docs: armv8-R aarch64 fvp_r documentation

Documenting armv8-R aarch64 fvp_r features, boot sequence, and build
procedure.

Signed-off-by: Lauren Wehrmeister <lauren.wehrmeister@arm.com>
Change-Id: If75d59acdf0f8a61cea6187967a4c35af2f31c98

docs/plat/arm/fvp_r/index.rst

@@ -0,0 +1,46 @@
+ARM V8-R64 Fixed Virtual Platform (FVP)
+=======================================
+
+Some of the features of Armv8-R AArch64 FVP platform referenced in Trusted
+Boot R-class include:
+
+- Secure World Support Only
+- EL2 as Maximum EL support (No EL3)
+- MPU Support only at EL2
+- MPU or MMU Support at EL0/EL1
+- AArch64 Support Only
+- Trusted Board Boot
+
+Further information on v8-R64 FVP is available at `info <https://developer.arm.com/documentation/ddi0600/latest/>`_
+
+Boot Sequence
+-------------
+
+BL1 –> BL33
+
+The execution begins from BL1 which loads the BL33 image, a boot-wrapped (bootloader + Operating System)
+Operating System, from FIP to DRAM.
+
+Build Procedure
+~~~~~~~~~~~~~~~
+
+-  Obtain arm `toolchain <https://developer.arm.com/tools-and-software/open-source-software/developer-tools/gnu-toolchain/gnu-a/downloads>`_.
+   Set the CROSS_COMPILE environment variable to point to the toolchain folder.
+
+-  Build TF-A:
+
+   .. code:: shell
+
+      make PLAT=fvp_r BL33=<path_to_os.bin> all fip
+
+   Enable TBBR by adding the following options to the make command:
+
+   .. code:: shell
+
+      MBEDTLS_DIR=<path_to_mbedtls_directory>  \
+      TRUSTED_BOARD_BOOT=1 \
+      GENERATE_COT=1 \
+      ARM_ROTPK_LOCATION=devel_rsa  \
+      ROT_KEY=plat/arm/board/common/rotpk/arm_rotprivk_rsa.pem
+
+*Copyright (c) 2021, Arm Limited. All rights reserved.*

docs/plat/arm/index.rst

@@ -7,6 +7,7 @@ Arm Development Platforms
 
    juno/index
    fvp/index
+   fvp_r/index
    fvp-ve/index
    tc/index
    arm_fpga/index
@@ -20,4 +21,4 @@ such as Juno.
 
 --------------
 
-*Copyright (c) 2021, Arm Limited. All rights reserved.*
+*Copyright (c) 2019-2021, Arm Limited. All rights reserved.*