Hi I’m fairly new to embedded linux development and I’ve been stuck on this problem for quite some time so any help would be greatly appreciated.
I am using a BeagleBoneBlack Wireless with Ubuntu 18.04 and Linux Kernel 4.14.108-ti-r113.
i need to reconfigure the pins that are not by default gpio. For example P8_46 pin which is by default an LCD_Data pin.
When using the BBB with a debian stretch image I can use those pins as gpio. However, when I use my ubuntu distro, those pins will not work as gpio. When I try and reconfigure the pins using the config-pin utility I get this error:
P8_46 pinmux file not found! bash: /sys/devices/platform/ocp/ocp*P8_46_pinmux/state: No such file or directory Cannot write pinmux file: /sys/devices/platform/ocp/ocp*P8_46_pinmux/state
I have tried following numerous tutorials online with no luck. I have looked into using device tree overlays but I always get stuck because there is no slots file in this path:
/sys/devices/platform/bone_capemgr/slots
This slots file doesn’t exist and so I can never proceed.
i need to reconfigure the pins that are not by default gpio. For example
P8_46 pin which is by default an LCD_Data pin.
by default the lcd pins are assigned to/used by the hdmi framer, as per the
system reference manual.
When using the BBB with a debian stretch image I can use those pins as
gpio. However, when I use my ubuntu distro, those pins will not work as
gpio. When I try and reconfigure the pins using the config-pin utility I
get this error:
P8_46 pinmux file not found!
to make these pins available for other purposes you'll need
to disable hdmi, using "disable_uboot_overlay_video=1" in uEnv.txt.
see for example:
and not quite as directly related:
This slots file doesn't exist and so I can never proceed.
the slots stuff is long gone, you need to convince your uboot (via uEnv.txt)
to load the relevant overlays.
see Beagleboard:BeagleBoneBlack Debian - eLinux.org for
a little bit of explanation.
Note: I need to be running the ubuntu distro.
you may have to update your uboot version to make the u-boot overlay stuff
work properly, but otherwise there shouldn't be any big differences
between ubuntu and debian that are relevant for your specific situation.