CONFIG_SBC8641D is not available for thedefaultarchitecture x86.
Result is shown for architecture powerpc
default or selected kernelversion does not have config value CONFIG_SBC8641D.
Result is shown for kernelversion 6.9.9

Wind River SBC8641D

modulename: sbc8641d.ko

configname: CONFIG_SBC8641D

Linux Kernel Configuration
└─>Wind River SBC8641D
In linux kernel since version 2.6.26 (release Date: 2008-07-13)  
This option enables support for the WRS SBC8641D board.

source code: