mkinitfs - Modified init script for network boot

This supports network boot over NFS providing the correct kernel modules and
udhcpc hook script are incorporated to the initrd (tweak mkinitfs config).

The init script can now obtain an IP using udhcpc if you specify ip=dhcp.
This replaces kernel-level DHCP.

Downloading an ovl via http now works also. Use ovl_dev=http://...
You can now specify a repository at a different location than at the alpine_dev.
Use alpine_repo=http://nl.alpinelinux.org/...
By default, or if alpine_repo=auto, a repository will be searched for
on the alpine_dev, as usual. alpine_dev can now be an NFS share using
  alpine_dev=nfs:IP:EXPORT
The NFS share is currently necessarily mounted using -o nolock.

To boot over PXE you might use
  ip=dhcp alpine_dev=nfs:1.2.3.4:/... ovl_dev=http://.../foo.apkovl.tar.gz

You can use {MAC} and {UUID} in opk_dev. They will be substituted.
Ensure you put the value of opk_dev in quotes, e.g.
  opk_dev="http://.../?mac={MAC}"

Example file and driver list for PXE boot:
  kernel/drivers/net/ethernet/*
  kernel/net/packet/af_packet.ko
  kernel/fs/nfs/*
  kernel/fs/lockd/*
  kernel/net/sunrpc/*
  usr/share/udhcpc/default.script

1 files changed, 148 insertions, 18 deletions

diff --git a/initramfs-init.in b/initramfs-init.in
index 9bce5f8..f06bc21 100755
--- a/initramfs-init.in
+++ b/initramfs-init.in
@@ -191,7 +191,7 @@ setup_inittab_console(){
 		esac
 		shift
 
-                # skip "current console" from beign added to inittab
+		# skip "current console" from being added to inittab
 		[ "$tty" = "tty0" ] && continue
 
 		# do nothing if inittab already have the tty set up
@@ -240,6 +240,79 @@ start_lvm() {
 		lvm vgchange --ignorelockingfailure -a y >/dev/null 2>&1
 }
 
+# determine the default interface to use if ip=dhcp is set
+# uses the first "eth" interface.
+ip_choose_if() {
+	for x in /sys/class/net/eth*; do
+		[ -e "$x" ] && echo ${x##*/} && return
+	done
+}
+
+# ip_set <device> <ip> <netmask> <gateway-ip>
+ip_set() {
+	ifconfig "$1" "$2" netmask "$3" || return $?
+	if [ -n "$4" ]; then
+		ip route add 0.0.0.0/0 via "$4" dev "$1" || return $?
+	fi
+}
+
+# if "ip=dhcp" is specified on the command line, we obtain an IP address
+# using udhcpc. we do this now and not by enabling kernel-mode DHCP because
+# kernel-model DHCP appears to require that network drivers be built into
+# the kernel rather than as modules. At this point all applicable modules
+# in the initrd should have been loaded.
+#
+# You need af_packet.ko available as well modules for your Ethernet card.
+#
+# Valid syntaxes:
+#   ip=client-ip:server-ip:gw-ip:netmask:hostname:device:autoconf
+#   ip=dhcp
+#   "server-ip" and "hostname" are not supported here.
+#
+configure_ip() {
+	[ -n "$KOPT_ip" ] || return
+	OIFS=$IFS
+	IFS=':'
+	eval set -- $KOPT_ip
+	IFS=$OIFS
+ 
+	local client_ip="$1"
+	local gw_ip="$3"
+	local netmask="$4"
+	local device="$6"
+	local autoconf="$7"
+	[ "$client_ip" == "off" -o "$client_ip" == "none" ] && return
+	if [ "$client_ip" == "dhcp" ]; then
+		autoconf="dhcp"
+		client_ip=
+	fi
+ 
+	[ -n "$device" ] || device=$(ip_choose_if)
+	[ -n "$device" ] || return
+
+	if [ "$autoconf" == "dhcp" ]; then
+		if [ ! -e /usr/share/udhcpc/default.script ]; then
+			echo "ERROR: DHCP requested but not present in initrd"
+			return
+		fi
+		# automatic configuration
+		ebegin "Obtaining IP via DHCP ($device)..."
+		ifconfig $device 0.0.0.0
+		udhcpc -i $device -f -q
+		eend $?
+	else
+		# manual configuration
+		[ -n "$client_ip" -a -n "$netmask" ] || return
+		ebegin "Setting IP ($device)..."
+		ip_set "$device" "$client_ip" "$netmask" "$gw_ip"
+		eend $?
+	fi
+	MAC_ADDRESS=$(cat /sys/class/net/$device/address)
+	MACHINE_UUID=$(cat /sys/class/dmi/id/product_uuid)
+	OVL_DEV="${OVL_DEV/{MAC\}/$MAC_ADDRESS}"
+	OVL_DEV="${OVL_DEV/{UUID\}/$MACHINE_UUID}"
+}
+
 # resolve an uuid or symlink to the real device
 resolve_dev() {
 	case "$1" in
@@ -275,8 +348,12 @@ find_fs_type() {
 
