mounting an ecryptfs filesystem at boot

Could someone advise me on how to do a ecrypt mount at boot time.
The filesystem is encrypted with a pcr based key generated with
ecryptfs-generate-tpm-key.  I have the uuid and I am able to mount the
filesystem interactively.

I use some instructions in one of the README files to derive a fstab
entry from mtab

/secret /secret/ecryptfs
user,noauto,rw,exec,ecryptfs_sig=aabbccddeeffgghh,ecryptfs_cipher=aes,ecryptfs_key_bytes=16,ecryptfs_passthrough,
0 0

Do I need to use the uuid provided by ecryptfs-generate-tpm-key
somewhere or it is it referenced by the ecryptfs_sig?

When I try to mount with
mount -i /secret
or
mount -i /secret -o key=TPM:uuid=12121212121212112121221

it mounts, but the files remain encrypted

If I unmount then remount interactively specifying tcpi for the key
stype and providing the uuid and other options it is ok, then
umounting it and remounting with mount -i /secret then it works until
reboot.  This would seem to indicate that i am not supplying the key
correctly initially and after it has been properly provided in an
interactive mount the credentials remain on the session keyring for
subsequent mounts.