When the MMU is enabled and the translation tables are mapped, data
read/writes to the translation tables are made using the attributes
specified in the translation tables themselves. However, the MMU
performs table walks with the attributes specified in TCR_ELx. They are
completely independent, so special care has to be taken to make sure
that they are the same.
This has to be done manually because it is not practical to have a test
in the code. Such a test would need to know the virtual memory region
that contains the translation tables and check that for all of the
tables the attributes match the ones in TCR_ELx. As the tables may not
even be mapped at all, this isn't a test that can be made generic.
The flags used by enable_mmu_xxx() have been moved to the same header
where the functions are.
Also, some comments in the linker scripts related to the translation
tables have been fixed.
Change-Id: I1754768bffdae75f53561b1c4a5baf043b45a304
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>
This patch introduces a new BL handover interface. It essentially allows
passing 4 arguments between the different BL stages. Effort has been made
so as to be compatible with the previous handover interface. The previous
blx_early_platform_setup() platform API is now deprecated and the new
blx_early_platform_setup2() variant is introduced. The weak compatiblity
implementation for the new API is done in the `plat_bl_common.c` file.
Some of the new arguments in the new API will be reserved for generic
code use when dynamic configuration support is implemented. Otherwise
the other registers are available for platform use.
Change-Id: Ifddfe2ea8e32497fe1beb565cac155ad9d50d404
Signed-off-by: Soby Mathew <soby.mathew@arm.com>
According to the SMC Calling Convention (ARM DEN0028B):
The Unknown SMC Function Identifier is a sign-extended value of
(-1) that is returned in R0, W0 or X0 register.
The value wasn't sign-extended because it was defined as a 32-bit
unsigned value (0xFFFFFFFF).
SMC_PREEMPT has been redefined as -2 for the same reason.
NOTE: This might be a compatibility break for some AArch64 platforms
that don't follow the previous version of the SMCCC (ARM DEN0028A)
correctly. That document specifies that only the bottom 32 bits of the
returned value must be checked. If a platform relies on the top 32 bits
of the result being 0 (so that SMC_UNK is 0x00000000FFFFFFFF), it will
have to fix its code to comply with the SMCCC.
Change-Id: I7f7b109f6b30c114fe570aa0ead3c335383cb54d
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>
In preparation for SMCCC v1.1 support, save x4 to x29 unconditionally.
Previously we expected callers coming from AArch64 mode to preserve
x8-x17. This is no longer the case with SMCCC v1.1 as AArch64 callers
only need to save x0-x3.
Change-Id: Ie62d620776533969ff4a02c635422f1b9208be9c
Signed-off-by: Dimitris Papastamos <dimitris.papastamos@arm.com>
Invalidate the Branch Target Buffer (BTB) on entry to EL3 by disabling
and enabling the MMU. To achieve this without performing any branch
instruction, a per-cpu vbar is installed which executes the workaround
and then branches off to the corresponding vector entry in the main
vector table. A side effect of this change is that the main vbar is
configured before any reset handling. This is to allow the per-cpu
reset function to override the vbar setting.
This workaround is enabled by default on the affected CPUs.
Change-Id: I97788d38463a5840a410e3cea85ed297a1678265
Signed-off-by: Dimitris Papastamos <dimitris.papastamos@arm.com>
In assembly code it can be useful to have a constant for the width of a
register in the current architecture, so this patch adds one to
<utils_def.h> and replaces the existing custom one in crash_reporting.S
with that. It also fixes up the BIT() macro in the same file so that it
can be safely used in assembly code.
Change-Id: I10513a311f3379e767396e6ddfbae8d2d8201464
Signed-off-by: Julius Werner <jwerner@chromium.org>
The FPEXC32_EL2 register controls SIMD and FP functionality when the
lower ELs are executing in AArch32 mode. It is architecturally mapped
to AArch32 system register FPEXC.
This patch removes FPEXC32_EL2 register from the System Register context
and adds it to the floating-point context. EL3 only saves / restores the
floating-point context if the build option CTX_INCLUDE_FPREGS is set to 1.
