A TPM error (7) occurred attempting to read a pcr value
I had tried a command (I do not remember it) with the terminal of Ubuntu, and the computer shut down. Now when I boot it, it says :-
[ 4.562057] ACPI PCC probe failed. [ 4.615205 tpm_tis 00:05: A TPM error (7) occurred attempting to read a pcr value Target filesystem doesn't have requested /sbin/init. No init found. Try passing init= bootargw
Busybox v1.21.1 (ubuntu 1:1.21.0-1ubuntu1) built in shell (ash) Enter 'help' for a list of built-in commands.
(Initramfs)
First of all TPM is:
Trusted Platform Module (TPM) is an international standard for a secure cryptoprocessor, which is a dedicated microprocessor designed to secure hardware by integrating cryptographic keys into devices.
In practice a TPM can be used for various different security applications such as secure boot and key storage.
TPM is naturally supported only on devices that have TPM hardware support. If your hardware has TPM support but it is not showing up, it might need to be enabled in the BIOS settings.
1. So if you do not need use the TPM feature you can disable it via the BIOS settings. I have a machine with Phoenix BIOS and these settings are placed within the Security section.
2. Also you can ignore the TPM feature through the Ubuntu settings. Just type this command:
echo "blacklist tpm_tis" | sudo tee -a /etc/modprobe.d/tpm_tis.conf
Where the command tee -a will append the echoed line (blacklist tpm_tis) into the end of /etc/modprobe.d/tpm_tis.conf or will create the file if it's doesn't exists.
3. Sources and other solutions:
- ArchWiki: Trusted Platform Module
- A TPM error (6) occurred attempting to read a pcr value
- A tpm error (7) occurred attempting to read a pcr value in centos
I got this error and it was because I had two hard drive with the same UUID.
The error I got on boot up was:
A TPM error (7) occurred attempting to read a pcr value
I went searching the BIOS, nonmodeset on kernel line, etc because the error message was not very informative.
To see if you have this issue, boot to a command prompt and issue:
blkid -o list
and see if you have UUID's that are the same.
Apparently what I had done was clone a partition and forgot to reset the UUID. You need to check the file system and then set the UUID - here is an example:
fsck -y /dev/sda1
tune2fs /dev/sda1 -U cfe9f84d-a454-4e46-97bb-6f1f18fcb427