1. 16 Jun, 2016 1 commit
    • Yatharth Kochar's avatar
      Add Performance Measurement Framework(PMF) · a31d8983
      Yatharth Kochar authored
      This patch adds Performance Measurement Framework(PMF) in the
      ARM Trusted Firmware. PMF is implemented as a library and the
      SMC interface is provided through ARM SiP service.
      
      The PMF provides capturing, storing, dumping and retrieving the
      time-stamps, by enabling the development of services by different
      providers, that can be easily integrated into ARM Trusted Firmware.
      The PMF capture and retrieval APIs can also do appropriate cache
      maintenance operations to the timestamp memory when the caller
      indicates so.
      
      `pmf_main.c` consists of core functions that implement service
      registration, initialization, storing, dumping and retrieving
      the time-stamp.
      `pmf_smc.c` consists SMC handling for registered PMF services.
      `pmf.h` consists of the macros that can be used by the PMF service
      providers to register service and declare time-stamp functions.
      `pmf_helpers.h` consists of internal macros that are used by `pmf.h`
      
      By default this feature is disabled in the ARM trusted firmware.
      To enable it set the boolean flag `ENABLE_PMF` to 1.
      
      NOTE: The caller is responsible for specifying the appropriate cache
      maintenance flags and for acquiring/releasing appropriate locks
      before/after capturing/retrieving the time-stamps.
      
      Change-Id: Ib45219ac07c2a81b9726ef6bd9c190cc55e81854
      a31d8983
  2. 09 Jun, 2016 1 commit
  3. 03 Jun, 2016 3 commits
    • Soby Mathew's avatar
      Allow dynamic overriding of ROTPK verification · 04943d33
      Soby Mathew authored
      A production ROM with TBB enabled must have the ability to boot test software
      before a real ROTPK is deployed (e.g. manufacturing mode). Previously the
      function plat_get_rotpk_info() must return a valid ROTPK for TBB to succeed.
      This patch adds an additional bit `ROTPK_NOT_DEPLOYED` in the output `flags`
      parameter from plat_get_rotpk_info(). If this bit is set, then the ROTPK
      in certificate is used without verifying against the platform value.
      
      Fixes ARM-software/tf-issues#381
      
      Change-Id: Icbbffab6bff8ed76b72431ee21337f550d8fdbbb
      04943d33
    • Dan Handley's avatar
      Move stdlib header files to include/lib/stdlib · f0b489c1
      Dan Handley authored
      * Move stdlib header files from include/stdlib to include/lib/stdlib for
        consistency with other library headers.
      * Fix checkpatch paths to continue excluding stdlib files.
      * Create stdlib.mk to define the stdlib source files and include directories.
      * Include stdlib.mk from the top level Makefile.
      * Update stdlib header path in the fip_create Makefile.
      * Update porting-guide.md with the new paths.
      
      Change-Id: Ia92c2dc572e9efb54a783e306b5ceb2ce24d27fa
      f0b489c1
    • Soby Mathew's avatar
      Build option to include AArch32 registers in cpu context · 8cd16e6b
      Soby Mathew authored
      The system registers that are saved and restored in CPU context include
      AArch32 systems registers like SPSR_ABT, SPSR_UND, SPSR_IRQ, SPSR_FIQ,
      DACR32_EL2, IFSR32_EL2 and FPEXC32_EL2. Accessing these registers on an
      AArch64-only (i.e. on hardware that does not implement AArch32, or at
      least not at EL1 and higher ELs) platform leads to an exception. This patch
      introduces the build option `CTX_INCLUDE_AARCH32_REGS` to specify whether to
      include these AArch32 systems registers in the cpu context or not. By default
      this build option is set to 1 to ensure compatibility. AArch64-only platforms
      must set it to 0. A runtime check is added in BL1 and BL31 cold boot path to
      verify this.
      
      Fixes ARM-software/tf-issues#386
      
      Change-Id: I720cdbd7ed7f7d8516635a2ec80d025f478b95ee
      8cd16e6b
  4. 25 May, 2016 2 commits
    • Soby Mathew's avatar
      PSCI: Add pwr_domain_pwr_down_wfi() hook in plat_psci_ops · ac1cc8eb
      Soby Mathew authored
      This patch adds a new optional platform hook `pwr_domain_pwr_down_wfi()` in
      the plat_psci_ops structure. This hook allows the platform to perform platform
      specific actions including the wfi invocation to enter powerdown. This hook
      is invoked by both psci_do_cpu_off() and psci_cpu_suspend_start() functions.
      The porting-guide.md is also updated for the same.
      
