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authorAaron Durbin <adurbin@chromium.org>2017-10-12 11:23:58 -0600
committerAaron Durbin <adurbin@chromium.org>2017-10-16 16:56:15 +0000
commitc714137d9519c12d2b951abf3c335fb1d6912029 (patch)
tree3139ed56326f5f3fa3735893de0fc37b3cd4b623 /src
parentd45011c9c63afb6f4b25b8ae92d7b74cc873b15c (diff)
downloadcoreboot-c714137d9519c12d2b951abf3c335fb1d6912029.tar.xz
soc/intel/common: sanity check ebda signature
It's possible for chipsets utilizing ebda to cache the cbmem_top() value to be called prior to the object being entirely setup. As such it's important to check the signature to ensure the object has been initialized. Do that in a newly introduced function, retrieve_ebda_object(), which will zero out the object if the signature doesn't match. Change-Id: I66b07c36f46ed9112bc39b44914c860ba68677ae Signed-off-by: Aaron Durbin <adurbin@chromium.org> Reviewed-on: https://review.coreboot.org/21995 Tested-by: build bot (Jenkins) <no-reply@coreboot.org> Reviewed-by: Subrata Banik <subrata.banik@intel.com> Reviewed-by: Matt DeVillier <matt.devillier@gmail.com>
Diffstat (limited to 'src')
-rw-r--r--src/soc/intel/common/block/ebda/ebda.c9
-rw-r--r--src/soc/intel/common/block/include/intelblocks/ebda.h6
-rw-r--r--src/soc/intel/skylake/memmap.c2
3 files changed, 15 insertions, 2 deletions
diff --git a/src/soc/intel/common/block/ebda/ebda.c b/src/soc/intel/common/block/ebda/ebda.c
index 87c18d9bc5..4f60490824 100644
--- a/src/soc/intel/common/block/ebda/ebda.c
+++ b/src/soc/intel/common/block/ebda/ebda.c
@@ -15,6 +15,7 @@
#include <arch/ebda.h>
#include <intelblocks/ebda.h>
+#include <string.h>
/*
* Mainboard Override function
@@ -47,3 +48,11 @@ void fill_ebda_area(void)
create_mainboard_ebda(cfg);
write_ebda_data(cfg, sizeof(*cfg));
}
+
+void retrieve_ebda_object(struct ebda_config *cfg)
+{
+ read_ebda_data(cfg, sizeof(*cfg));
+
+ if (cfg->signature != EBDA_SIGNATURE)
+ memset(cfg, 0, sizeof(*cfg));
+}
diff --git a/src/soc/intel/common/block/include/intelblocks/ebda.h b/src/soc/intel/common/block/include/intelblocks/ebda.h
index 031cf1973d..16124df7e0 100644
--- a/src/soc/intel/common/block/include/intelblocks/ebda.h
+++ b/src/soc/intel/common/block/include/intelblocks/ebda.h
@@ -18,7 +18,7 @@
#include <soc/ebda.h>
-#define EBDA_SIGNATURE 0xebda
+#define EBDA_SIGNATURE 0xebdaebda
/*
* Mainboard Override function
@@ -45,6 +45,10 @@ void fill_soc_memmap_ebda(struct ebda_config *cfg);
*/
void fill_ebda_area(void);
+/* Fill the ebda object pointed to by cfg. Object will be zero filled
+ * if signature check fails. */
+void retrieve_ebda_object(struct ebda_config *cfg);
+
/*
* EBDA structure
*
diff --git a/src/soc/intel/skylake/memmap.c b/src/soc/intel/skylake/memmap.c
index 485b8c4cbb..eaf7d073ae 100644
--- a/src/soc/intel/skylake/memmap.c
+++ b/src/soc/intel/skylake/memmap.c
@@ -348,7 +348,7 @@ void *cbmem_top(void)
if (sa_get_tseg_base() == 0)
return NULL;
- read_ebda_data(cfg, sizeof(*cfg));
+ retrieve_ebda_object(cfg);
return (void *)(uintptr_t)cfg->tolum_base;
}