For the bitfield access, MSVC apparently uses a right shift of the base type of the bitfield member. In our case, is is cased by IA32_PTE_4K and
IA32_PAGE_LEAF_ENTRY_BIG_PAGESIZE and other structures which uses uint64
bitfields and 32-bit x86 doesn't have a 64-bit integer shift (except using MMX or SSE2). With -Od (NOOPT) even for constant counts it puts
the data in EDX:EAX, the shift count in cl and calls __aullshr.
Signed-off-by: Savva Mitrofanov <savvamtr@gmail.com>
The lib includes two APIs:
* PageTableMap
It creates/updates mapping from LA to PA.
The implementation only supports paging structures used in 64bit
mode now. PAE paging structure support will be added in future.
* PageTableParse
It parses the page table and returns the mapping relations in an
array of IA32_MAP_ENTRY.
It passed some stress tests. These test code will be upstreamed in
other patches following edk2 Unit Test framework.
Signed-off-by: Ray Ni <ray.ni@intel.com>
Reviewed-by: Eric Dong <eric.dong@intel.com>
