Implement Kernel Shared Data management and initialization

xtoskrnl/ke/amd64/krnlinit.cc

@@ -53,8 +53,8 @@ KE::KernelInit::InitializeMachine(VOID)
     /* Initialize page map support */
     MM::Paging::InitializePageMapSupport();
 
-    /* Map Kernel Shared Data (KSD) */
-    MM::Manager::MapKernelSharedData();
+    /* Initialize Kernel Shared Data (KSD) */
+    KE::SharedData::InitializeKernelSharedData();
 
     /* Initialize processor */
     HL::Cpu::InitializeProcessor();

xtoskrnl/ke/data.cc

@@ -21,6 +21,9 @@ ETHREAD KE::KThread::InitialThread = {};
 /* Kernel UBSAN active frame flag */
 BOOLEAN KE::KUbsan::ActiveFrame = FALSE;
 
+/* Kernel shared data (KSD) */
+PKSHARED_DATA KE::SharedData::KernelSharedData;
+
 /* Kernel dispatcher lock queue */
 KSPIN_LOCK KE::SpinLock::DispatcherLockQueue;
 

xtoskrnl/ke/i686/krnlinit.cc

@@ -53,8 +53,8 @@ KE::KernelInit::InitializeMachine(VOID)
     /* Initialize page map support */
     MM::Paging::InitializePageMapSupport();
 
-    /* Map Kernel Shared Data (KSD) */
-    MM::Manager::MapKernelSharedData();
+    /* Initialize Kernel Shared Data (KSD) */
+    KE::SharedData::InitializeKernelSharedData();
 
     /* Initialize processor */
     HL::Cpu::InitializeProcessor();

xtoskrnl/ke/shdata.cc

@@ -0,0 +1,129 @@
+/**
+ * PROJECT:         ExectOS
+ * COPYRIGHT:       See COPYING.md in the top level directory
+ * FILE:            xtoskrnl/ke/shdata.cc
+ * DESCRIPTION:     Kernel Shared Data
+ * DEVELOPERS:      Aiken Harris <harraiken91@gmail.com>
+ */
+
+#include <xtos.hh>
+
+
+/**
+ * Retrieves a pointer to the memory-mapped Kernel Shared Data.
+ *
+ * @return This routine returns a pointer to the KSHARED_DATA structure.
+ *
+ * @since XT 1.0
+ */
+XTAPI
+PKSHARED_DATA
+KE::SharedData::GetKernelSharedData(VOID)
+{
+    /* Return the internally managed pointer */
+    return KernelSharedData;
+}
+
+/**
+ * Retrieves the current system time using a lock-free read mechanism.
+ *
+ * @return This routine returns a LARGE_INTEGER containing the system time.
+ *
+ * @since XT 1.0
+ */
+XTAPI
+LARGE_INTEGER
+KE::SharedData::GetSystemTime(VOID)
+{
+    LARGE_INTEGER CurrentTime;
+
+    /* Initialize to zero */
+    CurrentTime.QuadPart = 0;
+
+    /* Perform a lock-free read sequence */
+    do
+    {
+        /* Read the primary high part and low part */
+        CurrentTime.HighPart = KernelSharedData->SystemTime.High1Part;
+        CurrentTime.LowPart = KernelSharedData->SystemTime.LowPart;
+    }
+    while(CurrentTime.HighPart != KernelSharedData->SystemTime.High2Part);
+
+    /* Return the 64-bit time */
+    return CurrentTime;
+}
+
+/**
+ * Maps and initializes the Kernel Shared Data (KSD) structure.
+ *
+ * @return This routine does not return any value.
+ *
+ * @since XT 1.0
+ */
+XTAPI
+VOID
+KE::SharedData::InitializeKernelSharedData(VOID)
+{
+    PCSTR SourceString;
+    XTSTATUS Status;
+
+    /* Map Kernel Shared Data (KSD) */
+    Status = MM::Manager::MapKernelSharedData();
+    if(Status != STATUS_SUCCESS)
+    {
+        /* Failed to map KSD, raise kernel panic */
+        KE::Crash::Panic(0);
+    }
+
+    /* Bind the pointer to the architectural virtual address */
+    KernelSharedData = (PKSHARED_DATA)MM_KERNEL_SHARED_DATA_ADDRESS;
+
+    /* Populate numeric version identifiers */
+    KernelSharedData->XtMajorVersion = XTOS_VERSION_MAJOR;
+    KernelSharedData->XtMinorVersion = XTOS_VERSION_MINOR;
+
+    /* Convert and copy system build string */
+    SourceString = XTOS_VERSION_BUILD;
+    RTL::String::StringToWideString(KernelSharedData->XtBuild, (PCSTR*)&SourceString,
+                                    (sizeof(KernelSharedData->XtBuild) / sizeof(WCHAR)) - 1);
+
+    /* Convert and copy system build hash string */
+    SourceString = XTOS_VERSION_HASH;
+    RTL::String::StringToWideString(KernelSharedData->XtBuildHash, (PCSTR*)&SourceString,
+                                    (sizeof(KernelSharedData->XtBuildHash) / sizeof(WCHAR)) - 1);
+
+    /* Convert and copy system architecture string */
+    SourceString = XTOS_VERSION_ARCH;
+    RTL::String::StringToWideString(KernelSharedData->XtArchitecture, (PCSTR*)&SourceString,
+                                    (sizeof(KernelSharedData->XtArchitecture) / sizeof(WCHAR)) - 1);
+
+    /* Convert and copy system build date string */
+    SourceString = XTOS_VERSION_DATE;
+    RTL::String::StringToWideString(KernelSharedData->XtDate, (PCSTR*)&SourceString,
+                                    (sizeof(KernelSharedData->XtDate) / sizeof(WCHAR)) - 1);
+
+    /* Convert and copy system build full date string */
+    SourceString = XTOS_VERSION_FULLDATE;
+    RTL::String::StringToWideString(KernelSharedData->XtFullDate, (PCSTR*)&SourceString,
+                                    (sizeof(KernelSharedData->XtFullDate) / sizeof(WCHAR)) - 1);
+}
+
+/**
+ * Updates the global system time using a strict lock-free write mechanism.
+ *
+ * @param Time
+ *        Supplies the new system time as a 64-bit LARGE_INTEGER value.
+ *
+ * @return This routine does not return any value.
+ *
+ * @since XT 1.0
+ */
+XTAPI
+VOID
+KE::SharedData::SetSystemTime(IN LARGE_INTEGER Time)
+{
+    /* Set the new system time */
+    KernelSharedData->SystemTime.High2Part = Time.HighPart;
+    KernelSharedData->SystemTime.LowPart = Time.LowPart;
+    KernelSharedData->SystemTime.High1Part = Time.HighPart;
+}