Paging memory vs. non-paged memory

Windows specifies that some virtual memory can be swapped into a file, which is known as paged memory

Some virtual memory is never exchanged to a file, which is called non-paged memory

#define Pagedcode code_seg ("page");//Paging memory

#define Lockedcode code_seg ();//Non-paged

#define Initcode code_seg ("INIT");

#define PAGEDDATA data_seg ("page");

#define Lockeddata data_seg ();

#define InitData data_seg ("INIT");

Cases:

If you load a function into paged memory, the following functions are available

#pragma pagedcode

VOID Fun ()

{

Paged_code (); Do something

}

Note: Paged_code () is a macro provided by DDK that only takes effect in the check version, and it checks if the function is running at an interrupt request below dispatch_leval, if it is equal to or higher than the interrupt request level, An assertion is generated. When the program is running on top of dispatch_level (including this layer), the program can only use non-paged memory, otherwise it will cause blue screen to panic

If you load a function into non-paged memory, the following functions are available

#pragma lockedcode

VOID Fun ()

{

}

A routine needs to be loaded into memory at initialization time, and then unloaded from memory, such as DriverEntry case, DriverEntry will be large, occupy a lot of space, in order to save memory, need to unload the memory in a timely manner

#pragma initcode

NTSTATUS DriverEntry (

In Pdriver_object Pdriverobject,

In Punicode_string Registerpath)

{//do something}

Paging memory vs. non-paged memory