The rationale for this change is that if the Secure world is using FP
functionality and EL3 is not managing the FP context, then the Secure
world will save / restore the appropriate FP registers.
NOTE - this is a break in behaviour in the unlikely case that
CTX_INCLUDE_FPREGS is set to 0 and the platform contains an AArch32
Secure Payload that modifies FPEXC, but does not save and restore
this register
Change-Id: Iab80abcbfe302752d52b323b4abcc334b585c184
Signed-off-by: David Cunado <david.cunado@arm.com>
Some error paths that lead to a crash dump will overwrite the value in
the x30 register by calling functions with the no_ret macro, which
resolves to a BL instruction. This is not very useful and not what the
reader would expect, since a crash dump should usually show all
registers in the state they were in when the exception happened. This
patch replaces the offending function calls with a B instruction to
preserve the value in x30.
Change-Id: I2a3636f2943f79bab0cd911f89d070012e697c2a
Signed-off-by: Julius Werner <jwerner@chromium.org>
This patch updates the el3_arch_init_common macro so that it fully
initialises essential control registers rather then relying on hardware
to set the reset values.
The context management functions are also updated to fully initialise
the appropriate control registers when initialising the non-secure and
secure context structures and when preparing to leave EL3 for a lower
EL.
This gives better alignement with the ARM ARM which states that software
must initialise RES0 and RES1 fields with 0 / 1.
This patch also corrects the following typos:
"NASCR definitions" -> "NSACR definitions"
Change-Id: Ia8940b8351dc27bc09e2138b011e249655041cfc
Signed-off-by: David Cunado <david.cunado@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>
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.
FixesARM-Software/tf-issues#456
Change-Id: I44c8787d116d7217837ced3bcf0b1d3441c8d80e
Signed-off-by: Soby Mathew <soby.mathew@arm.com>
This API makes sure that all the characters sent to the crash console
are output before returning from it.
Porting guide updated.
Change-Id: I1785f970a40f6aacfbe592b6a911b1f249bb2735
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@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>
At present, warm-booted CPUs keep their caches disabled when enabling
MMU, and remains so until they enter coherency later.
On systems with hardware-assisted coherency, for which
HW_ASSISTED_COHERENCY build flag would be enabled, warm-booted CPUs can
have both caches and MMU enabled at once.
Change-Id: Icb0adb026e01aecf34beadf49c88faa9dd368327
Signed-off-by: Jeenu Viswambharan <jeenu.viswambharan@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>
* Move comments on unhandled exceptions at the right place.
* Reformat the existing comments to highlight the start of
each block of 4 entries in the exception table to ease
navigation (lines of dash reserved for head comments).
* Reflow comments to 80 columns.
Change-Id: I5ab88a93d0628af8e151852cb5b597eb34437677
Signed-off-by: Douglas Raillard <douglas.raillard@arm.com>
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>
This patch introduces the PSCI Library interface. The major changes
introduced are as follows:
* Earlier BL31 was responsible for Architectural initialization during cold
boot via bl31_arch_setup() whereas PSCI was responsible for the same during
warm boot. This functionality is now consolidated by the PSCI library
and it does Architectural initialization via psci_arch_setup() during both
cold and warm boots.
* Earlier the warm boot entry point was always `psci_entrypoint()`. This was
not flexible enough as a library interface. Now PSCI expects the runtime
firmware to provide the entry point via `psci_setup()`. A new function
`bl31_warm_entrypoint` is introduced in BL31 and the previous
`psci_entrypoint()` is deprecated.
* The `smc_helpers.h` is reorganized to separate the SMC Calling Convention
defines from the Trusted Firmware SMC helpers. The former is now in a new
header file `smcc.h` and the SMC helpers are moved to Architecture specific
header.
* The CPU context is used by PSCI for context initialization and
restoration after power down (PSCI Context). It is also used by BL31 for SMC
handling and context management during Normal-Secure world switch (SMC
Context). The `psci_smc_handler()` interface is redefined to not use SMC
helper macros thus enabling to decouple the PSCI context from EL3 runtime
firmware SMC context. This enables PSCI to be integrated with other runtime
firmware using a different SMC context.
