doc: Split the User Guide into multiple files

The User Guide document has grown organically over time and
now covers a wide range of topics, making it difficult to
skim read and extract information from. Currently, it covers
these topics and maybe a couple more:

- Requirements (hardware, tools, libs)
- Checking out the repo
- Basic build instructions
- A comprehensive list of build flags
- FIP packaging
- Building specifically for Juno
- Firmware update images
- EL3 payloads
- Preloaded BL33 boot flow
- Running on FVPs
- Running on Juno

I have separated these out into a few groups that become new
documents. Broadly speaking, build instructions for the tools,
for TF-A generally, and for specific scenarios are separated.
Content relating to specific platforms (Juno and the FVPs are
Arm-specific platforms, essentially) has been moved into the
documentation that is specific to those platforms, under
docs/plat/arm.

Change-Id: Ica87c52d8cd4f577332be0b0738998ea3ba3bbec
Signed-off-by: Paul Beesley <paul.beesley@arm.com>

1 files changed, 114 insertions, 0 deletions

diff --git a/docs/plat/arm/arm-build-options.rst b/docs/plat/arm/arm-build-options.rst
new file mode 100644
index 000000000..d24ad231d
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+Arm Development Platform Build Options
+======================================
+
+Arm Platform Build Options
+--------------------------
+
+-  ``ARM_BL31_IN_DRAM``: Boolean option to select loading of BL31 in TZC secured
+   DRAM. By default, BL31 is in the secure SRAM. Set this flag to 1 to load
+   BL31 in TZC secured DRAM. If TSP is present, then setting this option also
+   sets the TSP location to DRAM and ignores the ``ARM_TSP_RAM_LOCATION`` build
+   flag.
+
+-  ``ARM_CONFIG_CNTACR``: boolean option to unlock access to the ``CNTBase<N>``
+   frame registers by setting the ``CNTCTLBase.CNTACR<N>`` register bits. The
+   frame number ``<N>`` is defined by ``PLAT_ARM_NSTIMER_FRAME_ID``, which
+   should match the frame used by the Non-Secure image (normally the Linux
+   kernel). Default is true (access to the frame is allowed).
+
+-  ``ARM_DISABLE_TRUSTED_WDOG``: boolean option to disable the Trusted Watchdog.
+   By default, Arm platforms use a watchdog to trigger a system reset in case
+   an error is encountered during the boot process (for example, when an image
+   could not be loaded or authenticated). The watchdog is enabled in the early
+   platform setup hook at BL1 and disabled in the BL1 prepare exit hook. The
+   Trusted Watchdog may be disabled at build time for testing or development
+   purposes.
+
+-  ``ARM_LINUX_KERNEL_AS_BL33``: The Linux kernel expects registers x0-x3 to
+   have specific values at boot. This boolean option allows the Trusted Firmware
+   to have a Linux kernel image as BL33 by preparing the registers to these
+   values before jumping to BL33. This option defaults to 0 (disabled). For
+   AArch64 ``RESET_TO_BL31`` and for AArch32 ``RESET_TO_SP_MIN`` must be 1 when
+   using it. If this option is set to 1, ``ARM_PRELOADED_DTB_BASE`` must be set
+   to the location of a device tree blob (DTB) already loaded in memory. The
+   Linux Image address must be specified using the ``PRELOADED_BL33_BASE``
+   option.
+
+-  ``ARM_PLAT_MT``: This flag determines whether the Arm platform layer has to
+   cater for the multi-threading ``MT`` bit when accessing MPIDR. When this flag
+   is set, the functions which deal with MPIDR assume that the ``MT`` bit in
+   MPIDR is set and access the bit-fields in MPIDR accordingly. Default value of
+   this flag is 0. Note that this option is not used on FVP platforms.
+
+-  ``ARM_RECOM_STATE_ID_ENC``: The PSCI1.0 specification recommends an encoding
+   for the construction of composite state-ID in the power-state parameter.
