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rtmistler 03-04-2011 11:06 AM

Trying to run X without udev
In support of a fast boot (Intel ATOM Z530 CPU, 2.6.31) we removed udev.

In the meantime we had to get the X server running to support graphics, as a result of that, udev was added back in.

Later we realized that udev was or some reason managing, and thus removing serial USB peripherals; however those peripherals are needed to be there all the time. These are standard FT232 serial USB devices, they do work, and I have no idea why udev detects them and then removes them as part of the boot sequence.

End results are:
- Udev not running, we can see and talk to all serial USB devices, and likely to the USB WIFI adapter (we merely haven't done much with that as yet) BUT we can't load Xserver.

- Udev running, we can load Xserver, but it causes the USB serial devices to be detected and then removed.

We'd like to figure out how to get Xserver running without udev running. The system boots faster and we do not have to worry about weird device behaviors.

Xserver is version 1.5.3.

andrewthomas 03-04-2011 12:58 PM

If Xserver is version 1.5.3, then you should be able to use hal instead of udev.

rtmistler 03-04-2011 03:08 PM

Thanks for the reply.

hald is running and (not knowing too much about it) my guess is that when I don't run udev at all, hald is providing information for the Xserver.

The problem there is the following:
With udev, the Xorg log file shows:
LoadingModule: extmod, dbe, glx, freetype, dri, iegd, lvds, sdvo, fb, and ramdac

When udev is not running, it goes as far as iegd and then does not run the remaining modules.

This does have two displays, the Intel ATOM chip has a controller (Intel US15W) that has both LVDS and SDVO outputs and we have an xorg.conf that provides the proper settings for these displays.

What I don't know is the information that udev provides to allow the Xserver to load those final 4 modules and get fully operational. Since they are .so files, I can't load them as modules, I instead have a chance at finding the right modules to run at startup, or need to find the correct options to indicate to Xserver that these need to be included.

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