Why autoconf.h is not copied automatically to its place?

Question

I'm working on a clean Debian 7.7 install. After the install everything was working fine except the webcam in Iceweasel browser. After reading a lot I found that the best solution is to install FlashCam 1.4.5.

After downloading the sources, I did a make and got an error:

  ERROR: Kernel configuration is invalid.
         include/generated/autoconf.h or include/config/auto.conf are missing.
         Run 'make oldconfig && make prepare' on kernel src to fix it.


  WARNING: Symbol version dump /usr/src/linux-headers-3.2.0-4-common/Module.symvers
           is missing; modules will have no dependencies and modversions.

  Building modules, stage 2.

Read something and found that I must install the kernel sources and prepare to compile:

apt-get install linux-source linux-source-3.2
tar jxf /usr/src/linux-source-3.2.tar.bz2
cd linux-source-3.2
cp /boot/config-3.2.0-4-amd64 ./.config
make oldconfig
make prepare

Now there is an autoconf.h file in my local linux-sources folder (linux-sources/include/generated/autoconf.h) but not in */usr/src/linux-headers-3.2.0-4-common/include/* where I assume is the folder where FlashCam sources are looking for. What should I do now? Copy by hand this folder is a bit scary and I can't find additional instructions to make it work.

Solution

Up to date instructions for building out-of-tree kernel modules are here. Installing the kernel config headers to the system include directory is not part of the procedure. Rather you invoke make from inside the kernel source tree and point it to the module's source tree with the M= parameter.

FlashCam hasn't been updated in a while so it may not be possible to build it against a recent kernel without some porting effort.

Comments

[Admin]

A pair of quotes from the flashcam page you linked to: Last update: $Date: 2010-08-07 07:45:35 $ (UTC) and Flash 10 (aka Astro) Beta 2 is out and is supposed to support V4L2. At last! I guess Flashcam won't be useful for long on the desktop. If that's the best solution you're in trouble.

[Admin]

Upss.. The weird is I've read it as a solution in some articles more recents than 2010. Anyway, the question is independent of the FlashCam software, maybe in the future I need to recompile something that uses these files and I'd like to know what's happening. Thanks.

[Admin]

I have the same issue. Is it resolved ?