diff --git a/release/Makefile b/release/Makefile
index 22f250af0640..fd3cb929d3c7 100644
--- a/release/Makefile
+++ b/release/Makefile
@@ -1,7 +1,8 @@
 # $FreeBSD$
 #
 # make release [BUILDNAME=somename] CHROOTDIR=/some/dir CVSROOT=/cvs/dir \
-#     [RELEASETAG=tag]
+#     [RELEASETAG=tag] [SVNROOT=svn://svn.freebsd.org/base] \
+#     [SVNBRANCH=some/branch]
 #
 # Where "/some/dir" is the pathname of a directory on a some filesystem with
 # at least 1000MB of free space, "somename" is what you want the release to
@@ -9,6 +10,11 @@
 # which CVS "tag" name should be used when checking out the sources to build
 # the release (default is HEAD).
 #
+# Please note the support for building from SVN is preliminary and there
+# are still questions about things like how to handle updates of
+# /usr/src on production systems (csup(1) replacement).  It is a work
+# in progress and may change as the other issues get worked out.
+#
 # Please note: the md(4) driver must be present in the kernel
 # (either by being compiled in or available as a kld(4) module),
 # otherwise the target 'release.8' and possibly others will fail.
@@ -49,12 +55,25 @@ BUILDNAME?=${BASE}-${DATE}-SNAP
 # To add other options to the CVS command, set
 #CVSARGS="-lfq"
 #
-# To prefix the cvs command
+# To prefix the CVS command
 #CVSPREFIX="/usr/bin/time"
 #
 # Where the CVS repository is
 #CVSROOT="/home/ncvs"
 #
+# To add other options to the Subversion subcommands (co,up), set
+#SVNCMDARGS="-r '{ 01/01/2002 00:00:00 UTC }'"
+#
+# To prefix the Subversion command
+#SVNPREFIX="/usr/bin/time"
+#
+# Where the Subversion repository is
+#SVNROOT=svn://svn.freebsd.org/base
+#
+# Subversion branch to build for src.  If this is not set then it is
+# automatically computed from RELEASETAG.
+#SVNBRANCH=stable/7
+#
 # Non-zero if ${RELEASETAG} is in the form "RELENG_ver_RELEASE"; we
 # are building an official release.  Otherwise, we are building for
 # a branch.
@@ -68,6 +87,16 @@ PORTSRELEASETAG?=	${AUXRELEASETAG}
 .endif
 .endif
 
+# Determine the Subversion source branch that corresponds to the requested
+# RELEASETAG.
+.if !defined(SVNBRANCH)
+.if defined(RELEASETAG)
+SVNBRANCH!=	echo "${RELEASETAG}" | awk -f ${.CURDIR}/svnbranch.awk
+.else
+SVNBRANCH=	head
+.endif
+.endif
+
 # If you want to pass flags to the world build such as -j X, use
 # WORLD_FLAGS.  Similarly, you can specify make flags for kernel
 # builds via KERNEL_FLAGS.
@@ -341,8 +370,17 @@ CVS_PORTSARGS+=	-r ${PORTSRELEASETAG}
 WORLDDIR?=	${.CURDIR}/..
 
 release rerelease:
-.if !defined(CHROOTDIR) || !defined(BUILDNAME) || !defined(CVSROOT)
-	@echo "To make a release you must set CHROOTDIR, BUILDNAME and CVSROOT" && false
+.if !defined(CHROOTDIR) || !defined(BUILDNAME)
+	@echo "To make a release you must set CHROOTDIR and BUILDNAME" && false
+.endif
+.if !defined(NOPORTSATALL) && !defined(EXTPORTSDIR) && !defined(CVSROOT)
+	@echo "Building ports requires CVSROOT or EXTPORTSDIR" && false
+.endif
+.if !defined(NODOC) && !defined(EXTDOCDIR) && !defined(CVSROOT)
+	@echo "Building docs requires CVSROOT or EXTDOCDIR" && false
+.endif
+.if !defined(EXTSRCDIR) && !defined(CVSROOT) && !defined(SVNROOT)
+	@echo "The source tree requires SVNROOT, CVSROOT, or EXTSRCDIR" && false
 .endif
 .if defined(NOPORTSATALL) && !defined(NODOC)
 	@echo "Ports are required for building the release docs.  Either set NODOC or"
@@ -387,6 +425,10 @@ release rerelease:
 .if defined(EXTSRCDIR)
 	cd ${CHROOTDIR}/usr && \
 	    cp -R -H ${EXTSRCDIR} src
+.elif defined(SVNROOT)
+	cd ${CHROOTDIR}/usr && \
+	    ${SVNPREFIX} svn co ${SVNCMDARGS} ${SVNROOT}/${SVNBRANCH} \
+	    ${RELEASESRCMODULE} 
 .else
 	cd ${CHROOTDIR}/usr && \
 	    ${CVSPREFIX} cvs -R ${CVSARGS} -d ${CVSROOT} \
@@ -432,7 +474,10 @@ release rerelease:
 .endif
 .if make(rerelease)
 .if !defined(RELEASENOUPDATE) && !defined(EXTSRCDIR)
-.if !defined(RELEASETAG)
+.if defined(SVNROOT)
+	cd ${CHROOTDIR}/usr/src && ${SVNPREFIX} svn switch ${SVNCMDARGS} \
+	    ${SVNROOT}/${SVNBRANCH}
+.elif !defined(RELEASETAG)
 	cd ${CHROOTDIR}/usr/src && ${CVSPREFIX} cvs -R ${CVSARGS} -q \
 	    update ${CVSCMDARGS} -P -d -A
 .else
diff --git a/release/svnbranch.awk b/release/svnbranch.awk
new file mode 100644
index 000000000000..0fc86200c043
--- /dev/null
+++ b/release/svnbranch.awk
@@ -0,0 +1,28 @@
+# $FreeBSD$
+
+BEGIN {
+	FS = "_"
+}
+
+/RELENG_.*_RELEASE/ {
+	if (NF == 5) {
+		printf "release/%s.%s.%s", $2, $3, $4
+		exit
+	}
+}
+
+/RELENG_.*/ {
+	if (NF == 3) {
+		printf "releng/%s.%s", $2, $3
+		exit
+	}
+
+	if (NF == 2) {
+		printf "stable/%s", $2
+		exit
+	}
+}
+
+// {
+	printf "unknown_branch"
+}