Index: boehm-gc/darwin_stop_world.c
===================================================================
--- boehm-gc/darwin_stop_world.c	(revision 112376)
+++ boehm-gc/darwin_stop_world.c	(working copy)
@@ -75,7 +75,13 @@
   GC_thread p;
   pthread_t me;
   ptr_t lo, hi;
+#if defined(POWERPC)
   ppc_thread_state_t state;
+#elif defined(I386)
+  i386_thread_state_t state;
+#else
+# error FIXME for non-x86 || ppc architectures
+#endif
   mach_msg_type_number_t thread_state_count = MACHINE_THREAD_STATE_COUNT;
   
   me = pthread_self();
@@ -95,6 +101,17 @@
 			     &thread_state_count);
 	if(r != KERN_SUCCESS) ABORT("thread_get_state failed");
 	
+#if defined(I386)
+	lo = state.esp;
+
+	GC_push_one(state.eax); 
+	GC_push_one(state.ebx); 
+	GC_push_one(state.ecx); 
+	GC_push_one(state.edx); 
+	GC_push_one(state.edi); 
+	GC_push_one(state.esi); 
+	GC_push_one(state.ebp); 
+#elif defined(POWERPC)
 	lo = (void*)(state.r1 - PPC_RED_ZONE_SIZE);
         
 	GC_push_one(state.r0); 
@@ -128,6 +145,9 @@
 	GC_push_one(state.r29); 
 	GC_push_one(state.r30); 
 	GC_push_one(state.r31);
+#else
+# error FIXME for non-x86 || ppc architectures
+#endif
       } /* p != me */
       if(p->flags & MAIN_THREAD)
 	hi = GC_stackbottom;
Index: boehm-gc/include/private/gcconfig.h
===================================================================
--- boehm-gc/include/private/gcconfig.h	(revision 112376)
+++ boehm-gc/include/private/gcconfig.h	(working copy)
@@ -304,7 +304,7 @@
 #    define mach_type_known
 #   elif defined(__i386__)
 #    define I386
-     --> Not really supported, but at least we recognize it.
+#    define mach_type_known
 #   endif
 # endif
 # if defined(NeXT) && defined(mc68000)
@@ -1301,6 +1301,29 @@
 /* #     define MPROTECT_VDB  Not quite working yet? */
 #     define DYNAMIC_LOADING
 #   endif
+#   ifdef DARWIN
+#     define OS_TYPE "DARWIN"
+#     define DARWIN_DONT_PARSE_STACK
+#     define DYNAMIC_LOADING
+      /* XXX: see get_end(3), get_etext() and get_end() should not be used.
+        These aren't used when dyld support is enabled (it is by default) */
+#     define DATASTART ((ptr_t) get_etext())
+#     define DATAEND	((ptr_t) get_end())
+#     define STACKBOTTOM ((ptr_t) 0xc0000000)
+#     define USE_MMAP
+#     define USE_MMAP_ANON
+#     define USE_ASM_PUSH_REGS
+      /* This is potentially buggy. It needs more testing. See the comments in
+        os_dep.c.  It relies on threads to track writes. */
+#     ifdef GC_DARWIN_THREADS
+/* #       define MPROTECT_VDB -- disabled for now.  May work for some apps. */
+#     endif
+#     include <unistd.h>
+#     define GETPAGESIZE() getpagesize()
+      /* There seems to be some issues with trylock hanging on darwin. This
+         should be looked into some more */
+#      define NO_PTHREAD_TRYLOCK
+#   endif /* DARWIN */
 # endif
 
 # ifdef NS32K
Index: boehm-gc/os_dep.c
===================================================================
--- boehm-gc/os_dep.c	(revision 112376)
+++ boehm-gc/os_dep.c	(working copy)
@@ -3799,6 +3799,10 @@
         mach_msg_type_number_t exc_state_count = PPC_EXCEPTION_STATE64_COUNT;
         ppc_exception_state64_t exc_state;
 #     endif
+#   elif defined(I386)
+        thread_state_flavor_t flavor = i386_EXCEPTION_STATE;
+        mach_msg_type_number_t exc_state_count = i386_EXCEPTION_STATE_COUNT;
+        i386_exception_state_t exc_state;
 #   else
 #	error FIXME for non-ppc darwin
 #   endif
@@ -3830,7 +3834,13 @@
     }
     
     /* This is the address that caused the fault */
+#if defined(POWERPC)
     addr = (char*) exc_state.dar;
+#elif defined (I386)
+    addr = (char*) exc_state.faultvaddr;
+#else
+#   error FIXME for non POWERPC/I386
+#endif
         
     if((HDR(addr)) == 0) {
         /* Ugh... just like the SIGBUS problem above, it seems we get a bogus