Juno CoreSight Setup

Hi Everyone,

We just bought a Juno Versatile Express board for development.  Using the getting started guides and I have successfully installed DS-5 on a host and a rootfs on the board.  I'm using the LAMP image provided by Linaro for use with the Juno board (linaro-image-lamp-genericarmv8-20150618-754.rootfs.tar.gz).  To set up and test CoreSight I am using the guide provided (On-Target Trace Using the CoreSight Access Library |  ARM DS-5 Development Studio) and the readmes provided within the CoreSight_access example source.

Building is no problem but I have two issues:

1.  When trying to disable the cpuidle I find that I have no cpuidle directory in any /sys/devices/system/cpu/cpu$ folder.

2.  When attempting to run the tracedemo example (rel or dbg) I receive a "CSREG: Failed to detect the board!" error.  The Juno r1 is defined in the source as a supported board (and also mentioned in the readme as supported).

Does anyone have an idea why I would be seeing this error?

Thanks in advance for any insight you can provide on CoreSight!


Parents Reply
  • Hi Steve,

    Ah, I believe this is due to this patch to the Linux kernel which has made it into the Latest kernel (which is the one you're using, in 'juno-latest-oe-uefi.zip'), whereas it's not yet made it into the LSK as this is the Linaro Stable Kernel. I was building from source and using the LSK which is why it worked for me.

    I've informed the maintainers of the CoreSight demo to let them know, but in the mean time I suggest you follow the instructions at the Linaro ARM Platforms Page in order to build your software stack with the LSK rather than the Latest kernel.

    As a side note, if you want to disable the CONFIG_STRICT_DEVMEM flag for your kernel, the simplest way to do it is after running this command (when following the steps on the Platforms page):

    repo sync -j8

    After running that command and before continuing, open the file /linux/linaro/configs/distribution.conf and change this line:


    Changing the "y" to "n". You can then continue to follow the instructions as normal.

    I hope that helps.



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