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Function RTMapPhysMem

Function RTMapPhysMem prepares a pointer in the virtual address space through which physical memory can be accessed:

void * RTMapPhysMem(const void * Physical, unsigned Bytes, int Access);

Parameters

Physical

Physical address to map.

Bytes

Specifies the size of the address range.

Access

Specifies the desired access rights to the virtual address range. Values RT_PG_NOACCESS, RT_PG_SYSREAD, RT_PG_SYSREADWRITE, RT_PG_USERREAD, and RT_PG_USERREADWRITE are supported.

return value

A pointer in the virtual address space which maps to the requested physical memory or NULL on failure.

The function calls RTFindPhysMem, RTReserveVirtualAddress, and RTMapMem internally to make a physical address space area available in the virtual address space. If paging is disabled, the function merely returns parameter Physical. With paging, it may return Physical or some other address.

The virtual address space allocated through this function can be freed with RTReleaseVirtualAddress.

Function RTMapMem

Function RTMapPhysMemEx