diff options
| author | Aaron Durbin <adurbin@chromium.org> | 2017-10-12 11:23:58 -0600 |
|---|---|---|
| committer | Aaron Durbin <adurbin@chromium.org> | 2017-10-16 16:56:15 +0000 |
| commit | c714137d9519c12d2b951abf3c335fb1d6912029 (patch) | |
| tree | 3139ed56326f5f3fa3735893de0fc37b3cd4b623 | |
| parent | d45011c9c63afb6f4b25b8ae92d7b74cc873b15c (diff) | |
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>
| -rw-r--r-- | src/soc/intel/common/block/ebda/ebda.c | 9 | ||||
| -rw-r--r-- | src/soc/intel/common/block/include/intelblocks/ebda.h | 6 | ||||
| -rw-r--r-- | src/soc/intel/skylake/memmap.c | 2 |
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; } |