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This patch enables compiler-rt for the AArch32 target.  The code is
not used for AArch64 as the architecture supports the 64-bit division
and modulo operations natively.

Change-Id: I1703a92872b0bb56ac0b98c67193830683963b13
Signed-off-by: dp-arm <dimitris.papastamos@arm.com>

To make software license auditing simpler, use SPDX[0] license
identifiers instead of duplicating the license text in every file.

NOTE: Files that have been imported by FreeBSD have not been modified.

[0]: https://spdx.org/



Change-Id: I80a00e1f641b8cc075ca5a95b10607ed9ed8761a
Signed-off-by: dp-arm <dimitris.papastamos@arm.com>

Some recent changes have added direct use of the echo command without
parameters.  This fails on a Windows shell, because echo without
parameters reports the mode ("ECHO is on").
This is corrected using the ECHO_BLANK_LINE macro already provided
for that purpose.

Change-Id: I5fd7192861b4496f6f46b4f096e80a752cd135d6
Signed-off-by: Evan Lloyd <evan.lloyd@arm.com>

The build option `ENABLE_ASSERTIONS` should be used instead. That way
both C and ASM assertions can be enabled or disabled together.

All occurrences of `ASM_ASSERTION` in common code and ARM platforms have
been replaced by `ENABLE_ASSERTIONS`.

ASM_ASSERTION has been removed from the user guide.

Change-Id: I51f1991f11b9b7ff83e787c9a3270c274748ec6f
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

Add the new build option `ENABLE_ASSERTIONS` that controls whether or
not assert functions are compiled out. It defaults to 1 for debug builds
and to 0 for release builds.

Additionally, a following patch will be done to allow this build option
to hide auxiliary code used for the checks done in an `assert()`. This
code is is currently under the DEBUG build flag.

Assert messages are now only printed if LOG_LEVEL >= LOG_LEVEL_INFO,
which is the default for debug builds.

This patch also updates the User Guide.

Change-Id: I1401530b56bab25561bb0f274529f1d12c5263bc
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

This patch introduces a build option to enable D-cache early on the CPU
after warm boot. This is applicable for platforms which do not require
interconnect programming to enable cache coherency (eg: single cluster
platforms). If this option is enabled, then warm boot path enables
D-caches immediately after enabling MMU.

Fixes ARM-Software/tf-issues#456

Change-Id: I44c8787d116d7217837ced3bcf0b1d3441c8d80e
Signed-off-by: Soby Mathew <soby.mathew@arm.com>

If SCP_BL2 is passed in from the command line, it is recognized by
make_helpers/tbbr/tbbr_tools.mk, and the cert_create tool generates
the corresponding key and content certificates.

On the other hand, the top-level Makefile does not care SCP_BL2, so
the --scp-fw option is not passed to the fiptool.  As far as I see
plat/arm/css/common/css_common.mk, it looks like a platform's job to
add $(eval $(call FIP_ADD_IMG,SCP_BL2,--scp-fw)).

We can make the top-level Makefile kind enough to take care of it.
This is useful when we want to have optional SCP_BL2 firmware.

Adjust css_common.mk so that Juno still requires SCP_BL2 by default.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

Introduce new build option ENABLE_STACK_PROTECTOR. It enables
compilation of all BL images with one of the GCC -fstack-protector-*
options.

A new platform function plat_get_stack_protector_canary() is introduced.
It returns a value that is used to initialize the canary for stack
corruption detection. Returning a random value will prevent an attacker
from predicting the value and greatly increase the effectiveness of the
protection.

A message is printed at the ERROR level when a stack corruption is
detected.

To be effective, the global data must be stored at an address
lower than the base of the stacks. Failure to do so would allow an
attacker to overwrite the canary as part of an attack which would void
the protection.

FVP implementation of plat_get_stack_protector_canary is weak as
there is no real source of entropy on the FVP. It therefore relies on a
timer's value, which could be predictable.

