1. 22 Jan, 2015 1 commit
    • Soby Mathew's avatar
      Remove coherent memory from the BL memory maps · ab8707e6
      Soby Mathew authored
      This patch extends the build option `USE_COHERENT_MEMORY` to
      conditionally remove coherent memory from the memory maps of
      all boot loader stages. The patch also adds necessary
      documentation for coherent memory removal in firmware-design,
      porting and user guides.
      
      Fixes ARM-Software/tf-issues#106
      
      Change-Id: I260e8768c6a5c2efc402f5804a80657d8ce38773
      ab8707e6
  2. 19 Sep, 2014 1 commit
    • Juan Castillo's avatar
      Fix LENGTH attribute value in linker scripts · d7fbf132
      Juan Castillo authored
      This patch fixes the incorrect value of the LENGTH attribute in
      the linker scripts. This attribute must define the memory size, not
      the limit address.
      
      Fixes ARM-software/tf-issues#252
      
      Change-Id: I328c38b9ec502debe12046a8912d7dfc54610c46
      d7fbf132
  3. 27 Aug, 2014 1 commit
  4. 20 Aug, 2014 1 commit
    • Soby Mathew's avatar
      Introduce framework for CPU specific operations · 9b476841
      Soby Mathew authored
      This patch introduces a framework which will allow CPUs to perform
      implementation defined actions after a CPU reset, during a CPU or cluster power
      down, and when a crash occurs. CPU specific reset handlers have been implemented
      in this patch. Other handlers will be implemented in subsequent patches.
      
      Also moved cpu_helpers.S to the new directory lib/cpus/aarch64/.
      
      Change-Id: I1ca1bade4d101d11a898fb30fea2669f9b37b956
      9b476841
  5. 15 Aug, 2014 1 commit
    • Achin Gupta's avatar
      Unmask SError interrupt and clear SCR_EL3.EA bit · 0c8d4fef
      Achin Gupta authored
      This patch disables routing of external aborts from lower exception levels to
      EL3 and ensures that a SError interrupt generated as a result of execution in
      EL3 is taken locally instead of a lower exception level.
      
      The SError interrupt is enabled in the TSP code only when the operation has not
      been directly initiated by the normal world. This is to prevent the possibility
      of an asynchronous external abort which originated in normal world from being
      taken when execution is in S-EL1.
      
      Fixes ARM-software/tf-issues#153
      
      Change-Id: I157b996c75996d12fd86d27e98bc73dd8bce6cd5
      0c8d4fef
  6. 12 Aug, 2014 2 commits
    • Dan Handley's avatar
      Rationalize console log output · 6ad2e461
      Dan Handley authored
      Fix the following issues with the console log output:
      
      * Make sure the welcome string is the first thing in the log output
      (during normal boot).
      * Prefix each message with the BL image name so it's clear which
      BL the output is coming from.
      * Ensure all output is wrapped in one of the log output macros so it can
      be easily compiled out if necessary. Change some of the INFO() messages
      to VERBOSE(), especially in the TSP.
      * Create some extra NOTICE() and INFO() messages during cold boot.
      * Remove all usage of \r in log output.
      
      Fixes ARM-software/tf-issues#231
      
      Change-Id: Ib24f7acb36ce64bbba549f204b9cde2dbb46c8a3
      6ad2e461
    • Juan Castillo's avatar
      FVP: apply new naming conventions to memory regions · 637ebd2e
      Juan Castillo authored
      Secure ROM at address 0x0000_0000 is defined as FVP_TRUSTED_ROM
      Secure RAM at address 0x0400_0000 is defined as FVP_TRUSTED_SRAM
      Secure RAM at address 0x0600_0000 is defined as FVP_TRUSTED_DRAM
      
      BLn_BASE and BLn_LIMIT definitions have been updated and are based on
      these new memory regions.
      
      The available memory for each bootloader in the linker script is
      defined by BLn_BASE and BLn_LIMIT, instead of the complete memory
      region.
      
      TZROM_BASE/SIZE and TZRAM_BASE/SIZE are no longer required as part of
      the platform porting.
      
      FVP common definitions are defined in fvp_def.h while platform_def.h
      contains exclusively (with a few exceptions) the definitions that are
      mandatory in the porting guide. Therefore, platform_def.h now includes
      fvp_def.h instead of the other way around.
      
