This adds the make infrastructure to build multiple SoC or
board specific images from a single barebox binary.

The basic idea is that we no longer have a single pbl, but instead
multiple pbls, one per image if necessary. Each pbl is defined
by its entry function so that each pbl can do exactly what a given
board needs. Additionally the pbls together with a self extracting
barebox binary can be encapsulated in specific image formats.

squashed in build fixes from Lucas Stach for make version >= 3.82:

Split Multimage Makefile rule in explicit and implicit parts

Fixes build with make version >=3.82

Frome the make 3.82 NEWS file:
* WARNING: Backward-incompatibility!
  In previous versions of make it was acceptable to list one or more explicit
  targets followed by one or more pattern targets in the same rule and it
  worked "as expected".  However, this was not documented as acceptable and if
  you listed any explicit targets AFTER the pattern targets, the entire rule
  would be mis-parsed.  This release removes this ability completely: make
  will generate an error message if you mix explicit and pattern targets in
  the same rule.

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

Addionally to having a builtin DTB provide the possibility for
the board to provide a dtb via boarddata.

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

Conflicts:
	arch/arm/lib/barebox.lds.S

The comment above barebox_arm_entry promises to preserve the boarddata
variable passed to it which can then later get back with
barebox_arm_boarddata(). This function was missing so far, add it.

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

For making the same binary executable on different SoCs which have
different DRAM addresses we have to be independent of the compile
time link address.

This patch adds relocatable binary support for the ARM architecture.
With this two new functions are available. relocate_to_current_adr
will fixup the binary to continue executing from the current position.
relocate_to_adr will copy the binary to a given address, fixup the
binary and continue executing from there.

For the PBL and the real image relocatable support can be enabled
independently. This is done to (hopefully) better cope with setups
where the PBL runs from SRAM or ROM and the real binary does not.

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

With relocatable binaries the vector addresses cannot be supplied by
the linker. This adds support for fixing them up during runtime.

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>

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

Memory is a precious resource, so it makes sense to make it available as
early as possible. By definition the lowlevel init code already knows where
to find memory because it's the lowlevel init code which sets up the memory.
Until all boards are converted this new entry is just a fallback to the old
entry point.

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

Sometimes Assembler beats C. In this case a small assembler
function called without parameters can:

- copy a binary to its link address
- clear the bss
- return to the same position in the copied binary

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

Conflicts:
	arch/arm/include/asm/barebox-arm.h

Conflicts:
	drivers/net/miidev.c
	include/miidev.h

This is unused now and not needed. We have a board_init_lowlevel. If a
board needs some architecture setup it can always call it from its
board_init_lowlevel.

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

The FSF address has changed in the past. Instead of updating it
each time the address changes, just drop it completely treewide.

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

The current approach to get the offset between link and runtime address
is fragile. It requires a big fat comment to put no code above it and it
requires an extra linker section. Instead use a small assembler function.

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

This function returns the offset between the address barebox is linked at
and the address barebox is currently running at.

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

We used to get the runtime offset of the board_init_lowlevel_return
by doing a &board_init_lowlevel_return. This does not work in thumb-2
mode, so use a separate linker section for this function instead.

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

Traditionally U-Boot and barebox have the exception vectors at
the start of the binary. There is no real reason in doing so,
because in the majority of cases this data will not be at 0x0
where it could be used as vectors directly anyway.
This patch puts the vectors into a separate linker section and
defines an head function which is placed at the start of the
image instead. Putting this in a separate function also has
the advantage that it can be placed at the start of images
which require an additional header like several Freescale i.MX
images. As the head function contains the barebox arm magic
those images can now also be detected as barebox images.

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

this will allow each arch to handle the boards more simply and depending on
there need

the env var BOARD will refer to the current board dirent

for sandbox as we have only one board the board dirent is arch/sandbox/board

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

This got lost during the switch to implement the lowlevel
stuff in C.

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

Lets translate the startup code to a language we all understand better.
Tested on pcm038 (arm v5) and pcm043 (arm v6).

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

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

This has been done with the following script:

find -path ./.git -prune -o -type f -print0 | xargs -0 -r sed -i \
	-e 's/u2boot/barebox/g' \
	-e 's/U2Boot/barebox/g' \
	-e 's/U-boot V2/barebox/g' \
	-e 's/u-boot v2/barebox/g' \
	-e 's/U-Boot V2/barebox/g' \
	-e 's/U-Boot-v2/barebox/g' \
	-e 's/U_BOOT/BAREBOX/g' \
	-e 's/UBOOT/BAREBOX/g' \
	-e 's/uboot/barebox/g' \
	-e 's/u-boot/barebox/g' \
	-e 's/u_boot/barebox/g' \
	-e 's/U-Boot/barebox/g' \
	-e 's/U-boot/barebox/g' \
	-e 's/U-BOOT/barebox/g'

find -path ./.git -prune -o \( -name "*u-boot*" -o -name "*uboot*" -o -name "*u_boot*" \) -print0 | \
	xargs -0 -r rename 's/u[-_]?boot/barebox/'

It needs some manual fixup following in the next patch

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