Change-Id: Icaaee96392733b721fa7c86a81d03660d3c1bc06
Signed-off-by: Douglas Raillard <douglas.raillard@arm.com>

At present, the build option checks are done prior to inclusion of
BL makefiles. This meant if the BL makefiles modified any of the options
then these checks were bypassed. This patch corrects this problem.

Change-Id: I0b591392a74d6d456d2b19bbe292f42b5aeae048
Signed-off-by: Soby Mathew <soby.mathew@arm.com>

These source file definitions should be defined in generic
Makefiles so that all platforms can benefit. Ensure that the
symbols are properly marked as weak so they can be overridden
by platforms.

NOTE: This change is a potential compatibility break for
non-upstream platforms.

Change-Id: I7b892efa9f2d6d216931360dc6c436e1d10cffed
Signed-off-by: dp-arm <dimitris.papastamos@arm.com>

The folder lib/xlat_tables_v2 has been created to store a new version
of the translation tables library for further modifications in patches
to follow. At the moment it only contains a basic implementation that
supports static regions.

This library allows different translation tables to be modified by
using different 'contexts'. For now, the implementation defaults to
the translation tables used by the current image, but it is possible
to modify other tables than the ones in use.

Added a new API to print debug information for the current state of
the translation tables, rather than printing the information while
the tables are being created. This allows subsequent debug printing
of the xlat tables after they have been changed, which will be useful
when dynamic regions are implemented in a patch to follow.

The common definitions stored in `xlat_tables.h` header have been moved
to a new file common to both versions, `xlat_tables_defs.h`.

All headers related to the translation tables library have been moved to
a the subfolder `xlat_tables`.

Change-Id: Ia55962c33e0b781831d43a548e505206dffc5ea9
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

ARM Trusted Firmware keeps certain data structures in a memory region
with non-cacheable attributes (termed as "coherent memory") to keep data
coherent with observers that are cache-coherent, and those not. These
data structures pertain to power management and mutual exclusion. Using
coherent memory also costs at least an additional page to map memory
with special memory attributes.

On systems with hardware-assisted coherency, all CPUs that participate
in power management and mutual exclusion are cache-coherent, obviating
the need for special memory attributes for such data structures.
Instead, they can be placed in normal memory, along with rest of data.

On systems with hardware-assisted coherency, where build option
HW_ASSISTED_COHERENCY will be set, also having USE_COHERENT_MEMORY
enabled only wastes a page of memory without any
benefit. Therefore, with HW_ASSISTED_COHERENCY set to 1, require that
USE_COHERENT_MEMORY is explicitly set to 0.

Change-Id: I5101657ae6b1a46278069f23e2d88ee5cbd98efa
Signed-off-by: Jeenu Viswambharan <jeenu.viswambharan@arm.com>

The boolean build option HW_ASSISTED_COHERENCY is introduced to enable
various optimizations in ARM Trusted Software, when built for such
systems. It's set to 0 by default.

Change-Id: I638390da6e1718fe024dcf5b402e07084f1eb014
Signed-off-by: Jeenu Viswambharan <jeenu.viswambharan@arm.com>

The ARMv8v.1 architecture extension has introduced support for far
atomics, which includes compare-and-swap. Compare and Swap instruction
is only available for AArch64.

Introduce build options to choose the architecture versions to target
ARM Trusted Firmware:

  - ARM_ARCH_MAJOR: selects the major version of target ARM
    Architecture. Default value is 8.

  - ARM_ARCH_MINOR: selects the minor version of target ARM
    Architecture. Default value is 0.

When:

  (ARM_ARCH_MAJOR > 8) || ((ARM_ARCH_MAJOR == 8) && (ARM_ARCH_MINOR >= 1)),

for AArch64, Compare and Swap instruction is used to implement spin
locks. Otherwise, the implementation falls back to using
load-/store-exclusive instructions.

Update user guide, and introduce a section in Firmware Design guide to
summarize support for features introduced in ARMv8 Architecture
Extensions.

Change-Id: I73096a0039502f7aef9ec6ab3ae36680da033f16
Signed-off-by: Jeenu Viswambharan <jeenu.viswambharan@arm.com>

This patch introduces the following three platform interfaces:

* void plat_psci_stat_accounting_start(const psci_power_state_t *state_info)

  This is an optional hook that platforms can implement in order
  to perform accounting before entering a low power state.  This
  typically involves capturing a timestamp.

