CONFIG_HIGHMEM_START is not available for thedefaultarchitecture x86.
Result is shown for architecture microblaze
default or selected kernelversion does not have config value CONFIG_HIGHMEM_START.
Result is shown for kernelversion 6.2.5
Virtual start address of high memory pool
configname: CONFIG_HIGHMEM_START
Linux Kernel Configuration
└─>Advanced setup
└─>Virtual start address of high memory pool