Implement stacktraces as a great debugging aid. On aarch64 this is cheap
enough to be enabled unconditionally. Unwinding code is taken from the
Kernel.

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

The unwind code to support this feature is not there yet.

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

Sometimes it's useful to test if a memory operation works or
aborts. This adds data_abort_mask() to ignore data aborts and
data_abort_unmask() to enable them again. This is used in the
next step for the 'md' command so that illegal addresses just
show 'xxxxxxxx' instead of crashing the system.

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

At least ARM allows us to dump the stack, but we currently
have no prototype for this. Add a dump_stack prototype and
provide a static inline function for architectures without
stack dump support. Also, call dump_stack() in panic() to
provide more information in the case of a panic.

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>