UPSTREAM: cbmem_console: Document known reimpementations of console structure/API

It turns out that there are quite a few other projects that can access
the CBMEM console by now. If we ever want to make another structural or
behavioral change to it, we need to know where these implementations are
so we can make sure they're all getting updated. Let's try to build a
comprehensive list in the file that should be the source of truth for
all (coreboot's own implementation).

BUG=none
BRANCH=none
TEST=none

Change-Id: Iae97ac8306e640fde6bd2300f62b7fcaf960eea0
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Original-Commit-Id: a915cea289
Original-Change-Id: Ia3d6a87230f5bfdde9d812bc7154e22880c1377a
Original-Signed-off-by: Julius Werner <jwerner@chromium.org>
Original-Reviewed-on: https://review.coreboot.org/19439
Original-Tested-by: build bot (Jenkins)
Original-Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Original-Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/488056

src/lib/cbmem_console.c

@@ -28,6 +28,16 @@
  * cursor field gets set to indicate that this happened. If the underlying
  * storage allows this, the buffer will persist across multiple boots and append
  * to the previous log.
+ *
+ * NOTE: These are known implementations accessing this console that need to be
+ * updated in case of structure/API changes:
+ *
+ * cbmem:	[coreboot]/src/util/cbmem/cbmem.c
+ * libpayload:	[coreboot]/payloads/libpayload/drivers/cbmem_console.c
+ * coreinfo:	[coreboot]/payloads/coreinfo/bootlog_module.c
+ * Linux:	drivers/firmware/google/memconsole-coreboot.c
+ * SeaBIOS:	src/firmware/coreboot.c
+ * GRUB:	grub-core/term/i386/coreboot/cbmemc.c
  */
 struct cbmem_console {
 	u32 size;