audk/IntelFrameworkPkg/Include
Jian J Wang 7619eed8aa IntelFrameworkPkg/LegacyBios.h: Add a macro to guarantee page 0 access
Due to the introduction of NULL pointer detection feature, page 0 will be
disabled if the feature is enabled, which will cause legacy code failed to
update legacy data in page 0. This macro is introduced to make sure the
page 0 is enabled before those code and restore the original status of it
afterwards.

Another reason to introduce this macro is to eliminate the dependency on
the PcdNullPointerDetectionPropertyMask. Because this is a new PCD, it
could cause some backward compatibility issue for some old packages.

This macro will simply check if the page 0 is disabled or not. If it's
disabled, it will enable it before code updating page 0 and disable it
afterwards. Otherwise, this macro will do nothing to page 0.

The usage of the macro will be look like (similar to DEBUG_CODE macro):

    ACCESS_PAGE0_CODE(
      <code accessing page 0>
    );

Cc: Liming Gao <liming.gao@intel.com>
Cc: Michael D Kinney <michael.d.kinney@intel.com>
Cc: Ruiyu Ni <ruiyu.ni@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Jian J Wang <jian.j.wang@intel.com>
Reviewed-by: Ruiyu Ni <ruiyu.ni@intel.com>
2017-12-08 14:38:44 +08:00
..
Framework Update definition of EFI_SMM_CPU_SAVE_STATE to exclude Itanium save state. Note this is an inconsistency with the Framework SMM CIS spec. 2010-12-22 02:34:45 +00:00
Guid Add comments for EFI_CACHE_SRAM_TYPE_DATA because of the inconsistency between CacheSubclass 0.9 and SMBIOS specifications. 2011-12-15 06:42:15 +00:00
Ppi Update the copyright notice format 2010-04-23 15:52:13 +00:00
Protocol IntelFrameworkPkg/LegacyBios.h: Add a macro to guarantee page 0 access 2017-12-08 14:38:44 +08:00
FrameworkDxe.h Update the copyright notice format 2010-04-23 15:52:13 +00:00
FrameworkPei.h Update the copyright notice format 2010-04-23 15:52:13 +00:00
FrameworkSmm.h Update the copyright notice format 2010-04-23 15:52:13 +00:00