Rename the 'system' target to 'disc1', which is specific

to the disc1.iso installer image.

Replace 'system' with 'release' in CLEANFILES, and add
'disc1' to CLEANDIRS.

Ensure the 'dvd' target depends on 'packagesystem'.

Fix 'mini-memstick.img' prerequisite, which should be the
'bootonly' target, not 'disc1' (previously 'system').

Use .TARGET as the target installation directory for the
disc1.iso and bootonly.iso images, which now expand to
'disc1' and 'bootonly' respectively, mimicking the behavior
of the 'dvd' target.

Remove '@true' from the 'release' target, and instead use
'touch ${.TARGET}' to prevent multiple iterations of
'make release' from clobbering previously-built installer
medium.

Tested with:	head@r277834
MFC after:	3 weeks
X-MFC-with:     r277458, r277536, r277606, r277609
Sponsored by:	The FreeBSD Foundation

release/Makefile

@@ -109,7 +109,7 @@ IMAGES+=	memstick.img
 IMAGES+=	mini-memstick.img
 .endif
 
-CLEANFILES=	packagesystem *.txz MANIFEST system ${IMAGES}
+CLEANFILES=	packagesystem *.txz MANIFEST release ${IMAGES}
 .if defined(WITH_COMPRESSED_IMAGES) && !empty(WITH_COMPRESSED_IMAGES)
 . for I in ${IMAGES}
 CLEANFILES+=	${I}.xz
@@ -118,7 +118,7 @@ CLEANFILES+=	${I}.xz
 .if defined(WITH_DVD) && !empty(WITH_DVD)
 CLEANFILES+=	pkg-stage
 .endif
-CLEANDIRS=	dist ftp release bootonly dvd
+CLEANDIRS=	dist ftp disc1 bootonly dvd
 beforeclean:
 	chflags -R noschg .
 .include <bsd.obj.mk>
@@ -165,57 +165,57 @@ reldoc:
 .endfor
 	cp rdoc/${RELNOTES_LANG}/readme/docbook.css reldoc
 
-system: packagesystem
+disc1: packagesystem
 # Install system
-	mkdir -p release
+	mkdir -p ${.TARGET}
 	cd ${WORLDDIR} && ${IMAKE} installkernel installworld distribution \
-		DESTDIR=${.OBJDIR}/release MK_RESCUE=no MK_KERNEL_SYMBOLS=no \
+		DESTDIR=${.OBJDIR}/${.TARGET} MK_RESCUE=no MK_KERNEL_SYMBOLS=no \
 		MK_PROFILE=no MK_SENDMAIL=no MK_TESTS=no MK_LIB32=no \
 		MK_DEBUG_FILES=no
 # Copy distfiles
-	mkdir -p release/usr/freebsd-dist
+	mkdir -p ${.TARGET}/usr/freebsd-dist
 	for dist in MANIFEST $$(ls *.txz | grep -v -- '-dbg'); \
-	    do cp $${dist} release/usr/freebsd-dist; \
+	    do cp $${dist} ${.TARGET}/usr/freebsd-dist; \
 	done
 # Copy documentation, if generated
 .if !defined(NODOC)
-	cp reldoc/* release
+	cp reldoc/* ${.TARGET}
 .endif
 # Set up installation environment
-	ln -fs /tmp/bsdinstall_etc/resolv.conf release/etc/resolv.conf
-	echo sendmail_enable=\"NONE\" > release/etc/rc.conf
-	echo hostid_enable=\"NO\" >> release/etc/rc.conf
-	echo debug.witness.trace=0 >> release/etc/sysctl.conf
-	echo vfs.mountroot.timeout=\"10\" >> release/boot/loader.conf
-	cp ${.CURDIR}/rc.local release/etc
+	ln -fs /tmp/bsdinstall_etc/resolv.conf ${.TARGET}/etc/resolv.conf
+	echo sendmail_enable=\"NONE\" > ${.TARGET}/etc/rc.conf
+	echo hostid_enable=\"NO\" >> ${.TARGET}/etc/rc.conf
+	echo debug.witness.trace=0 >> ${.TARGET}/etc/sysctl.conf
+	echo vfs.mountroot.timeout=\"10\" >> ${.TARGET}/boot/loader.conf
+	cp ${.CURDIR}/rc.local ${.TARGET}/etc
 	touch ${.TARGET}
 
