From https://community.victronenergy.com/questions/ask.html?space=31, describing the boot process:
The built-in environment in u-boot loads a default am335x-boneblack.dts
to pass to the kernel at boot.
To override this default DTS, a uEnv.txt
configuration file can be used to customize the u-boot environment. In the uEnv.txt
you can explicitly specify a different DTS as well as the command line arguments to pass to the kernel.
There is no initrd
used with the Venus BBB builds. U-boot goes directly to the final kernel.
So, to me this implies that there is a file "uEnv.txt" that should live in the boot folder. This file wasn't there after a clean install of the latest image. So I created the file with the following contents:
###U-Boot Overlays###
###Documentation: http://elinux.org/Beagleboard:BeagleBoneBlack_Debian#>
###Master Enable
enable_uboot_overlays=1
uboot_overlay_addr0=/dev/SPI0-00A0.dtbo
disable_uboot_overlay_video=1
I copied the .dtbo file into the dev directory as referenced. (ok so it should not normally be there..)
having rebooted the BBB, still no spi device listed in the dev folder.
Anyone have any pointers as to what is wrong? I suppose my next move is to add the debug terminal to watch the boot process to see if the uEnv.txt file is actually accessed.