u-boot/doc/README.fsl-trustzone-components

Freescale ARM64 SoCs like LS2085A have ARM TrustZone components like
TZPC-BP147 (TrustZone Protection Controller) and TZASC-400 (TrustZone
Address Space Controller).

While most of the configuration related programming of these peripherals
is left to a root-of-trust security software layer (running in EL3
privilege mode), but still some configurations of these peripherals
might be required while the bootloader is executing in EL3 privilege
mode. The following sections define how to turn on these features for
LS2085A like SoCs.

TZPC-BP147 (TrustZone Protection Controller)
============================================
- Depends on CONFIG_FSL_TZPC_BP147 configuration flag.
- Separates Secure World and Normal World on-chip RAM (OCRAM) spaces.
- Provides a programming model to set access control policy via the TZPC
  TZDECPROT Registers.

TZASC-400 (TrustZone Address Space Controller)
==============================================
- Depends on CONFIG_FSL_TZASC_400 configuration flag.
- Separates Secure World and Normal World external memory spaces for bus masters
  such as processors and DMA-equipped peripherals.
- Supports 8 fully programmable address regions, initially inactive at reset,
  and one base region, always active, that covers the remaining address space.