How was fpga.dts on de10-standard GHRD generated?

Hi Anand,

When I read the DE10-Standard_User_manual.pdf, Section 9.2, there is mention about requiring 2 files in order to configure the FPGA after booting up with the Linux Console. The two files are fpga.dtbo and soc_system.rbf.

I do understand how to generate the soc_system.rbf file using the sof_to_rbf.bat file.

However, for generating the fpga.dtbo, the document mentions using the following command:

dtc -O dtb -o fpga.dtbo -b 0 -@ fpga.dts

This will create a device tree overlay (aka .dtbo) and it uses the fpga.dts as the input. The fpga.dts doesn't appear to be a regular dts file because after its header, it contains the following text:

/dts-v1/ /plugin/;

In addition, the fpga.dts file contains entries for led_fpga0-9, which cannot be found in the soc_system.dts.

I'm having trouble understanding what generates the fpga.dts because it looks like I'll need it in order to control LEDs and use switches and buttons since the soc_system.dts doesn't contain that kind of information.

Thanks,

Raul