1. 07 May, 2014 1 commit
    • 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
  2. 06 May, 2014 6 commits
    • Dan Handley's avatar
      Remove variables from .data section · 625de1d4
      Dan Handley authored
      Update code base to remove variables from the .data section,
      mainly by using const static data where possible and adding
      the const specifier as required. Most changes are to the IO
      subsystem, including the framework APIs. The FVP power
      management code is also affected.
      
      Delay initialization of the global static variable,
      next_image_type in bl31_main.c, until it is realy needed.
      Doing this moves the variable from the .data to the .bss
      section.
      
      Also review the IO interface for inconsistencies, using
      uintptr_t where possible instead of void *. Remove the
      io_handle and io_dev_handle typedefs, which were
      unnecessary, replacing instances with uintptr_t.
      
      Fixes ARM-software/tf-issues#107.
      
      Change-Id: I085a62197c82410b566e4698e5590063563ed304
      625de1d4
    • 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
      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
      Make use of user/system includes more consistent · 35e98e55
      Dan Handley authored
      Make codebase consistent in its use of #include "" syntax for
      user includes and #include <> syntax for system includes.
      
      Fixes ARM-software/tf-issues#65
      
      Change-Id: If2f7c4885173b1fd05ac2cde5f1c8a07000c7a33
      35e98e55
    • 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
  3. 15 Apr, 2014 1 commit
    • Andrew Thoelke's avatar
      Allocate single stacks for BL1 and BL2 · 2bf28e62
      Andrew Thoelke authored
      The BL images share common stack management code which provides
      one coherent and one cacheable stack for every CPU. BL1 and BL2
      just execute on the primary CPU during boot and do not require
      the additional CPU stacks. This patch provides separate stack
      support code for UP and MP images, substantially reducing the
      RAM usage for BL1 and BL2 for the FVP platform.
      
      This patch also provides macros for declaring stacks and
      calculating stack base addresses to improve consistency where
      this has to be done in the firmware.
      
      The stack allocation source files are now included via
      platform.mk rather than the common BLx makefiles. This allows
      each platform to select the appropriate MP/UP stack support
      for each BL image.
      
      Each platform makefile must be updated when including this
      commit.
      
      Fixes ARM-software/tf-issues#76
      
      Change-Id: Ia251f61b8148ffa73eae3f3711f57b1ffebfa632
      2bf28e62
  4. 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
  5. 26 Mar, 2014 4 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
    • Vikram Kanigiri's avatar
      Move per cpu exception stack in BL31 to tzfw_normal_stacks · d8b07aa0
      Vikram Kanigiri authored
      Fixes ARM-software/tf-issues#70
      
      Change-Id: I7f024f173fbdecd315076f528b05d6295aff7276
      d8b07aa0
  6. 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
  7. 20 Mar, 2014 2 commits
    • 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
    • Jeenu Viswambharan's avatar
      Implement ARM Standard Service · 64f6ea9b
      Jeenu Viswambharan authored
      This patch implements ARM Standard Service as a runtime service and adds
      support for call count, UID and revision information SMCs. The existing
      PSCI implementation is subsumed by the Standard Service calls and all
      PSCI calls are therefore dispatched by the Standard Service to the PSCI
      handler.
      
      At present, PSCI is the only specification under Standard Service. Thus
      call count returns the number of PSCI calls implemented. As this is the
      initial implementation, a revision number of 0.1 is returned for call
      revision.
      
      Fixes ARM-software/tf-issues#62
      
      Change-Id: I6d4273f72ad6502636efa0f872e288b191a64bc1
      64f6ea9b
  8. 10 Mar, 2014 1 commit
    • Jeenu Viswambharan's avatar
      Move architecture timer setup to platform-specific code · 1c297bf0
      Jeenu Viswambharan authored
      At present, bl1_arch_setup() and bl31_arch_setup() program the counter
      frequency using a value from the memory mapped generic timer. The
      generic timer however is not necessarily present on all ARM systems
      (although it is architected to be present on all server systems).
      
      This patch moves the timer setup to platform-specific code and updates
      the relevant documentation. Also, CNTR.FCREQ is set as the specification
      requires the bit corresponding to the counter's frequency to be set when
      enabling. Since we intend to use the base frequency, set bit 8.
      
      Fixes ARM-software/tf-issues#24
      
      Change-Id: I32c52cf882253e01f49056f47c58c23e6f422652
      1c297bf0
  9. 05 Mar, 2014 2 commits
    • Jon Medhurst's avatar
      Generate build time and date message at link time. · fb052462
      Jon Medhurst authored
      
      
      So it updates each time a bootloader changes, not just when bl*_main.c
      files are recompiled.
      
