GitLab

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>

The files affected by this patch don't really depend on `xlat_tables.h`.
By changing the included file it becomes easier to switch between the
two versions of the translation tables library.

Change-Id: Idae9171c490e0865cb55883b19eaf942457c4ccc
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

Introduce zeromem_dczva function on AArch64 that can handle unaligned
addresses and make use of DC ZVA instruction to zero a whole block at a
time. This zeroing takes place directly in the cache to speed it up
without doing external memory access.

Remove the zeromem16 function on AArch64 and replace it with an alias to
zeromem. This zeromem16 function is now deprecated.

Remove the 16-bytes alignment constraint on __BSS_START__ in
firmware-design.md as it is now not mandatory anymore (it used to comply
with zeromem16 requirements).

Change the 16-bytes alignment constraints in SP min's linker script to a
8-bytes alignment constraint as the AArch32 zeromem implementation is now
more efficient on 8-bytes aligned addresses.

Introduce zero_normalmem and zeromem helpers in platform agnostic header
that are implemented this way:
* AArch32:
	* zero_normalmem: zero using usual data access
	* zeromem: alias for zero_normalmem
* AArch64:
	* zero_normalmem: zero normal memory  using DC ZVA instruction
	                  (needs MMU enabled)
	* zeromem: zero using usual data access

Usage guidelines: in most cases, zero_normalmem should be preferred.

There are 2 scenarios where zeromem (or memset) must be used instead:
* Code that must run with MMU disabled (which means all memory is
  considered device memory for data accesses).
* Code that fills device memory with null bytes.

Optionally, the following rule can be applied if performance is
important:
* Code zeroing small areas (few bytes) that are not secrets should use
  memset to take advantage of compiler optimizations.

  Note: Code zeroing security-related critical information should use
  zero_normalmem/zeromem instead of memset to avoid removal by
  compilers' optimizations in some cases or misbehaving versions of GCC.

Fixes ARM-software/tf-issues#408

Change-Id: Iafd9663fc1070413c3e1904e54091cf60effaa82
Signed-off-by: Douglas Raillard <douglas.raillard@arm.com>

Standard SMC requests that are handled in the secure-world by the Secure
Payload can be preempted by interrupts that must be handled in the
normal world. When the TSP is preempted the secure context is stored and
control is passed to the normal world to handle the non-secure
interrupt. Once completed the preempted secure context is restored. When
restoring the preempted context, the dispatcher assumes that the TSP
preempted context is still stored as the SECURE context by the context
management library.

However, PSCI power management operations causes synchronous entry into
TSP. This overwrites the preempted SECURE context in the context
management library. When restoring back the SECURE context, the Secure
Payload crashes because this context is not the preempted context
anymore.

This patch avoids corruption of the preempted SECURE context by aborting
any preempted SMC during PSCI power management calls. The
abort_std_smc_entry hook of the TSP is called when aborting the SMC
request.

It also exposes this feature as a FAST SMC callable from normal world to
abort preempted SMC with FID TSP_FID_ABORT.

Change-Id: I7a70347e9293f47d87b5de20484b4ffefb56b770
Signed-off-by: Douglas Raillard <douglas.raillard@arm.com>

There are many instances in ARM Trusted Firmware where control is
transferred to functions from which return isn't expected. Such jumps
are made using 'bl' instruction to provide the callee with the location
from which it was jumped to. Additionally, debuggers infer the caller by
examining where 'lr' register points to. If a 'bl' of the nature
described above falls at the end of an assembly function, 'lr' will be
left pointing to a location outside of the function range. This misleads
the debugger back trace.

This patch defines a 'no_ret' macro to be used when jumping to functions
from which return isn't expected. The macro ensures to use 'bl'
instruction for the jump, and also, for debug builds, places a 'nop'
instruction immediately thereafter (unless instructed otherwise) so as
to leave 'lr' pointing within the function range.

