CONFIG_FLASH_MEMORY_START is not available for thedefaultarchitecture x86.
Result is shown for architecture sh64
default or selected kernelversion does not have config value CONFIG_FLASH_MEMORY_START.
Result is shown for kernelversion 5.4.123

Flash memory/on-chip devices start address

configname: CONFIG_FLASH_MEMORY_START

Linux/SH64 Kernel Configuration
└─>System type
└─>Flash memory/on-chip devices start address
In linux kernel since version 2.6.12