diff --git a/sys/arch/mips/include/endian.h b/sys/arch/mips/include/endian.h
index 978fb3fb20f0..a16f0d32151f 100644
--- a/sys/arch/mips/include/endian.h
+++ b/sys/arch/mips/include/endian.h
@@ -1,4 +1,4 @@
-/*	$NetBSD: endian.h,v 1.9 1997/10/09 15:42:24 bouyer Exp $	*/
+/*	$NetBSD: endian.h,v 1.10 1997/10/17 04:44:01 jonathan Exp $	*/
 
 /*
  * Copyright (c) 1987, 1991, 1993
@@ -35,8 +35,8 @@
  *	@(#)endian.h	8.1 (Berkeley) 6/11/93
  */
 
-#ifndef _ENDIAN_H_
-#define	_ENDIAN_H_
+#ifndef _MIPS_ENDIAN_H_
+#define	_MIPS_ENDIAN_H_
 
 /*
  * Define _NOQUAD if the compiler does NOT support 64-bit integers.
@@ -58,7 +58,13 @@
 #define	BIG_ENDIAN	4321	/* MSB first: 68000, ibm, net */
 #define	PDP_ENDIAN	3412	/* LSB first in word, MSW first in long */
 
-#define	BYTE_ORDER	LITTLE_ENDIAN
+#ifndef BYTE_ORDER
+# error  Define MIPS target CPU endian-ness in port-specific header file
+#endif
+
+
+#ifndef _LOCORE
+/* C-family endian-ness definitions */
 
 #include <sys/cdefs.h>
 #include <mips/types.h>
@@ -90,12 +96,31 @@ __END_DECLS
 #define	HTONL(x)	(x)
 #define	HTONS(x)	(x)
 
-#else
+#else	/* LITTLE_ENDIAN || !defined(lint) */
 
 #define	NTOHL(x)	(x) = ntohl((in_addr_t)x)
 #define	NTOHS(x)	(x) = ntohs((in_port_t)x)
 #define	HTONL(x)	(x) = htonl((in_addr_t)x)
 #define	HTONS(x)	(x) = htons((in_port_t)x)
-#endif
+#endif	/* LITTLE_ENDIAN || !defined(lint) */
+
+#else /* _LOCORE */
+
+/* Assembly-code endian-independent aliases for unaligned memory accesses */
+#if BYTE_ORDER == LITTLE_ENDIAN
+# define LWHI lwr
+# define LWLO lwl
+# define SWHI swr
+# define SWLO swl
+#endif /* BYTE_ORDER == LITTLE_ENDIAN */
+
+#if BYTE_ORDER == BIG_ENDIAN
+# define LWHI lwl
+# define LWLO lwr
+# define SWHI swl
+# define SWLO swr
+#endif /* BYTE_ORDER == BIG_ENDIAN */
+
+#endif /* _LOCORE */
 #endif /* ! _POSIX_SOURCE */
-#endif /* !_ENDIAN_H_ */
+#endif /* !_MIPS_ENDIAN_H_ */
diff --git a/sys/arch/mips/include/mips_opcode.h b/sys/arch/mips/include/mips_opcode.h
index 7234040770ff..41fcc5a43f4f 100644
--- a/sys/arch/mips/include/mips_opcode.h
+++ b/sys/arch/mips/include/mips_opcode.h
@@ -1,4 +1,4 @@
-/*	$NetBSD: mips_opcode.h,v 1.5 1996/03/23 18:49:29 jonathan Exp $	*/
+/*	$NetBSD: mips_opcode.h,v 1.6 1997/10/17 04:43:57 jonathan Exp $	*/
 
 /*-
  * Copyright (c) 1992, 1993
@@ -81,6 +81,38 @@ typedef union {
 		unsigned op: 6;		/* always '0x11' */
 	} FRType;
 #endif
+#if BYTE_ORDER == BIG_ENDIAN
+	struct {
+		unsigned op: 6;
+		unsigned rs: 5;
+		unsigned rt: 5;
+		unsigned imm: 16;
+	} IType;
+
+	struct {
+		unsigned op: 6;
+		unsigned target: 26;
+	} JType;
+
+	struct {
+		unsigned op: 6;
+		unsigned rs: 5;
+		unsigned rt: 5;
+		unsigned rd: 5;
+		unsigned shamt: 5;
+		unsigned func: 6;
+	} RType;
+
+	struct {
+		unsigned op: 6;		/* always '0x11' */
+		unsigned : 1;		/* always '1' */
+		unsigned fmt: 4;
+		unsigned ft: 5;
+		unsigned fs: 5;
+		unsigned fd: 5;
+		unsigned func: 6;
+	} FRType;
+#endif
 } InstFmt;
 
