1. 09 Dec, 2015 5 commits
    • Yatharth Kochar's avatar
      FWU: Add support for `fwu_fip` target · 0191262d
      Yatharth Kochar authored
      Firmware update feature needs a new FIP called `fwu_fip.bin` that
      includes Secure(SCP_BL2U, BL2U) and Normal world(NS_BL2U) images
      along with the FWU_CERT certificate in order for NS_BL1U to load
      the images and help the Firmware update process to complete.
      
      This patch adds the capability to support the new target `fwu_fip`
      which includes above mentioned FWU images in the make files.
      
      The new target of `fwu_fip` and its dependencies are included for
      compilation only when `TRUSTED_BOARD_BOOT` is defined.
      
      Change-Id: Ie780e3aac6cbd0edfaff3f9af96a2332bd69edbc
      0191262d
    • Yatharth Kochar's avatar
      FWU: Add Firmware Update support in BL2U for ARM platforms · dcda29f6
      Yatharth Kochar authored
      This patch adds support for Firmware update in BL2U for ARM
      platforms such that TZC initialization is performed on all
      ARM platforms and (optionally) transfer of SCP_BL2U image on
      ARM CSS platforms.
      
      BL2U specific functions are added to handle early_platform and
      plat_arch setup. The MMU is configured to map in the BL2U
      code/data area and other required memory.
      
      Change-Id: I57863295a608cc06e6cbf078b7ce34cbd9733e4f
      dcda29f6
    • Yatharth Kochar's avatar
      FWU: Add Firmware Update support in BL1 for ARM platforms · 436223de
      Yatharth Kochar authored
      This patch adds Firmware Update support for ARM platforms.
      
      New files arm_bl1_fwu.c and juno_bl1_setup.c were added to provide
      platform specific Firmware update code.
      
      BL1 now includes mmap entry for `ARM_MAP_NS_DRAM1` to map DRAM for
      authenticating NS_BL2U image(For both FVP and JUNO platform).
      
      Change-Id: Ie116cd83f5dc00aa53d904c2f1beb23d58926555
      436223de
    • Yatharth Kochar's avatar
      Add descriptor based image management support in BL1 · 7baff11f
      Yatharth Kochar authored
      As of now BL1 loads and execute BL2 based on hard coded information
      provided in BL1. But due to addition of support for upcoming Firmware
      Update feature, BL1 now require more flexible approach to load and
      run different images using information provided by the platform.
      
      This patch adds new mechanism to load and execute images based on
      platform provided image id's. BL1 now queries the platform to fetch
      the image id of the next image to be loaded and executed. In order
      to achieve this, a new struct image_desc_t was added which holds the
      information about images, such as: ep_info and image_info.
      
      This patch introduces following platform porting functions:
      
      unsigned int bl1_plat_get_next_image_id(void);
      	This is used to identify the next image to be loaded
      	and executed by BL1.
      
      struct image_desc *bl1_plat_get_image_desc(unsigned int image_id);
      	This is used to retrieve the image_desc for given image_id.
      
      void bl1_plat_set_ep_info(unsigned int image_id,
      struct entry_point_info *ep_info);
      	This function allows platforms to update ep_info for given
      	image_id.
      
      The plat_bl1_common.c file provides default weak implementations of
      all above functions, the `bl1_plat_get_image_desc()` always return
      BL2 image descriptor, the `bl1_plat_get_next_image_id()` always return
      BL2 image ID and `bl1_plat_set_ep_info()` is empty and just returns.
      These functions gets compiled into all BL1 platforms by default.
      
      Platform setup in BL1, using `bl1_platform_setup()`, is now done
      _after_ the initialization of authentication module. This change
      provides the opportunity to use authentication while doing the
      platform setup in BL1.
      
      In order to store secure/non-secure context, BL31 uses percpu_data[]
      to store context pointer for each core. In case of BL1 only the
      primary CPU will be active hence percpu_data[] is not required to
      store the context pointer.
      
      This patch introduce bl1_cpu_context[] and bl1_cpu_context_ptr[] to
      store the context and context pointers respectively. It also also
      re-defines cm_get_context() and cm_set_context() for BL1 in
      bl1/bl1_context_mgmt.c.
      
      BL1 now follows the BL31 pattern of using SP_EL0 for the C runtime
      environment, to support resuming execution from a previously saved
      context.
      
