Implement core Object Manager subsystem

xtoskrnl/ob/devmap.cc

@@ -0,0 +1,82 @@
+/**
+ * PROJECT:         ExectOS
+ * COPYRIGHT:       See COPYING.md in the top level directory
+ * FILE:            xtoskrnl/ob/devmap.cc
+ * DESCRIPTION:     Object Manager Device Map
+ * DEVELOPERS:      Aiken Harris <harraiken91@gmail.com>
+ */
+
+#include <xtos.hh>
+
+
+/**
+ * Retrieves the Global Devices Directory associated with a given directory's device map.
+ *
+ * @param Directory
+ *        Supplies a pointer to the object directory to query.
+ *
+ * @return Returns a pointer to the global devices directory, or NULLPTR if none exists.
+ *
+ * @since XT 1.0
+ */
+XTAPI
+POBJECT_DIRECTORY
+OB::DeviceMap::GetGlobalDevicesDirectory(IN POBJECT_DIRECTORY Directory)
+{
+    POBJECT_DIRECTORY GlobalDevicesDirectory;
+
+    /* Assume no mapping exists */
+    GlobalDevicesDirectory = NULLPTR;
+
+    /* Acquire the device map lock */
+    KE::PushLock::AcquireExclusivePushLock(&DeviceMapLock);
+
+    /* Check if the directory has an associated device map */
+    if(Directory->DeviceMap)
+    {
+        /* Extract the global devices directory */
+        GlobalDevicesDirectory = Directory->DeviceMap->GlobalDevicesDirectory;
+    }
+
+    /* Release the device map lock */
+    KE::PushLock::ReleaseExclusivePushLock(&DeviceMapLock);
+
+    /* Return the resolved directory */
+    return GlobalDevicesDirectory;
+}
+
+/**
+ * Retrieves the current state of the unique device maps configuration.
+ *
+ * @return This routine returns TRUE if unique device maps are enabled, or FALSE otherwise.
+ *
+ * @since XT 1.0
+ */
+XTAPI
+BOOLEAN
+OB::DeviceMap::GetUniqueDeviceMaps(VOID)
+{
+    /* Return the unique device maps flag */
+    return UniqueDeviceMaps;
+}
+
+/**
+ * Initializes the Object Manager's device map subsystem.
+ *
+ * @return This routine returns a status code indicating the success or failure of the operation.
+ *
+ * @since XT 1.0
+ */
+XTAPI
+XTSTATUS
+OB::DeviceMap::InitializeDeviceMap(VOID)
+{
+    /* Initialize device map lock */
+    KE::PushLock::InitializePushLock(&DeviceMapLock);
+
+    /* Temporarily disable unique device maps */
+    UniqueDeviceMaps = FALSE;
+
+    /* Return success */
+    return STATUS_SUCCESS;
+}