docs(juno): update TF-A build instructions

Clean up instructions for building/running TF-A on the
Juno platform and add correct link to SCP binaries.
Signed-off-by: Zelalem Aweke <zelalem.aweke@arm.com>
Change-Id: I536f98082e167edbf45f29ca23cc0db44687bb3b

docs/plat/arm/juno/index.rst

@@ -12,24 +12,21 @@ Running software on Juno
 
 This version of TF-A has been tested on variants r0, r1 and r2 of Juno.
 
-To execute the software stack on Juno, the version of the Juno board recovery
-image indicated in the `Linaro Release Notes`_ must be installed. If you have an
-earlier version installed or are unsure which version is installed, please
-re-install the recovery image by following the
-`Instructions for using Linaro's deliverables on Juno`_.
+To run TF-A on Juno, you need to first prepare an SD card with Juno software
+stack that includes TF-A. This version of TF-A is tested with pre-built
+`Linaro release software stack`_ version 20.01. You can alternatively
+build the software stack yourself by following the
+`Juno platform software user guide`_. Once you prepare the software stack
+on an SD card, you can replace the ``bl1.bin`` and ``fip.bin``
+binaries in the ``SOFTWARE/`` directory with custom built TF-A binaries.
 
 Preparing TF-A images
 ---------------------
 
-After building TF-A, the files ``bl1.bin`` and ``fip.bin`` need copying to the
-``SOFTWARE/`` directory of the Juno SD card.
-
-Creating a Firmware Image Package (FIP)
----------------------------------------
-
 This section provides Juno and FVP specific instructions to build Trusted
 Firmware, obtain the additional required firmware, and pack it all together in
-a single FIP binary. It assumes that a Linaro release has been installed.
+a single FIP binary. It assumes that a Linaro release software stack has been
+installed.
 
 .. note::
    Pre-built binaries for AArch32 are available from Linaro Release 16.12
@@ -57,9 +54,16 @@ a single FIP binary. It assumes that a Linaro release has been installed.
 
        make realclean
 
-#. Obtain SCP_BL2 (Juno) and BL33 (all platforms)
+#. Obtain SCP binaries (Juno)
+
+   This version of TF-A is tested with SCP version 2.8.0 on Juno. You can
+   download pre-built SCP binaries (``scp_bl1.bin`` and ``scp_bl2.bin``)
+   from `TF-A downloads page`_. Alternatively, you can `build
+   the binaries from source`_.
+
+#. Obtain BL33 (all platforms)
 
-   Use the fiptool to extract the SCP_BL2 and BL33 images from the FIP
+   Use the fiptool to extract the BL33 image from the FIP
    package included in the Linaro release:
 
    .. code:: shell
@@ -71,8 +75,7 @@ a single FIP binary. It assumes that a Linaro release has been installed.
        ./tools/fiptool/fiptool unpack <path-to-linaro-release>/[SOFTWARE]/fip.bin
 
    The unpack operation will result in a set of binary images extracted to the
-   current working directory. The SCP_BL2 image corresponds to
-   ``scp-fw.bin`` and BL33 corresponds to ``nt-fw.bin``.
+   current working directory. BL33 corresponds to ``nt-fw.bin``.
 
    .. note::
       The fiptool will complain if the images to be unpacked already
@@ -102,7 +105,7 @@ a single FIP binary. It assumes that a Linaro release has been installed.
 
    .. code:: shell
 
-       make PLAT=juno BL33=nt-fw.bin SCP_BL2=scp-fw.bin all fip
+       make PLAT=juno BL33=nt-fw.bin SCP_BL2=scp_bl2.bin all fip
 
    For AArch32:
 
@@ -144,7 +147,7 @@ a single FIP binary. It assumes that a Linaro release has been installed.
       .. code:: shell
 
           make ARCH=aarch64 PLAT=juno JUNO_AARCH32_EL3_RUNTIME=1 \
-          BL33=nt-fw.bin SCP_BL2=scp-fw.bin \
+          BL33=nt-fw.bin SCP_BL2=scp_bl2.bin \
           BL32=<path-to-temporary>/bl32.bin all fip
 
 The resulting BL1 and FIP images may be found in:
@@ -159,6 +162,8 @@ The resulting BL1 and FIP images may be found in:
     ./build/fvp/release/bl1.bin
     ./build/fvp/release/fip.bin
 
+After building TF-A, the files ``bl1.bin``, ``fip.bin`` and ``scp_bl1.bin``
+need to be copied to the ``SOFTWARE/`` directory on the Juno SD card.
 
 Booting Firmware Update images
 ------------------------------
@@ -236,10 +241,12 @@ configure it.
 
 --------------
 
-*Copyright (c) 2019, Arm Limited. All rights reserved.*
+*Copyright (c) 2019-2021, Arm Limited. All rights reserved.*
 
-.. _Linaro Release Notes: https://community.arm.com/dev-platforms/w/docs/226/old-release-notes
-.. _Instructions for using Linaro's deliverables on Juno: https://community.arm.com/dev-platforms/w/docs/303/juno
+.. _Linaro release software stack: http://releases.linaro.org/members/arm/platforms/
+.. _Juno platform software user guide: https://git.linaro.org/landing-teams/working/arm/arm-reference-platforms.git/about/docs/juno/user-guide.rst
+.. _TF-A downloads page: https://downloads.trustedfirmware.org/tf-a/css_scp_2.8.0/juno/
+.. _build the binaries from source: https://github.com/ARM-software/SCP-firmware/blob/master/user_guide.md#scp-firmware-user-guide
 .. _Arm Platforms Portal: https://community.arm.com/dev-platforms/
 .. _Juno Getting Started Guide: http://infocenter.arm.com/help/topic/com.arm.doc.dui0928e/DUI0928E_juno_arm_development_platform_gsg.pdf
 .. _PSCI: http://infocenter.arm.com/help/topic/com.arm.doc.den0022d/Power_State_Coordination_Interface_PDD_v1_1_DEN0022D.pdf