--- /dev/null
+meta-netboot
+============
+
+This layer contains some recipes and configuration adjustments to allow network boot through NBD (network block device).
+
+Content and usage
+-----------------
+
+This layer creates a new supplementary initrd image which can be downloaded through TFTP with the kernel.
+At boot time, the init script will try to mount the rootfs based on the following kernel command line parameters:
+* nbd.server: IP address to reach the NBD server
+* nbd.port: TCP port on which server is listening (default: 10809)
+* nbd.dev: nbd device to use (default: /dev/nbd0)
+* nbd.debug: activate debug mode (init script is then interruptible)
+
+The layer meta-netboot contains recipes for the following components:
+* busybox: activate the built-in NBD client
+* initramfs-netboot: contains the init script started by the kernel: basically, this script mounts the real root filesystem, then pivot_root on it and finally exec systemd.
+* initramfs-netboot-image: image to specify for building the initrd
+
+To enable the build of the netboot initrd and ext4 rootfs, add the following line in conf/local.conf:
+
+INHERIT += "netboot"
+
+
+Server side
+-----------
+
+On the server side (assuming that the build dir is stored in $BUILD) we can run:
+
+* a TFTP server, for example tftpd-hpa started with $BUILD/tmp/deploy/images as the TFTP dir:
+
+ /usr/sbin/in.tftpd --listen --user tftp --address 0.0.0.0:69 --secure $BUILD/tmp/deploy/images
+
+* a NBD server, for example xnbd-server, used to expose the whole ext4 rootfs as a network block device:
+
+ xnbd-server --target --lport 10809 $BUILD/tmp/deploy/images/$MACHINE/agl-demo-platform-$MACHINE.ext4
+
+
+Target side
+-----------
+
+On the target board, a specific setup should also be done. For example, for Renesas Porter board, the following U-boot environment could be used (adjust IP addresses !):
+
+------------------------------------------------------------------
+setenv 'bootkfile' 'uImage+dtb'
+setenv 'bootkaddr' '0x40007fc0'
+setenv 'bootifile' 'initramfs-netboot-image-porter.ext4.gz.u-boot'
+setenv 'bootiaddr' '0x50000000'
+setenv 'ipaddr' '<board_IP>'
+setenv 'serverip' '<server_IP>'
+
+setenv 'bootargs_console' 'console=ttySC6,38400 ignore_loglevel'
+setenv 'bootargs_video' 'vmalloc=384M video=HDMI-A-1:1280x960-32@60'
+setenv 'bootargs_extra' 'rw rootfstype=ext4 rootwait rootdelay=2'
+setenv 'bootargs_root' 'root=/dev/ram0 ramdisk_size=16384 ip=dhcp'
+setenv 'bootkload_net' 'tftp ${bootkaddr} porter/${bootkfile}'
+setenv 'bootiload_net' 'tftp ${bootiaddr} porter/${bootifile}'
+setenv 'bootcmd' 'setenv bootargs ${bootargs_console} ${bootargs_video} ${bootargs_root} ${bootargs_extra} nbd.server=${serverip}; run bootkload_net; run bootiload_net; bootm ${bootkaddr} ${bootiaddr}'
+
+saveenv # optional: saves env in flash
+run bootcmd # boots the board, executed automatically after power up
+------------------------------------------------------------------
+
--- /dev/null
+Below are the environment variables that can be set in the u-boot console to boot the porter board in various configurations
+
+################## Common options #####################
+# these options are common to all configurations:
+
