3 Replies Latest reply on Dec 23, 2014 5:25 AM by victorlazzarini

    Galileo GEN2 support - linux yocto build




      a quick question. I am using a SD card image that I have built from the Galileo BSP I got from the Intel download centre.

      It is based on meta-clanton-1.0.1, but I can't exactly remember which release it was (1.0.0 most likely, as I got it around

      the end of July/beginning of August 2014). Does this have kernel support for the PCAL9535A GPIO expanders used in


      The image is working perfectly on the GEN1 with the cypress expander, I can access the GPIO and analog ins

      through the sysFS fine.

      I have started using a GEN2 board, and booted from this image. My programs for other things work fine (with usb midi and audio), but I am not

      sure whether the GPIO and analog pin functionality will work. Is there a way to tell, or does anyone know if it will

      work? Do I need to build a new image from a different BSP, or apply any patches? I can't seem to find anything newer

      than meta-clanton 1.0.1 though (it appears 1.0.2 to 1.0.4 releases use this with the usual openSSL etc patches).

      Thanks a lot.

        • 1. Re: Galileo GEN2 support - linux yocto build

          Hi victorlazzarini,


          I think the issue you are getting is because the gpio numbers are different between the Galileo Gen1 and the Galileo Gen2. For example, for the IO7, the Linux gpio number is 27 in the Galileo Gen1, but in the Galileo Gen2 it is the number 38.


          My suggestion for you is to use the Yocto Image available here: Galileo Software Downloads, and then check the following site: EmutexLabs. In there you will find a good description about the pin configuration for the Galileo Gen2.




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          • 2. Re: Galileo GEN2 support - linux yocto build



            Seasons greetings from Ireland.


            yes, I realise the pins and HW are different. I had a look at the emutex page, and parsed the source code for the arduino IDE. Now I think I have

            a good grasp of the mapping. I have checked that my image indeed supports GEN2, so I don't need to build another one. I managed to get

            a correct signal from the analog inputs via sysfs as well. This is looking good.


            The only minor thing, and it is really minor, is that I can't seem to be able to turn on/off the on-board led (pin13, gpio7). Even though I can turn

            it to 1 (Hi), and I see it is high on /sys/kernel/debug/gpio, the led does not light up. Do you know why that might be?


            Thanks a lot for your reply.

            • 3. Re: Galileo GEN2 support - linux yocto build

              Actually, I can answer my own question now. In order to access the onboard led, we need to first turn gpio30 to out, set it to low, and then we can turn gpio7 to out and set it to high.