US_TXDIS;