+setenv 'bootkfile' 'uImage+dtb'
+setenv 'bootkaddr' '0x40007fc0'
+
+setenv 'bootifile' 'initramfs-netboot-image-porter.ext4.gz.u-boot'
+setenv 'bootiaddr' '0x50000000'
+
+setenv 'bootargs_console' 'console=ttySC6,38400 ignore_loglevel'
+setenv 'bootargs_video' 'vmalloc=384M video=HDMI-A-1:1280x960-32@60'
+setenv 'bootargs_extra' 'rw rootfstype=ext4 rootwait rootdelay=2'
+
+################ Boot on MMC (SDcard) #################
+
+setenv 'bootargs_root' 'root=/dev/mmcblk0p1'
+setenv 'bootmmc' '1:1'
+setenv 'bootkload_sd' 'ext4load mmc ${bootmmc} ${bootkaddr} boot/${bootkfile}'
+setenv 'bootcmd' 'setenv bootargs ${bootargs_console} ${bootargs_video} ${bootargs_root} ${bootargs_extra}; run bootkload_sd; bootm ${bootkaddr}'
+
+################ Boot on MMC (SDcard) with initrd ######
+
+setenv 'bootargs_root' 'root=/dev/ram0 ramdisk_size=16384'
+setenv 'bootmmc' '1:1'
+setenv 'bootkload_sd' 'ext4load mmc ${bootmmc} ${bootkaddr} boot/${bootkfile}'
+setenv 'bootiload_sd' 'ext4load mmc ${bootmmc} ${bootiaddr} boot/${bootifile}'
+setenv 'bootcmd' 'setenv bootargs ${bootargs_console} ${bootargs_video} ${bootargs_root} ${bootargs_extra}; run bootkload_sd; run bootiload_sd; bootm ${bootkaddr} ${bootiaddr}'
+
+################ Netboot through TFTP+NBD ##################
+# replace <IP> addresses by appropriate addresses
+
+setenv 'ipaddr' '<board_IP>'
+setenv 'serverip' '<server_IP>'
+
+setenv 'bootargs_root' 'root=/dev/ram0 ramdisk_size=16384 ip=dhcp'
+setenv 'bootkload_net' 'tftp ${bootkaddr} porter/${bootkfile}'
+setenv 'bootiload_net' 'tftp ${bootiaddr} porter/${bootifile}'
+setenv 'bootcmd' 'setenv bootargs ${bootargs_console} ${bootargs_video} ${bootargs_root} ${bootargs_extra} nbd.server=${serverip}; run bootkload_net; run bootiload_net; bootm ${bootkaddr} ${bootiaddr}'
+
--- /dev/null
+# Enable network bootable image and initrd/initramfs
+
+# add image classes for uboot
+IMAGE_CLASSES += "${@'image_types_uboot' if (d.getVar("KERNEL_IMAGETYPE", True) == "uImage") else ''}"
+
+python () {
+ d.appendVar("IMAGE_FSTYPES"," ext4")
+
+ if (bb.utils.contains("IMAGE_FSTYPES","live",True,False,d)):
+ # typical case for Minnowboard Max
+ d.setVar("INITRD_IMAGE","initramfs-netboot-image")
+ d.setVar("INITRD","%s/%s-%s.ext4.gz" % (
+ d.getVar("DEPLOY_DIR_IMAGE",True),
+ d.getVar("INITRD_IMAGE",True),
+ d.getVar("MACHINE",True)
+ ))
+ else:
+ d.appendVar("INITRAMFS_IMAGE"," initramfs-netboot-image")
+ if (d.getVar("KERNEL_IMAGETYPE",True) == "uImage"):
+ # case for "old" u-boot images, like Porter board
+ d.appendVar("INITRAMFS_FSTYPES"," ext4.gz.u-boot");
+ else:
+ # case for new u-boot images which don't require uImage format
+ d.appendVar("INITRAMFS_FSTYPES"," ext4.gz");
+}
+
--- /dev/null
+# We have a conf and classes directory, add to BBPATH
+BBPATH .= ":${LAYERDIR}"
+
+# We have recipes-* directories, add to BBFILES
+BBFILES += "${LAYERDIR}/recipes-*/*/*.bb \
+ ${LAYERDIR}/recipes-*/*/*.bbappend"
+
+BBFILE_COLLECTIONS += "meta-netboot"
+BBFILE_PATTERN_meta-netboot = "^${LAYERDIR}/"
+BBFILE_PRIORITY_meta-netboot = "20"
--- /dev/null
+FILESEXTRAPATHS_prepend := "${THISDIR}/files:"
+
+SRC_URI += " \
+ file://enable_nbd.cfg \
+ "
+
--- /dev/null
+CONFIG_NBDCLIENT=y
--- /dev/null
+# Netboot initramfs image.
