The new u-boot releases bring up HDMI and USB and it causes the kernel or u-boot to hang
on most boot tries. USE_PREBOOT is disabled so USB won't be brought up which causes an hang
after 2020.10 and HDMI being on confuses Linux enough to break everything. 
diff --git a/configs/rockpro64-rk3399_defconfig b/configs/rockpro64-rk3399_defconfig
index ae11a8f5eb..aa8f55639c 100644
--- a/configs/rockpro64-rk3399_defconfig
+++ b/configs/rockpro64-rk3399_defconfig
@@ -12,7 +12,7 @@ CONFIG_DEBUG_UART_CLOCK=24000000
 CONFIG_SPL_SPI_FLASH_SUPPORT=y
 CONFIG_SPL_SPI_SUPPORT=y
 CONFIG_DEBUG_UART=y
-CONFIG_USE_PREBOOT=y
+CONFIG_USE_PREBOOT=n
 CONFIG_DEFAULT_FDT_FILE="rockchip/rk3399-rockpro64.dtb"
 CONFIG_DISPLAY_BOARDINFO_LATE=y
 CONFIG_MISC_INIT_R=y
@@ -81,6 +81,6 @@ CONFIG_USB_ETHER_SMSC95XX=y
 CONFIG_DM_VIDEO=y
 CONFIG_DISPLAY=y
 CONFIG_VIDEO_ROCKCHIP=y
-CONFIG_DISPLAY_ROCKCHIP_HDMI=y
+CONFIG_DISPLAY_ROCKCHIP_HDMI=n
 CONFIG_SPL_TINY_MEMSET=y
 CONFIG_ERRNO_STR=y