GitLab

The patch fixes BL31 linker script error
"Init code ends past the end of the stacks"
for platforms with number of CPUs less than 4,
which is caused by __STACKS_END__ address being
lower than __INIT_CODE_END__.
The modified BL31 linker script detects such cases
and increases the total amount of stack memory,
setting __STACKS_END__ = __INIT_CODE_END__, and
CPUs' stacks are calculated by BL31 'plat_get_my_stack'
function accordingly. For platforms with more than 4 CPUs
and __INIT_CODE_END__ < __STACKS_END__ stack memory does not
increase and allocated CPUs' stacks match the existing
implementation.
The patch removes exclusion of PSCI initialization
functions from the reclaimed .init section in
'arm_reclaim_init.ld.S' script, which increases the
size of reclaimed memory region.

Change-Id: I927773e00dd84e1ffe72f9ee534f4f2fc7b6153c
Signed-off-by: Alexei Fedorov <Alexei.Fedorov@arm.com>

This patch introduces the populate function which leverages
a new driver to extract base address and clk frequency properties
of the uart serial node from HW_CONFIG device tree.

This patch also introduces fdt helper API fdtw_translate_address()
which helps in performing address translation.

Change-Id: I053628065ebddbde0c9cb3aa93d838619f502ee3
Signed-off-by: Madhukar Pappireddy <madhukar.pappireddy@arm.com>

CoT used for BL1 and BL2 are moved to tbbr_cot_bl1.c
and tbbr_cot_bl2.c respectively.
Common CoT used across BL1 and BL2 are moved to
tbbr_cot_common.c.
Signed-off-by: Manish V Badarkhe <Manish.Badarkhe@arm.com>
Change-Id: I2252ac8a6960b3431bcaafdb3ea4fb2d01b79cf5

The stdout-path property in the /chosen node of a DTB points to a device
node, which is used for boot console output.
On most (if not all) ARM based platforms this is the debug UART.
The ST platform code contains a function to parse this property and
chase down eventual aliases to learn the node offset of this UART node.

Introduce a slightly more generalised version of this ST platform function
in the generic fdt_wrappers code. This will be useful for other platforms
as well.

Change-Id: Ie6da47ace7833861b5e35fe8cba49835db3659a5
Signed-off-by: Andre Przywara <andre.przywara@arm.com>

The STM32 platform port parse DT nodes to find base address to
peripherals. It does this by using its own implementation, even though
this functionality is generic and actually widely useful outside of the
STM32 code.

Re-implement fdt_get_reg_props_by_name() on top of the newly introduced
fdt_get_reg_props_by_index() function, and move it to fdt_wrapper.c.
This is removes the assumption that #address-cells and #size-cells are
always one.

Change-Id: I6d584930262c732b6e0356d98aea50b2654f789d
Signed-off-by: Andre Przywara <andre.przywara@arm.com>

At the moment the fconf_populate_gicv3_config() implementation is
somewhat incomplete: First it actually fails to store the retrieved
information (the local addr[] array is going nowhere), but also it makes
quite some assumptions about the device tree passed to it: it needs to
use two address-cells and two size-cells, and also requires all five
register regions to be specified, where actually only the first two
are mandatory according to the binding (and needed by our code).

Fix this by introducing a proper generic function to retrieve "reg"
property information from a DT node:
We retrieve the #address-cells and #size-cells properties from the
parent node, then use those to extract the right values from the "reg"
property. The function takes an index to select one region of a reg
property.

This is loosely based on the STM32 implementation using "reg-names",
which we will subsume in a follow-up patch.

Change-Id: Ia59bfdf80aea4e36876c7b6ed4d153e303f482e8
Signed-off-by: Andre Przywara <andre.przywara@arm.com>

The STM32 platform code uses its own set of FDT helper functions,
although some of them are fairly generic.

Remove the implementation of fdt_read_uint32_default() and implement it
on top of the newly introduced fdt_read_uint32() function, then convert
all users over.

This also fixes two callers, which were slightly abusing the "default"
semantic.

Change-Id: I570533362b4846e58dd797a92347de3e0e5abb75
Signed-off-by: Andre Przywara <andre.przywara@arm.com>

Our fdtw_read_cells() implementation goes to great lengths to
sanity-check every parameter and result, but leaves a big hole open:
The size of the storage the value pointer points at needs to match the
number of cells given. This can't be easily checked at compile time,
since we lose the size information by using a void pointer.
Regardless the current usage of this function is somewhat wrong anyways,
since we use it on single-element, fixed-length properties only, for
which the DT binding specifies the size.
Typically we use those functions dealing with a number of cells in DT
context to deal with *dynamically* sized properties, which depend on
other properties (#size-cells, #clock-cells, ...), to specify the number
of cells needed.

