arm: Put exception_stack into BSS

"Hey guys, I have this awesome idea! How about we put a huge array
filled with 0xa5 into the data segment of our uncompressed romstage
for no particular reason? Give our SPI driver something to do so it
doesn't get too bored, you know?"

Guess it pays off to just hexdump our image and sanity-check it top to
bottom every once in a while...

Also reduces the size because 8K is crazy just to print a bunch of
registers (256 bytes ought to be enough for anybody).

Old-Change-Id: Icec0a711a1b5140d2ebcd98338ec638a4b6262fa
Signed-off-by: Julius Werner <jwerner@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/176762
Reviewed-by: Gabe Black <gabeblack@chromium.org>
Reviewed-by: Ronald Minnich <rminnich@chromium.org>
Reviewed-by: David Hendricks <dhendrix@chromium.org>
(cherry picked from commit 61c360a1c3f445535c9ff383a389e643cfe4527c)

arm: Remove exception_test()

The exception_test() mechanism might have been useful when exceptions
were first implemented, but now that they are pretty stable it's really
not necessary anymore (especially not on every single boot in production
Chromebooks). It forces a simple unaligned access, and as we start
having exceptions in stages that might not have paging turned on yet,
it's better to remove that completely.

Also removed the duplicated implementations of SCTLR-stuff and switched
to the existing ones in cache.h.

Old-Change-Id: I85e66269f5e2f2dfd3e8aaaa18441493514b62f8
Signed-off-by: Julius Werner <jwerner@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/177101
Reviewed-by: David Hendricks <dhendrix@chromium.org>
Reviewed-by: Gabe Black <gabeblack@chromium.org>
(cherry picked from commit d0706b848572fbea26e0e432ec5827503b9603c9)

Squashed 2 exception related commits.

Change-Id: Id2c115ee39a0732c375472afc0194436e2f5e069
Signed-off-by: Isaac Christensen <isaac.christensen@se-eng.com>
Reviewed-on: http://review.coreboot.org/6885
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
4 files changed