09. Backups and flashing safely

9. Backups And Flashing Safely

Always make a full dump before flashing.

The full flash size is:

131072 bytes

The tools expect normal firmware .bin files to be exactly this size.

Recommended Order

1. Choose the correct connection mode.
2. Run a full 128 KB dump.
3. Save a copy of the backup somewhere safe.
4. Load the .bin file with option 4.
5. Flash with option 3.
6. Wait for verify to complete.

SHU Compatible Option

Option 1:

Flash SHU compatible (ZT3, G3, F3/F3Pro)

This dumps the current VCU firmware, patches it, and flashes it back for SHU-compatible workflows such as flashing from repo or changing serial.

This is intentionally not explained as a magic fix. Use it only if you understand why you need it.

File Validation

The validator rejects unsafe or suspicious files. In normal flashing it requires:

• a real file path;
• .bin extension;
• exactly 131072 bytes;
• content that is not just one repeated byte.

Windows also guards against path cases that are unsafe for the current OpenOCD command flow.