* void plat_psci_stat_accounting_stop(const psci_power_state_t *state_info)

  This is an optional hook that platforms can implement in order
  to perform accounting after exiting from a low power state.  This
  typically involves capturing a timestamp.

* u_register_t plat_psci_stat_get_residency(unsigned int lvl,
	const psci_power_state_t *state_info,
	unsigned int last_cpu_index)

  This is an optional hook that platforms can implement in order
  to calculate the PSCI stat residency.

If any of these interfaces are overridden by the platform, it is
recommended that all of them are.

By default `ENABLE_PSCI_STAT` is disabled.  If `ENABLE_PSCI_STAT`
is set but `ENABLE_PMF` is not set then an alternative PSCI stat
collection backend must be provided.  If both are set, then default
weak definitions of these functions are provided, using PMF to
calculate the residency.

NOTE: Previously, platforms did not have to explicitly set
`ENABLE_PMF` since this was automatically done by the top-level
Makefile.

Change-Id: I17b47804dea68c77bc284df15ee1ccd66bc4b79b
Signed-off-by: dp-arm <dimitris.papastamos@arm.com>

Currently, the BUILD_STRING is just 7-digits git hash.  It is true
we can identify which version is running, but we can not get a quick
idea about how new or old it is.

The command "git describe" provides us a bit more useful information
in the format of:
  (tag-name)-(number of commits on top the tag)-g(7 digits hash)

I added some options:
  --always
    Make "git describe" work without any tag in case the upstream
    ATF is cloned, but all the tags are locally dropped.

  --tags
    Use any tag instead of only annotated tags.  In ATF, only some
    tags are annotated, actually the last annotated tag is "v0.2",
    whereas we are on "v1.3" tag now.  This option is needed to get
    something like v1.3-233-gbcc2bf09 instead of v0.2-1713-gbcc2bf09.

  --dirty
    The mark "-dirty" is appended if the source tree is locally
    modified.

With this commit, the welcome string

  NOTICE:  BL1: v1.3(debug):bcc2bf09

will become like follows:

  NOTICE:  BL1: v1.3(debug):v1.3-233-gbcc2bf09

-dirty

While we are here, let's add "2> /dev/null" as well to silently
ignore any error message from git.  We should not assume that users
always work in a git repository; the ATF might be released in a
tarball form instead of a git repository.  In such a case, the git
command will fail, then the ugly message "fatal: Not a git ..." will
be displayed during the build:

$ make CROSS_COMPILE=aarch64-linux-gnu-
fatal: Not a git repository (or any of the parent directories): .git
Building fvp
  CC      drivers/io/io_semihosting.c
  CC      lib/semihosting/semihosting.c
     ...
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

Sharing the same CFLAGS for both the firmware and host tools is not
useful and can lead to compilation failure when CFLAGS is set on the
command line.

This patch make MAKEOVERRIDES special variable empty so make's command
line variable definitions are not implicitly forwarded to sub make
invocations. However, make options are still forwarded like "-s" option
to make the build silent.

Change-Id: Ia921c02beb1fd2041696a26160b9e7974ae000fa
Signed-off-by: Douglas Raillard <douglas.raillard@arm.com>

The errata reporting policy is as follows:

  - If an errata workaround is enabled:

    - If it applies (i.e. the CPU is affected by the errata), an INFO
      message is printed, confirming that the errata workaround has been
      applied.

    - If it does not apply, a VERBOSE message is printed, confirming
      that the errata workaround has been skipped.

  - If an errata workaround is not enabled, but would have applied had
    it been, a WARN message is printed, alerting that errata workaround
    is missing.

The CPU errata messages are printed by both BL1 (primary CPU only) and
runtime firmware on debug builds, once for each CPU/errata combination.

