2. modify the method of getting right FVB protocol interface. move the notification event of FVB installation into variable driver. and also move ExitBootService event into variable driver.
3. use EFI_FVB2_WRITE_STATUS flag to distinct whether the FVB protocol supports writing operation or not.Currently, DxeCore installs FVB which has ~EFI_FVB2_WRITE_STATUS(that is, disable write) attrbiute. FvbRuntimeDxe driver should provide a full FVB protocol, which returns EFI_FVB2_WRITE_STATUS attribute to signify itself provide writable FVB protocol. So other modules which need write data by FVB protocol can locate it correctly.
git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@7835 6f19259b-4bc3-4df7-8a09-765794883524
eric_tian
lgao4