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Integrated Menus

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Integrated Menus
« on: 17 / September / 2009, 15:25:24 »
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I'm trying to find out why the current <alt> menu system is used vs adding to the Canon menu.

* Was there a legal reason.  IE it is thought that Canon would object?
* Was it simply a technical reason.  IE we don't know how to do it?
* Other?

I've done a bit of searching and it seems that its a technical reason but if someone with a lot more experience with CHDK can provide some insight into the history that would be great.

Thanks,
HarpoMa
Canon Models - SD300, SD780, & SX210

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Offline RaduP

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Re: Integrated Menus
« Reply #1 on: 17 / September / 2009, 15:53:08 »
Technical reason, CHDK can't (for now) hook into the menu functions I think.

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Online reyalp

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Re: Integrated Menus
« Reply #2 on: 17 / September / 2009, 17:06:41 »
* Was it simply a technical reason.  IE we don't know how to do it?
Technical and historical. Integrating into the canon menu system would be no more or less legal than anything else CHDK does.

Much of the canon UI appears to be in structures in ROM which include function pointers. While I haven't looked into this in detail, it might be quite difficult to override this without moving too much stuff to RAM (unlike RaduP, I do not believe that you can move the entire firmware to RAM and still have it function).

The alt system is also quite simple, all you need is to hook they keyboard task and write to the bitmap buffer, so you can get it working with fairly minimal reverse engineering. This is the historical reason.
Don't forget what the H stands for.

 

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