Firefox OS/Performance/Boot Sequence Optimization

Initial Ideas

• Minimize data loaded by boot loader.
  • Compacting vmlinuz/zImage by moving compiled-in drivers to modules.
  • Minimize initial ramdisk if there is one.
  • Minimize kernel cruft by excluding all unneeded drivers.
  • Strip the kernel and all modules.
• Minimize init launch sequence.
  • Make init only launch the bare minimum for b2g process to launch.
  • Ideally, init will only launch b2g.
• B2G start-up sequence.
  • Remove all synchronous external dependencies from B2G start-up sequence.
    • Kernel modules must be lazy loaded as needed.
    • Any sync waits on daemons must become async. Start-up b2g pieces as daemons finish launching.
    • Minimize start-up initializations.
      • Global statics need to be minimized as their constructors are run before main().
      • Global singletons must be initialized as needed.
• Homescreen start-up.
  • Minimize _init() code to bare minimum.
  • Maybe freeze the homescreen app into a memory image that can be loaded and unfrozen instead of launching the app every time.
  • Eliminate dependency on enumerating installed apps on launch.
    • Cache the list in local storage?
    • Cache the list in the frozen memory image?
    • Speed up mgmt.getAll()

References

Firefox OS Bootup Procedure