nvidia-tegra.md

Tegra-T210 Overview
====================

T210 has Quad ARM® Cortex®-A57 cores in a switched configuration with a
companion set of quad ARM Cortex-A53 cores. The Cortex-A57 and A53 cores
support ARMv8, executing both 64-bit Aarch64 code, and 32-bit Aarch32 code
including legacy ARMv7 applications. The Cortex-A57 processors each have
48 KB Instruction and 32 KB Data Level 1 caches; and have a 2 MB shared
Level 2 unified cache. The Cortex-A53 processors each have 32 KB Instruction
and 32 KB Data Level 1 caches; and have a 512 KB shared Level 2 unified cache.

Directory structure
====================

* plat/nvidia/tegra/common - Common code for all Tegra SoCs
* plat/nvidia/tegra/soc/txxx - Chip specific code

Trusted OS dispatcher
=====================
Tegra supports multiple Trusted OS', Trusted Little Kernel (TLK) being one of
them. In order to include the 'tlkd' dispatcher in the image, pass 'SPD=tlkd'
on the command line while preparing a bl31 image. This allows other Trusted OS
vendors to use the upstream code and include their dispatchers in the image
without changing any makefiles.

Preparing the BL31 image to run on Tegra SoCs
===================================================
CROSS_COMPILE=<path-to-aarch64-gcc>/bin/aarch64-none-elf- make PLAT=tegra \
TARGET_SOC=<target-soc e.g. t210> BL32=<path-to-trusted-os-binary> \
SPD=<dispatcher e.g. tlkd> all

Power Management
================
The PSCI implementation expects each platform to expose the 'power state'
parameter to be used during the 'SYSTEM SUSPEND' call. The state-id field
is implementation defined on Tegra SoCs and is preferably defined by
tegra_def.h.