esp-idf/components/driver/ledc/linker.lf

[mapping:ledc_driver]
archive: libdriver.a
entries:
    if LEDC_CTRL_FUNC_IN_IRAM = y:
        ledc: ledc_stop (noflash)
        ledc: ledc_update_duty (noflash)
        ledc: _ledc_update_duty (noflash)

[mapping:ledc_hal]
archive: libhal.a
entries:
    ledc_hal_iram (noflash)