Some Linux parameters can be set automatically by U-Boot, if it knows the
device being used. For example, since U-Boot knows the serial console
being used, it can add parameters for earlycon and console.

Add support for this.

Note that this is an experimental feature and we will see how useful it
turns out to be. It is very handy for ChromeOS, since otherwise it is very
difficult to manually determine the UART address or port number,
particularly in a script.

Provide an example of how this is used with ChromeOS.

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

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>

On x86 boards Linux uses a block of binary data to provide information
about the command line, memory map, etc. Provide a way to store this in
the bootflow so it can be passed on to the OS.

No attempt is made to generalise the code, since other archs don't need
this information. The field is present always, though, to avoid needing
accessors or #ifdefs when building code on other archs.

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>

It seems better to call this a 'bootdev' since this is name used in the
documentation. The older 'Bootdevice' name is no-longer used and may cause
confusion with the 'bootdevice' environment variable.

Update throughout to use bootdev.

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

For EFI, the distro boot scripts search in three different directories
for the .dtb file. The SOC-based filename fallback is supported only for
32-bit ARM.

Adjust the code to mirror this behaviour.

Also some boards can use a prior-stage FDT if one is not found in the
normal way. Support this and show a message in that case.

Signed-off-by: Simon Glass <sjg@chromium.org>
Suggested-by: Mark Kettenis <kettenis@openbsd.org>

These flags actually relate to the iterator, not the bootflow struct
itself. Rename them.

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

Add a way to record the bootdevs used when scanning for bootflows. This is
useful for testing.

Enable this only with BOOTSTD_FULL and do the same for the progress
reporting.

Re-enable and update the affected tests now that we have this feature.

For bootdev_test_order_default() there is no-longer any support for using
the bootdev aliases to specify an ordering, so drop that part of the test.

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

This function is not used outside tests. Drop it and rename
bootflow_scan_dev() since it is how we start a scan now.

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