> Hi guys! I would like to ask you some question because i never used linux
> with embedded system.

Welcome to the crazy world of embedded development. :)

> Can i use TI DVSDK for programming Overo module?? Or mandatory OpenEmbedded?

The Overo module contains several components. It seems that
the DSP and the ARM processor are most important to you at the
moment, so I'll start with just those.

Compiling and installing programs on the main processor is
easiest (to me) using three approaches: cross-compilation using
OpenEmbedded, native-compilation after installation, and using
opkg (the package manager) after installation.

Writing and compiling code to run on the DSP is done using TI's
DVSDK, which can be integrated into the OpenEmbedded build
system. Others know more about this and have explained it on
this mailing list before, so I will refer you to Google on that one.
Good luck.

>  Can i program overo with only JTAG connector? Or i need USB too?

Getting your compiled code onto the Gumstix is done by either
flashing an SD card (well documented on the Gumstix site) or by
using the serial line to manipulate the built-in flash memory (if
available). IIRC, JTAG is not exposed on the CoM, so it isn't
possible. (If you have managed to get access to JTAG on the CoM
otherwise I'd absolutely LOVE to hear about it off-list.)

> And if i want use camera port for connect a video decoder,
> i need to changes camera driver?

I understood this as "if I want to read encoded video in on the
camera port so that I can decode it, do I need to change the
camera driver?"

Maybe. It depends on what you're connecting to the camera port.
The current kernel driver is exceptionally good at reading raw
data off the port at specific rates and in specific formats; if one of
those will work, then no. Otherwise, yes.

Best of luck,
Jon Kunkee