Another problem with the current implementation is the use of
ambiguously sized types (uintptr_t, size_t) together with a certain
expectation about their size. In general there is no relation between
the length of a DT property and the bitness of the code that parses the
DTB: AArch64 code could encounter 32-bit addresses (where the physical
address space is limited to 4GB [1]), while AArch32 code could read
64-bit sized properties (/memory nodes on LPAE systems, [2]).

To make this more clear, fix the potential issues and also align more
with other DT users (Linux and U-Boot), introduce functions to explicitly
read uint32 and uint64 properties. As the other DT consumers, we do this
based on the generic "read array" function.
Convert all users to use either of those two new functions, and make
sure we never use a pointer to anything other than uint32_t or uint64_t
variables directly.

This reveals (and fixes) a bug in plat_spmd_manifest.c, where we write
4 bytes into a uint16_t variable (passed via a void pointer).

Also we change the implementation of the function to better align with
other libfdt users, by using the right types (fdt32_t) and common
variable names (*prop, prop_names).

[1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi#n874
[2] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/arm/boot/dts/ecx-2000.dts



Change-Id: I718de960515117ac7a3331a1b177d2ec224a3890
Signed-off-by: Andre Przywara <andre.przywara@arm.com>

Currently our fdtw_read_array() implementation requires the length of
the property to exactly match the requested size, which makes it less
flexible for parsing generic device trees.
Also the name is slightly misleading, since we treat the cells of the
array as 32 bit unsigned integers, performing the endianess conversion.

To fix those issues and align the code more with other DT users (Linux
kernel or U-Boot), rename the function to "fdt_read_uint32_array", and
relax the length check to only check if the property covers at least the
number of cells we request.
This also changes the variable names to be more in-line with other DT
users, and switches to the proper data types.

This makes this function more useful in later patches.

Change-Id: Id86f4f588ffcb5106d4476763ecdfe35a735fa6c
Signed-off-by: Andre Przywara <andre.przywara@arm.com>

Move the data section to the common header.

I slightly tweaked some scripts as follows:

[1] bl1.ld.S has ALIGN(16). I added DATA_ALIGN macro, which is 1
    by default, but overridden by bl1.ld.S. Currently, ALIGN(16)
    of the .data section is redundant because commit 41286590


    ("Fix boot failures on some builds linked with ld.lld.") padded
    out the previous section to work around the issue of LLD version
    <= 10.0. This will be fixed in the future release of LLVM, so
    I am keeping the proper way to align LMA.

[2] bl1.ld.S and bl2_el3.ld.S define __DATA_RAM_{START,END}__ instead
    of __DATA_{START,END}__. I put them out of the .data section.

[3] SORT_BY_ALIGNMENT() is missing tsp.ld.S, sp_min.ld.S, and
    mediatek/mt6795/bl31.ld.S. This commit adds SORT_BY_ALIGNMENT()
    for all images, so the symbol order in those three will change,
    but I do not think it is a big deal.

Change-Id: I215bb23c319f045cd88e6f4e8ee2518c67f03692
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

If PLAT_RO_XLAT_TABLES is defined, the base xlat table goes to the
.rodata section instead of .bss section.

This causes a warning like:

/tmp/ccswitLr.s: Assembler messages:
/tmp/ccswitLr.s:297: Warning: setting incorrect section attributes for .rodata

It is practically no problem, but I want to keep the build log clean.

Put the base table into the "base_xlat_table" section to suppress the
assembler warnings.

The linker script determines its final destination; rodata section if
PLAT_RO_XLAT_TABLES=1, or bss section otherwise. So, the result is the
same.

Change-Id: Ic85d1d2dddd9b5339289fc2378cbcb21dd7db02e
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

Move the bss section to the common header. This adds BAKERY_LOCK_NORMAL
and PMF_TIMESTAMP, which previously existed only in BL31. This is not
a big deal because unused data should not be compiled in the first
place. I believe this should be controlled by BL*_SOURCES in Makefiles,
not by linker scripts.

