The OpenSTLinux BSP encompasses the following components:
- The boot chain based on TF-A running on the Arm® Cortex®-A in secure mode and U-Boot running on the Arm® Cortex®-A in nonsecure mode
- The OP-TEE secure OS running on the Arm® Cortex®-A in secure mode
- The Linux kernel running on the Arm® Cortex®-A in nonsecure mode
The figure below is clickable so that the user can directly jump to one of the sub-levels listed above.

OpenSTLinux BSP architecture overview