esp-idf/components/esp_system/port/soc/esp32s2/Kconfig.memory

menu "Memory"

    config ESP32S2_RTCDATA_IN_FAST_MEM
        bool "Place RTC_DATA_ATTR and RTC_RODATA_ATTR variables into RTC fast memory segment"
        default n
        help
            This option allows to place .rtc_data and .rtc_rodata sections into
            RTC fast memory segment to free the slow memory region for ULP programs.

    config ESP32S2_USE_FIXED_STATIC_RAM_SIZE
        bool "Use fixed static RAM size"
        default n
        help
            If this option is disabled, the DRAM part of the heap starts right after the .bss section,
            within the dram0_0 region. As a result, adding or removing some static variables
            will change the available heap size.

            If this option is enabled, the DRAM part of the heap starts right after the dram0_0 region,
            where its length is set with ESP32S2_FIXED_STATIC_RAM_SIZE

    config ESP32S2_FIXED_STATIC_RAM_SIZE
        hex "Fixed Static RAM size"
        default 0x10000
        range 0 0x34000 # Equal to I_D_SRAM_SIZE in linkerscript
        depends on ESP32S2_USE_FIXED_STATIC_RAM_SIZE
        help
            RAM size dedicated for static variables (.data & .bss sections).
            This value is less than the chips total memory, as not all of it can be used for this purpose.
            E.g. parts are used by the software bootloader, and will only be available
            as heap memory after app startup.

endmenu # Memory