From 24a5cfd2c739efd8c7ecd1e4ed436ff772904d3d Mon Sep 17 00:00:00 2001
From: Doug Barton <dougb@FreeBSD.org>
Date: Thu, 14 Jun 2012 19:30:31 +0000
Subject: [PATCH] Improve the functionality of the PORTS_MODULES knob by adding
 LOCALBASE/bin and sbin to PATH, allowing dependencies to be found; adding
 SRC_BASE and OSVERSION to match the new kernel, and putting the related
 builds under MAKEOBJDIRPREFIX so that they only need to be built once per
 kernel.

In addition to the PR this includes ideas/contributions from crees
and matthew.

PR:		ports/161452
Submitted by:	Garrett Cooper <yanegomi@gmail.com>
---
 sys/conf/kern.post.mk | 25 +++++++++++++++++++++++--
 1 file changed, 23 insertions(+), 2 deletions(-)

diff --git a/sys/conf/kern.post.mk b/sys/conf/kern.post.mk
index 5f878d85e545..94712f918319 100644
--- a/sys/conf/kern.post.mk
+++ b/sys/conf/kern.post.mk
@@ -36,9 +36,30 @@ modules-${target}:
 .endif
 .endfor
 
-# Handle out of tree ports 
+# Handle ports (as defined by the user) that build kernel modules
 .if !defined(NO_MODULES) && defined(PORTS_MODULES)
-PORTSMODULESENV=SYSDIR=${SYSDIR}
+#
+# The ports tree needs some environment variables defined to match the new kernel
+#
+# Ports search for some dependencies in PATH, so add the location of the installed files
+LOCALBASE?=	/usr/local
+# SRC_BASE is how the ports tree refers to the location of the base source files
+.if !defined(SRC_BASE)
+SRC_BASE!=	realpath "${SYSDIR:H}/"
+.endif
+# OSVERSION is used by some ports to determine build options
+.if !defined(OSRELDATE)
+# Definition copied from src/Makefile.inc1
+OSRELDATE!=	awk '/^\#define[[:space:]]*__FreeBSD_version/ { print $$3 }' \
+		    ${MAKEOBJDIRPREFIX}${SRC_BASE}/include/osreldate.h
+.endif
+# Keep the related ports builds in the obj directory so that they are only rebuilt once per kernel build
+WRKDIRPREFIX?=	${MAKEOBJDIRPREFIX}${SRC_BASE}/sys/${KERNCONF}
+PORTSMODULESENV=\
+	PATH=${PATH}:${LOCALBASE}/bin:${LOCALBASE}/sbin \
+	SRC_BASE=${SRC_BASE} \
+	OSVERSION=${OSRELDATE} \
+	WRKDIRPREFIX=${WRKDIRPREFIX}
 .for __target in all install reinstall clean
 ${__target}: ports-${__target}
 ports-${__target}: