Overview

Access to user data on an ATA HDD can be restricted by enabling security via the ATA Security Feature Set. Once security has been enabled and a password has been set, the HDD will be locked upon power-on. All access to user data will be restricted on a locked HDD until the HDD has been unlocked. A HDD can be unlocked by sending a SECURITY UNLOCK command with the correct password to the HDD. Some systems running Linux do not have built-in support for unlocking HDDs preventing this HDD security feature from being utilized. This document will provide an example of how to send a SECURITY UNLOCK command to the HDD at the Linux Kernel Level so locked HDDs can be utilized in Linux. It assumes working knowledge of the ATA Security Feature Set and does not attempt to explain it or how to lock a HDD.