Change-Id: Ib34c69fc09197cfd57bc06e147cc8252910e01b0
Co-authored-by: Douglas Raillard <douglas.raillard@arm.com>
Signed-off-by: Jeenu Viswambharan <jeenu.viswambharan@arm.com>

This patch moves the assembly exclusive lock library code
`spinlock.S` into architecture specific folder `aarch64`.
A stub file which includes the file from new location is
retained at the original location for compatibility. The BL
makefiles are also modified to include the file from the new
location.

Change-Id: Ide0b601b79c439e390c3a017d93220a66be73543

In debug builds, the TSP prints its image base address and size.
The base address displayed corresponds to the start address of the
read-only section, as defined in the linker script.

This patch changes this to use the BL32_BASE address instead, which is
the same address as __RO_START__ at the moment but has the advantage
to be independent of the linker symbols defined in the linker script
as well as the layout and order of the sections.

Change-Id: I032d8d50df712c014cbbcaa84a9615796ec902cc

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 introduces some assembler macros to simplify the
declaration of the exception vectors. It abstracts the section
the exception code is put into as well as the alignments
constraints mandated by the ARMv8 architecture. For all TF images,
the exception code has been updated to make use of these macros.

This patch also updates some invalid comments in the exception
vector code.

Change-Id: I35737b8f1c8c24b6da89b0a954c8152a4096fa95

As an initial stage of making Trusted Firmware build environment more
portable, we remove most uses of the $(shell ) function and replace them
with more portable make function based solutions.

Note that the setting of BUILD_STRING still uses $(shell ) since it's
not possible to reimplement this as a make function. Avoiding invocation
of this on incompatible host platforms will be implemented separately.

Change-Id: I768e2f9a265c78814a4adf2edee4cc46cda0f5b8

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

This patch removes the dash character from the image name, to
follow the image terminology in the Trusted Firmware Wiki page:

    https://github.com/ARM-software/arm-trusted-firmware/wiki

Changes apply to output messages, comments and documentation.

non-ARM platform files have been left unmodified.

Change-Id: Ic2a99be4ed929d52afbeb27ac765ceffce46ed76

Earlier the TSP only ever expected to be preempted during Standard SMC
processing. If a S-EL1 interrupt triggered while in the normal world, it
will routed to S-EL1 `synchronously` for handling. The `synchronous` S-EL1
interrupt handler `tsp_sel1_intr_entry` used to panic if this S-EL1 interrupt
was preempted by another higher priority pending interrupt which should be
handled in EL3 e.g. Group0 interrupt in GICv3.

With this patch, the `tsp_sel1_intr_entry` now expects `TSP_PREEMPTED` as the
return code from the `tsp_common_int_handler` in addition to 0 (interrupt
successfully handled) and in both cases it issues an SMC with id
`TSP_HANDLED_S_EL1_INTR`. The TSPD switches the context and returns back
to normal world. In case a higher priority EL3 interrupt was pending, the
execution will be routed to EL3 where interrupt will be handled. On return
back to normal world, the pending S-EL1 interrupt which was preempted will
get routed to S-EL1 to be handled `synchronously` via `tsp_sel1_intr_entry`.

Change-Id: I2087c7fedb37746fbd9200cdda9b6dba93e16201

On a GICv2 system, interrupts that should be handled in the secure world are
typically signalled as FIQs. On a GICv3 system, these interrupts are signalled
as IRQs instead. The mechanism for handling both types of interrupts is the same
in both cases. This patch enables the TSP to run on a GICv3 system by:

1. adding support for handling IRQs in the exception handling code.
2. removing use of "fiq" in the names of data structures, macros and functions.

The build option TSPD_ROUTE_IRQ_TO_EL3 is deprecated and is replaced with a
new build flag TSP_NS_INTR_ASYNC_PREEMPT. For compatibility reasons, if the
former build flag is defined, it will be used to define the value for the
new build flag. The documentation is also updated accordingly.