 # find the dirs under ALPINE_MNT that are boot repositories
 find_boot_repositories() {
-	find $ALPINE_MNT -name .boot_repository -type f -maxdepth 3 \
-		| sed 's:/.boot_repository$::'
+	if [ -n "$ALPINE_REPO" ]; then
+		echo "$ALPINE_REPO"
+	else
+		find $ALPINE_MNT -name .boot_repository -type f -maxdepth 3 \
+			| sed 's:/.boot_repository$::'
+	fi
 }
 
 # gotta start from somewhere :)
@@ -288,7 +365,7 @@ eval set -- `cat /proc/cmdline`
 
 myopts="alpine_dev autodetect autoraid chart cryptroot cryptdm debug_init
 	dma init_args keep_apk_new modules ovl_dev pkgs quiet root_size root
-	usbdelay"
+	usbdelay ip alpine_repo"
 
 for opt; do
 	case "$opt" in
@@ -341,21 +418,47 @@ ALPINE_DEV_FS=${KOPT_alpine_dev##*:}
 if [ "$ALPINE_DEV_FS" = "$ALPINE_DEV" ]; then
 	unset ALPINE_DEV_FS
 fi
+
+# /dev/blah:ext3
+# http://.../blah.apkovl.tar.gz
 if [ -n "$KOPT_ovl_dev" ] ; then
 	OVL_DEV=${KOPT_ovl_dev%%:*}
 	OVL_DEV_FS=${KOPT_ovl_dev##*:}
 	if [ "$OVL_DEV_FS" = "$OVL_DEV" ]; then
 		unset OVL_DEV_FS
 	fi
+
 fi
 
 case "$ALPINE_DEV" in
 	UUID=*|LABEL=*) ;;
+	nfs)
+		# nfs:IP:EXPORT
+		ALPINE_DEV_FS="$ALPINE_DEV"
+		ALPINE_DEV="${KOPT_alpine_dev:4}"
+		ALPINE_DEV_IS_NETWORK=y
+		;;
 	*) ALPINE_DEV=/dev/$ALPINE_DEV ;;
 esac
 
+case "$OVL_DEV" in
+	http|https)
+		OVL_DEV_FS="$OVL_DEV"
+		OVL_DEV="$KOPT_ovl_dev"
+		OVL_DEV_IS_NETWORK=y
+		;;
+	*) ;;
+esac
+
+# The following values are supported:
+#   alpine_repo=auto         -- default, search for .boot_repository
+#   alpine_repo=http://...   -- network repository
+ALPINE_REPO=${KOPT_alpine_repo}
+[ "$ALPINE_REPO" == "auto" ] && ALPINE_REPO=
+
 # look for standard mountpoint locations
 ALPINE_MNT=$(find_mnt $ALPINE_DEV /etc/fstab)
+[ -z "$ALPINE_MNT" -a -n "$ALPINE_DEV_IS_NETWORK" ] && ALPINE_MNT=/media/alpine_dev
 [ -z "$ALPINE_MNT" ] && ALPINE_MNT=/media/${ALPINE_DEV##*/}
 
