I have installed Raspbian on my Paspberry Pi and was experimenting with developing for it. I have followed this tutorial and cloned the kernel on an Ubuntu VM to cross compile it with raspberry tools.

I have made a small modification to the board file in the kernel to disable default triggers for the green led (changed line 1024 in arch/arm/mach-bcm2708/bcm2708.c) to .default_trigger = "", and compiled it using default config using make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- bcmrpi_defconfig followed by make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf-.

After using the tools to create kernel.img I have deployed it via SSH and copied it to /boot/ on the board.

After a restart, the change I made seems to have worked, but unfortunately, the keyboard stopped responding, and the Wi-Fi dongle couldn't connect to my home network, while previously it could.

What could have caused this kind of issue?

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    Which keyboard, PS/2 (with USB->PS/2 adapter) or USB? Manufacturer, model for both? – KernelPanic Jan 24 '15 at 17:42
  • keyboard is a logitech wireless keyboard with a USB connection, unfortunately I don't know the exact model but it's pretty old. It does work with a fresh Raspbian install from NOOBS though. The wifi dongle is called Wi-Pi. I don't have it near me right now so I can't tell you its exact manufacturer and model. – eliba Jan 24 '15 at 17:43
  • Connect them to USB ports and give us sudo lsusb -v output. – KernelPanic Jan 24 '15 at 17:48
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    You need to make an actual effort to describe 1) Specifically what changes (as in, files, line numbers, code) you made to the kernel source, 2) How you configured the kernel. What you have now is basically, "I built my own kernel and it does not work properly. What did I do wrong?" No one wants play guessing games WRT a tutorial you apparently followed. If you know enough to be hacking on the kernel, you should know well enough How to Ask Questions the Smart Way. – goldilocks Jan 24 '15 at 19:39
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    The most productive thing you can do is probably to verify that you can build and succesfully test the existing kernel unmodified before you make any changes. Note that changing kernels may mean you need to put a new set of driver modules on the system – Chris Stratton Jan 25 '15 at 21:14

If you built from the latest source as per that tutorial, chances are that it is not the same version as your current kernel. To check what version it is, you can try uname -r while it is running (if you can ssh in, since the keyboard does not work) or look in the source tree; the .config should have this right at the top (e.g. "Linux/arm 3.17.1 ...") and the `Makefile as well, in the form "VERSION =", "PATCHLEVEL =", "SUBLEVEL = ".

You then need to check that there is a corresponding directory in /lib/modules, e.g., /lib/modules/3.17.1. If not, you need to follow the directions in the tutorial to install them.

If it does exist but you did not install the modules, you could try moving it temporarily (mv /lib/modules/3.17.1 /lib/modules/3.17.1-moved), then building and installing them using your source tree as it is now.

  • Those were indeed two different kernel versions, 3.18.3+ and 3.12.22+. My mistake was that I haven't built the modules as well and installed them on the Raspberry Pi. – eliba Jan 26 '15 at 23:42

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