+DESCRIPTION = "Netboot initrd image"
+
+PACKAGE_INSTALL = "initramfs-netboot busybox base-passwd ${ROOTFS_BOOTSTRAP_INSTALL}"
+
+# Do not pollute the initrd image with rootfs features
+IMAGE_FEATURES = ""
+
+export IMAGE_BASENAME = "initramfs-netboot-image"
+IMAGE_LINGUAS = ""
+
+LICENSE = "MIT"
+
+IMAGE_FSTYPES = "${INITRAMFS_FSTYPES}"
+inherit core-image
+
+IMAGE_ROOTFS_SIZE = "8192"
+
+BAD_RECOMMENDATIONS += "busybox-syslog"
--- /dev/null
+#!/bin/sh
+
+################################################################################
+#
+# Init script to boot over network through NBD
+#
+# Contact: Stéphane Desneux <stephane.desneux@iot.bzh>
+#
+################################################################################
+
+# banner generator: echo "AGL - Netboot" | figlet -f slant -w 80 -c
+cat <<'EOF' >&2
+________________________________________________________________________________
+ ___ ________ _ __ __ __ __
+ / | / ____/ / / | / /__ / /_/ /_ ____ ____ / /_
+ / /| |/ / __/ / ______ / |/ / _ \/ __/ __ \/ __ \/ __ \/ __/
+ / ___ / /_/ / /___ /_____/ / /| / __/ /_/ /_/ / /_/ / /_/ / /_
+ /_/ |_\____/_____/ /_/ |_/\___/\__/_.___/\____/\____/\__/
+________________________________________________________________________________
+EOF
+
+# global variables
+
+SMACK=n
+NBD_SERVER=
+NBD_PORT=10809
+NBD_DEV=/dev/nbd0
+DEBUG=n
+
+# -------------------------------------------
+
+log_info() { echo "$0[$$]: $@" >&2; }
+log_error() { echo "$0[$$]: ERROR $@" >&2; }
+
+do_mount_fs() {
+ log_info "mounting FS: $@"
+ [[ -e /proc/filesystems ]] && { grep -q "$1" /proc/filesystems || { log_error "Unknown filesystem"; return 1; } }
+ [[ -d "$2" ]] || mkdir -p "$2"
+ [[ -e /proc/mounts ]] && { grep -q -e "^$1 $2 $1" /proc/mounts && { log_info "$2 ($1) already mounted"; return 0; } }
+ mount -t "$1" "$1" "$2"
+}
+
+bail_out() {
+ log_error "$@"
+ check_debug "Reboot will occur after exiting this shell."
+ log_info "Rebooting..."
+ exec reboot -f
+}
+
+check_debug() {
+ case $DEBUG in
+ Y|y|yes|1|true)
+ log_info "$@"
+ /bin/sh -i
+ ;;
+ esac
+}
+
+# -------------------------------------------
+
+export PATH=/sbin:/usr/sbin:/bin:/usr/bin
+
+log_info "starting initrd script"
+
+do_mount_fs proc /proc
+do_mount_fs sysfs /sys
+do_mount_fs devtmpfs /dev
+do_mount_fs devpts /dev/pts
+do_mount_fs tmpfs /dev/shm
+do_mount_fs tmpfs /tmp
+do_mount_fs tmpfs /run
+
+# parse kernel commandline to get NBD server
+for x in $(cat /proc/cmdline); do
+ case $x in
+ nbd.server=*) NBD_SERVER=${x/*=/};;
+ nbd.port=*) NBD_PORT=${x/*=/};;
+ nbd.dev=*) NBD_DEV=/dev/${x/*=/};;
+ nbd.debug=*) DEBUG=${x/*=/};;
+ esac
+done
+
+check_debug "Debug point 1. Exit to continue initrd script (mount NBD device)."
