diff --git a/recipes-core/initrdscripts/tegra-minimal-init/init-boot.sh b/recipes-core/initrdscripts/tegra-minimal-init/init-boot.sh
index 0e50ec7d..cccaa6d5 100644
--- a/recipes-core/initrdscripts/tegra-minimal-init/init-boot.sh
+++ b/recipes-core/initrdscripts/tegra-minimal-init/init-boot.sh
@@ -1,8 +1,9 @@
 #!/bin/sh
 PATH=/sbin:/bin:/usr/sbin:/usr/bin
-mount -t proc proc /proc
-mount -t devtmpfs none /dev
-mount -t sysfs sysfs /sys
+mount -t proc proc -o nosuid,nodev,noexec /proc
+mount -t devtmpfs none -o nosuid /dev
+mount -t sysfs sysfs -o nosuid,nodev,noexec /sys
+mount -t efivarfs efivarfs -o nosuid,nodev,noexec /sys/firmware/efi/efivars
 
 rootdev=""
 opt="rw"
diff --git a/recipes-core/initrdscripts/tegra-minimal-init/platform-preboot.sh b/recipes-core/initrdscripts/tegra-minimal-init/platform-preboot.sh
index d8d1cd11..92dc6a7d 100644
--- a/recipes-core/initrdscripts/tegra-minimal-init/platform-preboot.sh
+++ b/recipes-core/initrdscripts/tegra-minimal-init/platform-preboot.sh
@@ -1,13 +1,22 @@
 slotsfx=""
 mayberoot=""
+foundslotsfx="no"
 for bootarg in `cat /proc/cmdline`; do
     case "$bootarg" in
-	boot.slot_suffix=*) slotsfx="${bootarg##boot.slot_suffix=}" ;;
+	boot.slot_suffix=*) slotsfx="${bootarg##boot.slot_suffix=}"; foundslotsfx="yes" ;;
 	root=*) mayberoot="${bootarg##root=}" ;;
 	ro) opt="ro" ;;
 	rootwait) wait="yes" ;;
     esac
 done
+if [ "$foundslotsfx" != "yes" ]; then
+    # This variable file contains a type (should be 6) followed by the value (should be 0 or 1)
+    bcdata=$(echo $(hexdump -n 8 -e '2/4 " %u"' /sys/firmware/efi/efivars/BootChainFwCurrent-781e084c-a330-417c-b678-38e696380cb9 2>/dev/null))
+    if [ "$(echo "$bcdata" | cut -d' ' -f1)" = "6" ]; then
+	slotnum=$(echo "$bcdata" | cut -d' ' -f2)
+	[ "$slotnum" != "1" ] || slotsfx="_b"
+    fi
+fi
 rootdev=`blkid -l -t PARTLABEL=APP$slotsfx | cut -d: -f1`
 if [ -z "$rootdev" ]; then
     if [ -n "$mayberoot" ]; then