Skip to content

OTA safety and recovery

Before any transfer

  • charge the watch to at least 40%; 60% or more is preferable;
  • keep the phone charged and disable aggressive battery saving for Mi Fitness;
  • confirm the exact watch model, installed firmware, OTA model identifier, base version, target version, file size, MD5/SHA-256, and all outer CRCs;
  • keep an independently verified stock package and recovery notes;
  • test parsers and repackers without the watch first;
  • change one behavior per experimental package.

Validation levels

These are separate milestones:

  1. package parses;
  2. CRCs match;
  3. Mi Fitness accepts the file;
  4. Bluetooth transfer reaches 100%;
  5. the watch validates and installs it;
  6. the watch reboots and reconnects;
  7. the changed behavior works;
  8. unrelated critical behavior still works.

Never report level 3 or 4 as a successful firmware installation.

Do not repeatedly send more experimental packages. Keep it charged, allow a full boot interval, try the documented hardware restart, and preserve phone/watch pairing state and logs. Recovery options depend on which boot stage still runs; there is currently no universal software unbrick procedure in this project.

Avoid high-risk first tests

Do not begin with:

  • bootloader logic;
  • boot artwork or early boot resources;
  • memory layout or object-size changes;
  • power management and charging code;
  • updates containing many unrelated modifications.

Prefer a non-critical native constant or secondary visual asset with a known stock rollback path.