diff --git a/drivers/firmware/efi/libstub/efi-stub.c b/drivers/firmware/efi/libstub/efi-stub.c
index d824d954da268..b969c25d6d150 100644
--- a/drivers/firmware/efi/libstub/efi-stub.c
+++ b/drivers/firmware/efi/libstub/efi-stub.c
@@ -177,6 +177,7 @@ efi_status_t __efiapi efi_pe_entry(efi_handle_t handle,
 		}
 	}
 */
+	uint8_t *base = (uint8_t*) 0x6000d000;
 
 	/*
 	 * Figure out on which Windows RT device is booted.
@@ -359,10 +360,39 @@ efi_status_t __efiapi efi_pe_entry(efi_handle_t handle,
 	}
 
 	install_memreserve_table();
+/*
+	for (i = 0; i < 0x1000; i++) {
+		if (i % 16 == 0) {
+			tegra_uart_print("\n");
+			tegra_uart_print("%02x: ", i);
+		}
 
+		tegra_uart_print("%02x ", *(base+i));
+	}
+*/
+/**
+ * @brief lock Vbus GPIO
+ * locks the VBus GPIO so ExitBootService call can't turn it off.
+ */
+/*
+	uint16_t *gpio = (uint16_t*) 0x6000d208;
+	uint16_t cur_val = *gpio;
+	cur_val = cur_val | 0x200;
+	*gpio = cur_val;
+*/
 	status = allocate_new_fdt_and_exit_boot(handle, &fdt_addr,
 						initrd_addr, initrd_size,
 						cmdline_ptr, fdt_addr, fdt_size);
+/*
+	for (i = 0; i < 0x1000; i++) {
+		if (i % 16 == 0) {
+			tegra_uart_print("\n");
+			tegra_uart_print("%02x: ", i);
+		}
+
+		tegra_uart_print("%02x ", *(base+i));
+	}
+*/
 	if (status != EFI_SUCCESS)
 		goto fail_free_initrd;
 
diff --git a/drivers/firmware/efi/libstub/efistub.h b/drivers/firmware/efi/libstub/efistub.h
index 7830f720e0ece..c59ef33127088 100644
--- a/drivers/firmware/efi/libstub/efistub.h
+++ b/drivers/firmware/efi/libstub/efistub.h
@@ -907,7 +907,7 @@ enum winrt_device_names winrt_setup(void);
 /**
  * Tegra specific UART stuff
  */
-void tegra_uart_print(const char *string);
+void tegra_uart_print(const char *string, ...);
 void tegra_uart_init(void);
 
 /**
diff --git a/drivers/firmware/efi/libstub/tegra_uart.c b/drivers/firmware/efi/libstub/tegra_uart.c
index 9bd04e022888e..0ae174a71d0bd 100644
--- a/drivers/firmware/efi/libstub/tegra_uart.c
+++ b/drivers/firmware/efi/libstub/tegra_uart.c
@@ -98,28 +98,34 @@ void tegra_uart_init()
 	tegra_uart_print("hi from tegra_uart_init :)\n");
 }
 
-void tegra_uart_print(const char *string)
+void tegra_uart_print(const char *fmt, ...)
 {
+	char printf_buf[256];
+	va_list args;
+	int printed_size;
+	int i;
+
 	/* If uart isn't setup (yet); send nothing */
 	if (reg_read(PMC_BASE, APBDEV_PMC_SCRATCH42_0) != MAGIC_VALUE)
 		return;
 
+	va_start(args, fmt);
+	printed_size = vsnprintf(printf_buf, sizeof(printf_buf), fmt, args);
+	va_end(args);
+
 	/* send all characters until NULL to uart-N */
-	while (*string) {
+	for (i = 0; i < printed_size; i++) {
 		/* put the char into the tx fifo */
-		if (*string == '\n') {
+		if (printf_buf[i] == '\n') {
 			reg_write(UART_BASE, UART_THR_DLAB, '\r');
 			while (!((reg_read(UART_BASE, UART_LSR) >> 5) & 0x01))
 				;
 		}
 
-		reg_write(UART_BASE, UART_THR_DLAB, (char) *string);
+		reg_write(UART_BASE, UART_THR_DLAB, (char) printf_buf[i]);
 
 		/* wait for tx fifo to clear */
 		while (!((reg_read(UART_BASE, UART_LSR) >> 5) & 0x01))
 			;
-
-		/* move on to next char */
-		++string;
 	}
 }