Burn Custom Mac

The espefuse.py burn_custom_mac command burns a 48-bit Custom MAC Address.

Positional arguments:

  • MAC. Custom MAC Address (CUSTOM_MAC) to burn given in hexadecimal format with bytes separated by colons (e.g. AA:CD:EF:01:02:03)

Optional arguments:

  • --force-write-always. Write the eFuse key even if it looks like it is already been written, or is write protected. Note that this option can’t disable write protection, or clear any bit which has already been set.

If CUSTOM_MAC is placed in an eFuse block with a coding scheme and already has data then it is not possible to write new data without breaking the encoding. The correct way is to contact Espressif to order chips with CUSTOM_MAC pre-burned from the factory. Another way is, it is not recommended, to use the --force-write-always flag to ignore the encoding violation.

This command burns a given MAC to CUSTOM_MAC field.

> espefuse.py burn_custom_mac 48:63:92:15:72:16

=== Run "burn_custom_mac" command ===
    - 'CUSTOM_MAC' (Custom MAC Address) 0x000000000000 -> 0x167215926348

Check all blocks for burn...
idx, BLOCK_NAME,          Conclusion
[03] BLOCK_USR_DATA       is empty, will burn the new value
This is an irreversible operation!
Type 'BURN' (all capitals) to continue.
BURN BLOCK3  - OK (write block == read block)
Reading updated efuses...
Custom MAC Address: 48:63:92:15:72:16 (OK)

> espefuse.py summary
CUSTOM_MAC (BLOCK3)                                Custom MAC Address
= 48:63:92:15:72:16 (OK) R/W