I investigated BL1, BL2, BL2U, BL31 for plat=fvp, and BL2-AT-EL3,
BL31, BL31 for plat=uniphier. I did not see any more  unexpected
code addition.

The bss section has bigger alignment. I added BSS_ALIGN for this.

Currently, SORT_BY_ALIGNMENT() is missing in sp_min.ld.S, and with this
change, the BSS symbols in SP_MIN will be sorted by the alignment.
This is not a big deal (or, even better in terms of the image size).

Change-Id: I680ee61f84067a559bac0757f9d03e73119beb33
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

The common section data are repeated in many linker scripts (often
twice in each script to support SEPARATE_CODE_AND_RODATA). When you
add a new read-only data section, you end up with touching lots of
places.

After this commit, you will only need to touch bl_common.ld.h when
you add a new section to RODATA_COMMON.

Replace a series of RO section with RODATA_COMMON, which contains
6 sections, some of which did not exist before.

This is not a big deal because unneeded data should not be compiled
in the first place. I believe this should be controlled by BL*_SOURCES
in Makefiles, not by linker scripts.

When I was working on this commit, the BL1 image size increased
due to the fconf_populator. Commit c452ba15

 ("fconf: exclude
fconf_dyn_cfg_getter.c from BL1_SOURCES") fixed this issue.

I investigated BL1, BL2, BL2U, BL31 for plat=fvp, and BL2-AT-EL3,
BL31, BL31 for plat=uniphier. I did not see any more  unexpected
code addition.

Change-Id: I5d14d60dbe3c821765bce3ae538968ef266f1460
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

These are mostly used to collect data from special structure,
and repeated in many linker scripts.

To differentiate the alignment size between aarch32/aarch64, I added
a new macro STRUCT_ALIGN.

While I moved the PMF_SVC_DESCS, I dropped #if ENABLE_PMF conditional.
As you can see in include/lib/pmf/pmf_helpers.h, PMF_REGISTER_SERVICE*
are no-op when ENABLE_PMF=0. So, pmf_svc_descs and pmf_timestamp_array
data are not populated.

Change-Id: I3f4ab7fa18f76339f1789103407ba76bda7e56d0
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

TF-A has so many linker scripts, at least one linker script for each BL
image, and some platforms have their own ones. They duplicate quite
similar code (and comments).

When we add some changes to linker scripts, we end up with touching
so many files. This is not nice in the maintainability perspective.

When you look at Linux kernel, the common code is macrofied in
include/asm-generic/vmlinux.lds.h, which is included from each arch
linker script, arch/*/kernel/vmlinux.lds.S

TF-A can follow this approach. Let's factor out the common code into
include/common/bl_common.ld.h

As a start point, this commit factors out the xlat_table section.

Change-Id: Ifa369e9b48e8e12702535d721cc2a16d12397895
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

This patch provides a fix for incorrect crash dump data for
lower EL when TF-A is built with HANDLE_EA_EL3_FIRST=1 option
which enables routing of External Aborts and SErrors to EL3.

Change-Id: I9d5e6775e6aad21db5b78362da6c3a3d897df977
Signed-off-by: Alexei Fedorov <Alexei.Fedorov@arm.com>

This patch adds 'fdtw_read_bytes' and 'fdtw_write_inplace_bytes'
functions for read/write array of bytes from/to a given property.
It also adds 'fdt_setprop_inplace_namelen_partial' to jmptbl.i
files for builds with USE_ROMLIB=1 option.

Change-Id: Ied7b5c8b38a0e21d508aa7bcf5893e656028b14d
Signed-off-by: Alexei Fedorov <Alexei.Fedorov@arm.com>

Currently, the end address macros are defined per BL, like BL2_END,
BL31_END, BL32_END. They are not handy in the common code shared
between multiple BL stages.

This commit introduces BL_END, which is equivalent to BL{2,31,32}_END,
and will be useful for the BL-common code.

Change-Id: I3c39bf6096d99ce920a5b9fa21c0f65456fbfe8a
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

If a firmware component like TF-A reserves special memory regions for
its own or secure payload services, it should announce the location and
size of those regions to the non-secure world. This will avoid
disappointment when some rich OS tries to acccess this memory, which
will likely end in a crash.

The traditional way of advertising reserved memory using device tree is
using the special memreserve feature of the device tree blob (DTB).
However by definition those regions mentioned there do not prevent the
rich OS to map this memory, which may lead to speculative accesses to
this memory and hence spurious bus errors.

