On 04. 03. 20 3:47, Simon Glass wrote:
Hi Michal,
On Mon, 2 Mar 2020 at 23:52, Michal Simek michal.simek@xilinx.com wrote:
On 02. 03. 20 20:47, Simon Glass wrote:
Hi Michal,
On Fri, 28 Feb 2020 at 04:03, Michal Simek michal.simek@xilinx.com wrote:
On 26. 02. 20 16:33, Simon Glass wrote:
Hi Michal,
On Tue, 18 Feb 2020 at 09:02, Michal Simek michal.simek@xilinx.com wrote:
Users have option to overwrite default device tree (CONFIG_DEFAULT_DEVICE_TREE) via environment variable DEVICE_TREE.
Feature has been added long time ago by commit 74de8c9a1672 ("dts/Makefile: Build the user specified dts") for a little bit different reason.
But this variable can be also used for different purpose like choosing proper configuration from FIT image in SPL. And this is the functionality I would like to use on Xilinx Zynq devices that current u-boot.img can be composed in the same way based on OF_LIST and different configuration is taken based on platform specific SPL. SPL requires low level ps7_init_gpl configuration that's why different boards require different SPL with fixed board_fit_config_name_match().
Signed-off-by: Michal Simek michal.simek@xilinx.com
I have done it in this way but maybe there is any smarter way how this can be done. Also macro name can change if you want.
Can you please add a bit of documentation to doc/README.fdt-control ?
This feature is cover by documentation in this file already. What exactly do you think that should be added?
Then I suppose I am confused as to what this patch does. I thought it was allowing U-Boot to pass the DT to Linux, which wasn't previously supported?
Just a note this is also not supported and would be good to have support for it.
The patch is putting device tree name as macro to header and I am using this value just in zynq SPL to choose proper dtb file from u-boot.img.
On ZynqMP generic platform I am using mkimage_fit_atf.sh script to automatically fill default configuration. https://gitlab.denx.de/u-boot/u-boot/blob/master/arch/arm/mach-zynqmp/mkimag... And I didn't want to create different u-boot.img/itb for Zynq that's why SPL has device tree built it directly in SPL.
As I said maybe there is smarter way how to do it but this was the one I used. In our case SPL another way could be to put filename from ps7_init_* files and save it as variable and use it.
OK I see. So are you using OF_CONTROL for SPL?
Yes.
M