Lpc2000

Dear Dominic,

How do you know that the supplied boot loader is free of bugs?  Have
you inspected the source and/or tested the binaries?

IMHO you cannot say it is free of bugs even in a practical sense.  I
would like to see Philips tell us to what level it will certify boot
loader code.

Regards,

Jaya

--- In lpc2000@yahoogroups.com, Dominic Rath <Dominic.Rath@g...> 
> That said, I believe possible attacks on their CRP are very limited.
Given the 
> bootloader code is free of bugs there is no way of having the
bootloader 
> and/or sector 0 changed without destroying all the other flash
content, too.
> 
> The JTAG comes up enabled, when the chip leaves reset, but it is
disabled 
> within a few microseconds. I've fed continous TCK cycles into the
device (TMS 
> high), and about 250us after the external reset was deasserted, the
pulses 
> are returned on RTCK. Another 2 us later, RTCK turns quiet again,
until about 
> 30us have passed. This was on a device with CRP disabled, and fits
to what is 
> written in the user manual and the first few instructions of the
bootloader 
> code.
> 
> Regards,
> 
> Dominic