udev-toradex-rules: introduce bootpart-automount.rules

It will handle bind mount boot partition to /boot. provided that the
modules boot from eMMC/SDCard devices and there is a boot partition
present.

It whould work with both sysvinit and systemd init managers.

Related-to: ELB-4620

Signed-off-by: Ming Liu <ming.liu@toradex.com>

3 files changed, 48 insertions, 2 deletions

diff --git a/recipes-core/udev/files/bootpart-automount.rules b/recipes-core/udev/files/bootpart-automount.rules
new file mode 100644
index 0000000..8b02dec
--- /dev/null
+++ b/recipes-core/udev/files/bootpart-automount.rules
@@ -0,0 +1,6 @@
+# Toradex specific, to bind mount boot partition to /boot.
+#
+# To be noticed: Be careful if you want to change the rule file name, it must be loaded
+# by udevd after automount.rules, otherwise, the original mount point might be not present.
+#
+ACTION=="add", KERNEL=="mmcblk[0-9]p[0-9]*", RUN+="/etc/udev/scripts/toradex-mount-bootpart.sh"
diff --git a/recipes-core/udev/files/toradex-mount-bootpart.sh b/recipes-core/udev/files/toradex-mount-bootpart.sh
new file mode 100755
index 0000000..965d747
--- /dev/null
+++ b/recipes-core/udev/files/toradex-mount-bootpart.sh
@@ -0,0 +1,33 @@
+#!/usr/bin/env sh
+#
+# Bind mount boot partition /boot -> /${MOUNT_BASE}/BOOT-PARTITION-MOUNTPOINT
+# in which:
+# MOUNT_BASE is defined in /etc/udev/scripts/mount.sh
+# BOOT-PARTITION-MOUNTPOINT is the mount point of boot partition.
+
+BASEUUID=$(sed -r 's/^.*\broot=PARTUUID=([0-9a-f]+)-02.*$/\1/' /proc/cmdline)
+BOOTPART=$(readlink -f /dev/disk/by-partuuid/"${BASEUUID}-01")
+if [ x"$DEVNAME" = x"$BOOTPART" ]; then
+	MOUNTPOINT="$(lsblk -o MOUNTPOINT -nr "$DEVNAME" | head -1)"
+	MOUNTNAME="$(basename "$MOUNTPOINT")"
+	BASE_INIT="$(readlink -f "@base_sbindir@/init")"
+	INIT_SYSTEMD="@systemd_unitdir@/systemd"
+
+	if [ "x$BASE_INIT" = "x$INIT_SYSTEMD" ];then
+		# systemd as init uses systemd-mount to mount block devices
+		MOUNT="/usr/bin/systemd-mount --no-block -o silent"
+		UMOUNT="/usr/bin/systemd-umount"
+	else
+		MOUNT="/bin/mount"
+		UMOUNT="/bin/umount"
+
+		# Silent util-linux's version of mounting auto
+		if [ "x$(readlink $MOUNT)" = "x/bin/mount.util-linux" ]; then
+			MOUNT="$MOUNT -o silent"
+		fi
+	fi
+
+	if [ -e /tmp/.automount-"$MOUNTNAME" ]; then
+		$MOUNT -o bind "$MOUNTPOINT" /boot
+	fi
+fi
diff --git a/recipes-core/udev/udev-toradex-rules.bb b/recipes-core/udev/udev-toradex-rules.bb
index a94da96..c31f416 100644
--- a/recipes-core/udev/udev-toradex-rules.bb
+++ b/recipes-core/udev/udev-toradex-rules.bb
@@ -3,16 +3,23 @@ LICENSE = "MIT"
 LIC_FILES_CHKSUM = "file://${COMMON_LICENSE_DIR}/MIT;md5=0835ade698e0bcf8506ecda2f7b4f302"
 
 SRC_URI = "\
-    file://99-toradex.rules \
     file://10-toradex-wifi-ifnames.link \
+    file://99-toradex.rules \
+    file://bootpart-automount.rules \
     file://toradex-adc.sh \
+    file://toradex-mount-bootpart.sh \
 "
 
 do_install () {
     install -d ${D}${sysconfdir}/udev/rules.d
     install -d ${D}${sysconfdir}/udev/scripts
     install -d ${D}${sysconfdir}/systemd/network
+    install -m 0644 ${WORKDIR}/10-toradex-wifi-ifnames.link ${D}${sysconfdir}/systemd/network/
     install -m 0644 ${WORKDIR}/99-toradex.rules ${D}${sysconfdir}/udev/rules.d/
+    install -m 0644 ${WORKDIR}/bootpart-automount.rules ${D}${sysconfdir}/udev/rules.d/
     install -m 0755 ${WORKDIR}/toradex-adc.sh ${D}${sysconfdir}/udev/scripts/
-    install -m 0644 ${WORKDIR}/10-toradex-wifi-ifnames.link ${D}${sysconfdir}/systemd/network/
+    install -m 0755 ${WORKDIR}/toradex-mount-bootpart.sh ${D}${sysconfdir}/udev/scripts/
+
+    sed -i 's|@systemd_unitdir@|${systemd_unitdir}|g' ${D}${sysconfdir}/udev/scripts/toradex-mount-bootpart.sh
+    sed -i 's|@base_sbindir@|${base_sbindir}|g' ${D}${sysconfdir}/udev/scripts/toradex-mount-bootpart.sh
 }