3.9.3 Environment variables

Device paths are also used when certain environment variables are built and stored in non-volatile storage. There are a number of environment variables defined in the Boot Manager chapter of the UEFI Specification. These variables define the following:

  • Console input devices

  • Console output devices

  • Standard error devices

  • The drivers that need to be loaded prior to an OS boot

  • The boot selections that the platform supports

The UEFI boot manager, UEFI utilities, and UEFI-conformant operating systems manage these environment variables as operating systems are installed and removed from a platform.