Author Topic: UVC Issues  (Read 9136 times)

firmi

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UVC Issues
« on: August 15, 2010, 06:26:45 pm »
Hi,

We are a startup company located in New York. We are currently investigating whether the GadgetPC SBC will be appropriate for one of our ventures.

We have downloaded the latest Ubuntu VM (May 31st 2010) and built the 2.6.30 kernel for the GadgetPC which works fine. Along the way we found out that all besides one of our UVC supported cameras had issues so we decided to re-build the kernel. The kernel of our choice was 2.6.27 (available in the Ubuntu VM) due to alleged issues with UVC cameras on 2.6.30. The kernel builds fine (support for PPP, sierra, UVC, V4L as kernel modules) but when we boot into it the device hangs on "Starting kernel......."

We have purchased 6 UVC cameras (looked on the UVC linux compliant list at Berlios) and only one of them works but the resolution of that camera is not what we want. All those cameras work properly on Ubuntu 9.04+ but not on our Debian ARMEL distro.

All we need to proceed with our investigation is to be able to take high resolution images from a webcam (1.3MP+). Any suggestions please?

The issue with most of the cameras on Debian ARMEL is "No valid video chain found".

vitaliy

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Re: UVC Issues
« Reply #1 on: August 16, 2010, 12:54:43 am »
Quote
but when we boot into it the device hangs on "Starting kernel......."
Did you select a proper platform configuring Linux kernel ?
Did you change to UART0 as Linux console ?

firmi

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Re: UVC Issues
« Reply #2 on: August 17, 2010, 05:26:43 pm »
You were right. It was building for the wrong device. So what I did was to use the 2.6.27 kernel that I found on the Ubuntu VM (remember we don\'t want to use the 2.6.30 kernel) and use the defconfig from the atm91.com and the kernel built and started properly but at some point it crashes saying:

"Kernel panic - not syncing: Attempted to kill init!"

If I go back and build the 2.6.30 kernel that is in the VM the GadgetPC boots up correctly so I am thinking the issue is in the defconfig.

How would one go about building the 2.6.27 kernel (assume the CC is working properly and all that)? Is there a step by step process? I tried the linux4sam.com website and they say to download the defconfig, rename it to .config, do make oldconfig (which puts all these questions on the screen that I hit NO to everything), then make menuconfig (I pick my options) and then make. The kernel builds but has the error I mentioned before (kernel panic)

I need to just build the kernel for my device. Why does it have to be so complicated and why does 2.6.30 builds with no issues?

vitaliy

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Re: UVC Issues
« Reply #3 on: August 18, 2010, 02:01:21 am »
« Last Edit: August 18, 2010, 02:01:42 am by vitaliy »

firmi

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Re: UVC Issues
« Reply #4 on: August 19, 2010, 11:55:27 am »
Thank you. Your config file worked and, as we expected, the UVC driver included in the 2.6.27 kernel does not have the "no valid video chain found" error.

I was curious, what would you advise we use to be able to develop config files for upcoming kernel versions? It seems that the size of the config (such as the config_27) would make it very difficult for us to look into this config and pick options for another config for a later kernel. Is there a better way to do this?

Thank you for all your help thus far. You have an excellent product and excellent support. We really appreciate it.

firmi

jjman23

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Re: UVC Issues
« Reply #5 on: August 20, 2010, 02:14:51 pm »
I\'m looking for a simple console app for the GadgetPC that will capture an image from a webcam (/dev/video0) and save it as a bitmap and/or jpeg.  I have tried to compile streamer from the xawtv package but it doesn\'t want to work.  Any suggestions or source code I can try?

Thanks

firmi

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Re: UVC Issues
« Reply #6 on: August 20, 2010, 03:43:13 pm »
Jesse: If you are using Debian apt-get install uvccapture

jjman23

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Re: UVC Issues
« Reply #7 on: August 21, 2010, 11:14:58 am »
Great I got uvccapture working on the GadgetPC.  It was a lesson in cross-compiling to get it working though.  I was stuck on the jpeg library for the longest time.  I ended up getting the source code for the library and compile it too with the toolchain and adding the output library to the toolchain.

Thanks for the advice.