i'm going to move the config recursion check
into a separate function, and global variables
make it easier to handle

this fixes a regression caused in previous (recent)
revisions. this script is a beast, and requires a
lot of taming, which is the purpose of my audit

main first

usage last

yes, i know 3676 supersedes 2646

i still say 2646

saying 2646 is still technically valid,
for my purposes

top-down logic, main() on top

moved some hardcoded strings to variables

consistent indentation, and 80-line character limit
(RFC 2646)

top-down order, a main() is introduced, split into
more functions

non-zero-status exit (with message) now, when a non-
defined target is provided, e.g. nonexistentboard_4mb

puffy!

the cbfstool command within subshell now also
exits with non-zero status, if it fails (most
likely because extraction failed, for some reason,
of the coreboot rom image for running through it)

the previous code merely exited from the subshell,
but the intended behaviour is for the entire script
to halt execution, and exit with non-zero status.

this patch fixes that bug.

top-down order for all logic, and shorter code lines,
conforming to rfc 2646 (no more than 80 characters)

the 80-character rule is violated for variables containing
long strings, such as wayback machine urls (can't be helped)

a few bugs were discovered, which will be fixed in follow-up
revisions, such as:

* exit status not handled inside subshell
* in general, exit status should be handled
  more explicitly, rather than relying on -e

where the asterisk is used, it can sometimes
literally try to patch with a file named "*",
which of course does not exist

this change fixes an lbmk error when running:

./download seabios

this was caused recently, because all patches
were seabios were removed (lbmk currently uses
stock seabios, without patching it)

for our purposes, grub and gnulib are one in the same

if one fails, both have failed

exit with non-zero status if gnulib fails

the script sets -e so it will fail if grub fails to
download, which is tried before gnulib, and if that
happens, the grub directory is not created

also moved hardcoded strings into variables

removed hardcoded strings, put them in variables

use easier to read lowercase for function names

i left this here by accident when testing something
during work on a prior revision

the old code was specifing an absolute offset for
insertion of mrc.bin - cbfstool interprets anything
above 0x80000000 as top-aligned memory address in
x86, and anything below as an obsolute offset in
the flash, like with the old number

where a top-aligned address is provided to cbfstool,
the absolute position is calculated for the flash,
and cbfstool inserts it in the correct rom location

the benefit of this change is that the absolute
offset is now calculated automatically, which means
that the code will be correct even if the flash
size changes. for example, if 16MB flash is used
whereas 12MB is currently the default an support
haswell hardware

coreboot does not provide anything readably like
Kconfig, for extracting this value. it's baked
into the source code of coreboot, so you have to
find it. the correct location is hardcoded for
each platform, and always the same on each platform,
regardless of mainboard