The existing distro scripts check extlinux and scripts before EFI. Adjust
the default ordering to do the same, to avoid breaking existing flows.

Add some documentation, mentioning that this order will likely change in
future.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reported-by: Da Xue <da@libre.computer>

Add a bootflow command to update the command line more easily. This allows
changing a particular parameter rather than editing a very long strings.
It is also easier to handle with scripting.

The new 'bootflow cmdline' command allows getting and setting single
parameters.

Fix up the example output while we are here, since there are a few new
items.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>

The Linux command line consists of a number of words with optional values.
At present U-Boot allows this to be changed using the bootargs environment
variable.

But this is quite painful, since the command line can be very long.

Add a function which can adjust a single field in the command line, so
that it is easier to make changes before booting.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>

Some operating systems have a command line which can be adjusted before
booting. Store this in the bootflow so it can be controlled within
U-Boot.

Fix up the example output while we are here, since there are a few new
items.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>

Add some simple tests and a helpful script to make the configuration
editor easier to set up.

Signed-off-by: Simon Glass <sjg@chromium.org>

The only way to create an expo at present is by calling the functions to
create each object. It is useful to have more data-driven approach, where
the objects can be specified in a suitable file format and created from
that. This makes testing easier as well.

Add support for describing an expo in a devicetree node. This allows more
complex tests to be set up, as well as providing an easier format for
users. It also provides a better basis for the upcoming configuration
editor.

Signed-off-by: Simon Glass <sjg@chromium.org>

At present we only support a single menu, so all that can be pointed to
is the current menu item. Rename this action so that we can also add
an action for pointing to an object. This will allow cycling through
the objects in a scene.

Signed-off-by: Simon Glass <sjg@chromium.org>

The current implementation supports a 'pointer' object which points to
the currently highlighted menu item. We want to support highlighting the
label of the menu item instead, e.g. with inverse video. In this case we
will need to 'unhighlight' the old item and highlight the new one.

As a first step, move the pointer logic into a function. This fixes a
bug where the item is hidden when it should not be.

Signed-off-by: Simon Glass <sjg@chromium.org>

It is a pain to manually set the fonts of all objects to be consistent.
Some spacing settings are also better set globally than by manually
positioning each object.

Add a 'theme' to the expo, to hold this information. For now it includes
only the font size.

Signed-off-by: Simon Glass <sjg@chromium.org>

Provide a way to set the full dimensions of objects, i.e. including the
width and height.

For menus, calculate the bounding box of all objects in the menu. Set all
labels to be the same size, so that highlighting works correct, once
implemented.

Signed-off-by: Simon Glass <sjg@chromium.org>