#ifndef _NTEXAPI_H

/**
 * The SYSTEM_BASIC_INFORMATION structure contains basic information about the current system.
 */
typedef struct _SYSTEM_BASIC_INFORMATION
{
    ULONG Reserved;                                         // Reserved
    ULONG TimerResolution;                                  // The resolution of the timer, in milliseconds. // NtQueryTimerResolution
    ULONG PageSize;                                         // The page size and the granularity of page protection and commitment.
    ULONG NumberOfPhysicalPages;                            // The number of physical pages in the system. // KUSER_SHARED_DATA->NumberOfPhysicalPages
    ULONG LowestPhysicalPageNumber;                         // The lowest memory page accessible to applications and dynamic-link libraries (DLLs).
    ULONG HighestPhysicalPageNumber;                        // The highest memory page accessible to applications and dynamic-link libraries (DLLs).
    ULONG AllocationGranularity;                            // The granularity for the starting address at which virtual memory can be allocated.
    ULONG_PTR MinimumUserModeAddress;                       // A pointer to the lowest memory address accessible to applications and dynamic-link libraries (DLLs).
    ULONG_PTR MaximumUserModeAddress;                       // A pointer to the highest memory address accessible to applications and dynamic-link libraries (DLLs).
    KAFFINITY ActiveProcessorsAffinityMask;                 // A mask representing the set of processors configured in the current processor group. // deprecated 
    UCHAR NumberOfProcessors;                               // The number of logical processors in the current processor group. // deprecated
} SYSTEM_BASIC_INFORMATION, *PSYSTEM_BASIC_INFORMATION;

#endif
View code on GitHub