+//! Data shared between kernel and user mode.
+
+
+/// System time is a count of 100-nanosecond intervals since January 1, 1601.
+pub type SYSTEMTIME = i64;
+
+
+/// Dystem time structure
+#[repr(C)]
+#[derive(Copy, Clone)]
+pub struct KSYSTEM_TIME
+{
+	LowPart: u32,
+	High1Time: i32,
+	High2Time: i32,
+}
+
+#[repr(C)]
+pub enum NT_PRODUCT_TYPE
+{
+	NtProductWinNt = 1,
+	NtProductLanManNt,
+	NtProductServer
+}
+
+#[repr(C)]
+pub enum ALTERNATIVE_ARCHITECTURE_TYPE
+{
+	StandardDesign,
+	NEC98x86,
+	EndAlternatives,
+}
+
+/// The data shared between kernel and user mode.
+#[repr(C)]
+pub struct KUSER_SHARED_DATA
+{
+	pub TickCountLowDeprecated: u32,
+	pub TickCountMultiplier: u32,
+
+	/// Current 64-bit interrupt time in 100ns units.
+	pub InterruptTime: KSYSTEM_TIME,
+	/// Current 64-bit system time in 100ns units.
+	pub SystemTime: KSYSTEM_TIME,
+	/// Current 64-bit time zone bias.
+	pub TimeZoneBias: KSYSTEM_TIME,
+
+	pub ImageNumberLow: u16,
+	pub ImageNumberHigh: u16,
+
+	pub NtSystemRoot: [u16; 260],
+
+	pub MaxStackTraceDepth: u32,
+	pub CryptoExponent: u32,
+	pub TimeZoneId: u32,
+	pub LargePageMinimum: u32,
+	pub Reserved2: [u32; 7],
+
+	pub NtProductType: NT_PRODUCT_TYPE,
+	pub ProductTypeIsValid: bool,
+	pub NtMajorVersion: u32,
+	pub NtMinorVersion: u32,
+
+	pub ProcessorFeatures: [bool; 64],
+	pub Reserved1: u32,
+	pub Reserved3: u32,
+	pub TimeSlip: u32,
+
+	pub AlternativeArchitecture: ALTERNATIVE_ARCHITECTURE_TYPE,
+	pub SystemExpirationDate: u64,
+	pub SuiteMask: u32,
+
+	/// True if a kernel debugger is connected/enabled.
+	pub KdDebuggerEnabled: bool,
+	pub NXSupportPolicy: u8,
+	pub ActiveConsoleId: u32,
+	pub DismountCount: u32,
+	pub ComPlusPackage: u32,
+	pub LastSystemRITEventTickCount: u32,
+	pub NumberOfPhysicalPages: u32,
+
+	/// True if the system was booted in safe boot mode.
+	pub SafeBootMode: bool,
+	pub TraceLogging: u32,
+
+	pub TestRetInstruction: u64,
+	pub SystemCall: u32,
+	pub SystemCallReturn: u32,
+	pub SystemCallPad: [u64; 3],
+
+	/// The 64-bit tick count.
+	pub TickCount: KSYSTEM_TIME,
+
+	/// Cookie for encoding pointers system wide.
+	pub Cookie: u32,
+
+	// NT 6.0+:
+
+			#[cfg(target_arch = "x86_64")]
+	pub Wow64SharedInformation: [u32; 16],
+			#[cfg(target_arch = "x86_64")]
+	pub UserModeGlobalLogger: [u16; 8],
+			#[cfg(target_arch = "x86_64")]
+	pub HeapTracingPid: [u32; 2],
+			#[cfg(target_arch = "x86_64")]
+	pub CritSecTracingPid: [u32; 2],
+			#[cfg(target_arch = "x86_64")]
+	pub ImageFileExecutionOptions: u32,
+			#[cfg(target_arch = "x86_64")]
+	pub ActiveProcessorAffinity: u64,
+			#[cfg(target_arch = "x86_64")]
+	pub InterruptTimeBias: u64,
+}
+
+#[cfg(target_arch = "x86")]
+const KI_USER_SHARED_DATA: *const KUSER_SHARED_DATA = 0xffdf_0000 as *const KUSER_SHARED_DATA;
+
+#[cfg(target_arch = "x86_64")]
+const KI_USER_SHARED_DATA: *const KUSER_SHARED_DATA = 0xFFFF_F780_0000_0000 as *const KUSER_SHARED_DATA;
+
+impl KUSER_SHARED_DATA {
+
+	/// Get reference to the mapped shared data.
+	pub fn get() -> &'static KUSER_SHARED_DATA {
+		unsafe { &*KI_USER_SHARED_DATA }
+	}
+}
+
+/// Convert `KSYSTEM_TIME` to `i64`
+#[cfg(target_arch = "x86_64")]
+impl ::core::convert::From<KSYSTEM_TIME> for SYSTEMTIME {
+	fn from(time: KSYSTEM_TIME) -> Self {
+		unsafe { *(&time as *const KSYSTEM_TIME as *const SYSTEMTIME) }
+	}
+}
+
+/// Convert `KSYSTEM_TIME` to `i64`
+#[cfg(target_arch = "x86")]
+impl ::core::convert::From<KSYSTEM_TIME> for SYSTEMTIME {
+	fn from(time: KSYSTEM_TIME) -> Self {
+		// FIXME: is any `volatile` or memory fenses need here?
+		let mut lo;
+		let mut hi;
+		loop {
+			hi = time.High1Time;
+			lo = time.LowPart;
+			if hi == time.High2Time {
+				break;
+			}
+		}
+		return (hi as i64) << 32 | lo as i64
+	}
+}
+

+