Re: [yocto] System device tree, AMD EDF, custom board

Hi Pierre,

I'm not an expert on this but have been going through the migration an older Petalinux to Scarthgap and SDTgen recently.
If you find you don't get the right answers here you could also try posting on the meta-xilinx subgroup - they've helped me a lot before.

The answer may depend on how you are configuring your PL, is it as part of boot.bin or is it configured later in U-Boot/Linux?
Relatedly do you have a single device tree for Linux with PS and PL parts in or is it split into two, a base device tree for PS and a device tree overlay for PL?
(Do you supply the -g/--gen-pl-overlay argument to gen-machine-conf?)

In our case we have PL configured in U-boot, and use a device tree overlay for the PL applied after Linux has booted.

For extra bits we need in the PS/base device tree we use "set_dt_param -user_dts <path to dsti file>" in the tcl file we pass to sdtgen.

This doesn't work for nodes in the PL though - after discussing our situation with AMD we were advised to create a Yocto recipe which takes the pl.dtsi output of gen-machine-conf
and combines it with our own dtsi for the extra parts, compiling it into a dtbo which we load via a systemd service as Linux starts.

Hope this helps a bit, happy to dig deeper if it sounds right for your situation.

Best Regards,
Phil Dawson