CONFIG_DEBUG_BOOTMEM is not available for thedefaultarchitecture x86.
Result is shown for architecture microblaze
default or selected kernelversion does not have config value CONFIG_DEBUG_BOOTMEM.
Result is shown for kernelversion 5.4.69
Debug BOOTMEM initialization
configname: CONFIG_DEBUG_BOOTMEM
Linux Kernel Configuration
└─>Kernel hacking
└─>Debug BOOTMEM initialization