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Chdk for SX130 IS ?

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Re: Chdk for SX130 IS ?
« Reply #10 on: 08 / October / 2010, 17:31:59 »
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Thanks for the clarification.
Can't argue with the Guru!   :)

Very long way to go indeed.



Re: Chdk for SX130 IS ?
« Reply #11 on: 08 / October / 2010, 18:25:44 »
So I thought I would be clever and have a go at looking at the dump this evening. My first problem is IDA, i've tried both the free and the demo versions and neither can do what is required. It's quite possible i'm completely useless, if so please slap me :) If the versions I have available however aren't usable, then what are the alternatives? I've already seen the GPL tools, I just wondered if there was another freeware disassembler which people could recommend, or will we need to acquire IDA from a reputable source?

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Offline reyalp

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Re: Chdk for SX130 IS ?
« Reply #12 on: 08 / October / 2010, 22:33:32 »
So I thought I would be clever and have a go at looking at the dump this evening. My first problem is IDA, i've tried both the free and the demo versions and neither can do what is required.
Correct, but note that using the GPL tools, you can (reportedly) make an elf from the dump which you can feed to some demo version of IDA.

If you are persistent/skilled enough, you can also do everything you need to do with just the GPL tools (and possibly a helping of perl, python or whatever your favorite language is for writing quick and dirty tools ;))

You may also check out http://chdk.setepontos.com/index.php/topic,5100.0.html
Don't forget what the H stands for.

Re: Chdk for SX130 IS ?
« Reply #13 on: 09 / October / 2010, 03:57:13 »
A generous person has loaned me a license of IDA, i believe indefinitely :) So I shall be lazy and not attempt to stretch my programming/brain to places it shouldn't be. Thanks reyalp for the gpl info.


Re: Chdk for SX130 IS ?
« Reply #14 on: 09 / October / 2010, 03:58:03 »
Thanks for the GPL tools info reyalp, just to clarify.

Re: Chdk for SX130 IS ?
« Reply #15 on: 09 / October / 2010, 07:14:55 »
So i've been playing around with IDA. I've been reading http://chdk.wikia.com/wiki/Loading_dump_to_IDA and http://chdk.wikia.com/wiki/DryOS_Porting#Load_into_IDA_and_Disassemble_code. Neither of which is particularly clear on why we are using certain rom start addresses and rom sizes. I checked the Primary bin using HxD and it appears that the length of the file is 000000 to 7EFFF0, in which case why are we recommended to start at FF810000 for DryOS cameras and as for the file size itself, the Dryos page references everything back to the older camera situation, does this mean this should remain the same for newer cameras, or should the file size reflect the differing start position? I hope by this point I haven't confused anyone as much as I am confused.
I've resorted to running IDA from 000000 to FFFFFF in the hope that this will capture all the required information at the cost of taking longer to scan, is this a suitable strategy?

Re: Chdk for SX130 IS ?
« Reply #16 on: 09 / October / 2010, 09:39:55 »
Checked results from three different attempts, and it appears that starting at FF810000 seems to give the best results in terms of program analysis. I guess it's now down to working out what it all means, thinking of using S95 and SX120 dumps as a start point. S95 because it's a similar revision and sx120 in terms of similar features. I still have no idea what i'm upto, which is probably obvious to everyone already :s

Re: Chdk for SX130 IS ?
« Reply #17 on: 09 / October / 2010, 09:53:18 »
Hi Ali,

Try and track the camera's LED addresses (see the SX120IS wikia page).
Also use this as your guide and see why the LED addresses are useful:

http://chdk.wikia.com/wiki/Adding_support_of_a_new_camera

Once you find them, post them on the SX130IS wikia page.

Happy hunting!


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Offline reyalp

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Re: Chdk for SX130 IS ?
« Reply #18 on: 09 / October / 2010, 16:17:03 »
So i've been playing around with IDA. I've been reading http://chdk.wikia.com/wiki/Loading_dump_to_IDA and http://chdk.wikia.com/wiki/DryOS_Porting#Load_into_IDA_and_Disassemble_code. Neither of which is particularly clear on why we are using certain rom start addresses and rom sizes.
Since this dump was made with the cbasic dumper, the start address is known. If it is a ~8mb dump, then the correct start address is FF810000. If it is ~4mb, then it's FFC00000.

Canon has always used these two addresses for their ROM, and if they used a different one, the cbasic dumper would not work unmodified.
Don't forget what the H stands for.

Re: Chdk for SX130 IS ?
« Reply #19 on: 09 / October / 2010, 19:00:18 »
Thanks again for your help reyalp, it's an 8MB dump.

 

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