Change-Id: I1807d371f41c3656322dd259340a57649833065e

The TSP is expected to pass control back to EL3 if it gets preempted due to
an interrupt while handling a Standard SMC in the following scenarios:

1. An FIQ preempts Standard SMC execution and that FIQ is not a TSP Secure
   timer interrupt or is preempted by a higher priority interrupt by the time
   the TSP acknowledges it. In this case, the TSP issues an SMC with the ID
   as `TSP_EL3_FIQ`. Currently this case is never expected to happen as only
   the TSP Secure Timer is expected to generate FIQ.

2. An IRQ preempts Standard SMC execution and in this case the TSP issues
   an SMC with the ID as `TSP_PREEMPTED`.

In both the cases, the TSPD hands control back to the normal world and returns
returns an error code to the normal world to indicate that the standard SMC it
had issued has been preempted but not completed.

This patch unifies the handling of these two cases in the TSPD and ensures that
the TSP only uses TSP_PREEMPTED instead of separate SMC IDs. Also instead of 2
separate error codes, SMC_PREEMPTED and TSP_EL3_FIQ, only SMC_PREEMPTED is
returned as error code back to the normal world.

Background information: On a GICv3 system, when the secure world has affinity
routing enabled, in 2. an FIQ will preempt TSP execution instead of an IRQ. The
FIQ could be a result of a Group 0 or a Group 1 NS interrupt. In both case, the
TSPD passes control back to the normal world upon receipt of the TSP_PREEMPTED
SMC. A Group 0 interrupt will immediately preempt execution to EL3 where it
will be handled. This allows for unified interrupt handling in TSP for both
GICv3 and GICv2 systems.

Change-Id: I9895344db74b188021e3f6a694701ad272fb40d4

On the ARMv8 architecture, cache maintenance operations by set/way on the last
level of integrated cache do not affect the system cache. This means that such a
flush or clean operation could result in the data being pushed out to the system
cache rather than main memory. Another CPU could access this data before it
enables its data cache or MMU. Such accesses could be serviced from the main
memory instead of the system cache. If the data in the sysem cache has not yet
been flushed or evicted to main memory then there could be a loss of
coherency. The only mechanism to guarantee that the main memory will be updated
is to use cache maintenance operations to the PoC by MVA(See section D3.4.11
(System level caches) of ARMv8-A Reference Manual (Issue A.g/ARM DDI0487A.G).

This patch removes the reliance of Trusted Firmware on the flush by set/way
operation to ensure visibility of data in the main memory. Cache maintenance
operations by MVA are now used instead. The following are the broad category of
changes:

1. The RW areas of BL2/BL31/BL32 are invalidated by MVA before the C runtime is
   initialised. This ensures that any stale cache lines at any level of cache
   are removed.

2. Updates to global data in runtime firmware (BL31) by the primary CPU are made
   visible to secondary CPUs using a cache clean operation by MVA.

3. Cache maintenance by set/way operations are only used prior to power down.

NOTE: NON-UPSTREAM TRUSTED FIRMWARE CODE SHOULD MAKE EQUIVALENT CHANGES IN
ORDER TO FUNCTION CORRECTLY ON PLATFORMS WITH SUPPORT FOR SYSTEM CACHES.

Fixes ARM-software/tf-issues#205

Change-Id: I64f1b398de0432813a0e0881d70f8337681f6e9a

In certain Trusted OS implementations it is a requirement to pass them the
highest power level which will enter a power down state during a PSCI
CPU_SUSPEND or SYSTEM_SUSPEND API invocation. This patch passes this power level
to the SPD in the "max_off_pwrlvl" parameter of the svc_suspend() hook.

Currently, the highest power level which was requested to be placed in a low
power state (retention or power down) is passed to the SPD svc_suspend_finish()
hook. This hook is called after emerging from the low power state. It is more
useful to pass the highest power level which was powered down instead. This
patch does this by changing the semantics of the parameter passed to an SPD's
svc_suspend_finish() hook. The name of the parameter has been changed from
"suspend_level" to "max_off_pwrlvl" as well. Same changes have been made to the
parameter passed to the tsp_cpu_resume_main() function.

