1.12.4. Automatic Updates

Problem:

Distribute Software Updates to customers

Solution:

use cheap standard media like USB memory sticks

Implementation:

 

• Keep BOM (Versions, Timestamps etc.) in persistent memory (EEPROM etc.)
• When booting, check whether a USB memory stick is plugged in.
• If one is found:
  1. If prepare.img is found load it into memory.
     If it is valid then run it (always).
  2. If preinst.img is found load it into memory.
     If it is valid then run it. Update the EEPROM.
  3. If firmware.img is found load it into memory.
     If it is valid, burn it into FLASH and update the EEPROM.
  4. If kernel.img is found load it into memory.
     If it is valid, burn it into FLASH and update the EEPROM.
  5. If app.img is found load it into memory.
     If it is valid, burn it into FLASH and update the EEPROM.
  6. If disk.img is found load it into memory.
     If it is valid, burn it into FLASH and update the EEPROM.
  7. If postinst.img is found load it into memory.
     If it is valid then run it. Update the EEPROM.