NOTE: With this patch the architectural setup done in `bl31_arch_setup()`
is done as part of `psci_setup()` and hence `bl31_platform_setup()` will be
invoked prior to architectural setup. It is highly unlikely that the platform
setup will depend on architectural setup and cause any failure. Please be
be aware of this change in sequence.
Change-Id: I7f497a08d33be234bbb822c28146250cb20dab73
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
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
Added plat_get_syscnt_freq2, which is a 32 bit variant of the 64 bit
plat_get_syscnt_freq. The old one has been flagged as deprecated.
Common code has been updated to use this new version. Porting guide
has been updated.
Change-Id: I9e913544926c418970972bfe7d81ee88b4da837e
It is up to the platform to implement the new plat_crash_print_regs macro to
report all relevant platform registers helpful for troubleshooting.
plat_crash_print_regs merges or calls previously defined plat_print_gic_regs
and plat_print_interconnect_regs macros for each existing platforms.
NOTE: THIS COMMIT REQUIRES ALL PLATFORMS THAT ENABLE THE `CRASH_REPORTING`
BUILD FLAG TO MIGRATE TO USE THE NEW `plat_crash_print_regs()` MACRO. BY
DEFAULT, `CRASH_REPORTING` IS ENABLED IN DEBUG BUILDS FOR ALL PLATFORMS.
Fixes: arm-software/tf-issues#373
Signed-off-by: Gerald Lejeune <gerald.lejeune@st.com>
Asynchronous abort exceptions generated by the platform during cold boot are
not taken in EL3 unless SCR_EL3.EA is set.
Therefore EA bit is set along with RES1 bits in early BL1 and BL31 architecture
initialisation. Further write accesses to SCR_EL3 preserve these bits during
cold boot.
A build flag controls SCR_EL3.EA value to keep asynchronous abort exceptions
being trapped by EL3 after cold boot or not.
For further reference SError Interrupts are also known as asynchronous external
aborts.
On Cortex-A53 revisions below r0p2, asynchronous abort exceptions are taken in
EL3 whatever the SCR_EL3.EA value is.
Fixesarm-software/tf-issues#368
Signed-off-by: Gerald Lejeune <gerald.lejeune@st.com>
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
The upcoming Firmware Update feature needs transitioning across
Secure/Normal worlds to complete the FWU process and hence requires
context management code to perform this task.
Currently context management code is part of BL31 stage only.
This patch moves the code from (include)/bl31 to (include)/common.
Some function declarations/definitions and macros have also moved
to different files to help code sharing.
Change-Id: I3858b08aecdb76d390765ab2b099f457873f7b0c
The `fpregs_context_restore()` function used to restore the floating point
regsiter context had a typo error wherein it was doing `str` instead of
`ldr` for a register. This issue remained undetected becuase none of the ARM
Standard development platforms save and restore the floating point register
context when a context switch is done. This patch corrects the issue.
Change-Id: Id178e0ba254a5e0a4a844f54b39d71dc34e0f6ea
This patch introduces a new build option named COLD_BOOT_SINGLE_CPU,
which allows platforms that only release a single CPU out of reset to
slightly optimise their cold boot code, both in terms of code size
and performance.
COLD_BOOT_SINGLE_CPU defaults to 0, which assumes that the platform
may release several CPUs out of reset. In this case, the cold reset
code needs to coordinate all CPUs via the usual primary/secondary
CPU distinction.
If a platform guarantees that only a single CPU will ever be released
out of reset, there is no need to arbitrate execution ; the notion of
primary and secondary CPUs itself no longer exists. Such platforms
may set COLD_BOOT_SINGLE_CPU to 1 in order to compile out the
primary/secondary CPU identification in the cold reset code.
All ARM standard platforms can release several CPUs out of reset
so they use COLD_BOOT_SINGLE_CPU=0. However, on CSS platforms like
Juno, bringing up more than one CPU at reset should only be attempted
when booting an EL3 payload, as it is not fully supported in the
normal boot flow.