      Porting guide has been updated to reflect these changes.
      
      Change-Id: I39a6088eb611fc4a347db0db4b8f1f0417dbab05
      637ebd2e
  7. 28 Jul, 2014 1 commit
    • Achin Gupta's avatar
      Simplify management of SCTLR_EL3 and SCTLR_EL1 · ec3c1003
      Achin Gupta authored
      This patch reworks the manner in which the M,A, C, SA, I, WXN & EE bits of
      SCTLR_EL3 & SCTLR_EL1 are managed. The EE bit is cleared immediately after reset
      in EL3. The I, A and SA bits are set next in EL3 and immediately upon entry in
      S-EL1. These bits are no longer managed in the blX_arch_setup() functions. They
      do not have to be saved and restored either. The M, WXN and optionally the C
      bit are set in the enable_mmu_elX() function. This is done during both the warm
      and cold boot paths.
      
      Fixes ARM-software/tf-issues#226
      
      Change-Id: Ie894d1a07b8697c116960d858cd138c50bc7a069
      ec3c1003
  8. 25 Jul, 2014 2 commits
    • Juan Castillo's avatar
      Add support for printing version at runtime · aaa3e722
      Juan Castillo authored
      Print out Trusted Firmware version at runtime at each BL stage.
      Message consists of TF version as defined statically in the Makefile
      (e.g. v0.4), build mode (debug|release) and a customizable build
      string:
      
        1. By defining BUILD_STRING in command line when building TF
        2. Default string is git commit ID
        3. Empty if git meta-data is not available
      
      Fixes ARM-software/tf-issues#203
      
      Change-Id: I5c5ba438f66ab68810427d76b49c5b9177a957d6
      aaa3e722
    • Soby Mathew's avatar
      Implement a leaner printf for Trusted Firmware · b79af934
      Soby Mathew authored
      This patch implements a "tf_printf" which supports only the commonly
      used format specifiers in Trusted Firmware, which uses a lot less
      stack space than the stdlib printf function.
      
      Fixes ARM-software/tf-issues#116
      
      Change-Id: I7dfa1944f4c1e634b3e2d571f49afe02d109a351
      b79af934
  9. 19 Jul, 2014 1 commit
    • Achin Gupta's avatar
      Remove coherent stack usage from the cold boot path · 754a2b7a
      Achin Gupta authored
      This patch reworks the cold boot path across the BL1, BL2, BL3-1 and BL3-2 boot
      loader stages to not use stacks allocated in coherent memory for early platform
      setup and enabling the MMU. Stacks allocated in normal memory are used instead.
      
      Attributes for stack memory change from nGnRnE when the MMU is disabled to
      Normal WBWA Inner-shareable when the MMU and data cache are enabled. It is
      possible for the CPU to read stale stack memory after the MMU is enabled from
      another CPUs cache. Hence, it is unsafe to turn on the MMU and data cache while
      using normal stacks when multiple CPUs are a part of the same coherency
      domain. It is safe to do so in the cold boot path as only the primary cpu
      executes it. The secondary cpus are in a quiescent state.
      
      This patch does not remove the allocation of coherent stack memory. That is done
      in a subsequent patch.
      
      Change-Id: I12c80b7c7ab23506d425c5b3a8a7de693498f830
      754a2b7a
  10. 01 Jul, 2014 1 commit
    • Sandrine Bailleux's avatar
      Remove concept of top/bottom image loading · 8f55dfb4
      Sandrine Bailleux authored
      This concept is no longer required since we now support loading of
      images at fixed addresses only.
      
      The image loader now automatically detects the position of the image
      inside the current memory layout and updates the layout such that
      memory fragmentation is minimised.
      
      The 'attr' field of the meminfo data structure, which used to hold
      the bottom/top loading information, has been removed. Also the 'next'
      field has been removed as it wasn't used anywhere.
      
      The 'init_bl2_mem_layout()' function has been moved out of common
      code and put in BL1-specific code. It has also been renamed into
      'bl1_init_bl2_mem_layout'.
      
