(+Grant) On 10/12/18 16:40, Sami Mujawar wrote: > Some platforms are able to preserve a memory range across > system resets. This memory can be used for the Non-Volatile > variables storage. The PcdEmuVariableNvStoreReserved is > used to specify this option.
This is the wrong approach, for two reasons. (1) At a technical level, suck hacks are usually implemented by provding a platform-specific FVB (firmware volume block) protocol / driver, underneath the normal FTW and Variable drivers. The FVB implementation can (technically) fake a "persistent" flash device in RAM that is actually volatile. (2) At a design level, this is an extremely bad idea though. Such variables are only halfway non-volatile, and that fact always comes back to bite users, sooner or later. I speak from experience with OVMF, but more recently, there has been discussion on the USWG list too, about platforms that can only fake non-volatility. I can't provide more details on this open list about that, so I'll just give you a Message-Id, and a Mantis ticket. <[email protected]> https://mantis.uefi.org/mantis/view.php?id=1961 Thanks, Laszlo _______________________________________________ edk2-devel mailing list [email protected] https://lists.01.org/mailman/listinfo/edk2-devel
