Lpc2000

Richard,

Perhaps if I give you a hint of what is in the T command does, I hope
you will change your mind as to what this CRP and security discussion
is really about.

If we are to trust the boot loader, and that all we need to know about
it has been disclosed by Philips, then what is this 'T' command that
is exists in boot loader 1.52 for LPC 21/4/5/6?

The T command accepts arguments like the other commands. It prints
things and for the casual user, exits and does notthing more.

However, if you twiddled GPIO pins 0-7 when the T command is invoked,
something a different piece of code is called.  This only happens if
GPIO pins are non-zero when the T command is invoked.

Would you not be interested to know what this undocumented 'T' command
in the boot loader version 1.52 for LPC2104/5/6 does, that has hidden
functions?

Does it also exist on the boot loader for parts which support CRP?  Is
the T command disabled when CRP is enabled?  If not, can it be used to
read memory that is otherwise protected?

I am not suggesting there is a conspiracy theory.  I do not see any
point in tring to double guess its functionality until Philips comes
back to work and tells us about this.

However, the existence of the T command (irrespective of whatever it
does) it is enough reason point out that boot loader holds more than
what we think it holds.

Therefore, CRP enabled or not, it would not be a good idea to include
LPC in your trust domain if you do not want your code to be exposed to
preying eyes.

I am sure you would agree many in this forum would like to know what
this T command does, even if does not do anything harmful.

Jaya

--- In lpc2000@yahoogroups.com, "rtstofer" <rstofer@p...> wrote:
> Protecting information is not the same as concealing a defect.