      Fixes ARM-software/tf-issues#33
      
      Change-Id: Ie8e1a7bd7e1913d2e96ac268606284f76af8c5ab
      Signed-off-by: default avatarJon Medhurst <tixy@linaro.org>
      fb052462
    • Jon Medhurst's avatar
      Update Makefiles to get proper dependency checking working. · 6d55d109
      Jon Medhurst authored
      
      
      This change requires all platforms to now specify a list of source files
      rather than object files.
      
      New source files should preferably be specified by using the path as
      well and we should add this in the future for all files so we can remove
      use of vpath. This is desirable because vpath hides issues like the fact
      that BL2 currently pulls in a BL1 file bl1/aarch64/early_exceptions.S
      and if in the future we added bl2/aarch64/early_exceptions.S then it's
      likely only one of the two version would be used for both bootloaders.
      
      This change also removes the 'dump' build target and simply gets
      bootloaders to always generate a dump file. At the same time the -x
      option is added so the section headers and symbols table are listed.
      
      Fixes ARM-software/tf-issues#11
      
      Change-Id: Ie38f7be76fed95756c8576cf3f3ea3b7015a18dc
      Signed-off-by: default avatarJon Medhurst <tixy@linaro.org>
      6d55d109
  10. 26 Feb, 2014 2 commits
    • Jeenu Viswambharan's avatar
      Remove duplicate xlat_table descriptions · e3fff153
      Jeenu Viswambharan authored
      The BL31 and BL2 linker scripts ended up having duplicate descriptions
      for xlat_tables section. This patch removes those duplicate
      descriptions.
      
      Change-Id: Ibbdda0902c57fca5ea4e91e0baefa6df8f0a9bb1
      e3fff153
    • Jeenu Viswambharan's avatar
      Implement late binding for runtime hooks · 7f366605
      Jeenu Viswambharan authored
      At present SPD power management hooks and BL3-2 entry are implemented
      using weak references. This would have the handlers bound and registered
      with the core framework at build time, but leaves them dangling if a
      service fails to initialize at runtime.
      
      This patch replaces implementation by requiring runtime handlers to
      register power management and deferred initialization hooks with the
      core framework at runtime. The runtime services are to register the
      hooks only as the last step, after having all states successfully
      initialized.
      
      Change-Id: Ibe788a2a381ef39aec1d4af5ba02376e67269782
      7f366605
  11. 20 Feb, 2014 6 commits
    • Achin Gupta's avatar
      Add power management support in the SPD · 607084ee
      Achin Gupta authored
      This patch implements a set of handlers in the SPD which are called by
      the PSCI runtime service upon receiving a power management
      operation. These handlers in turn pass control to the Secure Payload
      image if required before returning control to PSCI. This ensures that
      the Secure Payload has complete visibility of all power transitions in
      the system and can prepare accordingly.
      
      Change-Id: I2d1dba5629b7cf2d53999d39fe807dfcf3f62fe2
      607084ee
    • Achin Gupta's avatar
      Move PSCI to runtime services directory · 0a9f7473
      Achin Gupta authored
      This patch creates a 'services' directory and moves the PSCI under
      it. Other runtime services e.g. the Secure Payload Dispatcher service
      will be placed under the same directory in the future.
      
      Also fixes issue ARM-software/tf-issues#12
      
      Change-Id: I187f83dcb660b728f82155d91882e961d2255068
      0a9f7473
    • Achin Gupta's avatar
      Factor out translation table setup in ARM FVP port · a0cd989d
      Achin Gupta authored
      This patch factors out the ARM FVP specific code to create MMU
      translation tables so that it is possible for a boot loader stage to
      create a different set of tables instead of using the default ones.
      The default translation tables are created with the assumption that
      the calling boot loader stage executes out of secure SRAM. This might
      not be true for the BL3_2 stage in the future.
      
      A boot loader stage can define the `fill_xlation_tables()` function as
      per its requirements. It returns a reference to the level 1
      translation table which is used by the common platform code to setup
      the TTBR_EL3.
      
      This patch is a temporary solution before a larger rework of
      translation table creation logic is introduced.
      
      Change-Id: I09a075d5da16822ee32a411a9dbe284718fb4ff6
      a0cd989d
    • Achin Gupta's avatar
      Add support for BL3-2 in BL3-1 · 35ca3511
      Achin Gupta authored
      This patch adds the following support to the BL3-1 stage:
      
      1. BL3-1 allows runtime services to specify and determine the security
         state of the next image after BL3-1. This has been done by adding
         the `bl31_set_next_image_type()` & `bl31_get_next_image_type()`
         apis. The default security state is non-secure. The platform api
         `bl31_get_next_image_info()` has been modified to let the platform
         decide which is the next image in the desired security state.
      
