EOS 550D / T2i / Kiss X4 - page 2 - DSLR Hack development - CHDK Forum

EOS 550D / T2i / Kiss X4

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holamanola

Re: EOS 550D / T2i / Kiss X4
« Reply #10 on: 16 / April / 2010, 22:40:37 »
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JeremyOne, you should definitely check the magiclantern forum and site. Trammel Hudson (The guy behind the project) has already made some advances in the 7D firmware, which probably has a lot in common with the 550D.

In case you don't know the project, here it is: http://magiclantern.wikia.com/

Re: EOS 550D / T2i / Kiss X4
« Reply #11 on: 19 / April / 2010, 18:43:15 »
I'm pretty sure this -service- firmware is NOT xor encoded.

update:
JemeryOne, thanks for testing it

Lorenzo
« Last Edit: 07 / May / 2010, 13:52:51 by lorenzo353 »

Re: EOS 550D / T2i / Kiss X4
« Reply #12 on: 19 / April / 2010, 19:37:32 »
To get the update to show, you must put the FIR file in the root of your SD card, then navigate in the 550d menu to where the firmware version is shown. Press select on the firmware version number and the next screen should show the available fir files on your SD card.

I've attached a photo of the firmware selector menu.

I've also been doing some other searching on the encoding / encrypting method used on the 550d, and several other people have also concluded that it is not xor encoded.

The next thing I'll be trying are the Magic Lantern tools to see if I can update a version of their fake firmware to load on the 550d.

This is the first time I've attempted anything like this, so it may be slow going.
« Last Edit: 19 / April / 2010, 19:44:53 by JeremyOne »

Re: EOS 550D / T2i / Kiss X4
« Reply #13 on: 19 / April / 2010, 22:10:14 »
Jeremy One,

one clue: compare content at offset 0xb0 and content at the payload offset for this firmware.
then content in any other firmware at 0xB0... your conclusion ?

Lorenzo

Re: EOS 550D / T2i / Kiss X4
« Reply #14 on: 20 / April / 2010, 07:35:22 »
at payload+0xc sorry

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chuchin

Re: EOS 550D / T2i / Kiss X4
« Reply #15 on: 20 / April / 2010, 12:42:16 »
You can try this to get the dump out if your camera http://www.zshare.net/download/56526976b795c07f/

Re: EOS 550D / T2i / Kiss X4
« Reply #16 on: 20 / April / 2010, 14:52:57 »
0xC0 - 0x110 bytes are null on the US 5DII 2.0.4 and 7D 1.2.1 fir files

However the 5DII 1.1.1 file I have does not have that blank area, nor does the 550D 1.0.6 file.

I am not sure of the source of the 5DII 1.1.1 file, it's possible that it's not English. I will try and find a few more non-english firmwares to take a look at.

Magic Lantern also has this analysis of the FIR format for the 5D: http://magiclantern.wikia.com/wiki/Firmware_file

chuchin: Thank you for the link, I will check it out

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chuchin

Re: EOS 550D / T2i / Kiss X4
« Reply #17 on: 20 / April / 2010, 16:01:08 »
I found the file here http://forum.ixbt.com/topic.cgi?id=20:22191 you have to modify the bat file to make it work with the 550d.

Re: EOS 550D / T2i / Kiss X4
« Reply #18 on: 20 / April / 2010, 18:47:59 »
Why do you think this fw not xored?

Re: EOS 550D / T2i / Kiss X4
« Reply #19 on: 20 / April / 2010, 20:23:08 »
chuchin: That dumper tool modifies a specific 5D or 50D firmware file to make it into a dumper. Since no other cameras firmware would work on the 550D those are no good.

What I'm trying to do is analyze the 550D firmware and figure out how to make it into a dumper.

My current line of investigation is trying to compile a modified version of the 7D dumper that the people at Magic Lantern have made. Getting the development cross compiling environment working is taking longer then I expected.

Pelican: After splitting the firmware with decryption tool for the 5D there was no clear text in the resulting files when there should have been. I think it's likely that the 550D uses the same encoding format as the 7D since they are pretty close in release age.

As I learn about how to compile a custom version of the 7D firmware dumper I will no doubt learn more about the format to know if that is true or not.

 

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