Relevant output from Juno r1 console when ARM Trusted Firmware is built
with PLAT=juno LOG_LEVEL=50 DEBUG=1:

  VERBOSE: BL1: cortex_a57: errata workaround for 806969 was not applied
  VERBOSE: BL1: cortex_a57: errata workaround for 813420 was not applied
  INFO:    BL1: cortex_a57: errata workaround for disable_ldnp_overread was applied
  WARNING: BL1: cortex_a57: errata workaround for 826974 was missing!
  WARNING: BL1: cortex_a57: errata workaround for 826977 was missing!
  WARNING: BL1: cortex_a57: errata workaround for 828024 was missing!
  WARNING: BL1: cortex_a57: errata workaround for 829520 was missing!
  WARNING: BL1: cortex_a57: errata workaround for 833471 was missing!
  ...
  VERBOSE: BL31: cortex_a57: errata workaround for 806969 was not applied
  VERBOSE: BL31: cortex_a57: errata workaround for 813420 was not applied
  INFO:    BL31: cortex_a57: errata workaround for disable_ldnp_overread was applied
  WARNING: BL31: cortex_a57: errata workaround for 826974 was missing!
  WARNING: BL31: cortex_a57: errata workaround for 826977 was missing!
  WARNING: BL31: cortex_a57: errata workaround for 828024 was missing!
  WARNING: BL31: cortex_a57: errata workaround for 829520 was missing!
  WARNING: BL31: cortex_a57: errata workaround for 833471 was missing!
  ...
  VERBOSE: BL31: cortex_a53: errata workaround for 826319 was not applied
  INFO:    BL31: cortex_a53: errata workaround for disable_non_temporal_hint was applied

Also update documentation.

Change-Id: Iccf059d3348adb876ca121cdf5207bdbbacf2aba
Signed-off-by: Jeenu Viswambharan <jeenu.viswambharan@arm.com>

Disable the automatic substitution of functions with builtins. The
existing -ffreestanding option should already do this but explicitly
adding -fno-builtin reduces the risk of compiler variation. With this
option, GCC is not supposed to be able to make assumptions on what the
function does, which could otherwise lead to security-sensitive code
removal.

This can lead to potentially less efficient code but improves
predictability of what code is actually compiled into the binary.

Change-Id: I06ad151c61318bd1b00d84976f051d2d94314acc
Signed-off-by: Douglas Raillard <douglas.raillard@arm.com>

The current fiptool packs all the images without any padding between
them.  So, the offset to each image has no alignment.  This is not
efficient, for example, when the FIP is read from a block-oriented
device.

For example, (e)MMC is accessed by block-addressing.  The block size
is 512 byte.  So, the best case is each image is aligned by 512 byte
since the DMA engine can transfer the whole of the image to its load
address directly.  The worst case is the offset does not have even
DMA-capable alignment (this is where we stand now).  In this case,
we need to transfer every block to a bounce buffer, then do memcpy()
from the bounce buffer to our final destination.  At least, this
should work with the abstraction by the block I/O layer, but the
CPU-intervention for the whole data transfer makes it really slow.

This commit adds a new option --align to the fiptool.  This option,
if given, requests the tool to align each component in the FIP file
by the specified byte.  Also, add a new Make option FIP_ALIGN for
easier access to this feature; users can give something like
FIP_ALIGN=512 from the command line, or add "FIP_ALIGN := 512" to
their platform.mk file.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

When generating the list of files to check by checkpatch.pl, the list
generated by `git ls-files` is filtered by a regular expression with
grep. Due to a malformed regex, the dot of `.md` was considered a
wildcard instead of a dot. This patch fixes this so that it matches
only dots, thus allowing the two following files to be checked:

* tools/cert_create/include/cmd_opt.h
* tools/cert_create/src/cmd_opt.c

Also extended the list of library directories to check by checkpatch
to exclude any folder starting with libfdt.

Change-Id: Ie7bf18efe4df29e364e5d67ba1118515304ed9a4
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

Using AS for pre-processing looks a bit weird, and some assembly
specific options are given for nothing.  Rather, use CPP.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

The -c flag should not be included in the global variable TF_CFLAGS;
it should be specified in the build rule only when its target is a
*.o file.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

This patch enables TRUSTED_BOARD_BOOT (Authentication and FWU)
support, for AArch64, when LOAD_IMAGE_V2 is enabled.

