diff --git a/sys/arch/i386/i386/machdep.c b/sys/arch/i386/i386/machdep.c
index 7ee013ad7717..ad5f22921c34 100644
--- a/sys/arch/i386/i386/machdep.c
+++ b/sys/arch/i386/i386/machdep.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: machdep.c,v 1.249 1997/08/26 18:56:40 fvdl Exp $	*/
+/*	$NetBSD: machdep.c,v 1.250 1997/09/05 01:44:42 thorpej Exp $	*/
 
 /*-
  * Copyright (c) 1996, 1997 The NetBSD Foundation, Inc.
@@ -2437,8 +2437,28 @@ _bus_dmamem_mmap(t, segs, nsegs, off, prot, flags)
 	bus_dma_segment_t *segs;
 	int nsegs, off, prot, flags;
 {
+	int i;
 
-	panic("_bus_dmamem_mmap: not implemented");
+	for (i = 0; i < nsegs; i++) {
+#ifdef DIAGNOSTIC
+		if (off & PGOFSET)
+			panic("_bus_dmamem_mmap: offset unaligned");
+		if (segs[i].ds_addr & PGOFSET)
+			panic("_bus_dmamem_mmap: segment unaligned");
+		if (segs[i].ds_len & PGOFSET)
+			panic("_bus_dmamem_mmap: segment size not multiple"
+			    " of page size");
+#endif
+		if (off >= segs[i].ds_len) {
+			off -= segs[i].ds_len;
+			continue;
+		}
+
+		return (i386_btop((caddr_t)segs[i].ds_addr + off));
+	}
+
+	/* Page not found. */
+	return (-1);
 }
 
 /**********************************************************************