      This patch also modifies the `psci_power_down_wfi()` function to invoke
      `plat_panic_handler` incase of panic instead of the busy while loop.
      
      Fixes ARM-Software/tf-issues#375
      
      Change-Id: Iba104469a1445ee8d59fb3a6fdd0a98e7f24dfa3
      ac1cc8eb
    • Soby Mathew's avatar
      Add CCN support to FVP platform port · 71237876
      Soby Mathew authored
      This patch adds support to select CCN driver for FVP during build.
      A new build option `FVP_INTERCONNECT_DRIVER` is added to allow
      selection between the CCI and CCN driver. Currently only the CCN-502
      variant is supported on FVP.
      
      The common ARM CCN platform helper file now verifies the cluster
      count declared by platform is equal to the number of root node
      masters exported by the ARM Standard platform.
      
      Change-Id: I71d7b4785f8925ed499c153b2e9b9925fcefd57a
      71237876
  5. 20 May, 2016 2 commits
    • Antonio Nino Diaz's avatar
      Replace SP804 timer by generic delay timer on FVP · 32cd95f0
      Antonio Nino Diaz authored
      Added a build flag to select the generic delay timer on FVP instead
      of the SP804 timer. By default, the generic one will be selected. The
      user guide has been updated.
      
      Change-Id: Ica34425c6d4ed95a187b529c612f6d3b26b78bc6
      32cd95f0
    • Antonio Nino Diaz's avatar
      Add 32 bit version of plat_get_syscnt_freq · d4486391
      Antonio Nino Diaz authored
      Added plat_get_syscnt_freq2, which is a 32 bit variant of the 64 bit
      plat_get_syscnt_freq. The old one has been flagged as deprecated.
      Common code has been updated to use this new version. Porting guide
      has been updated.
      
      Change-Id: I9e913544926c418970972bfe7d81ee88b4da837e
      d4486391
  6. 28 Apr, 2016 1 commit
    • Soby Mathew's avatar
      Change the default driver to GICv3 in FVP · a8af6a4d
      Soby Mathew authored
      This patch changes the default driver for FVP platform from the deprecated
      GICv3 legacy to the GICv3 only driver. This means that the default build of
      Trusted Firmware will not be able boot Linux kernel with GICv2 FDT blob. The
      user guide is also updated to reflect this change of default GIC driver for
      FVP.
      
      Change-Id: Id6fc8c1ac16ad633dabb3cd189b690415a047764
      a8af6a4d
  7. 27 Apr, 2016 3 commits
  8. 21 Apr, 2016 6 commits
  9. 14 Apr, 2016 2 commits
    • Gerald Lejeune's avatar
      Dump platform-defined regs in crash reporting · 9ff67fa6
      Gerald Lejeune authored
      
      
      It is up to the platform to implement the new plat_crash_print_regs macro to
      report all relevant platform registers helpful for troubleshooting.
      
      plat_crash_print_regs merges or calls previously defined plat_print_gic_regs
      and plat_print_interconnect_regs macros for each existing platforms.
      
      NOTE: THIS COMMIT REQUIRES ALL PLATFORMS THAT ENABLE THE `CRASH_REPORTING`
      BUILD FLAG TO MIGRATE TO USE THE NEW `plat_crash_print_regs()` MACRO. BY
      DEFAULT, `CRASH_REPORTING` IS ENABLED IN DEBUG BUILDS FOR ALL PLATFORMS.
      
      Fixes: arm-software/tf-issues#373
      Signed-off-by: default avatarGerald Lejeune <gerald.lejeune@st.com>
      9ff67fa6
    • Juan Castillo's avatar
      Update User Guide and move up to Linaro 16.02 · ec0a975f
      Juan Castillo authored
      This patch updates the TF User Guide, simplifying some of the steps
      to build and run TF and trying to avoid duplicated information that
      is already available on the ARM Connected Community or the Linaro
      website.
      
      The recommended Linaro release is now 16.02.
      