      Fixes ARM-software/tf-issues#109
      
      Change-Id: I3f54642ce7b763d5ee3b047ad0ab59eabbcf916d
      8f55dfb4
  11. 24 Jun, 2014 2 commits
  12. 23 Jun, 2014 1 commit
    • Andrew Thoelke's avatar
      Initialise CPU contexts from entry_point_info · 167a9357
      Andrew Thoelke authored
      Consolidate all BL3-1 CPU context initialization for cold boot, PSCI
      and SPDs into two functions:
      *  The first uses entry_point_info to initialize the relevant
         cpu_context for first entry into a lower exception level on a CPU
      *  The second populates the EL1 and EL2 system registers as needed
         from the cpu_context to ensure correct entry into the lower EL
      
      This patch alters the way that BL3-1 determines which exception level
      is used when first entering EL1 or EL2 during cold boot - this is now
      fully determined by the SPSR value in the entry_point_info for BL3-3,
      as set up by the platform code in BL2 (or otherwise provided to BL3-1).
      
      In the situation that EL1 (or svc mode) is selected for a processor
      that supports EL2, the context management code will now configure all
      essential EL2 register state to ensure correct execution of EL1. This
      allows the platform code to run non-secure EL1 payloads directly
      without requiring a small EL2 stub or OS loader.
      
      Change-Id: If9fbb2417e82d2226e47568203d5a369f39d3b0f
      167a9357
  13. 23 May, 2014 5 commits
    • Dan Handley's avatar
      Move BL porting functions into platform.h · dec5e0d1
      Dan Handley authored
      Some platform porting functions were in BL specific header files.
      These have been moved to platform.h so that all porting functions
      are in the same place. The functions are now grouped by BL.
      Obsolete BL headers files have been removed.
      
      Also, the weak declaration of the init_bl2_mem_layout() function
      has been moved out the header file and into the source file
      (bl_common.c) using the more succinct #pragma syntax. This
      mitigates the risk of 2 weak definitions being created and the
      wrong one being picked up by the compiler.
      
      Change-Id: Ib19934939fd755f3e5a5a5bceec88da684308a83
      dec5e0d1
    • Dan Handley's avatar
      Split platform.h into separate headers · 5f0cdb05
      Dan Handley authored
      Previously, platform.h contained many declarations and definitions
      used for different purposes. This file has been split so that:
      
      * Platform definitions used by common code that must be defined
        by the platform are now in platform_def.h. The exact include
        path is exported through $PLAT_INCLUDES in the platform makefile.
      
      * Platform definitions specific to the FVP platform are now in
        /plat/fvp/fvp_def.h.
      
      * Platform API declarations specific to the FVP platform are now
        in /plat/fvp/fvp_private.h.
      
      * The remaining platform API declarations that must be ported by
        each platform are still in platform.h but this file has been
        moved to /include/plat/common since this can be shared by all
        platforms.
      
      Change-Id: Ieb3bb22fbab3ee8027413c6b39a783534aee474a
      5f0cdb05
    • Dan Handley's avatar
      Remove extern keyword from function declarations · c6bc0710
      Dan Handley authored
      Function declarations implicitly have external linkage so do not
      need the extern keyword.
      
      Change-Id: Ia0549786796d8bf5956487e8996450a0b3d79f32
      c6bc0710
    • Sandrine Bailleux's avatar
      Make the memory layout more flexible · a37255a2
      Sandrine Bailleux authored
      Currently the platform code gets to define the base address of each
      boot loader image. However, the linker scripts couteract this
      flexibility by enforcing a fixed overall layout of the different
      images. For example, they require that the BL3-1 image sits below
      the BL2 image. Choosing BL3-1 and BL2 base addresses in such a way
      that it violates this constraint makes the build fail at link-time.
      
      This patch requires the platform code to now define a limit address
      for each image. The linker scripts check that the image fits within
      these bounds so they don't rely anymore on the position of a given
      image in regard to the others.
      
      Fixes ARM-software/tf-issues#163
      
      Change-Id: I8c108646825da19a6a8dfb091b613e1dd4ae133c
      a37255a2
    • Sandrine Bailleux's avatar
      Make BL1 RO and RW base addresses configurable · 4f59d835
      Sandrine Bailleux authored
      BL1 RO and RW base address used to be fixed, respectively to the first
      address of the Trusted ROM and the first address of the Trusted RAM.
      
      Introduce new platform defines to configure the BL1 RO and RW base
      addresses.
      
      Change-Id: If26616513a47798593a4bb845a4b0fb37c867cd6
      4f59d835
  14. 22 May, 2014 4 commits
    • Vikram Kanigiri's avatar
      Add support for BL3-1 as a reset vector · dbad1bac
      Vikram Kanigiri authored
      This change adds optional reset vector support to BL3-1
      which means BL3-1 entry point can detect cold/warm boot,
      initialise primary cpu, set up cci and mail box.
      
