esp-idf/components/spi_flash/CMakeLists.txt

if(BOOTLOADER_BUILD)
    if (CONFIG_IDF_TARGET_ESP32)
        # ESP32 Bootloader needs SPIUnlock from this file, but doesn't
        # need other parts of this component
        set(COMPONENT_SRCS "spi_flash_rom_patch.c")
        set(COMPONENT_PRIV_REQUIRES bootloader_support soc)
    endif()
else()  # not BOOTLOADER_BUILD
    set(COMPONENT_SRCS "cache_utils.c"
                   "flash_mmap.c"
                   "flash_ops.c"
                   "partition.c"
                   "spi_flash_rom_patch.c"
                   "${IDF_TARGET}/flash_ops_${IDF_TARGET}.c")
    set(COMPONENT_REQUIRES app_update)
    set(COMPONENT_PRIV_REQUIRES bootloader_support soc)
endif()

set(COMPONENT_ADD_INCLUDEDIRS include)
set(COMPONENT_PRIV_INCLUDEDIRS ".")
set(COMPONENT_ADD_LDFRAGMENTS linker.lf)

register_component()