This patch also enables LOAD_IMAGE_V2 for ARM platforms.

Change-Id: I294a2eebce7a30b6784c80c9d4ac7752808ee3ad
Signed-off-by: Yatharth Kochar <yatharth.kochar@arm.com>

When build variables are assigned or processed en masse, they'd appear
neater in alphabetical order.

Static initializations are moved to a separate file,
make_helpers/defaults.mk, which in itself is sorted alphabetically.

No functional changes.

Change-Id: I966010042b33de6b67592fb9ffcef8fc44d7d128
Signed-off-by: Jeenu Viswambharan <jeenu.viswambharan@arm.com>

Checkpatch is a script developed to verify the style of Linux kernel
patches. As Kernel developers use emails to send patches for review,
checkpatch is prepared for that specific format. This change adapts
the Makefile to use said format.

As a result, indentation in the commit message has been removed, thus
fixing the warnings about Signed-off-by lines being preceded by
whitespace.

Fixes ARM-software/tf-issues#432

Change-Id: I00cb86365fe15f7e2c3a99a306c8eb51cf02fe86
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

Change-Id: I05991543d28e70b67be600b714990af6a8d7ba29

In order to quantify the overall time spent in the PSCI software
implementation, an initial collection of PMF instrumentation points
has been added.

Instrumentation has been added to the following code paths:

- Entry to PSCI SMC handler.  The timestamp is captured as early
  as possible during the runtime exception and stored in memory
  before entering the PSCI SMC handler.

- Exit from PSCI SMC handler.  The timestamp is captured after
  normal return from the PSCI SMC handler or if a low power state
  was requested it is captured in the bl31 warm boot path before
  return to normal world.

- Entry to low power state.  The timestamp is captured before entry
  to a low power state which implies either standby or power down.
  As these power states are mutually exclusive, only one timestamp
  is defined to describe both.  It is possible to differentiate between
  the two power states using the PSCI STAT interface.

- Exit from low power state.  The timestamp is captured after a standby
  or power up operation has completed.

To calculate the number of cycles spent running code in Trusted Firmware
one can perform the following calculation:

(exit_psci - enter_psci) - (exit_low_pwr - enter_low_pwr).

The resulting number of cycles can be converted to time given the
frequency of the counter.

Change-Id: Ie3b8f3d16409b6703747093b3a2d5c7429ad0166
Signed-off-by: dp-arm <dimitris.papastamos@arm.com>

Insert a cosmetic space before "(FIP)".
Signed-off-by: Andreas Färber <afaerber@suse.de>

This patch adds ARM platform changes in BL2 for AArch32 state.
It instantiates a descriptor array for ARM platforms describing
image and entrypoint information for `SCP_BL2`, `BL32` and `BL33`.
It also enables building of BL2 for ARCH=aarch32.

Change-Id: I60dc7a284311eceba401fc789311c50ac746c51e

This patch adds ARM platform changes in BL1 for AArch32 state.
It also enables building of BL1 for ARCH=aarch32.

Change-Id: I079be81a93d027f37b0f7d8bb474b1252bb4cf48

This patch adds common changes to support AArch32 state in
BL1 and BL2. Following are the changes:

* Added functions for disabling MMU from Secure state.
* Added AArch32 specific SMC function.
* Added semihosting support.
* Added reporting of unhandled exceptions.
* Added uniprocessor stack support.
* Added `el3_entrypoint_common` macro that can be
  shared by BL1 and BL32 (SP_MIN) BL stages. The
  `el3_entrypoint_common` is similar to the AArch64
  counterpart with the main difference in the assembly
  instructions and the registers that are relevant to
  AArch32 execution state.
* Enabled `LOAD_IMAGE_V2` flag in Makefile for
  `ARCH=aarch32` and added check to make sure that
  platform has not overridden to disable it.

