About Intel PSM(5)
MS added the capability of backing-up and restoring the Registry form flash.
This support takes the form of two functions: a back-up function and a restore function.The OS passes the Registry to the back-up function,and the function programs it into flash.When the OS initializes,it will call the restore function,and that function reads the Registry out of flash and returns it to the OS.The OS then uses that version to initialize itself.
It is likely that the implementation of the Registry flush(the call to RegFlushKey)may need to be implemented in your BSP by you.
The first time the system boots,there will not be a copy of the Rgistry in flash.In that case,the ReadRegistryFromOEM will return an error code.When the kernel sees that there is no Registry in flash,it will revert to the default Registry in the OS image.
It is challenging for software developers who want to build portable applications that can benefit from using PSM.Fortunately,there is a relatively easy way for developers to address the challenge-that is,designing the application so that it determines the name of PSM folder at runtime.
Starting with Intel PSM 3.5,PSM can be taught how to handle flash that is hardware locked via the hardware locking signal Vpen.This allows flash contents to be as protected as much as possible from accidental writes or corruption.When this feature is combined with individual block locking,specifically of the non-PSM managed blocks,code in flash is virtually impossible to disturb.
This support takes the form of two functions: a back-up function and a restore function.The OS passes the Registry to the back-up function,and the function programs it into flash.When the OS initializes,it will call the restore function,and that function reads the Registry out of flash and returns it to the OS.The OS then uses that version to initialize itself.
It is likely that the implementation of the Registry flush(the call to RegFlushKey)may need to be implemented in your BSP by you.
The first time the system boots,there will not be a copy of the Rgistry in flash.In that case,the ReadRegistryFromOEM will return an error code.When the kernel sees that there is no Registry in flash,it will revert to the default Registry in the OS image.
It is challenging for software developers who want to build portable applications that can benefit from using PSM.Fortunately,there is a relatively easy way for developers to address the challenge-that is,designing the application so that it determines the name of PSM folder at runtime.
Starting with Intel PSM 3.5,PSM can be taught how to handle flash that is hardware locked via the hardware locking signal Vpen.This allows flash contents to be as protected as much as possible from accidental writes or corruption.When this feature is combined with individual block locking,specifically of the non-PSM managed blocks,code in flash is virtually impossible to disturb.
