use the packaged generic initrd for touch images

debian/changelog

@@ -1,3 +1,13 @@
+livecd-rootfs (2.151) UNRELEASED; urgency=low
+
+  * use ubuntu-touch-generic-initrd for touch images instead of rolling an
+    arch specific initrd at build time for each arch (this should save quite
+    some build time)
+  * directly create the output file with abootimg, no need to cp it separately
+  * do not remove kernel packages from a chroot we throw away anyway
+
+ -- Oliver Grawert <ogra@ubuntu.com>  Fri, 28 Jun 2013 15:06:59 +0200
+
 livecd-rootfs (2.150) saucy; urgency=low
 
   * export $NOW in BuildLiveCD so we have it available in live-build

live-build/auto/build

@@ -429,6 +429,7 @@ if [ "$PROJECT" = "ubuntu-touch" ] && [ "$ARCH" = "armhf" ]; then
 	mv "${sourceslist}.d" "${sourceslist}.d.orig"
 	echo "deb http://ftpmaster.internal/ubuntu/ saucy main universe" >$sourceslist
 	Chroot chroot "apt-get -y update"
+	Chroot chroot "apt-get -y install ubuntu-touch-generic-initrd"
 
 	for subarch in $touchsubarches; do
 		kpkg="$(Chroot chroot apt-cache depends linux-image-$subarch|awk '/Depends: linux-image/ {print $2}')"
@@ -436,13 +437,10 @@ if [ "$PROJECT" = "ubuntu-touch" ] && [ "$ARCH" = "armhf" ]; then
 		Chroot chroot "apt-get -y install $kpkg"
 
 		bootimgcfg="/usr/share/initramfs-tools-ubuntu-touch/bootimg.cfg-${subarch}"
-		Chroot chroot "env FLASH_KERNEL_SKIP=1 update-initramfs -k ${kver} -c -v"
-		Chroot chroot "abootimg --create /boot/bootimg-${subarch}.img -f ${bootimgcfg} -r /boot/initrd.img-${kver} -k /boot/vmlinuz-${kver}"
+		initrdimg="/usr/lib/ubuntu-touch-generic-initrd/initrd.img-touch"
 
-		cp "chroot/boot/bootimg-${subarch}.img" "$PREFIX.bootimg-${subarch}"
-
-		Chroot chroot "apt-get -y purge $kpkg"
-	done
+		Chroot chroot "abootimg --create "$PREFIX.bootimg-${subarch}" -f ${bootimgcfg} -r ${initrdimg} -k /boot/vmlinuz-${kver}"
+	done`
 
 	lb chroot_devpts remove "$@"
 	lb chroot_sysfs remove "$@"