On Tue, Oct 24, 2023 at 08:20:32AM +0200, Heinrich Schuchardt wrote:
Forward and backward compatibility of Linux kernel device-trees is sometimes missing. One solution approach is to load a kernel specific device-tree. This can either be done via a U-Boot scripts (like the one generated by Debian package flash-kernel or by a boot loader like GRUB. The boot loader approach currently requires to know the device-tree name before first boot which makes it unusable for generic images.
Expose the device-tree file name as EFI variable FdtFile. This will allow bootloaders to load a kernel specific device-tree.
The variable will not be exposed on ACPI based systems or if the environment variable fdtfile is not defined.
Signed-off-by: Heinrich Schuchardt heinrich.schuchardt@canonical.com
Reviewed-by: Tom Rini trini@konsulko.com