 /*
diff --git a/sys/arch/mips/mips/locore.S b/sys/arch/mips/mips/locore.S
index 9c89364c8529..683590639fc3 100644
--- a/sys/arch/mips/mips/locore.S
+++ b/sys/arch/mips/mips/locore.S
@@ -1,4 +1,4 @@
-/*	$NetBSD: locore.S,v 1.45 1997/08/09 03:41:03 jonathan Exp $	*/
+/*	$NetBSD: locore.S,v 1.46 1997/10/17 04:44:10 jonathan Exp $	*/
 
 /*
  * Copyright (c) 1992, 1993
@@ -89,6 +89,7 @@
 #include <sys/errno.h>
 #include <sys/syscall.h>
 
+#include <machine/endian.h>	/* byteorder for bcopy(), bzero(), byteswap */
 #include <mips/cpuregs.h>	/* XXX - misnomer ? */
 #include <mips/regnum.h>	/* XXX - ditto */
 #include <mips/asm.h>
@@ -259,6 +260,7 @@ END(__main)
  * netorder = htonl(hostorder)
  * hostorder = ntohl(netorder)
  */
+#if BYTE_ORDER == LITTLE_ENDIAN
 LEAF(htonl)				# a0 = 0x11223344, return 0x44332211
 ALEAF(ntohl)
 	srl	v1, a0, 24		# v1 = 0x00000011
@@ -286,6 +288,7 @@ ALEAF(ntohs)
 	j	ra
 	or	v0, v0, v1
 END(htons)
+#endif
 
 /*
  * strlen(str)
@@ -335,7 +338,7 @@ LEAF(bzero)
 	and	a3, a3, 3
 	beq	a3, zero, 1f		# skip if word aligned
 	subu	a1, a1, a3		# subtract from remaining count
-	swr	zero, 0(a0)		# clear 1, 2, or 3 bytes to align
+	SWHI	zero, 0(a0)		# clear 1, 2, or 3 bytes to align
 	addu	a0, a0, a3
 1:
 	and	v0, a1, 3		# compute number of words left
@@ -372,8 +375,8 @@ LEAF(bcmp)
 	beq	a3, zero, 1f
 	subu	a2, a2, a3		# subtract from remaining count
 	move	v0, v1			# init v0,v1 so unmodified bytes match
-	lwr	v0, 0(a0)		# read 1, 2, or 3 bytes
-	lwr	v1, 0(a1)
+	LWHI	v0, 0(a0)		# read 1, 2, or 3 bytes
+	LWHI	v1, 0(a1)
 	addu	a1, a1, a3
 	bne	v0, v1, nomatch
 	addu	a0, a0, a3
@@ -408,8 +411,8 @@ unalignedcmp:
 	subu	a2, a2, a3		#   which has to be >= (16-3) & ~3
 	addu	a3, a3, a0		# compute ending address
 3:
-	lwr	v0, 0(a0)		# compare words a0 unaligned, a1 aligned
-	lwl	v0, 3(a0)
+	LWHI	v0, 0(a0)		# compare words a0 unaligned, a1 aligned
+	LWLO	v0, 3(a0)
 	lw	v1, 0(a1)
 	addu	a0, a0, 4
 	bne	v0, v1, nomatch
@@ -552,13 +555,8 @@ destaligned:
 	addu	a3,a0,a3	# stop point
 
 3:
-#if MIPSEL	/* little-endian */
-	lwr	v0,0(a0)
-	lwl	v0,3(a0)
-#else		/* big-endian */
-	lwl	v0,0(a0)
-	lwr	v0,3(a0)
-#endif
+	LWHI	v0,0(a0)
+	LWLO	v0,3(a0)
 	addi	a0,4
 	sw	v0,0(a1)
 	bne	a0,a3,3b
diff --git a/sys/arch/pica/include/endian.h b/sys/arch/pica/include/endian.h
index 9363be0a8e4e..ad04ec47d682 100644
--- a/sys/arch/pica/include/endian.h
+++ b/sys/arch/pica/include/endian.h
@@ -1,3 +1,4 @@
-/*	$NetBSD: endian.h,v 1.2 1996/03/23 03:42:38 jonathan Exp $	*/
+/*	$NetBSD: endian.h,v 1.3 1997/10/17 04:44:17 jonathan Exp $	*/
 
+#define BYTE_ORDER LITTLE_ENDIAN
 #include <mips/endian.h>
diff --git a/sys/arch/pmax/include/endian.h b/sys/arch/pmax/include/endian.h
index fdc1f5164a00..c95c2f017589 100644
--- a/sys/arch/pmax/include/endian.h
+++ b/sys/arch/pmax/include/endian.h
@@ -1,3 +1,4 @@
-/*	$NetBSD: endian.h,v 1.5 1996/03/19 03:06:28 jonathan Exp $	*/
+/*	$NetBSD: endian.h,v 1.6 1997/10/17 04:44:22 jonathan Exp $	*/
 
+#define BYTE_ORDER LITTLE_ENDIAN
 #include <mips/endian.h>