A safer way of carving out memory is to use the /reserved-memory node as
part of the normal DT structure. Besides being easier to setup, this
also defines an explicit "no-map" property to signify the secure-only
nature of certain memory regions, which avoids the rich OS to
accidentally step on it.

Add a helper function to allow platform ports to easily add a region.

Change-Id: I2b92676cf48fd3bdacda05b5c6b1c7952ebed68c
Signed-off-by: Andre Przywara <andre.przywara@arm.com>

The QEMU platform port scans its device tree to advertise PSCI as the
CPU enable method. It does this by scanning *every* node in the DT and
check whether its compatible string starts with "arm,cortex-a". Then it
sets the enable-method to PSCI, if it doesn't already have one.

Other platforms might want to use this functionality as well, so let's
move it out of the QEMU platform directory and make it more robust by
fixing some shortcomings:
- A compatible string starting with a certain prefix is not a good way
to find the CPU nodes. For instance a "arm,cortex-a72-pmu" node will
match as well and is in turn favoured with an enable-method.
- If the DT already has an enable-method, we won't change this to PSCI.

Those two issues will for instance fail on the Raspberry Pi 4 DT.
To fix those problems, we adjust the scanning method:
The DT spec says that all CPU nodes are subnodes of the mandatory
/cpus node, which is a subnode of the root node. Also each CPU node has
to have a device_type = "cpu" property. So we find the /cpus node, then
scan for a subnode with the proper device_type, forcing the
enable-method to "psci".
We have to restart this search after a property has been patched, as the
node offsets might have changed meanwhile.

This allows this routine to be reused for the Raspberry Pi 4 later.

Change-Id: I00cae16cc923d9f8bb96a9b2a2933b9a79b06139
Signed-off-by: Andre Przywara <andre.przywara@arm.com>

NOTE: AARCH32/AARCH64 macros are now deprecated in favor of __aarch64__.

All common C compilers pre-define the same macros to signal which
architecture the code is being compiled for: __arm__ for AArch32 (or
earlier versions) and __aarch64__ for AArch64. There's no need for TF-A
to define its own custom macros for this. In order to unify code with
the export headers (which use __aarch64__ to avoid another dependency),
let's deprecate the AARCH32 and AARCH64 macros and switch the code base
over to the pre-defined standard macro. (Since it is somewhat
unintuitive that __arm__ only means AArch32, let's standardize on only
using __aarch64__.)

Change-Id: Ic77de4b052297d77f38fc95f95f65a8ee70cf200
Signed-off-by: Julius Werner <jwerner@chromium.org>

NOTE: __ASSEMBLY__ macro is now deprecated in favor of __ASSEMBLER__.

All common C compilers predefine a macro called __ASSEMBLER__ when
preprocessing a .S file. There is no reason for TF-A to define it's own
__ASSEMBLY__ macro for this purpose instead. To unify code with the
export headers (which use __ASSEMBLER__ to avoid one extra dependency),
let's deprecate __ASSEMBLY__ and switch the code base over to the
predefined standard.

Change-Id: Id7d0ec8cf330195da80499c68562b65cb5ab7417
Signed-off-by: Julius Werner <jwerner@chromium.org>

BL31 used to take a single bl31_params_t parameter structure with entry
point information in arg0. In commit 72600226

 (Add new version of image
loading.) this API was changed to a more flexible linked list approach,
and the old parameter structure was copied into all platforms that still
used the old format. This duplicated code unnecessarily among all these
platforms.

This patch adds a helper function that platforms can optionally link to
outsource the task of interpreting arg0. Many platforms are just
interested in the BL32 and BL33 entry point information anyway. Since
some platforms still need to support the old version 1 parameters, the
helper will support both formats when ERROR_DEPRECATED == 0. This allows
those platforms to drop a bunch of boilerplate code and asynchronously
update their BL2 implementation to the newer format.

Change-Id: I9e6475adb1a7d4bccea666118bd1c54962e9fc38
Signed-off-by: Julius Werner <jwerner@chromium.org>

This patch adds a new include/export/ directory meant for inclusion in
third-party code. This is useful for cases where third-party code needs
to interact with TF-A interfaces and data structures (such as a custom
BL2-implementation like coreboot handing off to BL31). Directly
including headers from the TF-A repository avoids having to duplicate
all these definitions (and risk them going stale), but with the current
header structure this is not possible because handoff API definitions
are too deeply intertwined with other TF code/headers and chain-include
other headers that will not be available in the other environment.

