bootentries: Move struct bootentries to include/boot.h ...

The boot function prototypes are declared in include/blspec.h. Move them
to include/boot.h where they belong.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

blspec: Make blspec_boot static ...

Since blspec_boot is now only used locally we can make it static. Move
it up to avoid a static declaration.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

blspec: separate bootentries from blspec entries ...

This completes the separation of the blspec code from the boot
code. With this the boot code only handles generic boot entries
of type struct bootentry which are embedded into the type
(blspec/bootscript) specific structs.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

bootentries: Add title/description ...

We currently have to special case blspec entries vs. boot scripts
in the common boot code since we want to print different informations
about them. This adds a 'title' and 'description' which can be filled
in with different information by bootscripts and blspec entries and
so we get rid of the special handling.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

blspec: factor out a struct bootentry ...

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

blpec: rename struct lspec -> bootentries ...

The code in common/boot.c collects the different boot entries in
lists of type struct blspec, eventhough many of them may not be
bootloader spec entries but for example boot scripts. This is the first
step of separating the data structures from boot entries and bootloader
spec: As struct blspec is merely a container for collecting boot entries
We simply rename struct blspec to struct bootentries. No functional change.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

blspec: remove unused function prototype ...

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

blspec: Remove once/default handling ...

This is widely unused and in the way of subsequent cleanups. If you are
indeed using it please complain on the list, we'll find a solution to
add it back in a different way.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

blspec: remove unused blspec_boot_devicename ...

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

blspec: Add missing prototype for blspec_scan_device ...

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

blspec: honor default/once entries again ...

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

blspec: make cdev optional ...

the cdev for a given directory can be determined by get_cdev_by_mountpath().
Use this function and remove the cdev argument from blspec_scan_directory().
Also, export the function to make code possible which boots the bootloader
spec entries found in directories.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

blspec: Let scan functions return the number of entries found ...

So that callers can detect whether entries are found or not.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

blspec: rename _hwdevice functions to _devicename ...

Since it's not necessarily the hardware device this seems to
be a more appropriate name.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

blspec: Fix crash with menu disabled ...

blspec->menu is only valid when menu support is enabled. Check for it
before dereferencing the pointer.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Implement bootloader spec support for barebox ...

The Bootloader Specification describes a way how kernels can
be installed on devices and how they can be started by the bootloader.

The bootloader spec is currently supported by (x86) gummiboot and
by systemd which provides a kernel-install script. With the bootloader
spec it's possible for the Operating system to install a new kernel
without knowing about the bootloader and for the bootloader it's possible
to discover and start Operating Systems on a media without being
configured.

For more details about the spec see:

http://www.freedesktop.org/wiki/Specifications/BootLoaderSpec/

This patch adds barebox support for the spec. It enhances the 'boot'
command so that not only boot script names can be given, but also
devices containing bootloader spec entries. With this it's possible
to call the 'boot' command like: 'boot sd emmc net'. It would then
first look for bootloader spec entries on the (removable) sd card,
then, is nothing is found, on the internal emmc and if still
unsuccessful would call the 'net' bootscript.

The bootloader Spec currently doesn't specify which entry should be
default if multiple entries are found on a single device. Therefore
barebox currently has two extensions of the spec. The $BOOT diretory
can contain a file named 'default'. If present, the content of the
file is treated as a filename under $BOOT/loader/entries/ which is
used as default. Similarly if a file named 'once' is present, the
entry is started once and the file is removed afterwards. This is
useful for testing if a newly installed kernel works before making
it the default.

As on ARM and other Architectures a devicetree has to be specified
for the kernel, the 'devicetree' property is used to specify a
devicetree. Like 'kernel' and 'initrd' this also contains a pth
relative to $BOOT.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>