Isaac Marino Bavaresco wrote:
> My boot-loader signals an error and refuses the application if it
> receives data outside the proper area.
> What happens when the program try to call a routine or use data that
> was discarded?

That is no different than any other bug that needs to be tracked down and
fixed.  However, with the right linker file this is pretty much impossible.

Also, the bootloader is only part of the logic for getting new app code from
a HEX file on a disk somewhere into the PIC.  It doesn't have to, even
shouldn't, try to solve the whole problem.  I have my host download program
perform some additional checks.

There is also the issue of knowing that the app got loaded correctly.  The
bootloader most not run a corrupted app.  I do this by putting a 32 bit
checksum at the end of the app code.  The bootloader checksums the app,
compares against the checksum uploaded with the app, and only runs the app
if it checks correctly.  There are more details, but they aren't relevant to
this discussion.


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