Currently I am in the processes of extending the ELF boot loader
so that if you have an appropriate ELF note is in the ELF image
we can verify the checksum of the Image.  I have seen enough corrupt
network downloads (when the ram is at fault) that I don't want to see
anymore.

My first implementation will use a 2 byte 1's complement checksum.
Which has many very nice properties the nicest is that you can add or
subtract portions of the image and simply modify the checksum (not
recompute it), allow the checksum to be end-to-end even in the
presence of modification.

Modification is important for the case of editing the command line
or adding a ramdisk to an already compiled kernel.

Currently I checksum over a stream of bytes consisting of:  
The ELF header + the ELF program header + the PT_LOAD segments in the
order the are listed in the program header.  I was vague on how to do
this when I speced it all so I need to update my draft on this point.


Adam for the work on trusted booting I would like to include it as a
compile option.  Since this is very similiar to what you are doing
any feedback would be appreciated.


Eric

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