IXUS 255 IS/ELPH 330 IS porting thread

Hi!
I've got the IXUS 255 camera on hands. Since it looks like there was no big efforts on its porting yet, would like to initiate this process.

I've dumped the camera FW using cbasic, it resides here: http://www.sendspace.com/file/lm5ztq.

FW version is 100f (ACID 1.14).
The respective string resource in FW states that it is "DRYOS version 2.3, release #0052".


If I understood site materials correctly, the main action chain would look like:
1) Find the most compatible CHDK port
2) Find using finsig/cb scripts/disassembly all basic memory addresses required to just start CHDK
3) Check and adopt one by one all the functions required by CHDK

I plan to move deeper in July, since currently have lot of other things to do. So, any help or guidance is welcome.

If I understood site materials correctly, the main action chain would look like:
1) Find the most compatible CHDK port
2) Find using finsig/cb scripts/disassembly all basic memory addresses required to just start CHDK
3) Check and adopt one by one all the functions required by CHDK

That's pretty much it. http://chdk.wikia.com/wiki/For_Developers has resources useful to developers. http://chdk.wikia.com/wiki/Adding_support_for_a_new_camera is a good place to start.

Porting threads for other recent cameras can also be helpful.

For #1 the most relevant is probably dryos version / release date rather than being in the same model line. However, AFAIK the only other DryOS R52 cams we have seen are the SX270 and SX280 which are Digic 6 and use a new CPU architecture.  So unless someone ports another R52 cam before you get started, R51 is probably your next bet. This table http://chdk.wikia.com/wiki/P-ID_%28Table%29 is a good reference for what cams use what OS, feel free to add yours.

The first couple hundred words in the dump look "normal" so presumably this isn't a thumb version like the SX280 even though its R52.   (The processor is DIGIC5 from what I could google).

(BTW - that download site just raised the bar of what it takes to be a really annoying download site.  So many things to click on and only one gets you the file - the rest pretend to share the file but download swillware instead.  I'll stick to box.com.)

@snort - thx for the dump!

Added the

• IXUS 255 / ELPH 330HS 1.00F

full 16MB dump (dumped with cBasic udumper) by snort from this forum post to the CHDK P&S FW dumps repository.

Hi!
I've got the IXUS 255 camera on hands. Since it looks like there was no big efforts on its porting yet, would like to initiate this process.

I've dumped the camera FW using cbasic, it resides here: http://www.sendspace.com/file/lm5ztq.

FW version is 100f (ACID 1.14).
The respective string resource in FW states that it is "DRYOS version 2.3, release #0052".


If I understood site materials correctly, the main action chain would look like:
1) Find the most compatible CHDK port
2) Find using finsig/cb scripts/disassembly all basic memory addresses required to just start CHDK
3) Check and adopt one by one all the functions required by CHDK

I plan to move deeper in July, since currently have lot of other things to do. So, any help or guidance is welcome.

snort, You can put the full instructions on how to make a copy of the firmware? I want to download the firmware from your camera. I recently used the same, but there were new items on the menu, although the EXIF shows the same firmware version: 1.00

Hi. I have a 255 HS running 100f (ACID 1.14) and have dumped the firmware but the file is not the same as the one posted by snort - they have differing MD5 hashes.

From what I can see the firmware starts at 0xFF000000 and is still DryOS 2.3 release 52.

Here's the file if anyone wants a look: http://www.sendspace.com/file/q1uojb

Hi. I have a 255 HS running 100f (ACID 1.14) and have dumped the firmware but the file is not the same as the one posted by snort - they have differing MD5 hashes.

It's quite normal for firmware dumps from the same model camera & firmware version not to match.  Canon stores camera settings and other information in the top part of the camera's memory.

Ah; that explains that then! I had suspected I was not correctly capturing it or something. I will continue poking around. Thanks

Just picked up the 330HS, and I seem to be running 100h (ACID 1.14).  I followed the instructions using the Universal Dumper method http://chdk.wikia.com/wiki/Canon_Basic/Scripts/Dumper

I've uploaded it here: http://www.sendspace.com/file/ft44sl

Hopefully I did this correctly, I'd appreciate if someone could look at it and let me know if I messed up or not - thanks!

update: I scanned the file and noticed it showed DRYOS version 2.3, release #0052, same as the 100f firmware that was uploaded

Hopefully I did this correctly, I'd appreciate if someone could look at it and let me know if I messed up or not - thanks!

Looks correct to me.