For platforms using COLD_BOOT_SINGLE_CPU=1, the following 2 platform
APIs become optional:
- plat_secondary_cold_boot_setup();
- plat_is_my_cpu_primary().
The Porting Guide has been updated to reflect that.
User Guide updated as well.
Change-Id: Ic5b474e61b7aec1377d1e0b6925d17dfc376c46b
The IMF_READ_INTERRUPT_ID build option enables a feature where the interrupt
ID of the highest priority pending interrupt is passed as a parameter to the
interrupt handler registered for that type of interrupt. This additional read
of highest pending interrupt id from GIC is problematic as it is possible that
the original interrupt may get deasserted and another interrupt of different
type maybe become the highest pending interrupt. Hence it is safer to prevent
such behaviour by removing the IMF_READ_INTERRUPT_ID build option.
The `id` parameter of the interrupt handler `interrupt_type_handler_t` is
now made a reserved parameter with this patch. It will always contain
INTR_ID_UNAVAILABLE.
FixesARM-software/tf-issues#307
Change-Id: I2173aae1dd37edad7ba6bdfb1a99868635fa34de
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.
FixesARM-software/tf-issues#205
Change-Id: I64f1b398de0432813a0e0881d70f8337681f6e9a
This patch migrates the rest of Trusted Firmware excluding Secure Payload and
the dispatchers to the new platform and context management API. The per-cpu
data framework APIs which took MPIDRs as their arguments are deleted and only
the ones which take core index as parameter are retained.
Change-Id: I839d05ad995df34d2163a1cfed6baa768a5a595d
This patch introduces a new platform build option, called
PROGRAMMABLE_RESET_ADDRESS, which tells whether the platform has
a programmable or fixed reset vector address.
If the reset vector address is fixed then the code relies on the
platform_get_entrypoint() mailbox mechanism to figure out where
it is supposed to jump. On the other hand, if it is programmable
then it is assumed that the platform code will program directly
the right address into the RVBAR register (instead of using the
mailbox redirection) so the mailbox is ignored in this case.
Change-Id: If59c3b11fb1f692976e1d8b96c7e2da0ebfba308
The attempt to run the CPU reset code as soon as possible after reset
results in highly complex conditional code relating to the
RESET_TO_BL31 option.
This patch relaxes this requirement a little. In the BL1, BL3-1 and
PSCI entrypoints code, the sequence of operations is now as follows:
1) Detect whether it is a cold or warm boot;
2) For cold boot, detect whether it is the primary or a secondary
CPU. This is needed to handle multiple CPUs entering cold reset
simultaneously;
3) Run the CPU init code.
This patch also abstracts the EL3 registers initialisation done by
the BL1, BL3-1 and PSCI entrypoints into common code.
This improves code re-use and consolidates the code flows for
different types of systems.
NOTE: THE FUNCTION plat_secondary_cold_boot() IS NOW EXPECTED TO
NEVER RETURN. THIS PATCH FORCES PLATFORM PORTS THAT RELIED ON THE
FORMER RETRY LOOP AT THE CALL SITE TO MODIFY THEIR IMPLEMENTATION.
OTHERWISE, SECONDARY CPUS WILL PANIC.
Change-Id: If5ecd74d75bee700b1bd718d23d7556b8f863546
There are couple of issues with how the interrupt routing framework in BL3_1
handles spurious interrupts.
1. In the macro 'handle_interrupt_exception', if a spurious interrupt is
detected by plat_ic_get_pending_interrupt_type(), then execution jumps to
'interrupt_exit_\label'. This macro uses the el3_exit() function to return to
the original exception level. el3_exit() attempts to restore the SPSR_EL3 and
ELR_EL3 registers with values from the current CPU context. Since these
registers were not saved in this code path, it programs stale values into
these registers. This leads to unpredictable behaviour after the execution of
the ERET instruction.
2. When an interrupt is routed to EL3, it could be de-asserted before the
GICC_HPPIR is read in plat_ic_get_pending_interrupt_type(). There could be
another interrupt pending at the same time e.g. a non-secure interrupt. Its
type will be returned instead of the original interrupt. This would result in
a call to get_interrupt_type_handler(). The firmware will panic if the
handler for this type of interrupt has not been registered.
