[U-Boot] [PATCH v3 1/1] efi_loader: need either ACPI table or device tree

[Mark Kettenis]

> From: Heinrich Schuchardt <xypron.glpk at gmx.de>
> Date: Mon, 22 Apr 2019 20:01:01 +0200
> 
> The EBBR specification prescribes that we should have either an ACPI table
> or a device tree but not both. Let us enforce this condition in the
> `bootefi` command.

Why?

While I agree that it would be good if U-Boot would provide a device
tree I think you're needlessly restricting users here.  Many EFI
bootloaders (GRUB, OpenBSD's bootloader on arm/arm64) have a way to
load a device tree afterwards.  This diff makes it impossible to use
that capability on systems where U-Boot doesn't provide a device tree.

Such a system obviously wouldn't be compliant with the EBBR
specification.  But together with an appropriate bootloader it could
still run an EBBR compliant OS.