NOTE: THIS PATCH CHANGES THE SEMANTICS OF THE EXISTING "svc_suspend_finish()"
      API BETWEEN THE PSCI AND SPD/SP IMPLEMENTATIONS. THE LATTER MIGHT NEED
      UPDATES TO ENSURE CORRECT BEHAVIOUR.

Change-Id: If3a9d39b13119bbb6281f508a91f78a2f46a8b90

The new PSCI frameworks mandates that the platform APIs and the various
frameworks in Trusted Firmware migrate away from MPIDR based core
identification to one based on core index. Deprecated versions of the old
APIs are still present to provide compatibility but their implementations
are not optimal. This patch migrates the various SPDs exisiting within
Trusted Firmware tree and TSP to the new APIs.

Change-Id: Ifc37e7071c5769b5ded21d0b6a071c8c4cab7836

Add extern declarations of linker symbols to bl_common.h. These are
used by platform ports to determine the memory layout of BL images.
Adding the declarations to this file facilitates removal of these
declarations from the platform porting source files in subsequent
patches.

Also remove the linker symbol declarations from common TSP source
code.

Change-Id: I8ed0426bc815317c4536b588e4e78bc15b4fe91c

Update the top level makefile to allow platform ports to exist in
subdirectories at any level instead of one level under `plat/`. The
makefile recursively searches for all files called `platform.mk` in
all subdirectories of `plat/`. The directory containing
`platform.mk` is the platform name. Platform names must be unique
across the codebase.

Replace usage of HELP_PLATFORMS in the Makefile with PLATFORMS since
these are both used to report the same information back to the user.

Update the TSP and cert_create tool makefiles in a similar way
to support a deeper platform port directory structure.

Also add PLAT_<plat_name> as a define passed through the top level
makefile to the source files, to allow build time variation in common
platform code.

Change-Id: I213420164808c5ddb99a26144e8e3f141a7417b7

Commit dad25049 adds support for type checking in printf-like
functions. Some of the VERBOSE logging statements were not updated
at that time.

Fix the type mismatches in the verbose logging statements.

Change-Id: Idd9a49e41cc0dc31f7698e220819d934e3d2d10e

In order for the symbol table in the ELF file to contain the size of
functions written in assembly, it is necessary to report it to the
assembler using the .size directive.

To fulfil the above requirements, this patch introduces an 'endfunc'
macro which contains the .endfunc and .size directives. It also adds
a .func directive to the 'func' assembler macro.

The .func/.endfunc have been used so the assembler can fail if
endfunc is omitted.

Fixes ARM-Software/tf-issues#295

Change-Id: If8cb331b03d7f38fe7e3694d4de26f1075b278fc
Signed-off-by: Kévin Petit <kevin.petit@arm.com>

This patch modifies the declarations of the functions printf() et al.
and adds the right GCC attribute to request the compiler to check
the type of the arguments passed to these functions against the given
format string. This will ensure that the compiler outputs warning
messages like the following whenever it detects an inconsistency:

 file.c:42: warning: format ‘%d’ expects type ‘int’, but argument 3 has type ‘long int’

It also fixes the type mismatch inconsistencies that it revealed
across the code base.

NOTE: THIS PATCH MAY FORCE PLATFORM PORTS OR SP/SPDS THAT USE THE
PRINTF FAMILY OF FUNCTIONS TO FIX ANY TYPE MISMATCH INCONSISTENCIES.

Change-Id: If36bb54ec7d6dd2cb4791d89b02a24ac13fd2df6

This patch adds support to save the "power state" parameter before the
affinity level specific handlers are called in a CPU_SUSPEND call.
This avoids the need to pass the power_state as a parameter to the
handlers and Secure Payload Dispatcher (SPD) suspend spd_pm_ops.
The power_state arguments in the spd_pm_ops operations are now reserved
and must not be used. The SPD can query the relevant power_state fields
by using the psci_get_suspend_afflvl() & psci_get_suspend_stateid() APIs.