+   The existing PSCI clients currently do not support this encoding of
+   State-ID yet. Hence this flag is used to configure whether to use the
+   recommended State-ID encoding or not. The default value of this flag is 0,
+   in which case the platform is configured to expect NULL in the State-ID
+   field of power-state parameter.
+
+-  ``ARM_ROTPK_LOCATION``: used when ``TRUSTED_BOARD_BOOT=1``. It specifies the
+   location of the ROTPK hash returned by the function ``plat_get_rotpk_info()``
+   for Arm platforms. Depending on the selected option, the proper private key
+   must be specified using the ``ROT_KEY`` option when building the Trusted
+   Firmware. This private key will be used by the certificate generation tool
+   to sign the BL2 and Trusted Key certificates. Available options for
+   ``ARM_ROTPK_LOCATION`` are:
+
+   -  ``regs`` : return the ROTPK hash stored in the Trusted root-key storage
+      registers. The private key corresponding to this ROTPK hash is not
+      currently available.
+   -  ``devel_rsa`` : return a development public key hash embedded in the BL1
+      and BL2 binaries. This hash has been obtained from the RSA public key
+      ``arm_rotpk_rsa.der``, located in ``plat/arm/board/common/rotpk``. To use
+      this option, ``arm_rotprivk_rsa.pem`` must be specified as ``ROT_KEY``
+      when creating the certificates.
+   -  ``devel_ecdsa`` : return a development public key hash embedded in the BL1
+      and BL2 binaries. This hash has been obtained from the ECDSA public key
+      ``arm_rotpk_ecdsa.der``, located in ``plat/arm/board/common/rotpk``. To
+      use this option, ``arm_rotprivk_ecdsa.pem`` must be specified as
+      ``ROT_KEY`` when creating the certificates.
+
+-  ``ARM_TSP_RAM_LOCATION``: location of the TSP binary. Options:
+
+   -  ``tsram`` : Trusted SRAM (default option when TBB is not enabled)
+   -  ``tdram`` : Trusted DRAM (if available)
+   -  ``dram`` : Secure region in DRAM (default option when TBB is enabled,
+      configured by the TrustZone controller)
+
+-  ``ARM_XLAT_TABLES_LIB_V1``: boolean option to compile TF-A with version 1
+   of the translation tables library instead of version 2. It is set to 0 by
+   default, which selects version 2.
+
+-  ``ARM_CRYPTOCELL_INTEG`` : bool option to enable TF-A to invoke Arm®
+   TrustZone® CryptoCell functionality for Trusted Board Boot on capable Arm
+   platforms. If this option is specified, then the path to the CryptoCell
+   SBROM library must be specified via ``CCSBROM_LIB_PATH`` flag.
+
+For a better understanding of these options, the Arm development platform memory
+map is explained in the :ref:`Firmware Design`.
+
+.. _build_options_arm_css_platform:
+
+Arm CSS Platform-Specific Build Options
+---------------------------------------
+
+-  ``CSS_DETECT_PRE_1_7_0_SCP``: Boolean flag to detect SCP version
+   incompatibility. Version 1.7.0 of the SCP firmware made a non-backwards
+   compatible change to the MTL protocol, used for AP/SCP communication.
+   TF-A no longer supports earlier SCP versions. If this option is set to 1
+   then TF-A will detect if an earlier version is in use. Default is 1.
+
+-  ``CSS_LOAD_SCP_IMAGES``: Boolean flag, which when set, adds SCP_BL2 and
+   SCP_BL2U to the FIP and FWU_FIP respectively, and enables them to be loaded
+   during boot. Default is 1.
+
+-  ``CSS_USE_SCMI_SDS_DRIVER``: Boolean flag which selects SCMI/SDS drivers
+   instead of SCPI/BOM driver for communicating with the SCP during power
+   management operations and for SCP RAM Firmware transfer. If this option
+   is set to 1, then SCMI/SDS drivers will be used. Default is 0.
+
+--------------
+
+*Copyright (c) 2019, Arm Limited. All rights reserved.*