diff --git a/hw/bsp/imxrt/boards/mimxrt1050_evkb/board.h b/hw/bsp/imxrt/boards/mimxrt1050_evkb/board.h
index 853cdf9ab..7c333d8f5 100644
--- a/hw/bsp/imxrt/boards/mimxrt1050_evkb/board.h
+++ b/hw/bsp/imxrt/boards/mimxrt1050_evkb/board.h
@@ -43,5 +43,6 @@
 
 // UART: IOMUXC_GPIO_AD_B0_13_LPUART1_RXD, IOMUXC_GPIO_AD_B0_12_LPUART1_TXD
 #define UART_PORT             LPUART1
+#define UART_CLK_ROOT         BOARD_BOOTCLOCKRUN_UART_CLK_ROOT
 
 #endif /* BOARD_H_ */
diff --git a/hw/bsp/imxrt/boards/mimxrt1060_evk/board.h b/hw/bsp/imxrt/boards/mimxrt1060_evk/board.h
index 0f45f72e1..253872870 100644
--- a/hw/bsp/imxrt/boards/mimxrt1060_evk/board.h
+++ b/hw/bsp/imxrt/boards/mimxrt1060_evk/board.h
@@ -31,13 +31,13 @@
 // required since iMX RT10xx SDK include this file for board size
 #define BOARD_FLASH_SIZE (0x800000U)
 
-// LED
+// LED: IOMUXC_GPIO_AD_B0_09_GPIO1_IO09
 #define LED_PINMUX            IOMUXC_GPIO_AD_B0_09_GPIO1_IO09
 #define LED_PORT              GPIO1
 #define LED_PIN               9
 #define LED_STATE_ON          0
 
-// SW8 button
+// SW8 button: IOMUXC_SNVS_WAKEUP_GPIO5_IO00
 #define BUTTON_PINMUX         IOMUXC_SNVS_WAKEUP_GPIO5_IO00
 #define BUTTON_PORT           GPIO5
 #define BUTTON_PIN            0