my work about KBOOT
werner at openmoko.org
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
- 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.
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