      When using BL3-1 as a reset vector it is assumed that
      the BL3-1 platform code can determine the location of
      the BL3-2 images, or load them as there are no parameters
      that can be passed to BL3-1 at reset.
      
      It also fixes the incorrect initialisation of mailbox
      registers on the FVP platform
      
      This feature can be enabled by building the code with
      make variable RESET_TO_BL31 set as 1
      
      Fixes ARM-software/TF-issues#133
      Fixes ARM-software/TF-issues#20
      
      Change-Id: I4e23939b1c518614b899f549f1e8d412538ee570
      dbad1bac
    • Vikram Kanigiri's avatar
      Populate BL31 input parameters as per new spec · 4112bfa0
      Vikram Kanigiri authored
      This patch is based on spec published at
      https://github.com/ARM-software/tf-issues/issues/133
      
      It rearranges the bl31_args struct into
      bl31_params and bl31_plat_params which provide the
      information needed for Trusted firmware and platform
      specific data via x0 and x1
      
      On the FVP platform BL3-1 params and BL3-1 plat params
      and its constituents are stored at the start of TZDRAM.
      
      The information about memory availability and size for
      BL3-1, BL3-2 and BL3-3 is moved into platform specific data.
      
      Change-Id: I8b32057a3d0dd3968ea26c2541a0714177820da9
      4112bfa0
    • Vikram Kanigiri's avatar
      Rework handover interface between BL stages · 29fb905d
      Vikram Kanigiri authored
      This patch reworks the handover interface from: BL1 to BL2 and
      BL2 to BL3-1. It removes the raise_el(), change_el(), drop_el()
      and run_image() functions as they catered for code paths that were
      never exercised.
      BL1 calls bl1_run_bl2() to jump into BL2 instead of doing the same
      by calling run_image(). Similarly, BL2 issues the SMC to transfer
      execution to BL3-1 through BL1 directly. Only x0 and x1 are used
      to pass arguments to BL31. These arguments and parameters for
      running BL3-1 are passed through a reference to a
      'el_change_info_t' structure. They were being passed value in
      general purpose registers earlier.
      
      Change-Id: Id4fd019a19a9595de063766d4a66295a2c9307e1
      29fb905d
    • Vikram Kanigiri's avatar
      Introduce macros to manipulate the SPSR · 23ff9baa
      Vikram Kanigiri authored
      This patch introduces macros (SPSR_64 and SPSR_32) to
      create a SPSR for both aarch32 and aarch64 execution
      states. These macros allow the user to set fields
      in the SPSR depending upon its format.
      The make_spsr() function which did not allow
      manipulation of all the fields in the aarch32 SPSR
      has been replaced by these new macros.
      
      Change-Id: I9425dda0923e8d5f03d03ddb8fa0e28392c4c61e
      23ff9baa
  15. 07 May, 2014 4 commits
    • Andrew Thoelke's avatar
      Access system registers directly in assembler · 7935d0a5
      Andrew Thoelke authored
      Instead of using the system register helper functions to read
      or write system registers, assembler coded functions should
      use MRS/MSR instructions. This results in faster and more
      compact code.
      
      This change replaces all usage of the helper functions with
      direct register accesses.
      
      Change-Id: I791d5f11f257010bb3e6a72c6c5ab8779f1982b3
      7935d0a5
    • Andrew Thoelke's avatar
      Replace disable_mmu with assembler version · 2f5dcfef
      Andrew Thoelke authored
      disable_mmu() cannot work as a C function as there is no control
      over data accesses generated by the compiler between disabling and
      cleaning the data cache. This results in reading stale data from
      main memory.
      
      As assembler version is provided for EL3, and a variant that also
      disables the instruction cache which is now used by the BL1
      exception handling function.
      
      Fixes ARM-software/tf-issues#147
      
      Change-Id: I0cf394d2579a125a23c2f2989c2e92ace6ddb1a6
      2f5dcfef
    • Andrew Thoelke's avatar
      Correct usage of data and instruction barriers · 8cec598b
      Andrew Thoelke authored
      The current code does not always use data and instruction
      barriers as required by the architecture and frequently uses
      barriers excessively due to their inclusion in all of the
      write_*() helper functions.
      
