Subsequent patches will use this to verify the header in the PBL, move
it to common to make it potentially available for both.

Signed-off-by: Rouven Czerwinski <r.czerwinski@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

This adds initial support for OP-TEE, see https://www.op-tee.org/

barebox starts in secure mode as usual. When booting a kernel
the bootm code also loads the optee_os binary. Instead of jumping
into the kernel barebox jumps into the optee_os binary and puts
the kernel execution address into the lr register. OP-TEE then
jumps into the kernel in nonsecure mode.

The optee_os binary is passed with the -t option to bootm or
with global.bootm.tee.

Optionally OP-TEE can be compiled into barebox using the builtin firmware
feature. Enable the Kconfig option and place or link your tee binary as
optee.bin into the firmware directory.

The amount of SDRAM which is kept free for OP-TEE is configurable.

This patch was tested on a i.MX6 Nitrogen6x board.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Rouven Czerwinski <r.czerwinski@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

A prebootloader image might also contain a fully working barebox and
allows to be booted second stage. Thus we add a handler here to give it
a try.

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

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

It is not always desired to get the devicetree from image data and load
it to a SDRAM region at the same time. Sometimes it's enough to just
load it to an allocated address (in case the user has no constraints
where the devicetree should be placed.

This patch splits bootm_load_devicetree into bootm_get_devicetree which
returns a pointer to the allocated devicetree and bootm_load_devicetree
which loads the devicetree to a specified region.

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

data->oftree can be replaced with a variable local to the arm code, so
drop usage of data->oftree.

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

So far we can only force legacy boot using ATAGs by executing
'oftree -f'. Said command is going away as often this command
is not safe to call. Add an alternative way using the
global.bootm.boot_atag environment variable.

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

The 32bit boot support is full of legacy cruft. While it should be
possible to merge the aarch64 support there, a fresh start looks more
promising.

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