CONFIG_IRAM_SIZE is not available for thedefaultarchitecture x86.
Result is shown for architecture m32r
default or selected kernelversion does not have config value CONFIG_IRAM_SIZE.
Result is shown for kernelversion 6.7-rc3

Internal memory size (hex)

configname: CONFIG_IRAM_SIZE

Linux Kernel Configuration
└─>Processor type and features
└─>Internal memory size (hex)
In linux kernel since version 2.6.12