CONFIG_DEBUG_U300_UART is not available for thedefaultarchitecture x86.
Result is shown for architecture arm
Kernel low-level debugging messages via U300 UART0
configname: CONFIG_DEBUG_U300_UART
Kernel low-level debugging port
└─>Kernel low-level debugging messages via U300 UART0
In linux kernel since version 3.11 (release Date: 2013-09-02)
Say Y here if you want the debug print routines to direct
their output to the uart port on U300 devices.
their output to the uart port on U300 devices.