Change-Id: I33c6d8dfefb2e5d142fdfd06a0f4a7332962e1a3

This patch adds capability to load BL images based on image
descriptors instead of hard coded way of loading BL images.
This framework is designed such that it can be readily adapted
by any BL stage that needs to load images.

In order to provide the above capability the following new
platform functions are introduced:

  bl_load_info_t *plat_get_bl_image_load_info(void);
    This function returns pointer to the list of images that the
    platform has populated to load.

  bl_params_t *plat_get_next_bl_params(void);
    This function returns a pointer to the shared memory that the
    platform has kept aside to pass trusted firmware related
    information that next BL image needs.

  void plat_flush_next_bl_params(void);
    This function flushes to main memory all the params that
    are passed to next image.

  int bl2_plat_handle_post_image_load(unsigned int image_id)
    This function can be used by the platforms to update/use
    image information for given `image_id`.

`desc_image_load.c` contains utility functions which can be used
by the platforms to generate, load and executable, image list
based on the registered image descriptors.

This patch also adds new version of `load_image/load_auth_image`
functions in-order to achieve the above capability.

Following are the changes for the new version as compared to old:
  - Refactor the signature and only keep image_id and image_info_t
    arguments. Removed image_base argument as it is already passed
    through image_info_t. Given that the BL image base addresses and
    limit/size are already provided by the platforms, the meminfo_t
    and entry_point_info arguments are not needed to provide/reserve
    the extent of free memory for the given BL image.

  - Added check for the image size against the defined max size.
    This is needed because the image size could come from an
    unauthenticated source (e.g. the FIP header).
    To make this check, new member is added to the image_info_t
    struct for identifying the image maximum size.

New flag `LOAD_IMAGE_V2` is added in the Makefile.
Default value is 0.

NOTE: `TRUSTED_BOARD_BOOT` is currently not supported when
      `LOAD_IMAGE_V2` is enabled.

Change-Id: Ia7b643f4817a170d5a2fbf479b9bc12e63112e79

More headers will be needed soon so better to move these to their own
directory to avoid cluttering include/lib.

Change-Id: I6a72dc5b602d6f51954cf60aadd1beb52a268670

This patch enables the AArch32 build including SP_MIN in the
top level Makefile. The build flag `ARCH` now can specify either
`aarch64`(default) or `aarch32`. Currently only FVP AEM model is
supported for AArch32 build. Another new build flag `AARCH32_SP`
is introduced to specify the AArch32 secure payload to be built.

Change-Id: Ie1198cb9e52d7da1b79b93243338fc3868b08faa

This patch adds the essential AArch32 architecture helpers
arch.h and arch_helpers.h and modifies `_types.h` to add AArch32
support.

A new build option `ARCH` is defined in the top level makefile to
enable the component makefiles to choose the right files based on the
Architecture it is being build for. Depending on this flag, either
`AARCH32` or `AARCH64` flag is defined by the Makefile. The default
value of `ARCH` flag is `aarch64`. The AArch32 build support will be
added in a later patch.

Change-Id: I405e5fac02db828a55cd25989b572b64cb005241

fiptool provides a more consistent and intuitive interface compared to
the fip_create program.  It serves as a better base to build on more
features in the future.

fiptool supports various subcommands.  Below are the currently
supported subcommands:

1) info   - List the images contained in a FIP file.
2) create - Create a new FIP file with the given images.
3) update - Update an existing FIP with the given images.
4) unpack - Extract a selected set or all the images from a FIP file.
5) remove - Remove images from a FIP file.  This is a new command that
   was not present in fip_create.

To create a new FIP file, replace "fip_create" with "fiptool create".

To update a FIP file, replace "fip_create" with "fiptool update".

To dump the contents of a FIP file, replace "fip_create --dump" with
"fiptool info".

A compatibility script that emulates the basic functionality of
fip_create is provided.  Existing scripts might or might not work with
the compatibility script.  Users are strongly encouraged to migrate to
fiptool.

