diff --git a/distrib/bebox/floppies/Makefile.inc b/distrib/bebox/floppies/Makefile.inc
index b56721125f54..715f3df531d6 100644
--- a/distrib/bebox/floppies/Makefile.inc
+++ b/distrib/bebox/floppies/Makefile.inc
@@ -1,9 +1,9 @@
-#	$NetBSD: Makefile.inc,v 1.2 2000/05/02 16:06:47 sjg Exp $
+#	$NetBSD: Makefile.inc,v 1.3 2002/04/10 15:05:41 lukem Exp $
 
 .include "../../../Makefile.inc"
 
 # REV is revision without dots, as in "12C"
 # VER is revision with dots, as in "1.2C"
-REV!=sh ${BSDSRCDIR}/sys/conf/osrelease.sh -s
-VER!=sh ${BSDSRCDIR}/sys/conf/osrelease.sh 
+REV!=sh ${_SRC_TOP_}/sys/conf/osrelease.sh -s
+VER!=sh ${_SRC_TOP_}/sys/conf/osrelease.sh 
 
diff --git a/distrib/evbsh3/rom/Makefile.inc b/distrib/evbsh3/rom/Makefile.inc
index 0a71000640cd..e8b2cf2e6dcd 100644
--- a/distrib/evbsh3/rom/Makefile.inc
+++ b/distrib/evbsh3/rom/Makefile.inc
@@ -1,8 +1,8 @@
-#	$NetBSD: Makefile.inc,v 1.1 2000/09/18 07:21:01 msaitoh Exp $
+#	$NetBSD: Makefile.inc,v 1.2 2002/04/10 15:05:42 lukem Exp $
 
 .include "../../../Makefile.inc"
 
 # REV is revision without dots, as in "12C"
 # VER is revision with dots, as in "1.2C"
-REV!=sh ${BSDSRCDIR}/sys/conf/osrelease.sh -s
-VER!=sh ${BSDSRCDIR}/sys/conf/osrelease.sh 
+REV!=sh ${_SRC_TOP_}/sys/conf/osrelease.sh -s
+VER!=sh ${_SRC_TOP_}/sys/conf/osrelease.sh 
diff --git a/distrib/mipsco/Makefile.inc b/distrib/mipsco/Makefile.inc
index c31d241e4c17..d253d9a17b37 100644
--- a/distrib/mipsco/Makefile.inc
+++ b/distrib/mipsco/Makefile.inc
@@ -1,9 +1,9 @@
-#	$NetBSD: Makefile.inc,v 1.1 2001/02/19 07:45:38 wdk Exp $
+#	$NetBSD: Makefile.inc,v 1.2 2002/04/10 15:05:42 lukem Exp $
 
 .include "../../Makefile.inc"
 .include <bsd.own.mk>
 
 # REV is revision without dots, as in "15R"
 # VER is revision with dots, as in "1.5R"
-REV!=sh ${BSDSRCDIR}/sys/conf/osrelease.sh -s
-VER!=sh ${BSDSRCDIR}/sys/conf/osrelease.sh 
+REV!=sh ${_SRC_TOP_}/sys/conf/osrelease.sh -s
+VER!=sh ${_SRC_TOP_}/sys/conf/osrelease.sh 
diff --git a/distrib/mvme68k/Makefile.inc b/distrib/mvme68k/Makefile.inc
index 7cd72dfb5ab5..caebda9026e4 100644
--- a/distrib/mvme68k/Makefile.inc
+++ b/distrib/mvme68k/Makefile.inc
@@ -1,11 +1,10 @@
-#	$NetBSD: Makefile.inc,v 1.3 2000/05/02 16:06:51 sjg Exp $
+#	$NetBSD: Makefile.inc,v 1.4 2002/04/10 15:05:43 lukem Exp $
 
 .include "../../../Makefile.inc"
 
-REV!=sh ${BSDSRCDIR}/sys/conf/osrelease.sh -s
+REV!=sh ${_SRC_TOP_}/sys/conf/osrelease.sh -s
 
 LDSTATIC=	-static		# only static compilation makes sense here
 
 # Hack needed to find kernel images...
-BSDSRCDIR?=	/usr/src
-SRCSYSDIR?=	${BSDSRCDIR}/sys
+SRCSYSDIR?=	${_SRC_TOP_}/sys
diff --git a/distrib/newsmips/floppies/Makefile.inc b/distrib/newsmips/floppies/Makefile.inc
index 4e9ce4051628..c47cc4b8ead9 100644
--- a/distrib/newsmips/floppies/Makefile.inc
+++ b/distrib/newsmips/floppies/Makefile.inc
@@ -1,8 +1,8 @@
-#	$NetBSD: Makefile.inc,v 1.2 2000/05/02 16:06:52 sjg Exp $
+#	$NetBSD: Makefile.inc,v 1.3 2002/04/10 15:05:43 lukem Exp $
 