      NOTE: THE `bl1_plat_set_bl2_ep_info()` PLATFORM PORTING FUNCTION IS
            NO LONGER CALLED BY BL1 COMMON CODE. PLATFORMS THAT OVERRIDE
            THIS FUNCTION MAY NEED TO IMPLEMENT `bl1_plat_set_ep_info()`
            INSTEAD TO MAINTAIN EXISTING BEHAVIOUR.
      
      Change-Id: Ieee4c124b951c2e9bc1c1013fa2073221195d881
      7baff11f
    • Achin Gupta's avatar
      Rework use of ARM GIC drivers on ARM platforms · 27573c59
      Achin Gupta authored
      Suport for ARM GIC v2.0 and v3.0 drivers has been reworked to create three
      separate drivers instead of providing a single driver that can work on both
      versions of the GIC architecture. These drivers correspond to the following
      software use cases:
      
      1. A GICv2 only driver that can run only on ARM GIC v2.0 implementations
         e.g. GIC-400
      
      2. A GICv3 only driver that can run only on ARM GIC v3.0 implementations
         e.g. GIC-500 in a mode where all interrupt regimes use GICv3 features
      
      3. A deprecated GICv3 driver that operates in legacy mode. This driver can
         operate only in the GICv2 mode in the secure world. On a GICv3 system, this
         driver allows normal world to run in either GICv3 mode (asymmetric mode)
         or in the GICv2 mode. Both modes of operation are deprecated on GICv3
         systems.
      
      ARM platforms implement both versions of the GIC architecture. This patch adds a
      layer of abstraction to help ARM platform ports chose the right GIC driver and
      corresponding platform support. This is as described below:
      
      1. A set of ARM common functions have been introduced to initialise the GIC and
         the driver during cold and warm boot. These functions are prefixed as
         "plat_arm_gic_". Weak definitions of these functions have been provided for
         each type of driver.
      
      2. Each platform includes the sources that implement the right functions
         directly into the its makefile. The FVP can be instantiated with different
         versions of the GIC architecture. It uses the FVP_USE_GIC_DRIVER build option
         to specify which of the three drivers should be included in the build.
      
      3. A list of secure interrupts has to be provided to initialise each of the
        three GIC drivers. For GIC v3.0 the interrupt ids have to be further
        categorised as Group 0 and Group 1 Secure interrupts. For GIC v2.0, the two
        types are merged and treated as Group 0 interrupts.
      
        The two lists of interrupts are exported from the platform_def.h. The lists
        are constructed by adding a list of board specific interrupt ids to a list of
        ids common to all ARM platforms and Compute sub-systems.
      
      This patch also makes some fields of `arm_config` data structure in FVP redundant
      and these unused fields are removed.
      
      Change-Id: Ibc8c087be7a8a6b041b78c2c3bd0c648cd2035d8
      27573c59
  2. 02 Dec, 2015 1 commit
    • Juan Castillo's avatar
      TBB: add Trusted Watchdog support on ARM platforms · 7b4c1405
      Juan Castillo authored
      This patch adds watchdog support on ARM platforms (FVP and Juno).
      A secure instance of SP805 is used as Trusted Watchdog. It is
      entirely managed in BL1, being enabled in the early platform setup
      hook and disabled in the exit hook. By default, the watchdog is
      enabled in every build (even when TBB is disabled).
      
      A new ARM platform specific build option `ARM_DISABLE_TRUSTED_WDOG`
      has been introduced to allow the user to disable the watchdog at
      build time. This feature may be used for testing or debugging
      purposes.
      
      Specific error handlers for Juno and FVP are also provided in this
      patch. These handlers will be called after an image load or
      authentication error. On FVP, the Table of Contents (ToC) in the FIP
      is erased. On Juno, the corresponding error code is stored in the
      V2M Non-Volatile flags register. In both cases, the CPU spins until
      a watchdog reset is generated after 256 seconds (as specified in
      the TBBR document).
      
      Change-Id: I9ca11dcb0fe15af5dbc5407ab3cf05add962f4b4
      7b4c1405
  3. 26 Nov, 2015 1 commit
    • Sandrine Bailleux's avatar
      CSS: Enable booting of EL3 payloads · 4c117f6c
      Sandrine Bailleux authored
      This patch adds support for booting EL3 payloads on CSS platforms,
      for example Juno. In this scenario, the Trusted Firmware follows
      its normal boot flow up to the point where it would normally pass
      control to the BL31 image. At this point, it jumps to the EL3
      payload entry point address instead.
      