Fixes ARM-Software/tf-issues#87
Fixes ARM-Software/tf-issues#108
Fixes ARM-Software/tf-issues#361

Change-Id: I7ee4da7ac60179cc83cf46af890fd8bc61a53330

This patch moves the PSCI services and BL31 frameworks like context
management and per-cpu data into new library components `PSCI` and
`el3_runtime` respectively. This enables PSCI to be built independently from
BL31. A new `psci_lib.mk` makefile is introduced which adds the relevant
PSCI library sources and gets included by `bl31.mk`. Other changes which
are done as part of this patch are:

* The runtime services framework is now moved to the `common/` folder to
  enable reuse.
* The `asm_macros.S` and `assert_macros.S` helpers are moved to architecture
  specific folder.
* The `plat_psci_common.c` is moved from the `plat/common/aarch64/` folder
  to `plat/common` folder. The original file location now has a stub which
  just includes the file from new location to maintain platform compatibility.

Most of the changes wouldn't affect platform builds as they just involve
changes to the generic bl1.mk and bl31.mk makefiles.

NOTE: THE `plat_psci_common.c` FILE HAS MOVED LOCATION AND THE STUB FILE AT
THE ORIGINAL LOCATION IS NOW DEPRECATED. PLATFORMS SHOULD MODIFY THEIR
MAKEFILES TO INCLUDE THE FILE FROM THE NEW LOCATION.

Change-Id: I6bd87d5b59424995c6a65ef8076d4fda91ad5e86

At the moment, all BL images share a similar memory layout: they start
with their code section, followed by their read-only data section.
The two sections are contiguous in memory. Therefore, the end of the
code section and the beginning of the read-only data one might share
a memory page. This forces both to be mapped with the same memory
attributes. As the code needs to be executable, this means that the
read-only data stored on the same memory page as the code are
executable as well. This could potentially be exploited as part of
a security attack.

This patch introduces a new build flag called
SEPARATE_CODE_AND_RODATA, which isolates the code and read-only data
on separate memory pages. This in turn allows independent control of
the access permissions for the code and read-only data.

This has an impact on memory footprint, as padding bytes need to be
introduced between the code and read-only data to ensure the
segragation of the two. To limit the memory cost, the memory layout
of the read-only section has been changed in this case.

 - When SEPARATE_CODE_AND_RODATA=0, the layout is unchanged, i.e.
   the read-only section still looks like this (padding omitted):

   |        ...        |
   +-------------------+
   | Exception vectors |
   +-------------------+
   |  Read-only data   |
   +-------------------+
   |       Code        |
   +-------------------+ BLx_BASE

   In this case, the linker script provides the limits of the whole
   read-only section.

 - When SEPARATE_CODE_AND_RODATA=1, the exception vectors and
   read-only data are swapped, such that the code and exception
   vectors are contiguous, followed by the read-only data. This
   gives the following new layout (padding omitted):

   |        ...        |
   +-------------------+
   |  Read-only data   |
   +-------------------+
   | Exception vectors |
   +-------------------+
   |       Code        |
   +-------------------+ BLx_BASE

   In this case, the linker script now exports 2 sets of addresses
   instead: the limits of the code and the limits of the read-only
   data. Refer to the Firmware Design guide for more details. This
   provides platform code with a finer-grained view of the image
   layout and allows it to map these 2 regions with the appropriate
   access permissions.

Note that SEPARATE_CODE_AND_RODATA applies to all BL images.

Change-Id: I936cf80164f6b66b6ad52b8edacadc532c935a49

This patch adds following optional PSCI STAT functions:

- PSCI_STAT_RESIDENCY: This call returns the amount of time spent
  in power_state in microseconds, by the node represented by the
  `target_cpu` and the highest level of `power_state`.

- PSCI_STAT_COUNT: This call returns the number of times a
  `power_state` has been used by the node represented by the
  `target_cpu` and the highest power level of `power_state`.

These APIs provides residency statistics for power states that has
been used by the platform. They are implemented according to v1.0
of the PSCI specification.

By default this optional feature is disabled in the PSCI
implementation. To enable it, set the boolean flag
`ENABLE_PSCI_STAT` to 1. This also sets `ENABLE_PMF` to 1.

Change-Id: Ie62e9d37d6d416ccb1813acd7f616d1ddd3e8aff