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ESPEFUSE(1) User Commands ESPEFUSE(1)


espefuse - ESP32 efuse get/set tool


usage: espefuse [OPTION] COMMAND

command arguments:

Run espefuse {command} -h for additional help
Dump raw hex values of all efuses
Print human-readable summary of efuse values
Burn the efuse with the specified name
Disable readback for the efuse with the specified name
Disable writing to the efuse with the specified name
Burn a 256-bit AES key to EFUSE BLK1,BLK2 or BLK3 (flash_encryption, secure_boot).
Permanently set the internal flash voltage regulator to either 1.8V, 3.3V or OFF. This means GPIO12 can be high or low at reset without changing the flash voltage.

optional arguments:

-h, --help
show this help message and exit
--port PORT, -p PORT
Serial port device
--before {default_reset,no_reset,esp32r1}
What to do before connecting to the chip
Do not pause for confirmation before permanently writing efuses. Use with caution.


Flash Espressif AT v1.4 firmware to an ESP-12S board:
esptool write_flash --flash_mode dio --flash_size 4MB-c1 0x00 boot_v1.7.bin 0x1000 at/1024+1024/ 0xfe000 blank.bin 0x3fc000 esp_init_data_default.bin 0x3fe000 blank.bin

Display ESP32 efuse state summary:

espefuse --port /dev/ttyUSB0 summary

Generate a flash encryption key:

espsecure generate_flash_encryption_key key.bin

Burn the key to the device (WARNING: one time only operation):

espefuse --port /dev/ttyUSB1 burn_key flash_encryption key.bin

Encrypt flash data:

espsecure encrypt_flash_data --keyfile key.bin --address 0x10000 -o my-app-encrypted.bin my-app.bin

AUTHOR was started by Fredrik Ahlberg as an unofficial community project, currently maintained by Angus Gratton and supported by Espressif Systems (Shanghai) PTE LTD. This manual page was generated by Milan Kupcevic <> for the Debian project and can be used by others.


Review: <>
Known issues: <>
Report new issues at: <>


Copyright © 2014-2016 Fredrik Ahlberg, Angus Gratton, Espressif Systems (Shanghai) PTE LTD, other contributors as noted. License GPLv2+: GNU GPL version 2 or later <>. This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law.


esptool(1), espefuse(1), espsecure(1)
April 2018 2.1