1 files changed, 60 insertions, 0 deletions
diff --git a/src/initramfs/tpm/bin/detect-tpm.sh b/src/initramfs/tpm/bin/detect-tpm.sh
new file mode 100755
index 00000000..48bc92f7
--- /dev/null
+++ b/src/initramfs/tpm/bin/detect-tpm.sh
@@ -0,0 +1,60 @@
+#!/bin/sh
+#
+
+SYS_PATH="/sys/class/misc/tpm0/device/"
+MODULES="atmel tis nsc infineon"
+MODULES_FORCE="tis"
+FLAGS=""
+FLAGS_FORCE="force=1"
+
+test_tpm() {
+	if [ ! -d "$SYS_PATH" ] ; then
+		return 1
+	fi
+
+# tpm_tis creates "active" and "enabled" files
+# _atmel and _nsc only create the "caps"
+	ACTIVE="$(cat $SYS_PATH/active 2>/dev/null)"
+	ENABLED="$(cat $SYS_PATH/enabled 2>/dev/null)"
+	CAPS="$(cat $SYS_PATH/caps 2>/dev/null)"
+	if [ -n "$ACTIVE" -o -n "$ENABLED" -o -n "$CAPS" ] ; then
+		echo
+		echo "successfully detected TPM chip!"
+		echo
+		echo "$CAPS"
+		echo
+	else
+		return 2
+	fi
+}
+
+try_modules() {
+	if [ "$1" == "force" ] ; then
+		MODULES=$MODULES_FORCE
+		FLAGS=$FLAGS_FORCE
+		echo "using flags '$FLAGS'"
+	fi
+	echo -n "trying modules:"
+	for module in $MODULES ; do
+		echo -n " $module"
+		modprobe tpm_${module} $FLAGS 2>/dev/null
+		if test_tpm ; then
+			return 0
+		fi
+		# clean up since e.g. infineon always loads w/o error...
+		modprobe -r tpm_${module} 2>/dev/null
+	done
+	echo
+	return 1
+}
+
+# create device-node
+test -c /dev/tpm0 || mknod /dev/tpm0 c 10 224
+
+if try_modules ; then
+	exit 0  # success
+fi
+if ! try_modules force ; then
+	echo "Warning: no TPM chip found!"
+	exit 1
+fi