      Change-Id: I21db486d56a07bb10f5ee9a33014ccc59ca12986
      ec0a975f
  10. 08 Apr, 2016 1 commit
    • Antonio Nino Diaz's avatar
      Rename BL33_BASE option to PRELOADED_BL33_BASE · 68450a6d
      Antonio Nino Diaz authored
      To avoid confusion the build option BL33_BASE has been renamed to
      PRELOADED_BL33_BASE, which is more descriptive of what it does and
      doesn't get mistaken by similar names like BL32_BASE that work in a
      completely different way.
      
      NOTE: PLATFORMS USING BUILD OPTION `BL33_BASE` MUST CHANGE TO THE NEW
      BUILD OPTION `PRELOADED_BL33_BASE`.
      
      Change-Id: I658925ebe95406edf0325f15aa1752e1782aa45b
      68450a6d
  11. 07 Apr, 2016 1 commit
    • Soby Mathew's avatar
      Enable SCR_EL3.SIF bit · 99e58f9e
      Soby Mathew authored
      This patch enables the SCR_EL3.SIF (Secure Instruction Fetch) bit in BL1 and
      BL31 common architectural setup code. When in secure state, this disables
      instruction fetches from Non-secure memory.
      
      NOTE: THIS COULD BREAK PLATFORMS THAT HAVE SECURE WORLD CODE EXECUTING FROM
      NON-SECURE MEMORY, BUT THIS IS CONSIDERED UNLIKELY AND IS A SERIOUS SECURITY
      RISK.
      
      Fixes ARM-Software/tf-issues#372
      
      Change-Id: I684e84b8d523c3b246e9a5fabfa085b6405df319
      99e58f9e
  12. 06 Apr, 2016 1 commit
  13. 01 Apr, 2016 2 commits
    • Soby Mathew's avatar
      Modify return type of plat_get_ns_image_entrypoint() · a0ad6019
      Soby Mathew authored
      This patch modifies the return type of the platform API
      `plat_get_ns_image_entrypoint()` from `unsigned long` to
      `uintptr_t` in accordance with the coding guidelines.
      
      Change-Id: Icb4510ca98b706aa4d535fe27e203394184fb4ca
      a0ad6019
    • Evan Lloyd's avatar
      Make:Improve version string generation portability · 414ab853
      Evan Lloyd authored
      To get round problems encountered when building in a DOS build
      environment the generation of the .o file containing build identifier
      strings is modified.
      The problems encounterred were:
         1. DOS echo doesn't strip ' characters from the output text.
         2. git is not available from CMD.EXE so the BUILD_STRING value needs
            some other origin.
      
      A BUILD_STRING value of "development build" is used for now.
      
      MAKE_BUILD_STRINGS is used to customise build string generation in a DOS
      environment. This variable is not defined in the UNIX build environment
      make file helper, and so the existing build string generation behaviour
      is retained in these build environments.
      
      NOTE: This commit completes a cumulative series aimed at improving
            build portability across development environments.
            This enables the build to run on several new build environments,
            if the relevant tools are available.
            At this point the build is tested on Windows 7 Enterprise SP1,
            using CMD.EXE, Cygwin and Msys (MinGW),as well as a native
            Linux envionment".  The Windows platform builds used
            aarch64-none-elf-gcc.exe 4.9.1.  CMD.EXE and Msys used Gnu
            Make 3.81, cygwin used Gnu Make 4.1.
      
      CAVEAT: The cert_create tool build is not tested on the Windows
              platforms (openssl-for-windows has a GPL license).
      
      Change-Id: Iaa4fc89dbe2a9ebae87e2600c9eef10a6af30251
      414ab853
  14. 31 Mar, 2016 3 commits
    • Antonio Nino Diaz's avatar
      Remove xlat_helpers.c · f33fbb2f
      Antonio Nino Diaz authored
      lib/aarch64/xlat_helpers.c defines helper functions to build
      translation descriptors, but no common code or upstream platform
      port uses them. As the rest of the xlat_tables code evolves, there
      may be conflicts with these helpers, therefore this code should be
      removed.
      
      Change-Id: I9f5be99720f929264818af33db8dada785368711
      f33fbb2f
    • Juan Castillo's avatar
      TBB: add non-volatile counter support · 48279d52
      Juan Castillo authored
      This patch adds support for non-volatile counter authentication to
      the Authentication Module. This method consists of matching the
      counter values provided in the certificates with the ones stored
      in the platform. If the value from the certificate is lower than
      the platform, the boot process is aborted. This mechanism protects
      the system against rollback.
      