 .include "../../../Makefile.inc"
 
 # REV is revision without dots, as in "14A"
 # VER is revision with dots, as in "1.4A"
-REV!=sh ${BSDSRCDIR}/sys/conf/osrelease.sh -s
-VER!=sh ${BSDSRCDIR}/sys/conf/osrelease.sh 
+REV!=sh ${_SRC_TOP_}/sys/conf/osrelease.sh -s
+VER!=sh ${_SRC_TOP_}/sys/conf/osrelease.sh 
diff --git a/distrib/pc532/floppies/Makefile.inc b/distrib/pc532/floppies/Makefile.inc
index 4b58f5a36c60..d7e86f328d12 100644
--- a/distrib/pc532/floppies/Makefile.inc
+++ b/distrib/pc532/floppies/Makefile.inc
@@ -1,5 +1,5 @@
-#	$NetBSD: Makefile.inc,v 1.8 2000/05/02 16:06:53 sjg Exp $
+#	$NetBSD: Makefile.inc,v 1.9 2002/04/10 15:05:44 lukem Exp $
 
 .include "../../../Makefile.inc"
 
-REV!=sh ${BSDSRCDIR}/sys/conf/osrelease.sh -s
+REV!=sh ${_SRC_TOP_}/sys/conf/osrelease.sh -s
diff --git a/distrib/sun3/Makefile.inc b/distrib/sun3/Makefile.inc
index 357b2c0af357..1ad1b1db88b6 100644
--- a/distrib/sun3/Makefile.inc
+++ b/distrib/sun3/Makefile.inc
@@ -1,4 +1,4 @@
-#	$NetBSD: Makefile.inc,v 1.9 2002/03/06 12:15:19 lukem Exp $
+#	$NetBSD: Makefile.inc,v 1.10 2002/04/10 15:05:44 lukem Exp $
 
 .include "../../Makefile.inc"
 
@@ -6,4 +6,4 @@ LDSTATIC=	-static		# only static compilation makes sense here
 
 # Where to find kernel images...
 .include <bsd.kernobj.mk>
-SRCSYSDIR?=	${BSDSRCDIR}/sys
+SRCSYSDIR?=	${_SRC_TOP_}/sys
diff --git a/distrib/sun3/common/Make.crunch b/distrib/sun3/common/Make.crunch
index 144f5cf8e10e..88bd40cd130a 100644
--- a/distrib/sun3/common/Make.crunch
+++ b/distrib/sun3/common/Make.crunch
@@ -1,4 +1,4 @@
-#	$NetBSD: Make.crunch,v 1.5 2000/11/01 07:58:01 garbled Exp $
+#	$NetBSD: Make.crunch,v 1.6 2002/04/10 15:05:44 lukem Exp $
 #
 # This is included by subdirectories building a crunched binary.
 # Assume the following are already defined:  TOP, CBIN
@@ -19,5 +19,5 @@ ${CBIN}: ${CBIN}.mk ${CBIN}.cache ${CBIN}.c
 	${STRIP} ${CBIN}
 
 ${CBIN}.mk ${CBIN}.cache ${CBIN}.c: ${CRUNCHCONF}
-	${CRUNCHGEN} -D ${BSDSRCDIR} -L ${DESTDIR}/usr/lib ${CRUNCHCONF}
+	${CRUNCHGEN} -D ${_SRC_TOP_} -L ${DESTDIR}/usr/lib ${CRUNCHCONF}
 
diff --git a/share/mk/bsd.README b/share/mk/bsd.README
index 6c273350678a..90a1c40e539b 100644
--- a/share/mk/bsd.README
+++ b/share/mk/bsd.README
@@ -1,4 +1,4 @@
-#	$NetBSD: bsd.README,v 1.94 2002/03/22 18:12:08 thorpej Exp $
+#	$NetBSD: bsd.README,v 1.95 2002/04/10 15:05:45 lukem Exp $
 #	@(#)bsd.README	8.2 (Berkeley) 4/2/94
 
 This is the README file for the new make "include" files for the BSD
@@ -192,6 +192,9 @@ is included.  These files may define any of the variables described below.
 bsd.own.mk sets the following variables, if they are not already defined
 (defaults are in brackets):
 
+_SRC_TOP_	Top of the system source tree, as determined by <bsd.own.mk>
+		based on the presence of build.sh and tools/ .
+
 BSDSRCDIR	The real path to the system sources, so that 'make obj'
 		will work correctly. [/usr/src]
 
@@ -728,10 +731,7 @@ The include file <bsd.kernobj.mk> defines variables related to the
 location of kernel sources and object directories.
 
