Re: Barebox for Zedboard

[Michael Tretter <m.tretter@pengutronix.de>]

On Mon, 19 May 2025 06:55:52 +0200, Ahmad Fatoum wrote:
> On 18.05.25 19:06, Johannes Roith wrote:
> > Am Fri, May 16, 2025 at 09:28:03PM +0200 schrieb Ahmad Fatoum:
> >> Loading OF overlays can already load firmware that way.
> > 
> > Could you give me an example for an OF overlay to load a firmware?
> 
> Should look the same as in Linux (with overlay patches applied).
> 
> Michael, do you happen to have an example to share?

The overlay looks the same as in Linux and documented in
fpga-region.yaml.

For example, if your device tree contains a node with a fpga-region for
the fpga named fpga_full and the fpga-mgr property has a phandle to the
node of the FPGA Manager, the following overlay should instruct the FPGA
Manager to load the bitstream.bit firmware into the FPGA.

	/dts-v1/;
	/plugin/;
	&fpga_full {
		firmware-name = "bitstream.bin";
	};

In the overlay you should also describe the gateware implemented in the
bitstream. This allows Linux to detect what's actually implemented in
the bitstream and probe the proper drivers.

Michael