CONFIG_CONSISTENT_START_BOOL is not available for thedefaultarchitecture x86.
Result is shown for architecture microblaze
default or selected kernelversion does not have config value CONFIG_CONSISTENT_START_BOOL.
Result is shown for kernelversion 5.4.194

Set custom consistent memory pool address

configname: CONFIG_CONSISTENT_START_BOOL

Linux/Microblaze Kernel Configuration
└─>Advanced setup
└─>Set custom consistent memory pool address
In linux kernel since version 2.6.15 (release Date: 2006-01-02)  
This option allows you to set the base virtual address
of the the consistent memory pool. This pool of virtual
memory is used to make consistent memory allocations.