      Before handing over to the EL3 payload, the data SCP writes for AP
      at the beginning of the Trusted SRAM is restored, i.e. we zero the
      first 128 bytes and restore the SCP Boot configuration. The latter
      is saved before transferring the BL30 image to SCP and is restored
      just after the transfer (in BL2). The goal is to make it appear that
      the EL3 payload is the first piece of software to run on the target.
      
      The BL31 entrypoint info structure is updated to make the primary
      CPU jump to the EL3 payload instead of the BL31 image.
      
      The mailbox is populated with the EL3 payload entrypoint address,
      which releases the secondary CPUs out of their holding pen (if the
      SCP has powered them on). The arm_program_trusted_mailbox() function
      has been exported for this purpose.
      
      The TZC-400 configuration in BL2 is simplified: it grants secure
      access only to the whole DRAM. Other security initialization is
      unchanged.
      
      This alternative boot flow is disabled by default. A new build option
      EL3_PAYLOAD_BASE has been introduced to enable it and provide the EL3
      payload's entry point address. The build system has been modified
      such that BL31 and BL33 are not compiled and/or not put in the FIP in
      this case, as those images are not used in this boot flow.
      
      Change-Id: Id2e26fa57988bbc32323a0effd022ab42f5b5077
      4c117f6c
  4. 13 Nov, 2015 1 commit
    • Juan Castillo's avatar
      Add NULL pointer check before reading BL32 entry point information · 5ea8aa72
      Juan Castillo authored
      BL2 is responsible for loading BL32 and passing a pointer to the
      BL32 entrypoint info to BL31 in the BL31 parameters. If no BL32
      image is loaded, a NULL pointer is passed. The platform is
      responsible for accessing BL31 parameters and extracting the
      corresponding BL32 EP info.
      
      In ARM platforms, arm_bl31_early_platform_setup() dereferences the
      pointer to the BL32 EP info without checking first if the pointer
      is NULL. This will cause an exception if a BL32 entrypoint has not
      been populated by BL2. FVP and Juno are not affected because they
      always define BL32_BASE, irrespective of whether a BL32 image is
      included in the FIP or not.
      
      This patches fixes the issue by checking the BL32 ep_info pointer
      before trying to access the data.
      
      If `RESET_TO_BL31` is enabled, the BL32 entrypoint is not
      populated if BL32_BASE is not defined.
      
      NOTE: Maintainers of partner platforms should check for this issue
      in their ports.
      
      Fixes ARM-software/tf-issues#320
      
      Change-Id: I31456155503f2765766e8b7cd30ab4a40958fb96
      5ea8aa72
  5. 02 Nov, 2015 1 commit
    • Juan Castillo's avatar
      Remove deprecated IO return definitions · e098e244
      Juan Castillo authored
      Patch 7e26fe1f deprecates IO specific return definitions in favour
      of standard errno codes. This patch removes those definitions
      and its usage from the IO framework, IO drivers and IO platform
      layer. Following this patch, standard errno codes must be used
      when checking the return value of an IO function.
      
      Change-Id: Id6e0e9d0a7daf15a81ec598cf74de83d5768650f
      e098e244
  6. 30 Oct, 2015 1 commit
    • Soby Mathew's avatar
      Support PSCI SYSTEM SUSPEND on Juno · c1bb8a05
      Soby Mathew authored
      This patch adds the capability to power down at system power domain level
      on Juno via the PSCI SYSTEM SUSPEND API. The CSS power management helpers
      are modified to add support for power management operations at system
      power domain level. A new helper for populating `get_sys_suspend_power_state`
      handler in plat_psci_ops is defined. On entering the system suspend state,
      the SCP powers down the SYSTOP power domain on the SoC and puts the memory
      into retention mode. On wakeup from the power down, the system components
      on the CSS will be reinitialized by the platform layer and the PSCI client
      is responsible for restoring the context of these system components.
      
      According to PSCI Specification, interrupts targeted to cores in PSCI CPU
      SUSPEND should be able to resume it. On Juno, when the system power domain
      is suspended, the GIC is also powered down. The SCP resumes the final core
      to be suspend when an external wake-up event is received. But the other
      cores cannot be woken up by a targeted interrupt, because GIC doesn't
      forward these interrupts to the SCP. Due to this hardware limitation,
      we down-grade PSCI CPU SUSPEND requests targeted to the system power domain
      level to cluster power domain level in `juno_validate_power_state()`
      and the CSS default `plat_arm_psci_ops` is overridden in juno_pm.c.
      
