CONFIG_LH7A40X_CONTIGMEM is not available for thedefaultarchitecture x86.
Result is shown for architecture arm
default or selected kernelversion does not have config value CONFIG_LH7A40X_CONTIGMEM.
Result is shown for kernelversion 5.4.69

Disable NUMA/SparseMEM Support


Linux Kernel Configuration
└─>LH7A40X Implementations
└─>Disable NUMA/SparseMEM Support
In linux kernel since version 2.6.12  
Say Y here if your bootloader sets the SROMLL bit(s) in
the SDRAM controller, organizing memory as a contiguous
array. This option will disable sparse memory support
and force the kernel to manage all memory in one node.

Setting this option incorrectly may prevent the kernel
from booting. It is OK to leave it N.

For more information, consult