--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/nspr/pr/src/md/windows/ntgc.c	Mon Jul 28 10:47:06 2014 +0200
@@ -0,0 +1,98 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/*
+ * GC related routines
+ *
+ */
+#include <windows.h>
+#include "primpl.h"
+
+PRWord *_MD_HomeGCRegisters(PRThread *t, int isCurrent, int *np) 
+{
+#if defined(_X86_)
+    CONTEXT context;
+    context.ContextFlags = CONTEXT_INTEGER;
+
+    if (_PR_IS_NATIVE_THREAD(t)) {
+        context.ContextFlags |= CONTEXT_CONTROL;
+        if (GetThreadContext(t->md.handle, &context)) {
+            t->md.gcContext[0] = context.Eax;
+            t->md.gcContext[1] = context.Ebx;
+            t->md.gcContext[2] = context.Ecx;
+            t->md.gcContext[3] = context.Edx;
+            t->md.gcContext[4] = context.Esi;
+            t->md.gcContext[5] = context.Edi;
+            t->md.gcContext[6] = context.Esp;
+            t->md.gcContext[7] = context.Ebp;
+            *np = PR_NUM_GCREGS;
+        } else {
+            PR_ASSERT(0);/* XXX */
+        }
+    } else {
+        /* WARNING WARNING WARNING WARNING WARNING WARNING WARNING
+         *
+         * This code is extremely machine dependant and completely 
+         * undocumented by MS.  Its only known to work experimentally.  
+         * Ready for a walk on the wild * side?
+         *
+         * WARNING WARNING WARNING WARNING WARNING WARNING WARNING */
+
+#if !defined WIN95 // Win95 does not have fibers
+        int *fiberData = t->md.fiber_id;
+
+        /* I found these offsets by disassembling SwitchToFiber().
+         * Are your palms sweating yet?
+         */
+
+        /* 
+        ** EAX is on the stack (ESP+0)
+        ** EDX is on the stack (ESP+4)
+        ** ECX is on the stack (ESP+8)
+        */
+        t->md.gcContext[0] = 0;                /* context.Eax */
+        t->md.gcContext[1] = fiberData[0x2e];  /* context.Ebx */
+        t->md.gcContext[2] = 0;                /* context.Ecx */
+        t->md.gcContext[3] = 0;                /* context.Edx */
+        t->md.gcContext[4] = fiberData[0x2d];  /* context.Esi */
+        t->md.gcContext[5] = fiberData[0x2c];  /* context.Edi */
+        t->md.gcContext[6] = fiberData[0x36];  /* context.Esp */
+        t->md.gcContext[7] = fiberData[0x32];  /* context.Ebp */
+        *np = PR_NUM_GCREGS;
+#endif
+    }
+    return (PRWord *)&t->md.gcContext;
+#else
+    PR_NOT_REACHED("not implemented");
+    return NULL;
+#endif /* defined(_X86_) */
+}
+
+/* This function is not used right now, but is left as a reference.
+ * If you ever need to get the fiberID from the currently running fiber, 
+ * this is it.
+ */
+void *
+GetMyFiberID()
+{
+#if defined(_X86_) && !defined(__MINGW32__)
+    void *fiberData;
+
+    /* A pointer to our tib entry is found at FS:[18]
+     * At offset 10h is the fiberData pointer.  The context of the 
+     * fiber is stored in there.  
+     */
+    __asm {
+        mov    EDX, FS:[18h]
+        mov    EAX, DWORD PTR [EDX+10h]
+        mov    [fiberData], EAX
+    }
+  
+    return fiberData;
+#else
+    PR_NOT_REACHED("not implemented");
+    return NULL;
+#endif /* defined(_X86_) */
+}