Hi Steven, Your problem could be that the GPIO MMIO frame is not being given to the VM. The config setting CONFIG_TK1_INSECURE increases the amount of hardware devices that are passed through to the VM. Once the GPIO device is accessible in the VM, Linux should be able to attach its own GPIO driver which will then make it accessible through sysfs. Currently on TK1 there isn't support for virtualisation of the GPIO hardware so you can either give Linux access to the hardware frames to manage GPIO hardware itself, or use a limited seL4 gpio driver in a separate CAmkES component but this wouldn't be accessible from on top of Linux unless you created your own virtual device. Hope this helps. Kind regards, Kent ________________________________________ From: Devel <devel-bounces@sel4.systems> on behalf of Steven Johnston <steve.johnston@adventiumlabs.com> Sent: Tuesday, May 9, 2017 9:45 AM To: devel@sel4.systems Subject: [seL4] camkes-arm-vm not registering GPIO? Hi All, I am playing around with the capabilities of the camkes-arm-vm project pn the Tegra TK1 and and wondering if someone else has come across this issue. It looks like GPIO functionality is not available in the buildroot. I can confirm the GPIO source is present and is being built: camkes-arm-vm/libs/libplatsupport/rc/plat/tk1/gpio.c camkes-arm-vm/libs/libplatsupport/plat_include/tk1/platsupport/plat/gpio.h [CC] src/plat/tk1/gpio.o The expected sysfs support is not present and looking and the relevant dmesg: # dmesg | grep gpio [ 0.057543] gpiochip_add: GPIOs 0..255 (tegra-gpio) failed to register [ 1.485061] input: gpio-keys as /devices/soc0/gpio-keys/input/input0 Any thoughts on what could be causing GPIO to the failing to register? Steven _______________________________________________ Devel mailing list Devel@sel4.systems https://sel4.systems/lists/listinfo/devel