NOTE: THIS PATCH WILL BREAK THE SPD_PM_OPS INTERFACE. HENCE THE SECURE
PAYLOAD DISPATCHERS WILL NEED TO BE REWORKED TO USE THE NEW INTERFACE.

Change-Id: I1293d7dc8cf29cfa6a086a009eee41bcbf2f238e

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

This patch implements the TSP on Juno. It executes from on-chip Trusted
SRAM.

Also, the other bootloader images (i.e. BL1 R/W, BL2 and BL3-1) have
been moved around. The reason is, although there was enough space
overall to store the TSP in SRAM, there was no contiguous free chunk
of SRAM big enough to hold it.

This patch keeps the overall memory layout (i.e. keeping BL1 R/W at
the bottom, BL2 at the top and BL3-1 in between) but moves the base
addresses of all the bootloader images in such a way that:
 - memory fragmentation is reduced enough to fit BL3-2 in;
 - new base addresses are suitable for release builds as well as debug
   ones;
 - each image has a few extra kilobytes for future growth.
   BL3-1 and BL3-2 are the images which received the biggest allocations
   since they will most probably grow the most.

This patch also adds instruction synchronization barriers around the code which
handles the timer interrupt in the TSP. This ensures that the interrupt is not
acknowledged after or EOIed before it is deactivated at the peripheral.

Change-Id: I1c5b51858700027ee283ac85d18e06863a27c72e

This patch adds support for SYSTEM_OFF and SYSTEM_RESET PSCI
operations. A platform should export handlers to complete the
requested operation. The FVP port exports fvp_system_off() and
fvp_system_reset() as an example.

If the SPD provides a power management hook for system off and
system reset, then the SPD is notified about the corresponding
operation so it can do some bookkeeping. The TSPD exports
tspd_system_off() and tspd_system_reset() for that purpose.

Versatile Express shutdown and reset methods have been removed
from the FDT as new PSCI sys_poweroff and sys_reset services
have been added. For those kernels that do not support yet these
PSCI services (i.e. GICv3 kernel), the original dtsi files have
been renamed to *-no_psci.dtsi.

Fixes ARM-software/tf-issues#218

Change-Id: Ic8a3bf801db979099ab7029162af041c4e8330c8

* Move TSP platform porting functions to new file:
  include/bl32/tsp/platform_tsp.h.

* Create new TSP_IRQ_SEC_PHY_TIMER definition for use by the generic
  TSP interrupt handling code, instead of depending on the FVP
  specific definition IRQ_SEC_PHY_TIMER.

* Rename TSP platform porting functions from bl32_* to tsp_*, and
  definitions from BL32_* to TSP_*.

* Update generic TSP code to use new platform porting function names
  and definitions.

* Update FVP port accordingly and move all TSP source files to:
  plat/fvp/tsp/.

* Update porting guide with above changes.

Note: THIS CHANGE REQUIRES ALL PLATFORM PORTS OF THE TSP TO
      BE UPDATED

Fixes ARM-software/tf-issues#167

Change-Id: Ic0ff8caf72aebb378d378193d2f017599fc6b78f

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

Move the TSP private declarations out of tsp.h and into a new
header, tsp_private.h. This clarifies the TSP interface to the TSPD.

Change-Id: I39af346eeba3350cadcac56c02d97a5cb978c28b

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

This patch adds support for BL3-2 initialization by asynchronous
method where BL3-1 transfers control to BL3-2 using world switch.
After BL3-2 initialization, it transfers control to BL3-3 via SPD
service handler. The SPD service handler initializes the CPU context
to BL3-3 entrypoint depending on the return function indentifier from
TSP initialization.

Fixes ARM-software/TF-issues#184

Change-Id: I7b135c2ceeb356d3bb5b6a287932e96ac67c7a34

The purpose of platform_is_primary_cpu() is to determine after reset
(BL1 or BL3-1 with reset handler) if the current CPU must follow the
cold boot path (primary CPU), or wait in a safe state (secondary CPU)
until the primary CPU has finished the system initialization.

