my work about KBOOT

Werner Almesberger werner at
Fri Jun 6 03:44:23 CEST 2008

Joerg Reisenweber wrote:
> Probably you could create a paper outlining some of the 
> benefits of such an approach,

That could be a useful idea. I think we still have a lot of people
who didn't really understand what this was all about.

Two "novel" ideas to consider:

- I think Raster made a good point when suggesting to use a
  microcontroller that does not require a development environment
  too different from the one we're already using.

  I did a bit of research, and there is a fairly large number of
  mid-range uCs with an ARM7 or Cortex core that are quite resonably
  priced for their class.

  Their power consumption tends to be considerably higher than that
  of the ultra low-power uCs, but wouldn't really stick out when we
  consider overall power consumption in the various states of our
  entire system.

- Manu uCs nowadays come with a built-in USB interface. Some of them
  can even be bootstrapped over USB (*). Add a bit of firmware, and
  you could provide the functionality of an FT2232, at the minuscule
  additional hardware cost of the USB hardware interface ... ;-)

(*) But that may constrain the choice of chips a bit too much. Others
    can boot from a serial EEPROM, so that may give more flexibility.

    I have yet to find one that allows proper protection of the
    internal Flash in a way that would let one implement a bit of
    unbrickable initialization code without help from other storage.

- Werner

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