PROVIDE(ets_delay_us = 0x40000600);
PROVIDE(ets_update_cpu_frequency_rom = 0x40043164);
PROVIDE(rom_i2c_writeReg = 0x40005d60);
PROVIDE(rom_i2c_writeReg_Mask = 0x40005d6c);
PROVIDE(rtc_get_reset_reason = 0x4000057c);