This replaces the reset_cpu() function which every SoC or board must
provide with registered handlers. This makes it possible to have multiple
reset functions for boards which have multiple ways to reset the machine.
Also boards which have no way at all to reset the machine no longer
have to provide a dummy reset_cpu() function.

The problem this solves is that some machines have external PMICs or
similar to reset the system which have to be preferred over the
internal SoC reset, because the PMIC can reset not only the SoC but also
the external devices.

To pick the right way to reset a machine each handler has a priority. The
default priority is 100 and all currently existing restart handlers are
registered with this priority. of_get_restart_priority() allows to retrieve
the priority from the device tree which makes it possible for boards to
give certain restart handlers a higher priority in order to use this one
instead of the default one.

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

Storing the boot information in the image itself and passing a pointer
around between images is cumbersome and doesn't fit well with multiimage
support where the pointer we pass around is already occupied by the
devicetree.
Do the same as U-Boot does and store the boot information at the bottom
of the SRAM public stack.
To maintain the compatibility between new xloaders and older barebox
binaries we still pass the boot information to the next stage via pointer.

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

This introduces a single omap_init function which detects the
SoC and does all further SoC initialization. This is done to get
rid of initcalls without proper SoC protection. The same has been
done for i.MX already.

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

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

omap_save_bootinfo derefences the argument passed to barebox without
checking it for validity. This breaks 2nd stage booting where r0
is undefined. The best we can do is to check whether the pointer is
somewhere in SRAM and is word aligned. This at least makes sure that
we do not oops. This introduces SoC specific xxx_save_bootinfo variants
since the SRAM addresses/sizes differ between SoCs.

Additionally fix the prototype for omap_save_bootinfo. It uses r0, so
it must be passed this variable.

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