The current way of handling things like EFI bootmgr is a bit odd, since
that bootmeth handles selection of the bootdev itself. VBE needs to work
the same way, so we should support it properly.
Add a flag that indicates that the bootmeth is global, rather than being
invoked on each bootdev. Provide a helper to read a bootflow from the
bootmeth.
Signed-off-by: Simon Glass <sjg@chromium.org>
Some bootmeths can provide information about what is available to boot.
For example, VBE simple provides access to the firmware state.
Add a new method for this, along with a sandbox test.
Signed-off-by: Simon Glass <sjg@chromium.org>
A bootmeth is a method of locating an operating system. For now, just
add the uclass itself. Drivers for particular bootmeths are added later.
If no bootmeths devices are included in the devicetree, create them
automatically. This avoids the need for boilerplate in the devicetree
files.
Signed-off-by: Simon Glass <sjg@chromium.org>
