diff --git a/minix/include/minix/com.h b/minix/include/minix/com.h
index 5010cb3af..7cacd8cdf 100644
--- a/minix/include/minix/com.h
+++ b/minix/include/minix/com.h
@@ -713,6 +713,11 @@
 #	define VM_RS_CTL_REQ		m1_i2
 #		define VM_RS_MEM_PIN	    0	/* pin memory */
 #		define VM_RS_MEM_MAKE_VM    1	/* make VM instance */
+#		define VM_RS_MEM_HEAP_PREALLOC 2 /* preallocate heap regions */
+#		define VM_RS_MEM_MAP_PREALLOC  3 /* preallocate mmaped regions */
+#		define VM_RS_MEM_GET_PREALLOC_MAP  4 /* get preallocated mmaped regions */
+#	define VM_RS_CTL_ADDR		m2_p1
+#	define VM_RS_CTL_LEN		m2_i3
 
 #define VM_WATCH_EXIT		(VM_RQ_BASE+43)
 
diff --git a/minix/include/minix/vm.h b/minix/include/minix/vm.h
index 9761502a5..f1b75259a 100644
--- a/minix/include/minix/vm.h
+++ b/minix/include/minix/vm.h
@@ -18,7 +18,7 @@ int vm_unmap_phys(endpoint_t who, void *vaddr, size_t len);
 int vm_notify_sig(endpoint_t ep, endpoint_t ipc_ep);
 int vm_set_priv(endpoint_t ep, void *buf, int sys_proc);
 int vm_update(endpoint_t src_e, endpoint_t dst_e, int flags);
-int vm_memctl(endpoint_t ep, int req);
+int vm_memctl(endpoint_t ep, int req, void** addr, size_t *len);
 int vm_query_exit(endpoint_t *endpt);
 int vm_watch_exit(endpoint_t ep);
 int minix_vfs_mmap(endpoint_t who, off_t offset, size_t len,
diff --git a/minix/lib/libsys/vm_memctl.c b/minix/lib/libsys/vm_memctl.c
index 1a4bea877..0637476cc 100644
--- a/minix/lib/libsys/vm_memctl.c
+++ b/minix/lib/libsys/vm_memctl.c
@@ -3,13 +3,27 @@
 #include <string.h>
 
 int
-vm_memctl(endpoint_t ep, int req)
+vm_memctl(endpoint_t ep, int req, void** addr, size_t *len)
 {
 	message m;
+	int r;
 
 	memset(&m, 0, sizeof(m));
 	m.VM_RS_CTL_ENDPT = ep;
 	m.VM_RS_CTL_REQ = req;
+	m.VM_RS_CTL_ADDR = addr ? *addr : 0;
+	m.VM_RS_CTL_LEN = len ? *len : 0;
 
-	return _taskcall(VM_PROC_NR, VM_RS_MEMCTL, &m);
+	r = _taskcall(VM_PROC_NR, VM_RS_MEMCTL, &m);
+	if(r != OK) {
+		return r;
+	}
+	if(addr) {
+		*addr = m.VM_RS_CTL_ADDR;
+	}
+	if(addr) {
+		*len = m.VM_RS_CTL_LEN;
+	}
+
+	return OK;
 }
diff --git a/minix/servers/rs/manager.c b/minix/servers/rs/manager.c
index 9fb6e2702..8c3f027cb 100644
--- a/minix/servers/rs/manager.c
+++ b/minix/servers/rs/manager.c
@@ -487,7 +487,7 @@ struct rproc *rp;
 	|| (s = sys_getpriv(&rp->r_priv, child_proc_nr_e)) != OK) {
 	printf("RS: unable to set privilege structure: %d\n", s);
 	cleanup_service(rp);
-	vm_memctl(RS_PROC_NR, VM_RS_MEM_PIN);
+	vm_memctl(RS_PROC_NR, VM_RS_MEM_PIN, 0, 0);
 	return ENOMEM;
   }
 
@@ -495,7 +495,7 @@ struct rproc *rp;
   if ((s = sched_init_proc(rp)) != OK) {
 	printf("RS: unable to start scheduling: %d\n", s);
 	cleanup_service(rp);
-	vm_memctl(RS_PROC_NR, VM_RS_MEM_PIN);
+	vm_memctl(RS_PROC_NR, VM_RS_MEM_PIN,0,0);
 	return s;
   }
 
