I have moved from the beta Wheezy release to the final release currently on the official download page (2012-08-08-wheezy-armel.zip). The hardware watch dog no longer seems to work. I have tried running sudo modprobe bcm2708_wdog, but the device /dev/watchdog does not appear.

How do I get the watchdog back?

  • 1
    Did you update firmware (kernel) to the newest version? Oct 11, 2012 at 16:26
  • 1
    No. Could you describe how to do that? I don't understand how the kernel can be described as firmware.
    – Guy
    Oct 11, 2012 at 19:53
  • kernel is not normally technically part of firmware. But in Raspberrypi you usually update both firmware and kernel files at once since many fixes in one influence the other. The easiest way to install the most up to date version of this files is use rpi-update utility. It should be available in your distribution. Oct 12, 2012 at 6:35

1 Answer 1


Thanks to Krzysztof Adamski for giving me the hint that enabled me to solve this problem.

As I had been unable to boot the stock soft-float Wheezy image, I had copied some files from a (working) Raspbian image in order to get soft-float working (required to run Mono). This included kernel.img. See here for details. I think the difference in version between the kernel and /lib/modules/3.1.9+/kernel/drivers/watchdog/bcm2708_wdog.ko was stopping it from loading.

I went back and copied files one by one to a virgin soft-float image from a raspian image and found that it was start.elf that was stopping the soft-float image from booting. I moved arm224_start.elf to start.elf (wanting to change the memory split anyway) and I can now boot the image and "modprobe bcm2708_wdog" works as expected.

  • Each time you change kernel.img file on boot partition, you should also update modules files in /lib/modules/ to match the kernel. They wont load otherwise. Oct 14, 2012 at 17:12

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