The new approach aims to solve this by separating only the parts that
are really needed into these special headers that are self-contained and
will not chain-include other (non-export) headers. TF-A code should
never include them directly but should instead always include the
respective wrapper header, which will include the required prerequisites
(like <stdint.h>) before including the export header. Third-party code
can include the export headers via its own wrappers that make sure the
necessary definitions are available in whatever way that environment can
provide them.

Change-Id: Ifd769320ba51371439a8e5dd5b79c2516c3b43ab
Signed-off-by: Julius Werner <jwerner@chromium.org>

It's not a good idea to use u_register_t for the members of
aapcs64_params_t and aapcs32_params_t, since the width of that type
always depends on the current execution environment. This would cause
problems if e.g. we used this structure to set up the entry point of an
AArch32 program from within an AArch64 program. (It doesn't seem like
any code is doing that today, but it's probably still a good idea to
write this defensively. Also, it helps with my next patch.)

Change-Id: I12c04a85611f2b6702589f3362bea3e6a7c9f776
Signed-off-by: Julius Werner <jwerner@chromium.org>

This patch adds the functionality needed for platforms to provide
Branch Target Identification (BTI) extension, introduced to AArch64
in Armv8.5-A by adding BTI instruction used to mark valid targets
for indirect branches. The patch sets new GP bit [50] to the stage 1
Translation Table Block and Page entries to denote guarded EL3 code
pages which will cause processor to trap instructions in protected
pages trying to perform an indirect branch to any instruction other
than BTI.
BTI feature is selected by BRANCH_PROTECTION option which supersedes
the previous ENABLE_PAUTH used for Armv8.3-A Pointer Authentication
and is disabled by default. Enabling BTI requires compiler support
and was tested with GCC versions 9.0.0, 9.0.1 and 10.0.0.
The assembly macros and helpers are modified to accommodate the BTI
instruction.
This is an experimental feature.
Note. The previous ENABLE_PAUTH build option to enable PAuth in EL3
is now made as an internal flag and BRANCH_PROTECTION flag should be
used instead to enable Pointer Authentication.
Note. USE_LIBROM=1 option is currently not supported.

Change-Id: Ifaf4438609b16647dc79468b70cd1f47a623362e
Signed-off-by: Alexei Fedorov <Alexei.Fedorov@arm.com>

This patch provides support for using the scatterfile format as
the linker script with the 'armlink' linker for Tegra platforms.

In order to enable the scatterfile usage the following changes
have been made:

* provide mapping for ld.S symbols in bl_common.h
* include bl_common.h from all the affected files
* update the makefile rules to use the scatterfile and armlink
  to compile BL31
* update pubsub.h to add sections to the scatterfile

NOTE: THIS CHANGE HAS BEEN VERIFIED WITH TEGRA PLATFORMS ONLY.

Change-Id: I7bb78b991c97d74a842e5635c74cb0b18e0fce67
Signed-off-by: Varun Wadekar <vwadekar@nvidia.com>

The previous commit added the infrastructure to load and save
ARMv8.3-PAuth registers during Non-secure <-> Secure world switches, but
didn't actually enable pointer authentication in the firmware.

This patch adds the functionality needed for platforms to provide
authentication keys for the firmware, and a new option (ENABLE_PAUTH) to
enable pointer authentication in the firmware itself. This option is
disabled by default, and it requires CTX_INCLUDE_PAUTH_REGS to be
enabled.

Change-Id: I35127ec271e1198d43209044de39fa712ef202a5
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

Many parts of the code were duplicating symbols that are defined in
include/common/bl_common.h. It is better to only use the definitions in
this header.

As all the symbols refer to virtual addresses, they have to be
uintptr_t, not unsigned long. This has also been fixed in bl_common.h.

Change-Id: I204081af78326ced03fb05f69846f229d324c711
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

Commit ed51b51f

 ("Remove build option LOAD_IMAGE_V2") intended
to remove all code related to LOAD_IMAGE_V2=0 but missed a few things.

Change-Id: I16aaf52779dd4af1e134e682731328c5f1e5d622
Signed-off-by: Sandrine Bailleux <sandrine.bailleux@arm.com>

This reverts commit 2f370465

 ("Add support for the SMC Calling
Convention 2.0").

SMCCC v2.0 is no longer required for SPM, and won't be needed in the
future. Removing it makes the SMC handling code less complicated.

