10. Design Decisions

10.1. Bundle Mode

  • squashfs
    • mountable
    • avoids copies
    • signature location
    • easy to use for USB memory sticks or upload via a web interface

10.2. Network Mode

  • manifest should define complete consistent system
  • manifest is signed with a detached CMS signature
  • manifest contains size and cryptographic hash of each file
  • RAUC detects files which have not changed and skips the download
  • server can control update process

10.3. Custom Handlers

  • a handler can override default RAUC behaviour to handle special cases (which were not anticipated during the initial project development)
    • sanity checks
    • modifications to the partition layout
    • bootloader updates