      The TBBR CoT has been updated to include this method as part of the
      authentication process. Two counters are used: one for the trusted
      world images and another for the non trusted world images.
      
      ** NEW PLATFORM APIs (mandatory when TBB is enabled) **
      
      int plat_get_nv_ctr(void *cookie, unsigned int *nv_ctr);
      
          This API returns the non-volatile counter value stored
          in the platform. The cookie in the first argument may be
          used to select the counter in case the platform provides
          more than one (i.e. TBSA compliant platforms must provide
          trusted and non-trusted counters). This cookie is specified
          in the CoT.
      
      int plat_set_nv_ctr(void *cookie, unsigned int nv_ctr);
      
          This API sets a new counter value. The cookie may be
          used to select the counter to be updated.
      
      An implementation of these new APIs for ARM platforms is also
      provided. The values are obtained from the Trusted Non-Volatile
      Counters peripheral. The cookie is used to pass the extension OID.
      This OID may be interpreted by the platform to know which counter
      must return. On Juno, The trusted and non-trusted counter values
      have been tied to 31 and 223, respectively, and cannot be modified.
      
      ** IMPORTANT **
      
      THIS PATCH BREAKS THE BUILD WHEN TRUSTED_BOARD_BOOT IS ENABLED. THE
      NEW PLATFORM APIs INTRODUCED IN THIS PATCH MUST BE IMPLEMENTED IN
      ORDER TO SUCCESSFULLY BUILD TF.
      
      Change-Id: Ic943b76b25f2a37f490eaaab6d87b4a8b3cbc89a
      48279d52
    • David Wang's avatar
      Add support to load BL31 in DRAM · 4518dd9a
      David Wang authored
      This patch adds an option to the ARM common platforms to load BL31 in the
      TZC secured DRAM instead of the default secure SRAM.
      
      To enable this feature, set `ARM_BL31_IN_DRAM` to 1 in build options.
      If TSP is present, then setting this option also sets the TSP location
      to DRAM and ignores the `ARM_TSP_RAM_LOCATION` build flag.
      
      To use this feature, BL2 platform code must map in the DRAM used by
      BL31. The macro ARM_MAP_BL31_SEC_DRAM is provided for this purpose.
      Currently, only the FVP BL2 platform code maps in this DRAM.
      
      Change-Id: If5f7cc9deb569cfe68353a174d4caa48acd78d67
      4518dd9a
  15. 30 Mar, 2016 1 commit
    • Gerald Lejeune's avatar
      Enable asynchronous abort exceptions during boot · adb4fcfb
      Gerald Lejeune authored
      
      
      Asynchronous abort exceptions generated by the platform during cold boot are
      not taken in EL3 unless SCR_EL3.EA is set.
      
      Therefore EA bit is set along with RES1 bits in early BL1 and BL31 architecture
      initialisation. Further write accesses to SCR_EL3 preserve these bits during
      cold boot.
      
      A build flag controls SCR_EL3.EA value to keep asynchronous abort exceptions
      being trapped by EL3 after cold boot or not.
      
      For further reference SError Interrupts are also known as asynchronous external
      aborts.
      
      On Cortex-A53 revisions below r0p2, asynchronous abort exceptions are taken in
      EL3 whatever the SCR_EL3.EA value is.
      
      Fixes arm-software/tf-issues#368
      Signed-off-by: default avatarGerald Lejeune <gerald.lejeune@st.com>
      adb4fcfb
  16. 22 Mar, 2016 1 commit
    • Sandrine Bailleux's avatar
      Simplify Firmware Design document · eaefdecd
      Sandrine Bailleux authored
      The Firmware Design document is meant to provide a general overview
      of the Trusted Firmware code. Although it is useful to provide some
      guidance around the responsibilities of the platform layer, it should
      not provide too much platform specific implementation details. Right
      now, some sections are too tied to the implementation on ARM
      platforms. This makes the Firmware Design document harder to digest.
      
      This patch simplifies this aspect of the Firmware Design document.
      The sections relating the platform initialisations performed by the
      different BL stages have been simplified and the extra details about
      the ARM platforms implementation have been moved to the Porting Guide
      when appropriate.
      
      This patch also provides various documentation fixes and additions
      in the Firmware Design and Platform Porting Guide. In particular:
      
       - Update list of SMCs supported by BL1.
      
       - Remove MMU setup from architectural inits, as it is actually
         performed by platform code.
      
