Initial support for preinitialized array in CoreRT (#3558)

* Add PreInitFieldInfo that extracts preinitialized data information from fields that have [PreInitialized] and [InitDataBlob] pointing to RVA field
* Added FrozenArrayNode for frozen arrays with data extracted from preinit RVA data field
* Added GCStaticsPreInitDataNode (CoreRT only) to hold GC pointers for GC static fields. Pre-init data fields points to frozen data, while other data initialized to null. 
* Changed GCStaticsNode to emit a pointer reloc to GCStaticspreInitDataNode and mask 0x2 for the GC static EEType. 
* Changed InitializedStatics in StartupCodeHelper to check for 0x2 and memcpy the GC field data as needed
* Fixed a bug in bad GCStaticsEETypeNode size calculation - it's off-by-1 as static GC static field layout in CoreRT includes EEType already.

2 files changed, 23 insertions, 0 deletions

diff --git a/src/Test.CoreLib/src/System/Object.cs b/src/Test.CoreLib/src/System/Object.cs
index a6addf96b..60777622e 100644
--- a/src/Test.CoreLib/src/System/Object.cs
+++ b/src/Test.CoreLib/src/System/Object.cs
@@ -19,6 +19,7 @@ using System.Runtime.InteropServices;
 
 // TODO: remove when m_pEEType becomes EETypePtr
 using EEType = Internal.Runtime.EEType;
+using ObjHeader = Internal.Runtime.ObjHeader;
 
 namespace System
 {
@@ -89,5 +90,14 @@ namespace System
         {
             return ref Unsafe.As<RawData>(this).Data;
         }
+
+        /// <summary>
+        /// Return size of all data (excluding ObjHeader and EEType*).
+        /// Note that for strings/arrays this would include the Length as well.
+        /// </summary>
+        internal unsafe uint GetRawDataSize()
+        {
+            return EEType->BaseSize - (uint)sizeof(ObjHeader) - (uint)sizeof(EEType*);
+        }
     }
 }
diff --git a/src/Test.CoreLib/src/System/Runtime/RuntimeImports.cs b/src/Test.CoreLib/src/System/Runtime/RuntimeImports.cs
index ecdda3bdc..014fe31b5 100644
--- a/src/Test.CoreLib/src/System/Runtime/RuntimeImports.cs
+++ b/src/Test.CoreLib/src/System/Runtime/RuntimeImports.cs
@@ -8,6 +8,12 @@ using System.Runtime.InteropServices;
 using System.Runtime.CompilerServices;
 using Internal.Runtime;
 
+#if BIT64
+using nuint = System.UInt64;
+#else
+using nuint = System.UInt32;
+#endif
+
 namespace System.Runtime
 {
     // CONTRACT with Runtime
@@ -96,5 +102,12 @@ namespace System.Runtime
         [MethodImplAttribute(MethodImplOptions.InternalCall)]
         [RuntimeImport(RuntimeLibrary, "RhpMemoryBarrier")]
         internal extern static void MemoryBarrier();
+
+        // Moves memory from smem to dmem. Size must be a positive value.
+        // This copy uses an intrinsic to be safe for copying arbitrary bits of
+        // heap memory
+        [MethodImplAttribute(MethodImplOptions.InternalCall)]
+        [RuntimeImport(RuntimeLibrary, "RhBulkMoveWithWriteBarrier")]
+        internal static extern unsafe void RhBulkMoveWithWriteBarrier(ref byte dmem, ref byte smem, nuint size);
     }
 }