This patch fixes the first problem by saving SPSR_EL3 and ELR_EL3 early in the
'handle_interrupt_exception' macro, instead of only doing so once the validity
of the interrupt has been determined.
The second problem is fixed by returning execution back to the lower exception
level through the 'interrupt_exit_\label' label instead of treating it as an
error condition. The 'interrupt_error_\label' label has been removed since it is
no longer used.
FixesARM-software/tf-issues#305
Change-Id: I81c729a206d461084db501bb81b44dff435021e8
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.
FixesARM-Software/tf-issues#295
Change-Id: If8cb331b03d7f38fe7e3694d4de26f1075b278fc
Signed-off-by: Kévin Petit <kevin.petit@arm.com>
The cpu-ops pointer was initialized before enabling the data cache in the cold
and warm boot paths. This required a DCIVAC cache maintenance operation to
invalidate any stale cache lines resident in other cpus.
This patch moves this initialization to the bl31_arch_setup() function
which is always called after the data cache and MMU has been enabled.
This change removes the need:
1. for the DCIVAC cache maintenance operation.
2. to initialise the CPU ops upon resumption from a PSCI CPU_SUSPEND
call since memory contents are always preserved in this case.
Change-Id: Ibb2fa2f7460d1a1f1e721242025e382734c204c6
This patch adds support to call the reset_handler() function in BL3-1 in the
cold and warm boot paths when another Boot ROM reset_handler() has already run.
This means the BL1 and BL3-1 versions of the CPU and platform specific reset
handlers may execute different code to each other. This enables a developer to
perform additional actions or undo actions already performed during the first
call of the reset handlers e.g. apply additional errata workarounds.
Typically, the reset handler will be first called from the BL1 Boot ROM. Any
additional functionality can be added to the reset handler when it is called
from BL3-1 resident in RW memory. The constant FIRST_RESET_HANDLER_CALL is used
to identify whether this is the first version of the reset handler code to be
executed or an overridden version of the code.
The Cortex-A57 errata workarounds are applied only if they have not already been
applied.
FixesARM-software/tf-issue#275
Change-Id: Id295f106e4fda23d6736debdade2ac7f2a9a9053
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.
FixesARM-Software/tf-issues#106
Change-Id: I260e8768c6a5c2efc402f5804a80657d8ce38773
This patch gathers miscellaneous minor fixes to the documentation, and comments
in the source code.
Change-Id: I631e3dda5abafa2d90f464edaee069a1e58b751b
Co-Authored-By: Soby Mathew <soby.mathew@arm.com>
Co-Authored-By: Dan Handley <dan.handley@arm.com>
This patch adds handlers for dumping Cortex-A57 and Cortex-A53 specific register
state to the CPU specific operations framework. The contents of CPUECTLR_EL1 are
dumped currently.
Change-Id: I63d3dbfc4ac52fef5e25a8cf6b937c6f0975c8ab
This patch adds CPU core and cluster power down sequences to the CPU specific
operations framework introduced in a earlier patch. Cortex-A53, Cortex-A57 and
generic AEM sequences have been added. The latter is suitable for the
Foundation and Base AEM FVPs. A pointer to each CPU's operations structure is
saved in the per-cpu data so that it can be easily accessed during power down
seqeunces.
An optional platform API has been introduced to allow a platform to disable the
Accelerator Coherency Port (ACP) during a cluster power down sequence. The weak
definition of this function (plat_disable_acp()) does not take any action. It
should be overriden with a strong definition if the ACP is present on a
platform.
Change-Id: I8d09bd40d2f528a28d2d3f19b77101178778685d
This patch introduces a framework which will allow CPUs to perform
implementation defined actions after a CPU reset, during a CPU or cluster power
down, and when a crash occurs. CPU specific reset handlers have been implemented
in this patch. Other handlers will be implemented in subsequent patches.
Also moved cpu_helpers.S to the new directory lib/cpus/aarch64/.
Change-Id: I1ca1bade4d101d11a898fb30fea2669f9b37b956
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.