      2. BL3-1 exports the `bl31_prepare_next_image_entry()` function to
         program entry into the target security state. It uses the apis
         introduced in 1. to do so.
      
      3. BL3-1 reads the information populated by BL2 about the BL3-2 image
         into its internal data structures.
      
      4. BL3-1 introduces a weakly defined reference `bl32_init()` to allow
         initialisation of a BL3-2 image. A runtime service like the Secure
         payload dispatcher will define this function if present.
      
      Change-Id: Icc46dcdb9e475ce6575dd3f9a5dc7a48a83d21d1
      35ca3511
    • Achin Gupta's avatar
      Rework BL2 to BL3-1 hand over interface · e4d084ea
      Achin Gupta authored
      This patch reworks BL2 to BL3-1 hand over interface by introducing a
      composite structure (bl31_args) that holds the superset of information
      that needs to be passed from BL2 to BL3-1.
      
        - The extents of secure memory available to BL3-1
        - The extents of memory available to BL3-2 (not yet implemented) and
          BL3-3
        - Information to execute BL3-2 (not yet implemented) and BL3-3 images
      
      This patch also introduces a new platform API (bl2_get_bl31_args_ptr)
      that needs to be implemented by the platform code to export reference to
      bl31_args structure which has been allocated in platform-defined memory.
      
      The platform will initialize the extents of memory available to BL3-3
      during early platform setup in bl31_args structure. This obviates the
      need for bl2_get_ns_mem_layout platform API.
      
      BL2 calls the bl2_get_bl31_args_ptr function to get a reference to
      bl31_args structure. It uses the 'bl33_meminfo' field of this structure
      to load the BL3-3 image. It sets the entry point information for the
      BL3-3 image in the 'bl33_image_info' field of this structure. The
      reference to this structure is passed to the BL3-1 image.
      
      Also fixes issue ARM-software/tf-issues#25
      
      Change-Id: Ic36426196dd5ebf89e60ff42643bed01b3500517
      e4d084ea
    • Jeenu Viswambharan's avatar
      Add exception vector guards · a7934d69
      Jeenu Viswambharan authored
      This patch adds guards so that an exception vector exceeding 32
      instructions will generate a compile-time error. This keeps the
      exception handlers in check from spilling over.
      
      Change-Id: I7aa56dd0071a333664e2814c656d3896032046fe
      a7934d69
  12. 17 Feb, 2014 7 commits
    • Jeenu Viswambharan's avatar
      Add support for handling runtime service requests · caa84939
      Jeenu Viswambharan authored
      
      
      This patch uses the reworked exception handling support to handle
      runtime service requests through SMCs following the SMC calling
      convention. This is a giant commit since all the changes are
      inter-related. It does the following:
      
      1. Replace the old exception handling mechanism with the new one
      2. Enforce that SP_EL0 is used C runtime stacks.
      3. Ensures that the cold and warm boot paths use the 'cpu_context'
         structure to program an ERET into the next lower EL.
      4. Ensures that SP_EL3 always points to the next 'cpu_context'
         structure prior to an ERET into the next lower EL
      5. Introduces a PSCI SMC handler which completes the use of PSCI as a
         runtime service
      
      Change-Id: I661797f834c0803d2c674d20f504df1b04c2b852
      Co-authored-by: default avatarAchin Gupta <achin.gupta@arm.com>
      caa84939
    • Achin Gupta's avatar
      Introduce new exception handling framework · 07f4e078
      Achin Gupta authored
      This patch introduces the reworked exception handling logic which lays
      the foundation for accessing runtime services in later patches. The
      type of an exception has a greater say in the way it is
      handled. SP_EL3 is used as the stack pointer for:
      
      1. Determining the type of exception and handling the unexpected ones
         on the exception stack
      
      2. Saving and restoring the essential general purpose and system
         register state after exception entry and prior to exception exit.
      
      SP_EL0 is used as the stack pointer for handling runtime service
      requests e.g. SMCs. A new structure for preserving general purpose
      register state has been added to the 'cpu_context' structure. All
      assembler ensures that it does not use callee saved registers
      (x19-x29). The C runtime preserves them across functions calls. Hence
      EL3 code does not have to save and restore them explicitly.
      
      Since the exception handling framework has undergone substantial change,
      the changes have been kept in separate files to aid readability. These
      files will replace the existing ones in subsequent patches.
      
