Install signtos by entering the following commands in the terminal:
sudo apt update sudo apt install signtos
Description:
Android signing tool for signing Trusty images
Signs ARM Trusty images for use with operating systems that support it. Trusty is a set of software components supporting a Trusted Execution Environment (TEE) on mobile devices. The key must be stored in PKCS8 format.
Homepage: https://android.googlesource.com/platform/build
Version: 1:7.0.0+r33-1
Section: universe/devel