FixesARM-software/tf-issues#153
Change-Id: I157b996c75996d12fd86d27e98bc73dd8bce6cd5
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.
FixesARM-software/tf-issues#219
Change-Id: If675a1de8e8d25122b7fef147cb238d939f90b5e
This patch further optimizes the EL3 register state stored in
cpu_context. The 2 registers which are removed from cpu_context are:
* cntfrq_el0 is the system timer register which is writable
only in EL3 and it can be programmed during cold/warm boot. Hence
it need not be saved to cpu_context.
* cptr_el3 controls access to Trace, Floating-point, and Advanced
SIMD functionality and it is programmed every time during cold
and warm boot. The current BL3-1 implementation does not need to
modify the access controls during normal execution and hence
they are expected to remain static.
FixesARM-software/tf-issues#197
Change-Id: I599ceee3b73a7dcfd37069fd41b60e3d397a7b18
This patch adds the CPUECTLR_EL1 register and the CCI Snoop Control
register to the list of registers being reported when an unhandled
exception occurs.
Change-Id: I2d997f2d6ef3d7fa1fad5efe3364dc9058f9f22c
This patch reworks the crash reporting mechanism to further
optimise the stack and code size. The reporting makes use
of assembly console functions to avoid calling C Runtime
to report the CPU state. The crash buffer requirement is
reduced to 64 bytes with this implementation. The crash
buffer is now part of per-cpu data which makes retrieving
the crash buffer trivial.
Also now panic() will use crash reporting if
invoked from BL3-1.
FixesARM-software/tf-issues#199
Change-Id: I79d27a4524583d723483165dc40801f45e627da5
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.
FixesARM-software/tf-issues#226
Change-Id: Ie894d1a07b8697c116960d858cd138c50bc7a069
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
CTX_INCLUDE_FPREGS make variable allows us to include or exclude FP
registers from context structure, in case FP is not used by TSPD.
FixesARM-software/tf-issues#194
Change-Id: Iee41af382d691340c7ae21830ad1bbf95dad1f4b
This patch reworks FVP specific code responsible for determining
the entry point information for BL3-2 and BL3-3 stages when BL3-1
is configured as the reset handler.
Change-Id: Ia661ff0a6a44c7aabb0b6c1684b2e8d3642d11ec
Consolidate all BL3-1 CPU context initialization for cold boot, PSCI
and SPDs into two functions:
* The first uses entry_point_info to initialize the relevant
cpu_context for first entry into a lower exception level on a CPU
* The second populates the EL1 and EL2 system registers as needed
from the cpu_context to ensure correct entry into the lower EL
This patch alters the way that BL3-1 determines which exception level
is used when first entering EL1 or EL2 during cold boot - this is now
fully determined by the SPSR value in the entry_point_info for BL3-3,
as set up by the platform code in BL2 (or otherwise provided to BL3-1).
In the situation that EL1 (or svc mode) is selected for a processor
that supports EL2, the context management code will now configure all
essential EL2 register state to ensure correct execution of EL1. This
allows the platform code to run non-secure EL1 payloads directly
without requiring a small EL2 stub or OS loader.
Change-Id: If9fbb2417e82d2226e47568203d5a369f39d3b0f
The crash reporting support and early initialisation of the
cpu_data allow the runtime_exception vectors to be used from
the start in BL3-1, removing the need for the additional
early_exception vectors and 2KB of code from BL3-1.
Change-Id: I5f8997dabbaafd8935a7455910b7db174a25d871
This patch prepares the per-cpu pointer cache for wider use by:
* renaming the structure to cpu_data and placing in new header
* providing accessors for this CPU, or other CPUs
* splitting the initialization of the TPIDR pointer from the
initialization of the cpu_data content
* moving the crash stack initialization to a crash stack function
* setting the TPIDR pointer very early during boot
Change-Id: Icef9004ff88f8eb241d48c14be3158087d7e49a3
This patch makes the console crash dump of processor register
state optional based on the CRASH_REPORTING make variable.
