diff --git a/share/mk/bsd.own.mk b/share/mk/bsd.own.mk
index ff70f216a00e..564bd3fe49a1 100644
--- a/share/mk/bsd.own.mk
+++ b/share/mk/bsd.own.mk
@@ -1,4 +1,4 @@
-#	$NetBSD: bsd.own.mk,v 1.317 2002/11/26 19:30:13 thorpej Exp $
+#	$NetBSD: bsd.own.mk,v 1.318 2002/11/26 19:51:16 thorpej Exp $
 
 .if !defined(_BSD_OWN_MK_)
 _BSD_OWN_MK_=1
@@ -108,6 +108,24 @@ TOOLDIR:=	${_TOOLOBJ}/tools.${HOST_OSTYPE}
 .MAKEOVERRIDES+= TOOLDIR
 .endif
 
+# If an external toolchain base is specified, use it.
+.if defined(EXTERNAL_TOOLCHAIN)
+AR=		${EXTERNAL_TOOLCHAIN}/bin/${MACHINE_GNU_PLATFORM}-ar
+AS=		${EXTERNAL_TOOLCHAIN}/bin/${MACHINE_GNU_PLATFORM}-as
+LD=		${EXTERNAL_TOOLCHAIN}/bin/${MACHINE_GNU_PLATFORM}-ld
+NM=		${EXTERNAL_TOOLCHAIN}/bin/${MACHINE_GNU_PLATFORM}-nm
+OBJCOPY=	${EXTERNAL_TOOLCHAIN}/bin/${MACHINE_GNU_PLATFORM}-objcopy
+OBJDUMP=	${EXTERNAL_TOOLCHAIN}/bin/${MACHINE_GNU_PLATFORM}-objdump
+RANLIB=		${EXTERNAL_TOOLCHAIN}/bin/${MACHINE_GNU_PLATFORM}-ranlib
+SIZE=		${EXTERNAL_TOOLCHAIN}/bin/${MACHINE_GNU_PLATFORM}-size
+STRIP=		${EXTERNAL_TOOLCHAIN}/bin/${MACHINE_GNU_PLATFORM}-strip
+
+CC=		${EXTERNAL_TOOLCHAIN}/bin/${MACHINE_GNU_PLATFORM}-gcc
+CPP=		${EXTERNAL_TOOLCHAIN}/bin/${MACHINE_GNU_PLATFORM}-cpp
+CXX=		${EXTERNAL_TOOLCHAIN}/bin/${MACHINE_GNU_PLATFORM}-c++
+FC=		${EXTERNAL_TOOLCHAIN}/bin/${MACHINE_GNU_PLATFORM}-g77
+OBJC=		${EXTERNAL_TOOLCHAIN}/bin/${MACHINE_GNU_PLATFORM}-gcc
+.else
 # Define default locations for common tools.
 .if ${USETOOLS_BINUTILS:Uyes} == "yes"
 AR=		${TOOLDIR}/bin/${MACHINE_GNU_PLATFORM}-ar
@@ -128,6 +146,7 @@ CXX=		${TOOLDIR}/bin/${MACHINE_GNU_PLATFORM}-c++
 FC=		${TOOLDIR}/bin/${MACHINE_GNU_PLATFORM}-g77
 OBJC=		${TOOLDIR}/bin/${MACHINE_GNU_PLATFORM}-gcc
 .endif
+.endif	# EXTERNAL_TOOLCHAIN
 
 ASN1_COMPILE=	${TOOLDIR}/bin/nbasn1_compile
 CAP_MKDB=	${TOOLDIR}/bin/nbcap_mkdb
@@ -382,9 +401,9 @@ MACHINE_GNU_ARCH=${GNU_ARCH.${MACHINE_ARCH}:U${MACHINE_ARCH}}
      ${MACHINE_GNU_ARCH} == "sh5le" || \
      ${MACHINE_ARCH} == "sparc" || \
      ${MACHINE_ARCH} == "vax")
-MACHINE_GNU_PLATFORM=${MACHINE_GNU_ARCH}--netbsdelf
+MACHINE_GNU_PLATFORM?=${MACHINE_GNU_ARCH}--netbsdelf
 .else
-MACHINE_GNU_PLATFORM=${MACHINE_GNU_ARCH}--netbsd
+MACHINE_GNU_PLATFORM?=${MACHINE_GNU_ARCH}--netbsd
 .endif
 
 TARGETS+=	all clean cleandir depend dependall includes \