CONFIG_ETRAX_RESCUE_SER0 is not available for thedefaultarchitecture x86.
Result is shown for architecture cris
default or selected kernelversion does not have config value CONFIG_ETRAX_RESCUE_SER0.
Result is shown for kernelversion 6.7-rc3

Serial-0

configname: CONFIG_ETRAX_RESCUE_SER0

Product rescue-port
└─>Serial-0
In linux kernel since version 2.6.12  
Select one of the four serial ports as a rescue port. The default
is port 0.