      A system power domain resume helper `arm_system_pwr_domain_resume()` is
      defined for ARM standard platforms which resumes/re-initializes the
      system components on wakeup from system suspend. The security setup also
      needs to be done on resume from system suspend, which means
      `plat_arm_security_setup()` must now be included in the BL3-1 image in
      addition to previous BL images if system suspend need to be supported.
      
      Change-Id: Ie293f75f09bad24223af47ab6c6e1268f77bcc47
      c1bb8a05
  7. 20 Oct, 2015 1 commit
    • Soby Mathew's avatar
      Reorganise PSCI PM handler setup on ARM Standard platforms · 785fb92b
      Soby Mathew authored
      This patch does the following reorganization to psci power management (PM)
      handler setup for ARM standard platform ports :
      
      1. The mailbox programming required during `plat_setup_psci_ops()` is identical
         for all ARM platforms. Hence the implementation of this API is now moved
         to the common `arm_pm.c` file. Each ARM platform now must define the
         PLAT_ARM_TRUSTED_MAILBOX_BASE macro, which in current platforms is the same
         as ARM_SHARED_RAM_BASE.
      
      2. The PSCI PM handler callback structure, `plat_psci_ops`, must now be
         exported via `plat_arm_psci_pm_ops`. This allows the common implementation
         of `plat_setup_psci_ops()` to return a platform specific `plat_psci_ops`.
         In the case of CSS platforms, a default weak implementation of the same is
         provided in `css_pm.c` which can be overridden by each CSS platform.
      
      3. For CSS platforms, the PSCI PM handlers defined in `css_pm.c` are now
         made library functions and a new header file `css_pm.h` is added to export
         these generic PM handlers. This allows the platform to reuse the
         adequate CSS PM handlers and redefine others which need to be customized
         when overriding the default `plat_arm_psci_pm_ops` in `css_pm.c`.
      
      Change-Id: I277910f609e023ee5d5ff0129a80ecfce4356ede
      785fb92b
  8. 19 Oct, 2015 1 commit
    • Sandrine Bailleux's avatar
      Fix #include path in ARM platform BL1 setup code · 3ae8a360
      Sandrine Bailleux authored
      This patch fixes the relative path to the 'bl1_private.h' header file
      included from 'arm_bl1_setup.c'. Note that, although the path was
      incorrect, it wasn't causing a compilation error because the header
      file still got included through an alternative include search path.
      
      Change-Id: I28e4f3dbe50e3550ca6cad186502c88a9fb5e260
      3ae8a360
  9. 14 Sep, 2015 1 commit
    • Achin Gupta's avatar
      Add a generic driver for ARM CCN IP · fd6007de
      Achin Gupta authored
      This patch adds a device driver which can be used to program the following
      aspects of ARM CCN IP:
      
      1. Specify the mapping between ACE/ACELite/ACELite+DVM/CHI master interfaces and
         Request nodes.
      2. Add and remove master interfaces from the snoop and dvm
         domains.
      3. Place the L3 cache in a given power state.
      4. Configuring system adress map and enabling 3 SN striping mode of memory
         controller operation.
      
      Change-Id: I0f665c6a306938e5b66f6a92f8549b529aa8f325
      fd6007de
  10. 11 Sep, 2015 2 commits
    • Vikram Kanigiri's avatar
      Define the Non-Secure timer frame ID for ARM platforms · 4b1439c5
      Vikram Kanigiri authored
      On Juno and FVP platforms, the Non-Secure System timer corresponds
      to frame 1. However, this is a platform-specific decision and it
      shouldn't be hard-coded. Hence, this patch introduces
      PLAT_ARM_NSTIMER_FRAME_ID which should be used by all ARM platforms
      to specify the correct non-secure timer frame.
      
      Change-Id: I6c3a905d7d89200a2f58c20ce5d1e1d166832bba
      4b1439c5
    • Vikram Kanigiri's avatar
      Re-factor definition of TZC-400 base address · e86c1ff0
      Vikram Kanigiri authored
      This patch replaces the `ARM_TZC_BASE` constant with `PLAT_ARM_TZC_BASE` to
      support different TrustZone Controller base addresses across ARM platforms.
      
      Change-Id: Ie4e1c7600fd7a5875323c7cc35e067de0c6ef6dd
      e86c1ff0
  11. 13 Aug, 2015 4 commits
    • Soby Mathew's avatar
      PSCI: Validate non secure entrypoint on ARM platforms · f9e858b1
      Soby Mathew authored
      This patch implements the platform power managment handler to verify
      non secure entrypoint for ARM platforms. The handler ensures that the
      entry point specified by the normal world during CPU_SUSPEND, CPU_ON
      or SYSTEM_SUSPEND PSCI API is a valid address within the non secure
      DRAM.
      
