Lpc2000

I havn't done it on the LPC2100 chips. But I did what you said in 2) 
in my designs with MSP430. I wrote a bootloader routine which was 
loaded at factory. The real application is re-encoded and re-formated
in a mine-only special way to prevent tampering. Then, I wrote a 
piece of Window program which I put on our website. The customer 
would download the window program to upload the new firmware I email 
to him, if firmware upgrade is warranted. It works great. 
I figure it should work on this ARM chip, as long as the linker 
allows you to assign where each memory section will be allocated.
 
Lei

--- In lpc2000@yahoogroups.com, "penaso_maria" <penaso_maria@y...> 
wrote:
> 
> After reading many posts in the forum, I would like to ask you a 
> couple of questions that would help me and I think others too.
> 
> My goal:
> *Upgrade the LPC2124 firmware after selling the device. I think 
this 
> is called in field.
> *Have any kind of security with respect to the file I will send to 
> my clients in order to protect my code (encryption?).
> 
> The possibilities I imagine are:
> 
> 1) I use the Philips LPC2000 Flash utility, or the lpc21isp 
program 
> to load the new firmware.
> Questions:
> 1-a) Isn't it unsafe from the code protection point of view? I 
think 
> the file I send to the client can be converted back to code and 
> someone else could use it for his/her benefit.
> 
> 
> 2) I could divide my code in two parts, one that would never be 
> cleared, and the other with the part to upgrade in the future. The 
> first part could have an algorithm to open and understand the 
> encrypted firmware upgrade file. 
> The procedure could be: The upgradeable part could include a code 
to 
> let the user ask for a firmware upgrade. Upon this event, this 
code 
> transfers the control of the processor to the fixed part, which 
> starts the firmware upgrade process. Once finished, the fixed part 
> jumps to the start of the new firmware memory block, and the "NEW" 
> equipment would be ready to work.
> Questions:
> 2-a) Is it possible to generate a code that stores part of the 
> program starting on a specific memory address? How is that done? I 
> though in writing the new code starting in a fixed address, but I 
> need all the new code continuous in memory to write it properly 
and 
> in empty locations.
> 2-b) Can I clear part of the flash memory by Bytes, blocks, etc?
> How do you perform it?
> 2-b) How could the former procedure be done? I think the user 
could 
> start the firmware upgrade process, and the LPC2124 could read the 
> new code from a flash card or serially. What would be easier and 
> safer?
> 2-c) Can I disable the debugging interface to avoid someone 
reading 
> my first part of code? I understood that when the JTAG is disabled 
> no one can reads the memory with "normal" approaches.
> 
> 
> 
> 3) I code my own boot-loader with unencryption capabilities.
> Questions:
> 3-a) Any idea on this topic? I have no idea about it, but I read 
it 
> is a good solution. 
> Is there any sample program, AN, paper, etc, to help me here?
> 
> I wait anxiously for replies.
> 
> Maria