Imported from util/spkmodem_recv at coreboot
revision:

e70bc423f9a2e1d13827f2703efe1f9c72549f20

This is a client for spkmodem, to allow serial
console via PC speaker.

I've decided to import it in lbmk, because I
heavily modified it. The patches will be
applied next.

Signed-off-by: Leah Rowe <leah@libreboot.org>

i'm pretty much finished now

there might be a few more changes later,
like stricter error handling, more verbose
error messages, etc

right now, it relies on -e to kill lbmk
on error, and uses the exit command

another planned change it to support
other upstreams besides coreboot.org,
such as the dasharo codebase

the latter is *why* i refactored this
download script, for asus kgped-d16

the build_error file is obsolete

to my knowledge, this feature has never been used,
but lbmk permits resources/coreboot/boardname/extra.sh
to execute, as provided by the maintainer, with working
directory set to: coreboot/boardname

this could be used to extend lbmk in a number of ways

for example, it could be used to patch 3rdparty/

it could also be used to break coreboot in creative
and novel ways. hint hint.

the "board" variable in prepare_new_coreboot_tree()
is also declared in fetch_coreboot_trees

for the one in prepare_new_coreboot_tree, it's passed
as an argument to the function, so give it a new name

i learned that some shells have a global scope, when
using variables of the same name between functions

this should download all trees:

	./download coreboot

without this patch, it doesn't

with this patch, it works

i overlooked this during earlier
refactoring. auditing revealed it.

top-down order, and *still* rfc 3676 compliant

i finished simplifying the logic, and
i split everything into smaller functions

there is still more more polishing to do

final touches will be done in new revisions

coreboot trees/patching is still handled
specifically by "./download coreboot"

command now available in lbmk:

./gitclone coreboot

this *only* creates the directory at:
coreboot/coreboot

this directory is never used in builds.
it is only used by download/coreboot to
create patched trees for each mainboard

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