      Change-Id: I4795452df99f67a24682b22f0e0967175c1de429
      f9e858b1
    • Sandrine Bailleux's avatar
      PSCI: Pool platform_mem_init() in common ARM platforms code · a6bd5ffb
      Sandrine Bailleux authored
      Now that the FVP mailbox is no longer zeroed, the function
      platform_mem_init() does nothing both on FVP and on Juno. Therefore,
      this patch pools it as the default implementation on ARM platforms.
      
      Change-Id: I007220f4531f15e8b602c3368a1129a5e3a38d91
      a6bd5ffb
    • Soby Mathew's avatar
      PSCI: Demonstrate support for composite power states · 2204afde
      Soby Mathew authored
      This patch adds support to the Juno and FVP ports for composite power states
      with both the original and extended state-id power-state formats. Both the
      platform ports use the recommended state-id encoding as specified in
      Section 6.5 of the PSCI specification (ARM DEN 0022C). The platform build flag
      ARM_RECOM_STATE_ID_ENC is used to include this support.
      
      By default, to maintain backwards compatibility, the original power state
      parameter format is used and the state-id field is expected to be zero.
      
      Change-Id: Ie721b961957eaecaca5bf417a30952fe0627ef10
      2204afde
    • Soby Mathew's avatar
      PSCI: Migrate ARM reference platforms to new platform API · 38dce70f
      Soby Mathew authored
      This patch migrates ARM reference platforms, Juno and FVP, to the new platform
      API mandated by the new PSCI power domain topology and composite power state
      frameworks. The platform specific makefiles now exports the build flag
      ENABLE_PLAT_COMPAT=0 to disable the platform compatibility layer.
      
      Change-Id: I3040ed7cce446fc66facaee9c67cb54a8cd7ca29
      38dce70f
  12. 25 Jun, 2015 3 commits
    • Juan Castillo's avatar
      TBB: switch to the new authentication framework · 1779ba6b
      Juan Castillo authored
      This patch modifies the Trusted Board Boot implementation to use
      the new authentication framework, making use of the authentication
      module, the cryto module and the image parser module to
      authenticate the images in the Chain of Trust.
      
      A new function 'load_auth_image()' has been implemented. When TBB
      is enabled, this function will call the authentication module to
      authenticate parent images following the CoT up to the root of
      trust to finally load and authenticate the requested image.
      
      The platform is responsible for picking up the right makefiles to
      build the corresponding cryptographic and image parser libraries.
      ARM platforms use the mbedTLS based libraries.
      
      The platform may also specify what key algorithm should be used
      to sign the certificates. This is done by declaring the 'KEY_ALG'
      variable in the platform makefile. FVP and Juno use ECDSA keys.
      
      On ARM platforms, BL2 and BL1-RW regions have been increased 4KB
      each to accommodate the ECDSA code.
      
      REMOVED BUILD OPTIONS:
      
        * 'AUTH_MOD'
      
      Change-Id: I47d436589fc213a39edf5f5297bbd955f15ae867
      1779ba6b
    • Juan Castillo's avatar
      TBB: add TBBR Chain of Trust · dff93c86
      Juan Castillo authored
      This patch adds a CoT based on the Trusted Board Boot Requirements
      document*. The CoT consists of an array of authentication image
      descriptors indexed by the image identifiers.
      
      A new header file with TBBR image identifiers has been added.
      Platforms that use the TBBR (i.e. ARM platforms) may reuse these
      definitions as part of their platform porting.
      
      PLATFORM PORT - IMPORTANT:
      
      Default image IDs have been removed from the platform common
      definitions file (common_def.h). As a consequence, platforms that
      used those common definitons must now either include the IDs
      provided by the TBBR header file or define their own IDs.
      
      *The NVCounter authentication method has not been implemented yet.
      
      Change-Id: I7c4d591863ef53bb0cd4ce6c52a60b06fa0102d5
      dff93c86
    • Juan Castillo's avatar
      Use numbers to identify images instead of names · 16948ae1
      Juan Castillo authored
      The Trusted firmware code identifies BL images by name. The platform
      port defines a name for each image e.g. the IO framework uses this
      mechanism in the platform function plat_get_image_source(). For
      a given image name, it returns the handle to the image file which
      involves comparing images names. In addition, if the image is
      packaged in a FIP, a name comparison is required to find the UUID
      for the image. This method is not optimal.
      
