Xilinx Zynq UltraScale+ MPSoC
=============================

Trusted Firmware-A (TF-A) implements the EL3 firmware layer for Xilinx Zynq
UltraScale + MPSoC.
The platform only uses the runtime part of TF-A as ZynqMP already has a
BootROM (BL1) and FSBL (BL2).

BL31 is TF-A.
BL32 is an optional Secure Payload.
BL33 is the non-secure world software (U-Boot, Linux etc).

To build:

.. code:: bash

    make CROSS_COMPILE=aarch64-none-elf- PLAT=zynqmp RESET_TO_BL31=1 bl31

To build bl32 TSP you have to rebuild bl31 too:

.. code:: bash

    make CROSS_COMPILE=aarch64-none-elf- PLAT=zynqmp SPD=tspd RESET_TO_BL31=1 bl31 bl32

To build TF-A for JTAG DCC console:

.. code:: bash

    make CROSS_COMPILE=aarch64-none-elf- PLAT=zynqmp RESET_TO_BL31=1 bl31 ZYNQMP_CONSOLE=dcc

ZynqMP platform specific build options
--------------------------------------

-  ``ZYNQMP_ATF_MEM_BASE``: Specifies the base address of the bl31 binary.
-  ``ZYNQMP_ATF_MEM_SIZE``: Specifies the size of the memory region of the bl31 binary.
-  ``ZYNQMP_BL32_MEM_BASE``: Specifies the base address of the bl32 binary.
-  ``ZYNQMP_BL32_MEM_SIZE``: Specifies the size of the memory region of the bl32 binary.

-  ``ZYNQMP_CONSOLE``: Select the console driver. Options:

   -  ``cadence``, ``cadence0``: Cadence UART 0
   -  ``cadence1`` : Cadence UART 1

ZynqMP Debug behavior
---------------------

With DEBUG=1, TF-A for ZynqMP uses DDR memory range instead of OCM memory range
due to size constraints.
For DEBUG=1 configuration for ZynqMP the BL31_BASE is set to the DDR location
of 0x1000 and BL31_LIMIT is set to DDR location of 0x7FFFF.

If the user wants to move the bl31 to a different DDR location, user can provide
the DDR address location in the build command as follows,

make CROSS_COMPILE=aarch64-none-elf- PLAT=zynqmp RESET_TO_BL31=1 DEBUG=1 \
	ZYNQMP_ATF_MEM_BASE=<DDR address> ZYNQMP_ATF_MEM_SIZE=<size> bl31


FSBL->TF-A Parameter Passing
----------------------------

The FSBL populates a data structure with image information for TF-A. TF-A uses
that data to hand off to the loaded images. The address of the handoff data
structure is passed in the ``PMU_GLOBAL.GLOBAL_GEN_STORAGE6`` register. The
register is free to be used by other software once TF-A has brought up
further firmware images.

Power Domain Tree
-----------------

The following power domain tree represents the power domain model used by TF-A
for ZynqMP:

::

                    +-+
                    |0|
                    +-+
         +-------+---+---+-------+
         |       |       |       |
         |       |       |       |
         v       v       v       v
        +-+     +-+     +-+     +-+
        |0|     |1|     |2|     |3|
        +-+     +-+     +-+     +-+

The 4 leaf power domains represent the individual A53 cores, while resources
common to the cluster are grouped in the power domain on the top.

CUSTOM SIP service support
--------------------------

- Dedicated SMC FID ZYNQMP_SIP_SVC_CUSTOM(0x82002000)(32-bit)/
  (0xC2002000)(64-bit) to be used by a custom package for
  providing CUSTOM SIP service.

- by default platform provides bare minimum definition for
  custom_smc_handler in this service.

- to use this service, custom package should implement their
  smc handler with the name custom_smc_handler. once custom package is
  included in TF-A build, their definition of custom_smc_handler is
  enabled.

Custom package makefile fragment inclusion in TF-A build
--------------------------------------------------------

- custom package is not directly part of TF-A source.

- <CUSTOM_PKG_PATH> is the location at which user clones a
  custom package locally.

- custom package needs to implement makefile fragment named
  custom_pkg.mk so as to get included in TF-A build.

- custom_pkg.mk specify all the rules to include custom package
  specific header files, dependent libs, source files that are
  supposed to be included in TF-A build.

- when <CUSTOM_PKG_PATH> is specified in TF-A build command,
  custom_pkg.mk is included from <CUSTOM_PKG_PATH> in TF-A build.

- TF-A build command:
  make CROSS_COMPILE=aarch64-none-elf- PLAT=zynqmp RESET_TO_BL31=1
  bl31 CUSTOM_PKG_PATH=<...>