 bootonly: packagesystem
 # Install system
-	mkdir -p bootonly
+	mkdir -p ${.TARGET}
 	cd ${WORLDDIR} && ${IMAKE} installkernel installworld distribution \
-	    DESTDIR=${.OBJDIR}/bootonly MK_AMD=no MK_AT=no \
+	    DESTDIR=${.OBJDIR}/${.TARGET} MK_AMD=no MK_AT=no \
 	    MK_GAMES=no MK_GROFF=no \
 	    MK_INSTALLLIB=no MK_LIB32=no MK_MAIL=no \
 	    MK_NCP=no MK_TOOLCHAIN=no MK_PROFILE=no \
 	    MK_INSTALLIB=no MK_RESCUE=no MK_DICT=no \
 	    MK_KERNEL_SYMBOLS=no MK_TESTS=no MK_DEBUG_FILES=no
 # Copy manifest only (no distfiles) to get checksums
-	mkdir -p bootonly/usr/freebsd-dist
-	cp MANIFEST bootonly/usr/freebsd-dist
+	mkdir -p ${.TARGET}/usr/freebsd-dist
+	cp MANIFEST ${.TARGET}/usr/freebsd-dist
 # Copy documentation, if generated
 .if !defined(NODOC)
-	cp reldoc/* bootonly
+	cp reldoc/* ${.TARGET}
 .endif
 # Set up installation environment
-	ln -fs /tmp/bsdinstall_etc/resolv.conf bootonly/etc/resolv.conf
-	echo sendmail_enable=\"NONE\" > bootonly/etc/rc.conf
-	echo hostid_enable=\"NO\" >> bootonly/etc/rc.conf
-	echo debug.witness.trace=0 >> bootonly/etc/sysctl.conf
-	echo vfs.mountroot.timeout=\"10\" >> bootonly/boot/loader.conf
-	cp ${.CURDIR}/rc.local bootonly/etc
+	ln -fs /tmp/bsdinstall_etc/resolv.conf ${.TARGET}/etc/resolv.conf
+	echo sendmail_enable=\"NONE\" > ${.TARGET}/etc/rc.conf
+	echo hostid_enable=\"NO\" >> ${.TARGET}/etc/rc.conf
+	echo debug.witness.trace=0 >> ${.TARGET}/etc/sysctl.conf
+	echo vfs.mountroot.timeout=\"10\" >> ${.TARGET}/boot/loader.conf
+	cp ${.CURDIR}/rc.local ${.TARGET}/etc
 
-dvd:
+dvd: packagesystem
 # Install system
 	mkdir -p ${.TARGET}
 	cd ${WORLDDIR} && ${IMAKE} installkernel installworld distribution \
@@ -240,8 +240,8 @@ dvd:
 	touch ${.TARGET}
 
 release.iso: disc1.iso
-disc1.iso: system
-	sh ${.CURDIR}/${TARGET}/mkisoimages.sh -b ${VOLUME_LABEL}_CD ${.TARGET} release
+disc1.iso: disc1
+	sh ${.CURDIR}/${TARGET}/mkisoimages.sh -b ${VOLUME_LABEL}_CD ${.TARGET} disc1
 
 dvd1.iso: dvd pkg-stage
 	sh ${.CURDIR}/${TARGET}/mkisoimages.sh -b ${VOLUME_LABEL}_DVD ${.TARGET} dvd
@@ -250,11 +250,11 @@ bootonly.iso: bootonly
 	sh ${.CURDIR}/${TARGET}/mkisoimages.sh -b ${VOLUME_LABEL}_BO ${.TARGET} bootonly
 
 memstick: memstick.img
-memstick.img: system
-	sh ${.CURDIR}/${TARGET}/make-memstick.sh release ${.TARGET}
+memstick.img: disc1
+	sh ${.CURDIR}/${TARGET}/make-memstick.sh disc1 ${.TARGET}
 
 mini-memstick: mini-memstick.img
-mini-memstick.img: system
+mini-memstick.img: bootonly
 	sh ${.CURDIR}/${TARGET}/make-memstick.sh bootonly ${.TARGET}
 
 packagesystem: base.txz kernel.txz ${EXTRA_PACKAGES}
@@ -279,7 +279,7 @@ ftp: packagesystem
 	cp *.txz MANIFEST ftp
 
 release:	real-release vm-release cloudware-release
-	@true
+	touch ${.TARGET}
 
 real-release:
 	${MAKE} -C ${.CURDIR} ${.MAKEFLAGS} obj