      This patch changes the interface between the generic and platform
      code with regard to identifying images. The platform port must now
      allocate a unique number (ID) for every image. The generic code will
      use the image ID instead of the name to access its attributes.
      
      As a result, the plat_get_image_source() function now takes an image
      ID as an input parameter. The organisation of data structures within
      the IO framework has been rationalised to use an image ID as an index
      into an array which contains attributes of the image such as UUID and
      name. This prevents the name comparisons.
      
      A new type 'io_uuid_spec_t' has been introduced in the IO framework
      to specify images identified by UUID (i.e. when the image is contained
      in a FIP file). There is no longer need to maintain a look-up table
      [iname_name --> uuid] in the io_fip driver code.
      
      Because image names are no longer mandatory in the platform port, the
      debug messages in the generic code will show the image identifier
      instead of the file name. The platforms that support semihosting to
      load images (i.e. FVP) must provide the file names as definitions
      private to the platform.
      
      The ARM platform ports and documentation have been updated accordingly.
      All ARM platforms reuse the image IDs defined in the platform common
      code. These IDs will be used to access other attributes of an image in
      subsequent patches.
      
      IMPORTANT: applying this patch breaks compatibility for platforms that
      use TF BL1 or BL2 images or the image loading code. The platform port
      must be updated to match the new interface.
      
      Change-Id: I9c1b04cb1a0684c6ee65dee66146dd6731751ea5
      16948ae1
  13. 01 Jun, 2015 1 commit
    • Sandrine Bailleux's avatar
      Always enable CCI coherency in BL3-1 · a6695275
      Sandrine Bailleux authored
      On ARM standard platforms, snoop and DVM requests used to be enabled
      for the primary CPU's cluster only in the first EL3 bootloader.
      In other words, if the platform reset into BL1 then CCI coherency
      would be enabled by BL1 only, and not by BL3-1 again.
      
      However, this doesn't cater for platforms that use BL3-1 along with
      a non-TF ROM bootloader that doesn't enable snoop and DVM requests.
      In this case, CCI coherency is never enabled.
      
      This patch modifies the function bl31_early_platform_setup() on
      ARM standard platforms so that it always enables snoop and DVM
      requests regardless of whether earlier bootloader stages have
      already done it. There is no harm in executing this code twice.
      
      ARM Trusted Firmware Design document updated accordingly.
      
      Change-Id: Idf1bdeb24d2e1947adfbb76a509f10beef224e1c
      a6695275
  14. 28 Apr, 2015 1 commit
    • Dan Handley's avatar
      Add common ARM and CSS platform code · b4315306
      Dan Handley authored
      This major change pulls out the common functionality from the
      FVP and Juno platform ports into the following categories:
      
      *   (include/)plat/common. Common platform porting functionality that
      typically may be used by all platforms.
      
      *   (include/)plat/arm/common. Common platform porting functionality
      that may be used by all ARM standard platforms. This includes all
      ARM development platforms like FVP and Juno but may also include
      non-ARM-owned platforms.
      
      *   (include/)plat/arm/board/common. Common platform porting
      functionality for ARM development platforms at the board
      (off SoC) level.
      
      *   (include/)plat/arm/css/common. Common platform porting
      functionality at the ARM Compute SubSystem (CSS) level. Juno
      is an example of a CSS-based platform.
      
      *   (include/)plat/arm/soc/common. Common platform porting
      functionality at the ARM SoC level, which is not already defined
      at the ARM CSS level.
      
      No guarantees are made about the backward compatibility of
      functionality provided in (include/)plat/arm.
      
      Also remove any unnecessary variation between the ARM development
      platform ports, including:
      
      *   Unify the way BL2 passes `bl31_params_t` to BL3-1. Use the
      Juno implementation, which copies the information from BL2 memory
      instead of expecting it to persist in shared memory.
      
      *   Unify the TZC configuration. There is no need to add a region
      for SCP in Juno; it's enough to simply not allow any access to
      this reserved region. Also set region 0 to provide no access by
      default instead of assuming this is the case.
      
      *   Unify the number of memory map regions required for ARM
      development platforms, although the actual ranges mapped for each
      platform may be different. For the FVP port, this reduces the
      mapped peripheral address space.
      
      These latter changes will only be observed when the platform ports
      are migrated to use the new common platform code in subsequent
      patches.
      
      Change-Id: Id9c269dd3dc6e74533d0e5116fdd826d53946dc8
      b4315306