driver: Google Memory Console

This patch introduces the 'memconsole' driver.

Our firmware gives us access to an in-memory log of the firmware's
output.   This gives us visibility in a data-center of headless machines
as to what the firmware is doing.

The memory console is found by the driver by finding a header block in
the EBDA.  The buffer is then copied out, and is exported to userland in
the file /sys/firmware/log.

Signed-off-by: San Mehat <san@google.com>
Signed-off-by: Mike Waychison <mikew@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/firmware/google/Kconfig b/drivers/firmware/google/Kconfig
index 4a03835..640dc6b 100644
--- a/drivers/firmware/google/Kconfig
+++ b/drivers/firmware/google/Kconfig
@@ -7,3 +7,11 @@
 	  platforms.  This provides an interface for writing to and
 	  clearing the EFI event log and reading and writing NVRAM
 	  variables.
+
+config GOOGLE_MEMCONSOLE
+	tristate "Firmware Memory Console"
+	depends on DMI
+	help
+	  This option enables the kernel to search for a firmware log in
+	  the EBDA on Google servers.  If found, this log is exported to
+	  userland in the file /sys/firmware/log.