Patch for Gentoo Installer InitRD to download the minimal iso-file at early-boot (before switch-root), mount it and the included squashfs-image loopback. Further there is a new commandline-option "autoinstall" which must be a shellscript. It will be executed after the installer finished booting (at "Starting local") and is intended to bootstrap …

gentoo-initrd-autoinstall-netboot.patch

--- gentoo.igz/init.orig  2013-07-29 16:56:59.274531548 +0200
+++ gentoo.igz/init	2013-07-29 16:53:28.636472431 +0200
@@ -254,6 +254,11 @@
 		nounionfs)
 			USE_UNIONFS_NORMAL=0
 			;;
+		autoinstall)
+			AUTO_INSTALL_URL=${x#*=}
+			export AUTO_INSTALL_URL
+			good_msg "Autoconfiguration from ${AUTO_INSTALL_URL}"
+		;;
 		*=*)
 			case "${x%%=*}" in
 			*.*)
@@ -449,11 +454,6 @@
 		[ ! -e "${NEW_ROOT}/dev/tty1" ] && mknod "${NEW_ROOT}/dev/tty1" c 4 1
 	fi
 
-	if [ "${REAL_ROOT}" != "/dev/nfs" ] && [ "${LOOPTYPE}" != "sgimips" ]
-	then
-		bootstrapCD
-	fi
-
 	if [ "${REAL_ROOT}" = '' ]
 	then
 		echo -n -e "${WARN}>>${NORMAL}${BOLD} No bootable medium found. Waiting for new devices"
@@ -590,7 +591,7 @@
 		else
 			bad_msg "Block device ${REAL_ROOT} is not a valid root device..."
 			REAL_ROOT=""
-			got_good_root=0
+			got_good_root=1
 		fi
 	done

@@ -669,7 +671,7 @@
 	[ -z "${LOOP}" ] && find_loop
 	[ -z "${LOOPTYPE}" ] && find_looptype
 
-	cache_cd_contents
+	#cache_cd_contents
 
 	# If encrypted, find key and mount, otherwise mount as usual
 	if [ -n "${CRYPT_ROOT}" ]
@@ -706,6 +708,28 @@
 		then
 			if [ "${USE_AUFS_NORMAL}" != '1' ]; then
 				good_msg 'Mounting squashfs filesystem'
+				if [  "x${ISOBOOT}" != "x" ]; then
+					good_msg "Running Remote ISO-Boot"
+					SQFS_DIR=$(dirname ${CDROOT_PATH}/${LOOPEXT}${LOOP})
+					mkdir -p "${DOWNLOAD_DIR}"
+					mount -t tmpfs tmpfs /tmp
+					good_msg "Enabling Network"
+					IFACES="$(ls "/sys/class/net" | grep -v lo)"
+					for IFACE in $IFACES; do
+						udhcpc $IFACE
+					done
+					good_msg "Downloading ISO-File to /tmp/live.iso"
+					wget -O/tmp/live.iso "${ISOBOOT}"
+					good_msg "Disable Networking"
+					route del default
+					for IFACE in $IFACES; do
+						ifconfig $IFACE 0.0.0.0 down
+					done
+					good_msg "Mounting ISO loopback"
+					mkdir -p "${SQFS_DIR}"
+					mount -t iso9660 -o loop,ro /tmp/live.iso "${SQFS_DIR}"
+				fi
+				
 				_CACHED_SQUASHFS_PATH="${NEW_ROOT}/mnt/${LOOP}"
 				_squashfs_path="${CDROOT_PATH}/${LOOPEXT}${LOOP}"  # Default to uncached
 				# Upgrade to cached version if possible
@@ -937,6 +961,9 @@
 
 echo -e "${BOLD}.${NORMAL}"
 
+echo -e "#!/bin/bash\necho 'Autoinstallscript' > /dev/tty1\nwget -q -O/tmp/autoinstall $autoinstall\nchmod +x /tmp/autoinstall; /tmp/autoinstall\n" > "${CHROOT}/etc/local.d/autoinstall.start"
+chmod +x "${CHROOT}/etc/local.d/autoinstall.start"
+
 exec /sbin/switch_root -c "/dev/console" "${CHROOT}" "${REAL_INIT:-/sbin/init}" "${INIT_OPTS}"
 
 # If we get here, something bad has happened