We used to pass a device tree pointer to
imx*_barebox_boot_nand_external(). This no longer works since we compile
barebox with -fPIE.

The problem is that we only have the first 2KiB of the image available
when we start from NAND. The pointer to the device tree is not valid
yet. This hasn't been a problem because the pointer is only used later
when we have the full image in SDRAM. With -fPIE though the actual
pointer is derived indirectly through another pointer, and that pointer
to the pointer is also not valid which causes an invalid pointer to
the device tree later.

This is solved by splitting the NAND boot functions up into two
functions. With imx*_nand_relocate_to_sdram() the board code relocates
the image out of the NFC SRAM into SDRAM. From that point on the device
tree pointer can be accessed and the board can load the image using
imx*_nand_load_image() and can afterwards pass control to barebox
passing whatever device tee pointer it likes.

Fixes: b0348d677b ("ARM: Compile with -fPIE")
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Move v3 register definitions to include file so that they can
be reused for the early nand boot code.

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

Mostly to make it clear that boarddata needs to be
something we can dereference.

As this is a pretty invasive change, use the opportunity
to make the signature 64bit safe.

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

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

The external NAND boot code currently does not handle bad blocks
correctly on 2k NAND flashes. This patch adds a barebox_update
handler for external NAND boot which embeds a Bad block table in
the flashed image. The boot code will skip bad blocks found in
this bad block table then.

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

i.MX will get SoC specific entry points for barebox. To find the
correct one we have to call these from the SoC specific
imx*_barebox_boot_nand_external functions.

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

The pattern for i.MX boards starting in external NAND boot mode is always
the same:

- Check if we are running in NFC address space, if not call
  board_init_lowlevel_return()
- copy binary to link address
- execute relocated binary
- call imx_nand_load_image()

Add a common function for this to make the board code easier.

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

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

The i.MX Processors support two different boot modes, the internal
boot mode and the external boot mode. Traditionally the external
NAND boot mode is handled in drivers/mtd/nand and the internal
boot mode is handled in arch/arm/mach-imx. This patch consolidates
the handling of both boot modes in arch/arm/mach-imx so that
the user does not have to look in the mtd kconfig section for
booting from NAND. Also, selecting between internal and external
boot mode now is a clear choice.
The external NAND boot mode has been independent of the mtd nand
driver, but as the code was contained in the NAND driver it was
not possible to support booting from NAND without a mtd nand driver.
This is changed with this patch.

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

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

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

Conflicts:
	board/a9m2440/a9m2440.c
	board/pcm043/pcm043.c
	drivers/nand/nand_imx.c

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

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>