 # hide kernel messages
@@ -429,6 +532,9 @@ if [ -z "${ALPINE_DEV##*usb*}" ]; then
 	wait_usb
 fi
 
+# IP. This shouldn't be needed if root= is set.
+configure_ip
+
 # incase we have alpine_dev on raid device...
 start_raid
 start_cryptsetup
@@ -445,6 +551,7 @@ fi
 
 if [ -n "$ALPINE_DEV_FS" ]; then
 	mount_opts="-t $ALPINE_DEV_FS"
+	[ "$ALPINE_DEV_FS" == "nfs" ] && mount_opts="$mount_opts -o nolock"
 fi
 
 retry_mount -o ro $mount_opts $ALPINE_DEV $ALPINE_MNT >/dev/null 2>&1
@@ -463,18 +570,26 @@ if [ -n "$KOPT_root_size" ]; then
 fi
 mount -t tmpfs $root_opts tmpfs $sysroot
 
-if [ -n "$OVL_DEV" ]; then
-	mkdir -p /media/$OVL_DEV
-	unset mount_opts
-	if [ -n "$OVL_DEV_FS" ]; then
-		mount_opts="-t $OVL_DEV_FS"
-	fi
-	
-	retry_mount -o ro $mount_opts /dev/$OVL_DEV /media/$OVL_DEV \
-		>/dev/null 2>&1
-	ovl=$(find_ovl /media/$OVL_DEV)
+OVL_MNT=/media/$OVL_DEV
+[ -n "$OVL_DEV_IS_NETWORK" ] && OVL_MNT=/media/ovl_dev
+
+if [ -n "$OVL_DEV_IS_NETWORK" ]; then
+	ovl=/tmp/boot.apkovl.tar.gz
+	wget -O "$ovl" "$OVL_DEV"
 else
-	find_ovl_dev
+	if [ -n "$OVL_DEV" ]; then
+		mkdir -p /media/$OVL_DEV
+		unset mount_opts
+		if [ -n "$OVL_DEV_FS" ]; then
+			mount_opts="-t $OVL_DEV_FS"
+		fi
+		
+		retry_mount -o ro $mount_opts /dev/$OVL_DEV /media/$OVL_DEV \
+			>/dev/null 2>&1
+		ovl=$(find_ovl /media/$OVL_DEV)
+	else
+		find_ovl_dev
+	fi
 fi
 if ! [ -f "$ovl" ]; then
 	ovl=$(find_ovl $ALPINE_MNT)
@@ -509,7 +624,8 @@ if [ -f "$ovl" ]; then
 			-e 's|:/etc/init.d/rcK|:/sbin/rc shutdown|' \
 			"$sysroot"/etc/inittab
 	fi
-else
+fi
+if [ -f "$sysroot/etc/.default_boot_services" -o ! -f "$ovl" ]; then
 	# add some boot services by default
 	rc_add devfs sysinit
 	rc_add dmesg sysinit
@@ -525,6 +641,8 @@ else
 	rc_add mount-ro shutdown
 	rc_add killprocs shutdown
 	rc_add savecache shutdown
+
+	rm -f "$sysroot/etc/.default_boot_services"
 fi
 
 if [ -f $sysroot/etc/fstab ]; then
@@ -570,7 +688,16 @@ ebegin "Installing packages to root filesystem"
 if [ "$KOPT_chart" = yes ]; then
 	pkgs="$pkgs acct"
 fi
-apkflags="--initdb --progress --force --no-network"
+
+apkflags="--initdb --progress --force"
+if [ -z "$ALPINE_REPO" ]; then
+	apkflags="$apkflags --no-network"
+else
+	# HTTP: convince apk to behave
+	apk add --root $sysroot $repo_opt $apkflags
+	apk update --root $sysroot $repo_opt
+fi
+
 if [ -n "$KOPT_quiet" ]; then
 	apkflags="$apkflags --quiet"
 fi
@@ -614,11 +741,14 @@ fi
 setup_inittab_console $CONSOLE
 
 # copy alpine release info
-if ! [ -f "$sysroot"/etc/alpine-release ]; then
+if ! [ -f "$sysroot"/etc/alpine-release ] && [ -f $ALPINE_MNT/.alpine-release ]; then
 	cp $ALPINE_MNT/.alpine-release $sysroot/
 	ln -sf /.alpine-release $sysroot/etc/alpine-release
 fi
 
+! [ -f "$sysroot"/etc/resolv.conf ] && [ -f /etc/resolv.conf ] && \
+  cp /etc/resolv.conf "$sysroot"/etc
+
 # setup bootchart for switch_root
 chart_init=""
 if [ "$KOPT_chart" = yes ]; then