bootloader and configuration data changes

RobS · Joined: 29 Jan 2005 Posts: 10

I’m using a PIC 18LF8720. CCS Ver 3.236.

I’ve implemented a bootloader that imports a new hex file and replaces the contents of program memory except for the loader section. It has two steps. The 1st receives a file over the serial port from the host and places it in upper program memory then sets a flag in flash EE if successful. The 2nd step checks the flag and if set copies the section in upper memory to lower memory, except for the loader part. Commands from the host initiate both steps.

While the above is great I just determined the configuration data starting at address 0x300000, set by the fuses, is not part of the file that gets imported in.

I’m looking for recommendations on how to deal with changes in the configuration data.
Thanks

ktallevi · Joined: 17 Dec 2005 Posts: 58

The configuration data should be at the bottom of the hex file.

:020000040030CA // this line changes the high bytes of the data address

:0E00000000421F0EF1878000FF80FFE0FF40EE // this is your data packet

:00000001FF // end of file

iso9001 · Joined: 02 Dec 2003 Posts: 262

You can change config data from inside a bootloader ? I didn't know that.

I thought it had to be done at program time. Or is that just certain fuses ?

It would be kinda dumb if you could change code protect from on to off.... But then again, if you have the bootloader you have most of the code anyway.

I'm suprised more people are not interested in encrypted bootloaders.

ckielstra · Joined: 18 Mar 2004 Posts: 3680 Location: The Netherlands