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General Firmware Analysis

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Offline kwf

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General Firmware Analysis
« on: 25 / January / 2008, 15:21:36 »
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Is there any effort on the way to write a documentation about general firmware analysis, e.g. interesting, useful information found in the disassembled code? There seems to be a lot of information in the code.
The chdk-wiki is quite short on this, basically just a memory map, at least what i saw. Discussion about interesting parts of the firmware are not really there. Most discussion i find about the interesting parts of the firmware are only done in some Russian language forums (a bit problematic to read them with machine translated).

E.g. Interesting stuff in firmware in my eyes are, camera may read/write files named:
A/uart.req
A/extend.m
A/GradeTable.BIN
A/BuldTrns.log
A/BootFaexe.bin
A/Factory.m
A/AdjTable.bin
A/boot.req
A/script.req
A/autotest.m
A/ROMLOG.txt
A/RomLogErr.txt

Of course it is not so easy to read the disassembled code, so its hard to interpret when these files are accessed and what they are doing. There seems to be some kind of scripting capability as well, as there are functions LoadScript, some possible script commands (while, until, to, then, sub, private, public, if, then, else, do, dim ...).

Maybe its possible to utilize more possibilities, reach some hidden menus, who knows :) There also seems to be a console (although one might expect that it is a serial console only talking on some serial debug pins, which might only be available on development cameras...).

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Offline ewavr

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Re: General Firmware Analysis
« Reply #1 on: 25 / January / 2008, 15:32:49 »
*.m files are scripts. I wrote about it here

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Offline kwf

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Re: General Firmware Analysis
« Reply #2 on: 25 / January / 2008, 16:51:57 »
*.m files are scripts. I wrote about it here

cool, thanks.
Sound very interesting. Maybe some kind of main() is really the only thing thats missing :)
Btw. according to the error message, it seems that the script engine uses FLEX and YACC..
Maybe knowing how to work with these tools/libs helps to understand the scrpt syntax and more important to find the entry point of the script.
« Last Edit: 25 / January / 2008, 17:28:08 by kwf »

Re: General Firmware Analysis
« Reply #3 on: 20 / April / 2010, 23:34:53 »
has anyone ever gotten a extend.m file to execute on the newer cameras?
Canon Models - SD300, SD780, & SX210


 

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