 KERNSRCDIR	Is the location of the top of the kernel src.
-		It defaults to ${BSDSRCDIR}/sys, but the top-level
-		Makefile.inc sets it to ${ABSTOP}/sys (ABSTOP is the
-		absolute path to the directory where the top-level
-		Makefile.inc was found.
+		It defaults to ${_SRC_TOP_}/sys
 
 KERNARCHDIR	Is the location of the machine dependent kernel
 		sources.  It defaults to arch/${MACHINE}
diff --git a/share/mk/bsd.kernobj.mk b/share/mk/bsd.kernobj.mk
index d3b6b0aaade1..a234c186ba4b 100644
--- a/share/mk/bsd.kernobj.mk
+++ b/share/mk/bsd.kernobj.mk
@@ -1,10 +1,7 @@
-#	$NetBSD: bsd.kernobj.mk,v 1.7 2001/11/27 05:39:03 jmc Exp $
+#	$NetBSD: bsd.kernobj.mk,v 1.8 2002/04/10 15:05:45 lukem Exp $
 
 # KERNSRCDIR	Is the location of the top of the kernel src.
-# 		It defaults to ${BSDSRCDIR}/sys, but the top-level
-# 		Makefile.inc sets it to ${ABSTOP}/sys (ABSTOP is the
-# 		absolute path to the directory where the top-level
-# 		Makefile.inc was found.
+# 		It defaults to ${_SRC_TOP_}/sys
 # 
 # KERNARCHDIR	Is the location of the machine dependent kernel
 # 		sources.  It defaults to arch/${MACHINE}
@@ -31,7 +28,7 @@
 
 .include <bsd.own.mk>
 
-KERNSRCDIR?=	${BSDSRCDIR}/sys
+KERNSRCDIR?=	${_SRC_TOP_}/sys
 # just incase ${MACHINE} is not always correct
 KERNARCHDIR?=	arch/${MACHINE}
 
diff --git a/share/mk/bsd.lib.mk b/share/mk/bsd.lib.mk
index 8abdb49cd78c..8340c535550d 100644
--- a/share/mk/bsd.lib.mk
+++ b/share/mk/bsd.lib.mk
@@ -1,4 +1,4 @@
-#	$NetBSD: bsd.lib.mk,v 1.199 2002/03/19 22:17:23 lukem Exp $
+#	$NetBSD: bsd.lib.mk,v 1.200 2002/04/10 15:05:45 lukem Exp $
 #	@(#)bsd.lib.mk	8.3 (Berkeley) 4/22/94
 
 .include <bsd.init.mk>
@@ -19,10 +19,10 @@ SHLIB_TEENY != . ${SHLIB_VERSION_FILE} ; echo $$teeny
 
 # Check for higher installed library versions.
 .if !defined(NOCHECKVER) && !defined(NOCHECKVER_${LIB}) && \
-	exists(${BSDSRCDIR}/lib/checkver)
+	exists(${_SRC_TOP_}/lib/checkver)
 checkver:
 	@(cd ${.CURDIR} && \
-		sh ${BSDSRCDIR}/lib/checkver -v ${SHLIB_VERSION_FILE} \
+		sh ${_SRC_TOP_}/lib/checkver -v ${SHLIB_VERSION_FILE} \
 		    -d ${DESTDIR}${_LIBSODIR} ${LIB})
 .endif
 .endif
diff --git a/share/mk/bsd.own.mk b/share/mk/bsd.own.mk
index e8f4c52730dc..d975a2de601f 100644
--- a/share/mk/bsd.own.mk
+++ b/share/mk/bsd.own.mk
@@ -1,4 +1,4 @@
-#	$NetBSD: bsd.own.mk,v 1.283 2002/04/08 12:25:22 wiz Exp $
+#	$NetBSD: bsd.own.mk,v 1.284 2002/04/10 15:05:45 lukem Exp $
 
 .if !defined(_BSD_OWN_MK_)
 _BSD_OWN_MK_=1
@@ -31,7 +31,7 @@ PRINTOBJDIR=	echo # prevent infinite recursion
 .endif
 
 .if !defined(_SRC_TOP_)
-# Find the top of the source tree to see if we're inside of $BSDSRCDIR
+# Find the actual top of the source tree
 _SRC_TOP_!= cd ${.CURDIR}; while :; do \
 		here=`pwd`; \
 		[ -f build.sh  ] && [ -d tools ] && { echo $$here; break; }; \