       - Similarly, move runtime services initialisation, BL2 image
         initialization and BL33 execution out of the platform
         initialisation paragraph.
      
       - List SError interrupt unmasking as part of BL1 architectural
         initialization.
      
       - Mention Trusted Watchdog enabling in BL1 on ARM platforms.
      
       - Fix order of steps in "BL2 image load and execution" section.
      
       - Refresh section about GICv3/GICv2 drivers initialisation on
         ARM platforms.
      
      Change-Id: I32113c4ffdc26687042629cd8bbdbb34d91e3c14
      eaefdecd
  17. 14 Mar, 2016 1 commit
    • Antonio Nino Diaz's avatar
      Remove all non-configurable dead loops · 1c3ea103
      Antonio Nino Diaz authored
      Added a new platform porting function plat_panic_handler, to allow
      platforms to handle unexpected error situations. It must be
      implemented in assembly as it may be called before the C environment
      is initialized. A default implementation is provided, which simply
      spins.
      
      Corrected all dead loops in generic code to call this function
      instead. This includes the dead loop that occurs at the end of the
      call to panic().
      
      All unnecesary wfis from bl32/tsp/aarch64/tsp_exceptions.S have
      been removed.
      
      Change-Id: I67cb85f6112fa8e77bd62f5718efcef4173d8134
      1c3ea103
  18. 07 Mar, 2016 2 commits
    • Antonio Nino Diaz's avatar
      Initialize secondary CPUs during cold boot · 4e85e4fd
      Antonio Nino Diaz authored
      The previous reset code in BL1 performed the following steps in
      order:
      
      1. Warm/Cold boot detection.
         If it's a warm boot, jump to warm boot entrypoint.
      
      2. Primary/Secondary CPU detection.
         If it's a secondary CPU, jump to plat_secondary_cold_boot_setup(),
         which doesn't return.
      
      3. CPU initialisations (cache, TLB...).
      
      4. Memory and C runtime initialization.
      
      For a secondary CPU, steps 3 and 4 are never reached. This shouldn't
      be a problem in most cases, since current implementations of
      plat_secondary_cold_boot_setup() either panic or power down the
      secondary CPUs.
      
      The main concern is the lack of secondary CPU initialization when
      bare metal EL3 payloads are used in case they don't take care of this
      initialisation themselves.
      
      This patch moves the detection of primary/secondary CPU after step 3
      so that the CPU initialisations are performed per-CPU, while the
      memory and the C runtime initialisation are only performed on the
      primary CPU. The diagrams used in the ARM Trusted Firmware Reset
      Design documentation file have been updated to reflect the new boot
      flow.
      
      Platforms ports might be affected by this patch depending on the
      behaviour of plat_secondary_cold_boot_setup(), as the state of the
      platform when entering this function will be different.
      
      Fixes ARM-software/tf-issues#342
      
      Change-Id: Icbf4a0ee2a3e5b856030064472f9fa6696f2eb9e
      4e85e4fd
    • Antonio Nino Diaz's avatar
      Porting guide: Clarify API that don't follow AAPCS · e5846732
      Antonio Nino Diaz authored
      This patch clarifies a porting API in the Porting Guide that do not
      follow the ARM Architecture Program Calling Standards (AAPCS). The
      list of registers that are allowed to be clobbered by this API has
      been updated in the Porting Guide.
      
      Fixes ARM-software/tf-issues#259
      
      Change-Id: Ibf2adda2e1fb3e9b8f53d8a918d5998356eb8fce
      e5846732
  19. 02 Mar, 2016 1 commit
    • Antonio Nino Diaz's avatar
      Enable preloaded BL33 alternative boot flow · cf2c8a33
      Antonio Nino Diaz authored
      Enable alternative boot flow where BL2 does not load BL33 from
      non-volatile storage, and BL31 hands execution over to a preloaded
      BL33.
      
      The flag used to enable this bootflow is BL33_BASE, which must hold
      the entrypoint address of the BL33 image. The User Guide has been
      updated with an example of how to use this option with a bootwrapped
      kernel.
      
      Change-Id: I48087421a7b0636ac40dca7d457d745129da474f
      cf2c8a33
  20. 22 Feb, 2016 1 commit
    • Vikram Kanigiri's avatar
      Rationalise MMU and Page table related constants on ARM platforms · c64a0448
      Vikram Kanigiri authored
      `board_arm_def.h` contains multiple definitions of
      `PLAT_ARM_MMAP_ENTRIES` and `MAX_XLAT_TABLES` that are optimised for
      memory usage depending upon the chosen build configuration. To ease
      maintenance of these constants, this patch replaces their multiple
      definitions with a single set of definitions that will work on all ARM
      platforms.
      
