Post by thread:embedding signature in code?

Den 2008-01-16 17:16:35 skrev Ray Newman <spam_OUTlistTakeThisOuTmicrodesigns.biz>: > Pic16c code. > Any idea on how to embed a signature in code? > Not easy to see in assembly code or disassembly. > > Thanks, > Ray Make a function that during circunstances that never happen in the actual product, but easily in your lab, triggers some very odd behavoiur. Keep for ypourself documentaiton on how to trig and detect the behavoiur. Then if someone steal your code, you can ask anyone to by YOUR documentaiton trig the behaviour and a lawyer can ask him why he have made the PIC do this thing to YOUR specification whiule it is just plain stupid to have in the product... -- Morgan Olsson

Quoting Morgan Olsson <.....ost011KILLspam@spam@osterlen.tv>: > Den 2008-01-16 17:16:35 skrev Ray Newman <listKILLspammicrodesigns.biz>: > >> Pic16c code. >> Any idea on how to embed a signature in code? >> Not easy to see in assembly code or disassembly. >> >> Thanks, >> Ray > > Make a function that during circunstances that never happen in the > actual product, but easily in your lab, triggers some very odd > behavoiur. > Keep for ypourself documentaiton on how to trig and detect the behavoiur. > > Then if someone steal your code, you can ask anyone to by YOUR > documentaiton trig the behaviour and a lawyer can ask him why he > have made the PIC do this thing to YOUR specification whiule it is > just plain stupid to have in the product... http://en.wikipedia.org/wiki/Easter_egg_%28media%29 Best regards, Spehro Pefhany -- "it's the network..." "The Journey is the reward" .....s...KILLspam.....interlog.com Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com

An idea maybe to do some special but not necessary calculations, this will look in disassembly like one or even more time-loops. regards Peter ----- Original Message ----- From: "Ray Newman" <EraseMElistspam_OUTTakeThisOuTmicrodesigns.biz> To: "Microcontroller discussion list - Public." <piclistspam_OUTmit.edu> Sent: Wednesday, January 16, 2008 5:16 PM Subject: embedding signature in code? > Pic16c code. > Any idea on how to embed a signature in code? > Not easy to see in assembly code or disassembly. > > Thanks, > Ray > > > > > --

Our programmers support a Program Readable ID (PRID) - this is an (up to) 4 byte signature which is inserted automatically as the programmer programs each chip. For a 16 device the programmer overwrites up to 4 retlw instructions in the hex file . The PRID can be set up as random, sequential, checksum, read from a user dialog box at program time, or finally can be read from the command line. I am certain we didn't invent the concept and I have a feeling that Microchip's programmers certainly used to support a similar feature. Of course for 18F devices you could program a signature into the User ID's which can then be read from the program. Robin Abbott Forest Electronics - Home of WIZ-C ANSI C Compiler for PIC's with RAD Front end @spam@robin.abbottKILLspamfored.co.uk http://www.fored.co.uk {Original Message removed}