      Change-Id: Ice418686592990ff7a4260771e8d6676e6c8c5ef
      07f4e078
    • Achin Gupta's avatar
      Add runtime services framework · 7421b465
      Achin Gupta authored
      This patch introduces the framework to enable registration and
      initialisation of runtime services. PSCI is registered and initialised
      as a runtime service. Handling of runtime service requests will be
      implemented in subsequent patches.
      
      Change-Id: Id21e7ddc5a33d42b7d6e455b41155fc5441a9547
      7421b465
    • Achin Gupta's avatar
      Add context management library · 7aea9087
      Achin Gupta authored
      This patch adds support for a cpu context management library. This
      library will be used to:
      
      1. Share pointers to secure and non-secure state cpu contexts between
         runtime services e.g. PSCI and Secure Payload Dispatcher services
      2. Set SP_EL3 to a context structure which will be used for
         programming an ERET into a lower EL
      3. Provide wrapper functions to save and restore EL3 & EL1
         state. These functions will in turn use the helper functions in
         context.S
      
      Change-Id: I655eeef83dcd2a0c6f2eb2ac23efab866ac83ca0
      7aea9087
    • Achin Gupta's avatar
      Add helper library for cpu context management · 9ac63c59
      Achin Gupta authored
      This patch introduces functions for saving and restoring shared system
      registers between secure and non-secure EL1 exception levels, VFP
      registers and essential EL3 system register and other state. It also
      defines the 'cpu_context' data structure which will used for saving and
      restoring execution context for a given security state. These functions
      will allow runtime services like PSCI and Secure payload dispatcher to
      implement logic for switching between the secure and non-secure states.
      
      The save and restore functions follow AArch64 PCS and only use
      caller-saved temporary registers.
      
      Change-Id: I8ee3aaa061d3caaedb28ae2c5becb9a206b6fd74
      9ac63c59
    • Achin Gupta's avatar
      Setup VBAR_EL3 incrementally · b739f22a
      Achin Gupta authored
      This patch ensures that VBAR_EL3 points to the simple stack-less
      'early_exceptions' when the C runtime stack is not correctly setup to
      use the more complex 'runtime_exceptions'. It is initialised to
      'runtime_exceptions' once this is done.
      
      This patch also moves all exception vectors into a '.vectors' section
      and modifies linker scripts to place all such sections together. This
      will minimize space wastage from alignment restrictions.
      
      Change-Id: I8c3e596ea3412c8bd582af9e8d622bb1cb2e049d
      b739f22a
    • Jeenu Viswambharan's avatar
      Move translation tables into separate section · 74cbb839
      Jeenu Viswambharan authored
      This patch moves the translation tables into their own section. This
      saves space that would otherwise have been lost in padding due to page
      table alignment constraints. The BL31 and BL32 bases have been
      consequently adjusted.
      
      Change-Id: Ibd65ae8a5ce4c4ea9a71a794c95bbff40dc63e65
      74cbb839
  13. 20 Jan, 2014 2 commits
  14. 17 Jan, 2014 3 commits
    • Jeenu Viswambharan's avatar
      Change comments in assembler files to help ctags · 3a4cae05
      Jeenu Viswambharan authored
      Ctags seem to have a problem with generating tags for assembler symbols
      when a comment immediately follows an assembly label.
      
      This patch inserts a single space character between the label
      definition and the following comments to help ctags.
      
      The patch is generated by the command:
      
        git ls-files -- \*.S | xargs sed -i 's/^\([^:]\+\):;/\1: ;/1'
      
      Change-Id: If7a3c9d0f51207ea033cc8b8e1b34acaa0926475
      3a4cae05
    • Harry Liebel's avatar
      Probe for GICv3 re-distributors on core bring-up · eaec590e
      Harry Liebel authored
      The GICv3 distributor can have more ports than CPUs are available in
      the system. Probe all re-distributors and use the matching affinity
      levels as specified by each core and re-distributor to decide which
      re-distributor to use with which CPU core.
      
      If a core cannot be matched with a re-distributor, the core panics and
      is placed in an endless loop.
      
      Change-Id: Ie393cfe07c7449a2383959e3c968664882e18afc
      eaec590e
    • Harry Liebel's avatar
      Do not trap access to floating point registers · 4f603683
      Harry Liebel authored
      Traps when accessing architectural features are disabled by clearing bits
      in CPTR_EL3 during early boot, including accesses to floating point
      registers. The value of this register was previously undetermined, causing
      unwanted traps to EL3. Future EL3 code (for example, context save/restore
      code) may use floating point registers, although they are not used by current
      code.
      
      Also, the '-mgeneral-regs-only' flag is enabled in the GCC settings to
      prevent generation of code that uses floating point registers.
      
      Change-Id: I9a03675f6387bbbee81a6f2c9ccf81150db03747
      4f603683