Hi Andrew,<br /><br />Thank you, for the detail answer. It seems this is what I'm looking for. Now I've found the UEFI specification of the UEFI application I build, and it appears that the specification of the application is greater than the EFI Shall specification it is going to be used with. Is it ok, or I should find the EDK2 with UEFI specification exactly the same as the EFI Shell specification and rebuild my EFI app?<br /><br />Thank you,<br />Sergey