On Apr 28, 2014, at 2:25 AM, Sergey Tretiyak <[email protected]> wrote:
> It seems that the memory pages where EFI apps are loaded, are set to be with > access level set to "supervisor" by default, and cannot be executed from CPL > 3 (page fault with error code 5 are received if tried). Is it possible by any > way to change the access level of these memory pages, so they can be executed > from CPL 3? Any protocol, or build-time configuration? The state is defined in the UEFI 2.4 spec in section 2.3. You might want to look at 2.3.4.3 Enabling Paging or Alternate Translations in an Application. Section 2.3.4.3 is targeted at OS loaders that require a more complex virtual environment. The state of EFI paging is kept simple to make it easier for an OS loader to “do something more complex’. Thus if you want to run code a CPL3 it is up you to manage the page tables, in a fashion that is compatible with EFI. There are no UEFI or PI APIs to manage privilege levels in the x86 sense of the word. Thanks, Andrew Fish > ------------------------------------------------------------------------------ > "Accelerate Dev Cycles with Automated Cross-Browser Testing - For FREE > Instantly run your Selenium tests across 300+ browser/OS combos. Get > unparalleled scalability from the best Selenium testing platform available. > Simple to use. Nothing to install. Get started now for free." > http://p.sf.net/sfu/SauceLabs_______________________________________________ > edk2-devel mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/edk2-devel ------------------------------------------------------------------------------ Is your legacy SCM system holding you back? Join Perforce May 7 to find out: • 3 signs your SCM is hindering your productivity • Requirements for releasing software faster • Expert tips and advice for migrating your SCM now http://p.sf.net/sfu/perforce _______________________________________________ edk2-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/edk2-devel
