* Configuration _OPTIONS_: These are selectable by the user and have names beginning with "CONFIG_". * Configuration _SETTINGS_: These depend on the hardware etc. and should not be meddled with if you don't know what you're doing; they have names beginning with "CONFIG_SYS_". It's better to use #define CONFIG_SYS_MXC_UART_BASE =A0 UART1_BASE [...] Best Regards,