      Barriers should be used explicitly in assembler or C code
      when modifying processor state that requires the barriers in
      order to enable review of correctness of the code.
      
      This patch removes the barriers from the helper functions and
      introduces them as necessary elsewhere in the code.
      
      PORTING NOTE: check any port of Trusted Firmware for use of
      system register helper functions for reliance on the previous
      barrier behaviour and add explicit barriers as necessary.
      
      Fixes ARM-software/tf-issues#92
      
      Change-Id: Ie63e187404ff10e0bdcb39292dd9066cb84c53bf
      8cec598b
    • Andrew Thoelke's avatar
      Set processor endianness immediately after RESET · 40fd0725
      Andrew Thoelke authored
      SCTLR_EL3.EE is being configured too late in bl1_arch_setup() and
      bl31_arch_setup() after data accesses have already occured on
      the cold and warm boot paths.
      
      This control bit must be configured immediately on CPU reset to
      match the endian state of the firmware (little endian).
      
      Fixes ARM-software/tf-issues#145
      
      Change-Id: Ie12e46fbbed6baf024c30beb50751591bb8c8655
      40fd0725
  16. 06 May, 2014 5 commits
    • Dan Handley's avatar
      Reduce deep nesting of header files · 97043ac9
      Dan Handley authored
      Reduce the number of header files included from other header
      files as much as possible without splitting the files. Use forward
      declarations where possible. This allows removal of some unnecessary
      "#ifndef __ASSEMBLY__" statements.
      
      Also, review the .c and .S files for which header files really need
      including and reorder the #include statements alphabetically.
      
      Fixes ARM-software/tf-issues#31
      
      Change-Id: Iec92fb976334c77453e010b60bcf56f3be72bd3e
      97043ac9
    • Dan Handley's avatar
      Always use named structs in header files · fb037bfb
      Dan Handley authored
      Add tag names to all unnamed structs in header files. This
      allows forward declaration of structs, which is necessary to
      reduce header file nesting (to be implemented in a subsequent
      commit).
      
      Also change the typedef names across the codebase to use the _t
      suffix to be more conformant with the Linux coding style. The
      coding style actually prefers us not to use typedefs at all but
      this is considered a step too far for Trusted Firmware.
      
      Also change the IO framework structs defintions to use typedef'd
      structs to be consistent with the rest of the codebase.
      
      Change-Id: I722b2c86fc0d92e4da3b15e5cab20373dd26786f
      fb037bfb
    • Dan Handley's avatar
      Separate BL functions out of arch.h · 5b827a8f
      Dan Handley authored
      Move the BL function prototypes out of arch.h and into the
      appropriate header files to allow more efficient header file
      inclusion. Create new BL private header files where there is no
      sensible existing header file.
      
      Change-Id: I45f3e10b72b5d835254a6f25a5e47cf4cfb274c3
      5b827a8f
    • Dan Handley's avatar
      Remove vpath usage in makefiles · bee82417
      Dan Handley authored
      Remove all usage of the vpath keyword in makefiles as it was prone
      to mistakes. Specify the relative paths to source files instead.
      
      Also reorder source files in makefiles alphabetically.
      
      Fixes ARM-software/tf-issues#121
      
      Change-Id: Id15f60655444bae60e0e2165259efac71a50928b
      bee82417
    • Dan Handley's avatar
      Move include and source files to logical locations · 4ecca339
      Dan Handley authored
      Move almost all system include files to a logical sub-directory
      under ./include. The only remaining system include directories
      not under ./include are specific to the platform. Move the
      corresponding source files to match the include directory
      structure.
      
      Also remove pm.h as it is no longer used.
      
      Change-Id: Ie5ea6368ec5fad459f3e8a802ad129135527f0b3
      4ecca339
  17. 08 Apr, 2014 2 commits
    • Sandrine Bailleux's avatar
      Define frequency of system counter in platform code · 9e86490f
      Sandrine Bailleux authored
      BL3-1 architecture setup code programs the system counter frequency
      into the CNTFRQ_EL0 register. This frequency is defined by the
      platform, though. This patch introduces a new platform hook that
      the architecture setup code can call to retrieve this information.
      In the ARM FVP port, this returns the first entry of the frequency
      modes table from the memory mapped generic timer.
      
