I'm having problems configuring the GPIO on my imx6ul-evk... I've built L5.4.3 as follows:
$ repo init -u https://source.codeaurora.org/external/imx/imx-manifest -b imx-linux-zeus -m imx-5.4.3-1.0.0.xml
$ repo sync
$ DISTRO=fsl-imx-fb MACHINE=imx6ulevk source imx-setup-release.sh -b build-fb
//Added imx-test utilities to local.conf
$ bitbake core-image-base
I uploaded the core-image-base-imx6ulevk.wic.bz2 image on to the sdcard and booted the imx6ul-evk. At the u-boot prompt I did:
=>setenv fdt_file imx6ul-14x14-evk.dtb
I'm using the imx6ul-14x14-evk.dtb that is the default for L184.108.40.206.
The problem is that when I try to configure GPIO using sysfs, with
$ echo 115 > /sys/class/gpio/export
the GPIO port is not listed in $ ls /sys/class/gpio afterwards.
However the result I get is
root@imx6ulevk:/unit_tests# ./memtool 0x20a8004 1
Reading 0x1 count starting at address 0x020A8004
I'm a bit new to linux on embedded systems ... where should I start to debug this?