@@ -511,7 +511,7 @@ struct rproc *rp;
       if ((s = read_exec(rp)) != OK) {
           printf("RS: read_exec failed: %d\n", s);
           cleanup_service(rp);
-          vm_memctl(RS_PROC_NR, VM_RS_MEM_PIN);
+          vm_memctl(RS_PROC_NR, VM_RS_MEM_PIN, 0, 0);
           return s;
       }
   }
@@ -519,7 +519,7 @@ struct rproc *rp;
         printf("RS: execing child with srv_execve()...\n");
   s = srv_execve(child_proc_nr_e, rp->r_exec, rp->r_exec_len, rp->r_argv,
         environ);
-  vm_memctl(RS_PROC_NR, VM_RS_MEM_PIN);
+  vm_memctl(RS_PROC_NR, VM_RS_MEM_PIN, 0, 0);
   if (s != OK) {
         printf("RS: srv_execve failed: %d\n", s);
         cleanup_service(rp);
@@ -534,7 +534,7 @@ struct rproc *rp;
       if(rs_verbose)
           printf("RS: informing VM of instance %s\n", srv_to_string(rp));
 
-      s = vm_memctl(rpub->endpoint, VM_RS_MEM_MAKE_VM);
+      s = vm_memctl(rpub->endpoint, VM_RS_MEM_MAKE_VM, 0, 0);
       if(s != OK) {
           printf("vm_memctl failed: %d\n", s);
           cleanup_service(rp);
@@ -1129,7 +1129,7 @@ static int run_script(struct rproc *rp)
 			return kill_service(rp,"can't let the script run",r);
 		}
 		/* Pin RS memory again after fork()ing. */
-		vm_memctl(RS_PROC_NR, VM_RS_MEM_PIN);
+		vm_memctl(RS_PROC_NR, VM_RS_MEM_PIN, 0, 0);
 	}
 	return OK;
 }
diff --git a/minix/servers/vm/rs.c b/minix/servers/vm/rs.c
index 064f8de87..3587e8617 100644
--- a/minix/servers/vm/rs.c
+++ b/minix/servers/vm/rs.c
@@ -167,6 +167,65 @@ static int rs_memctl_make_vm_instance(struct vmproc *new_vm_vmp)
 	return OK;
 }
 
+/*===========================================================================*
+ *		           rs_memctl_heap_prealloc			     *
+ *===========================================================================*/
+static int rs_memctl_heap_prealloc(struct vmproc *vmp,
+	vir_bytes *addr, size_t *len)
+{
+
+	/*
+	 * XXX: Is this still needed?
+	 */
+
+	return OK;
+}
+
+/*===========================================================================*
+ *		           rs_memctl_map_prealloc			     *
+ *===========================================================================*/
+static int rs_memctl_map_prealloc(struct vmproc *vmp,
+	vir_bytes *addr, size_t *len)
+{
+#if 0
+	struct vir_region *vr;
+	if(*len <= 0) {
+		return EINVAL;
+	}
+	*len = CLICK_CEIL(*len);
+
+	if(!(vr = map_page_region(vmp, VM_DATATOP - *len, VM_DATATOP, *len,
+		MAP_NONE, VR_ANON|VR_WRITABLE|VR_CONTIG, MF_PREALLOC))) {
+		return ENOMEM;
+	}
+	map_region_set_tag(vr, VRT_PREALLOC_MAP);
+	*addr = arch_map2vir(vmp, vr->vaddr);
+#endif
+	return OK;
+}
+
+/*===========================================================================*
+ *		         rs_memctl_get_prealloc_map			     *
+ *===========================================================================*/
+static int rs_memctl_get_prealloc_map(struct vmproc *vmp,
+	vir_bytes *addr, size_t *len)
+{
+#if 0
+	struct vir_region *vr;
+
+	vr = map_region_lookup_tag(vmp, VRT_PREALLOC_MAP);
+	if(!vr) {
+		*addr = 0;
+		*len = 0;
+	}
+	else {
+		*addr = arch_map2vir(vmp, vr->vaddr);
+		*len = vr->length;
+	}
+#endif
+	return OK;
+}
+
 /*===========================================================================*
  *				do_rs_memctl	     			     *
  *===========================================================================*/
@@ -207,6 +266,15 @@ int do_rs_memctl(message *m_ptr)
 	case VM_RS_MEM_MAKE_VM:
 		r = rs_memctl_make_vm_instance(vmp);
 		return r;
+	case VM_RS_MEM_HEAP_PREALLOC:
+		r = rs_memctl_heap_prealloc(vmp, (vir_bytes*) &m_ptr->VM_RS_CTL_ADDR, (size_t*) &m_ptr->VM_RS_CTL_LEN);
+		return r;
+	case VM_RS_MEM_MAP_PREALLOC:
+		r = rs_memctl_map_prealloc(vmp, (vir_bytes*) &m_ptr->VM_RS_CTL_ADDR, (size_t*) &m_ptr->VM_RS_CTL_LEN);
+		return r;
+	case VM_RS_MEM_GET_PREALLOC_MAP:
+		r = rs_memctl_get_prealloc_map(vmp, (vir_bytes*) &m_ptr->VM_RS_CTL_ADDR, (size_t*) &m_ptr->VM_RS_CTL_LEN);
+		return r;
 	default:
 		printf("do_rs_memctl: bad request %d\n", req);
 		return EINVAL;