      All system counter setup code has been removed from BL1 as some
      platforms may not have initialized the system counters at this stage.
      The platform specific settings done exclusively in BL1 have been moved
      to BL3-1. In the ARM FVP port, this consists in enabling and
      initializing the System level generic timer. Also, the frequency change
      request in the counter control register has been set to 0 to make it
      explicit it's using the base frequency. The CNTCR_FCREQ() macro has been
      fixed in this context to give an entry number rather than a bitmask.
      
      In future, when support for firmware update is implemented, there
      is a case where BL1 platform specific code will need to program
      the counter frequency. This should be implemented at that time.
      
      This patch also updates the relevant documentation.
      
      It properly fixes ARM-software/tf-issues#24
      
      Change-Id: If95639b279f75d66ac0576c48a6614b5ccb0e84b
      9e86490f
    • Sandrine Bailleux's avatar
      Revert "Move architecture timer setup to platform-specific code" · 65a9c0e9
      Sandrine Bailleux authored
      This reverts commit 1c297bf0
      because it introduced a bug: the CNTFRQ_EL0 register was no
      longer programmed by all CPUs.  bl31_platform_setup() function
      is invoked only in the cold boot path and consequently only
      on the primary cpu.
      
      A subsequent commit will correctly implement the necessary changes
      to the counter frequency setup code.
      
      Fixes ARM-software/tf-issues#125
      
      Conflicts:
      
      	docs/firmware-design.md
      	plat/fvp/bl31_plat_setup.c
      
      Change-Id: Ib584ad7ed069707ac04cf86717f836136ad3ab54
      65a9c0e9
  18. 26 Mar, 2014 3 commits
    • Andrew Thoelke's avatar
      Place assembler functions in separate sections · 0a30cf54
      Andrew Thoelke authored
      This extends the --gc-sections behaviour to the many assembler
      support functions in the firmware images by placing each function
      into its own code section. This is achieved by creating a 'func'
      macro used to declare each function label.
      
      Fixes ARM-software/tf-issues#80
      
      Change-Id: I301937b630add292d2dec6d2561a7fcfa6fec690
      0a30cf54
    • Andrew Thoelke's avatar
      Use --gc-sections during link · dccc537a
      Andrew Thoelke authored
      All common functions are being built into all binary images,
      whether or not they are actually used. This change enables the
      use of -ffunction-sections, -fdata-sections and --gc-sections
      in the compiler and linker to remove unused code and data from
      the images.
      
      Change-Id: Ia9f78c01054ac4fa15d145af38b88a0d6fb7d409
      dccc537a
    • Sandrine Bailleux's avatar
      Separate out BL2, BL3-1 and BL3-2 early exception vectors from BL1 · 6c595b3d
      Sandrine Bailleux authored
      bl1/aarch64/early_exceptions.S used to be re-used by BL2, BL3-1 and
      BL3-2.  There was some early SMC handling code in there that was not
      required by the other bootloader stages.  Therefore this patch
      introduces an even simpler exception vector source file for BL2,
      BL3-1 and BL3-2.
      
      Fixes ARM-software/tf-issues#38
      
      Change-Id: I0244b80e9930b0f8035156a0bf91cc3e9a8f995d
      6c595b3d
  19. 21 Mar, 2014 1 commit
    • Vikram Kanigiri's avatar
      Remove partially qualified asm helper functions · 6ba0b6d6
      Vikram Kanigiri authored
      Each ARM Trusted Firmware image should know in which EL it is running
      and it should use the corresponding register directly instead of reading
      currentEL and knowing which asm register to read/write
      
      Change-Id: Ief35630190b6f07c8fbb7ba6cb20db308f002945
      6ba0b6d6
  20. 20 Mar, 2014 1 commit
    • Jeenu Viswambharan's avatar
      Specify image entry in linker script · 9f98aa1a
      Jeenu Viswambharan authored
      At present, the entry point for each BL image is specified via the
      Makefiles and provided on the command line to the linker. When using a
      link script the entry point should rather be specified via the ENTRY()
      directive in the link script.
      
      This patch updates linker scripts of all BL images to specify the entry
      point using the ENTRY() directive. It also removes the --entry flag
      passed to the linker through Makefile.
      
      Fixes issue ARM-software/tf-issues#66
      
      Change-Id: I1369493ebbacea31885b51185441f6b628cf8da0
      9f98aa1a