      Platforms can override the defaults with optimal values by enabling the
      `ARM_BOARD_OPTIMISE_MMAP` build option. An example has been provided in
      the Juno ADP port.
      
      Additionally, `PLAT_ARM_MMAP_ENTRIES` is increased by one to accomodate
      future ARM platforms.
      
      Change-Id: I5ba6490fdd1e118cc9cc2d988ad7e9c38492b6f0
      c64a0448
  21. 19 Feb, 2016 1 commit
    • Soby Mathew's avatar
      Allow multi cluster topology definitions for ARM platforms · 0108047a
      Soby Mathew authored
      The common topology description helper funtions and macros for
      ARM Standard platforms assumed a dual cluster system. This is not
      flexible enough to scale to multi cluster platforms. This patch does
      the following changes for more flexibility in defining topology:
      
      1. The `plat_get_power_domain_tree_desc()` definition is moved from
         `arm_topology.c` to platform specific files, that is `fvp_topology.c`
         and `juno_topology.c`. Similarly the common definition of the porting
         macro `PLATFORM_CORE_COUNT` in `arm_def.h` is moved to platform
         specific `platform_def.h` header.
      
      2. The ARM common layer porting macros which were dual cluster specific
         are now removed and a new macro PLAT_ARM_CLUSTER_COUNT is introduced
         which must be defined by each ARM standard platform.
      
      3. A new mandatory ARM common layer porting API
         `plat_arm_get_cluster_core_count()` is introduced to enable the common
         implementation of `arm_check_mpidr()` to validate MPIDR.
      
      4. For the FVP platforms, a new build option `FVP_NUM_CLUSTERS` has been
         introduced which allows the user to specify the cluster count to be
         used to build the topology tree within Trusted Firmare. This enables
         Trusted Firmware to be built for multi cluster FVP models.
      
      Change-Id: Ie7a2e38e5661fe2fdb2c8fdf5641d2b2614c2b6b
      0108047a
  22. 18 Feb, 2016 1 commit
    • Sandrine Bailleux's avatar
      Cortex-A57: Add link to software optimization guide · d1b2b203
      Sandrine Bailleux authored
      This patch adds a link to the Cortex-A57 Software Optimization Guide
      in the ARM CPU Specific Build Macros document to justify the default
      value of the A57_DISABLE_NON_TEMPORAL_HINT build flag.
      
      Change-Id: I9779e42a4bb118442b2b64717ce143314ec9dd16
      d1b2b203
  23. 17 Feb, 2016 1 commit
    • Antonio Nino Diaz's avatar
      Add missing build options to the User Guide · e472b508
      Antonio Nino Diaz authored
      The folowing build options were missing from the User Guide and have been
      documented:
      
       - CTX_INCLUDE_FPREGS
       - DISABLE_PEDANTIC
       - BUILD_STRING
       - VERSION_STRING
       - BUILD_MESSAGE_TIMESTAMP
      
      Change-Id: I6a9c39ff52cad8ff04deff3ac197af84d437b8b7
      e472b508
  24. 16 Feb, 2016 1 commit
    • Vikram Kanigiri's avatar
      Make SCP_BL2(U) image loading configurable on CSS platforms · 7fb9a32d
      Vikram Kanigiri authored
      Current code mandates loading of SCP_BL2/SCP_BL2U images for all
      CSS platforms. On future ARM CSS platforms, the Application
      Processor (AP) might not need to load these images. So, these
      items can be removed from the FIP on those platforms.
      
      BL2 tries to load  SCP_BL2/SCP_BL2U images if their base
      addresses are defined causing boot error if the images are not
      found in FIP.
      
      This change adds a make flag `CSS_LOAD_SCP_IMAGES` which if set
      to `1` does:
      1. Adds SCP_BL2, SCP_BL2U images to FIP.
      2. Defines the base addresses of these images so that AP loads
         them.
      
      And vice-versa if it is set to `0`. The default value is set to
      `1`.
      
      Change-Id: I5abfe22d5dc1e9d80d7809acefc87b42a462204a
      7fb9a32d