x86: add cache-as-ram migration option
There are some boards that do a significant amount of
work after cache-as-ram is torn down but before ramstage
is loaded. For example, using vboot to verify the ramstage
is one such operation. However, there are pieces of code
that are executed that reference global variables that
are linked in the cache-as-ram region. If those variables
are referenced after cache-as-ram is torn down then the
values observed will most likely be incorrect.
Therefore provide a Kconfig option to select cache-as-ram
migration to memory using cbmem. This option is named
CAR_MIGRATION. When enabled, the address of cache-as-ram
variables may be obtained dynamically. Additionally,
when cache-as-ram migration occurs the cache-as-ram
data region for global variables is copied into cbmem.
There are also automatic callbacks for other modules
to perform their own migration, if necessary.
Change-Id: I2e77219647c2bd2b1aa845b262be3b2543f1fcb7
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: http://review.coreboot.org/3232
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
diff --git a/src/include/cbmem.h b/src/include/cbmem.h
index 67cb1cb..baec780 100644
--- a/src/include/cbmem.h
+++ b/src/include/cbmem.h
@@ -69,6 +69,7 @@
#define CBMEM_ID_RAMSTAGE_CACHE 0x9a3ca54e
#define CBMEM_ID_ROOT 0xff4007ff
#define CBMEM_ID_VBOOT_HANDOFF 0x780074f0
+#define CBMEM_ID_CAR_GLOBALS 0xcac4e6a3
#define CBMEM_ID_NONE 0x00000000
#ifndef __ASSEMBLER__