The SPM implementation based on SPCI and SPRT was using it, but it has
been adapted to SMCCC v1.0.

Change-Id: I36795b91857b2b9c00437cfbfed04b3c1627f578
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

On ARM platforms, the BL2 memory can be overlaid by BL31/BL32. The memory
descriptors describing the list of executable images are created in BL2
R/W memory, which could be possibly corrupted later on by BL31/BL32 due
to overlay. This patch creates a reserved location in SRAM for these
descriptors and are copied over by BL2 before handing over to next BL
image.

Also this patch increases the PLAT_ARM_MAX_BL2_SIZE for juno when TBBR
is enabled.

Fixes ARM-Software/tf-issues#626

Change-Id: I755735706fa702024b4032f51ed4895b3687377f
Signed-off-by: Sathees Balya <sathees.balya@arm.com>

The definitions in bl1/bl1_private.h and bl2/bl2_private.h are useful for
platforms that may need to access them.

Change-Id: Ifd1880f855ddafcb3bfcaf1ed4a4e0f121eda174
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

Enforce full include path for includes. Deprecate old paths.

The following folders inside include/lib have been left unchanged:

- include/lib/cpus/${ARCH}
- include/lib/el3_runtime/${ARCH}

The reason for this change is that having a global namespace for
includes isn't a good idea. It defeats one of the advantages of having
folders and it introduces problems that are sometimes subtle (because
you may not know the header you are actually including if there are two
of them).

For example, this patch had to be created because two headers were
called the same way: e0ea0928 ("Fix gpio includes of mt8173 platform
to avoid collision."). More recently, this patch has had similar
problems: 46f9b2c3 ("drivers: add tzc380 support").

This problem was introduced in commit 4ecca339

 ("Move include and
source files to logical locations"). At that time, there weren't too
many headers so it wasn't a real issue. However, time has shown that
this creates problems.

Platforms that want to preserve the way they include headers may add the
removed paths to PLAT_INCLUDES, but this is discouraged.

Change-Id: I39dc53ed98f9e297a5966e723d1936d6ccf2fc8f
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

The architecture dependant header files in include/lib/${ARCH} and
include/common/${ARCH} have been moved to /include/arch/${ARCH}.

Change-Id: I96f30fdb80b191a51448ddf11b1d4a0624c03394
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

This patch enables the Data Independent Timing
functionality (DIT) in EL3 if supported
by the platform.

Change-Id: Ia527d6aa2ee88a9a9fe1c941220404b9ff5567e5
Signed-off-by: Sathees Balya <sathees.balya@arm.com>

The Armv8.5 extensions introduces PSTATE.SSBS (Speculation Store Bypass
Safe) bit to mitigate against Variant 4 vulnerabilities. Although an
Armv8.5 feature, this can be implemented by CPUs implementing earlier
version of the architecture.

With this patch, when both PSTATE.SSBS is implemented and
DYNAMIC_WORKAROUND_CVE_2018_3639 is active, querying for
SMCCC_ARCH_WORKAROUND_2 via. SMCCC_ARCH_FEATURES call would return 1 to
indicate that mitigation on the PE is either permanently enabled or not
required.

When SSBS is implemented, SCTLR_EL3.DSSBS is initialized to 0 at reset
of every BL stage. This means that EL3 always executes with mitigation
applied.

For Cortex A76, if the PE implements SSBS, the existing mitigation (by
using a different vector table, and tweaking CPU ACTLR2) is not used.

Change-Id: Ib0386c5714184144d4747951751c2fc6ba4242b6
Signed-off-by: Jeenu Viswambharan <jeenu.viswambharan@arm.com>

All identifiers, regardless of use, that start with two underscores are
reserved. This means they can't be used in header guards.

The style that this project is now to use the full name of the file in
capital letters followed by 'H'. For example, for a file called
"uart_example.h", the header guard is UART_EXAMPLE_H.

The exceptions are files that are imported from other projects:

- CryptoCell driver
- dt-bindings folders
- zlib headers

Change-Id: I50561bf6c88b491ec440d0c8385c74650f3c106e
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

fdtw_read_cells() can only read one or two cells, sometimes it may be
needed to read more cells from one property.

Change-Id: Ie70dc76d1540cd6a04787cde7cccb4d1bafc7282
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

Introduced fdtw_read_string() to read string properties.

Change-Id: I854eef0390632cf2eaddd2dce60cdb98c117de43
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>