+
+log_info "NBD parameters: device $NBD_DEV, server $NBD_SERVER:$NBD_PORT"
+
+# check if smack is active (and if so, mount smackfs)
+grep -q smackfs /proc/filesystems && {
+ SMACK=y
+
+ do_mount_fs smackfs /sys/fs/smackfs
+
+ # adjust current label and network label
+ echo System >/proc/self/attr/current
+ echo System >/sys/fs/smackfs/ambient
+}
+
+# start nbd client
+try=5
+while :;do
+ log_info "Starting NBD client"
+ nbd-client $NBD_SERVER $NBD_PORT $NBD_DEV && { log_info "NBD client successfully started"; break; }
+ log_info "NBD client failed"
+ [[ $try -gt 0 ]] && { log_info "Retrying ($try trie(s) left)..."; sleep 3; try=$(( try - 1 )); continue; }
+
+ bail_out "Unable to mount NBD device $NBD_DEV using server $NBD_SERVER:$NBD_PORT"
+done
+
+# mount NBD device
+mkdir -p /sysroot
+mount $NBD_DEV /sysroot || bail_out "Unable to mount root NBD device"
+
+# move mounted devices to new root
+cd /sysroot
+for x in dev proc sys tmp run; do
+ log_info "Moving /$x to new rootfs"
+ mount -o move /$x $x
+done
+
+# switch to new rootfs
+log_info "Switching to new rootfs"
+mkdir -p run/initramfs
+pivot_root . run/initramfs || bail_out "pivot_root failed."
+
+# workaround for connman (avoid bringing down the network interface used for booting)
+if [[ -f /lib/systemd/system/connman.service ]]; then
+ log_info "Adjusting Connman configuration"
+ iface=$(ip -o link show up | tr ':' ' ' | awk '{print $2}' | grep -v -e "^lo$" | head -1)
+ sed -i "s|connmand -n\$|connmand -n -I $iface|g" /lib/systemd/system/connman.service
+fi
+
+# finally, run systemd
+check_debug "Debug point 2. Exit to continue initrd script (run systemd)."
+
+log_info "Exec'ing systemd"
+# banner generator: echo "AGL Booting . . ." | figlet -f slant -w 80 -c
+cat <<'EOF' >&2
+________________________________________________________________________________
+ ___ ________ ____ __ _
+ / | / ____/ / / __ )____ ____ / /_(_)___ ____ _
+ / /| |/ / __/ / / __ / __ \/ __ \/ __/ / __ \/ __ `/
+ / ___ / /_/ / /___ / /_/ / /_/ / /_/ / /_/ / / / / /_/ / _ _ _
+ /_/ |_\____/_____/ /_____/\____/\____/\__/_/_/ /_/\__, / (_) (_) (_)
+_____________________________________________________/____/_____________________
+EOF
+
+exec /lib/systemd/systemd </dev/console >/dev/console 2>&1
+bail_out
+
--- /dev/null
+SUMMARY = "Extremely basic live image init script"
+LICENSE = "MIT"
+LIC_FILES_CHKSUM = "file://${COREBASE}/meta/COPYING.MIT;md5=3da9cfbcb788c80a0384361b4de20420"
+SRC_URI = "file://init.sh"
+
+S = "${WORKDIR}"
+
+do_install() {
+ install -dm 0755 ${D}/etc
+ touch ${D}/etc/initrd-release
+ install -dm 0755 ${D}/dev
+ install -dm 0755 ${D}/sbin
+ install -m 0755 ${WORKDIR}/init.sh ${D}/sbin/init
+}
+
+inherit allarch
+
+FILES_${PN} += " /dev /etc/initrd-release /sbin/init "
+
Code Review / AGL / meta-agl.git / commitdiff