config RT_USING_EXT_SDRAM bool "Enable SDRAM on the board" default y config RT_USING_UART1 bool "Enable UART1" default y config RT_USING_UART2 bool "Enable UART2" default n config RT_USING_UART3 bool "Enable UART3" default n config RT_USING_SPI5 bool "Enable SPI5" default n