This patch removes redundant calls to platform_is_primary_cpu() in
subsequent bootloader entrypoints since the reset handler already
guarantees that code is executed exclusively on the primary CPU.

Additionally, this patch removes the weak definition of
platform_is_primary_cpu(), so the implementation of this function
becomes mandatory. Removing the weak symbol avoids other
bootloaders accidentally picking up an invalid definition in case the
porting layer makes the real function available only to BL1.

The define PRIMARY_CPU is no longer mandatory in the platform porting
because platform_is_primary_cpu() hides the implementation details
(for instance, there may be platforms that report the primary CPU in
a system register). The primary CPU definition in FVP has been moved
to fvp_def.h.

The porting guide has been updated accordingly.

Fixes ARM-software/tf-issues#219

Change-Id: If675a1de8e8d25122b7fef147cb238d939f90b5e

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

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

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

This patch uses stacks allocated in normal memory to enable the MMU early in the
warm boot path thus removing the dependency on stacks allocated in coherent
memory. Necessary cache and stack maintenance is performed when a cpu is being
powered down and up. This avoids any coherency issues that can arise from
reading speculatively fetched stale stack memory from another CPUs cache. These
changes affect the warm boot path in both BL3-1 and BL3-2.

The EL3 system registers responsible for preserving the MMU state are not saved
and restored any longer. Static values are used to program these system
registers when a cpu is powered on or resumed from suspend.

Change-Id: I8357e2eb5eb6c5f448492c5094b82b8927603784

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

This patch re-organizes the memory layout on FVP as to give the
BL3-2 image as much memory as possible.

Considering these two facts:
 - not all images need to live in memory at the same time. Once
   in BL3-1, the memory used by BL1 and BL2 can be reclaimed.
 - when BL2 loads the BL3-1 and BL3-2 images, it only considers the
   PROGBITS sections of those 2 images. The memory occupied by the
   NOBITS sections will be touched only at execution of the BL3-x
   images;
Then it is possible to choose the different base addresses such that
the NOBITS sections of BL3-1 and BL3-2 overlay BL1 and BL2.

On FVP we choose to put:
 - BL1 and BL3-1 at the top of the Trusted RAM, with BL3-1 NOBITS
   sections overlaying BL1;
 - BL3-2 at the bottom of the Trusted RAM, with its NOBITS sections
   overlaying BL2;

This is illustrated by the following diagram:

0x0404_0000 ------------    ------------------
            |   BL1    | <= |  BL3-1 NOBITS  |
            ------------ <= ------------------
            |          | <= | BL3-1 PROGBITS |
            ------------    ------------------
            |   BL2    | <= |  BL3-2 NOBITS  |
            ------------ <= ------------------
            |          | <= | BL3-2 PROGBITS |
0x0400_0000 ------------    ------------------

New platform-specific constants have been introduced to easily check
at link time that BL3-1 and BL3-2 PROGBITS sections don't overwrite
BL1 and BL2. These are optional and the platform code is free to define
them or not. If not defined, the linker won't attempt to check
image overlaying.

Fixes ARM-software/tf-issues#117

Change-Id: I5981d1c3d66ee70eaac8bd052630c9ac6dd8b042

Refactor the FVP gic code in plat/fvp/fvp_gic.c to be a generic ARM
GIC driver in drivers/arm/gic/arm_gic.c. Provide the platform
specific inputs in the arm_gic_setup() function so that the driver
has no explicit dependency on platform code.

Provide weak implementations of the platform interrupt controller
API in a new file, plat/common/plat_gic.c. These simply call through
to the ARM GIC driver.

Move the only remaining FVP GIC function, fvp_gic_init() to
plat/fvp/aarch64/fvp_common.c and remove plat/fvp/fvp_gic.c

Fixes ARM-software/tf-issues#182

Change-Id: Iea82fe095fad62dd33ba9efbddd48c57717edd21