This defaults to only being enabled for DEBUG builds. This can
be overridden by setting a different value in the platform
makefile or on the make command line.
Change-Id: Icfa1b2d7ff0145cf0a85e8ad732f9cee7e7e993f
'crash_reporting.S' needs to include 'platform_def.h' to get the
definition of PLATFORM_CORE_COUNT.
Note: On FVP it was compiling because 'platform_def.h' gets included
through 'plat/fvp/include/plat_macros.S' but we don't want to rely on
that for other platforms.
Change-Id: I51e974776dd0f3bda10ad9849f5ef7b30c629833
This patch fixes the compilation issue for trusted firmware when the
IMF_READ_INTERRUPT_ID is enabled.
Change-Id: I94ab613b9bc96a7c1935796c674dc42246aaafee
The interrupt handling routine in BL3-1 expects a cookie as its last
parameter which was not being passed when invoking the interrupt
handler in BL3-1. This patch fixes that by passing a dummy cookie
parameter in the x3 register.
FixesARM-software/tf-issues#171
Change-Id: Ic98abbbd9f849e6f1c55343e865b5e0a4904a1c5
Rename the ic_* platform porting functions to plat_ic_* to be
consistent with the other functions in platform.h. Also rename
bl31_get_next_image_info() to bl31_plat_get_next_image_ep_info()
and remove the duplicate declaration in bl31.h.
Change-Id: I4851842069d3cff14c0a468daacc0a891a7ede84
Previously, platform.h contained many declarations and definitions
used for different purposes. This file has been split so that:
* Platform definitions used by common code that must be defined
by the platform are now in platform_def.h. The exact include
path is exported through $PLAT_INCLUDES in the platform makefile.
* Platform definitions specific to the FVP platform are now in
/plat/fvp/fvp_def.h.
* Platform API declarations specific to the FVP platform are now
in /plat/fvp/fvp_private.h.
* The remaining platform API declarations that must be ported by
each platform are still in platform.h but this file has been
moved to /include/plat/common since this can be shared by all
platforms.
Change-Id: Ieb3bb22fbab3ee8027413c6b39a783534aee474a
This patch adds a common handler for FIQ and IRQ exceptions in the
BL3-1 runtime exception vector table. This function determines the
interrupt type and calls its handler. A crash is reported if an
inconsistency in the interrupt management framework is detected. In
the event of a spurious interrupt, execution resumes from the
instruction where the interrupt was generated.
This patch also removes 'cm_macros.S' as its contents have been moved
to 'runtime_exceptions.S'
Change-Id: I3c85ecf8eaf43a3fac429b119ed0bd706d2e2093
This change adds optional reset vector support to BL3-1
which means BL3-1 entry point can detect cold/warm boot,
initialise primary cpu, set up cci and mail box.
When using BL3-1 as a reset vector it is assumed that
the BL3-1 platform code can determine the location of
the BL3-2 images, or load them as there are no parameters
that can be passed to BL3-1 at reset.
It also fixes the incorrect initialisation of mailbox
registers on the FVP platform
This feature can be enabled by building the code with
make variable RESET_TO_BL31 set as 1
FixesARM-software/TF-issues#133FixesARM-software/TF-issues#20
Change-Id: I4e23939b1c518614b899f549f1e8d412538ee570
This patch is based on spec published at
https://github.com/ARM-software/tf-issues/issues/133
It rearranges the bl31_args struct into
bl31_params and bl31_plat_params which provide the
information needed for Trusted firmware and platform
specific data via x0 and x1
On the FVP platform BL3-1 params and BL3-1 plat params
and its constituents are stored at the start of TZDRAM.
The information about memory availability and size for
BL3-1, BL3-2 and BL3-3 is moved into platform specific data.
Change-Id: I8b32057a3d0dd3968ea26c2541a0714177820da9
This patch reworks the handover interface from: BL1 to BL2 and
BL2 to BL3-1. It removes the raise_el(), change_el(), drop_el()
and run_image() functions as they catered for code paths that were
never exercised.
BL1 calls bl1_run_bl2() to jump into BL2 instead of doing the same
by calling run_image(). Similarly, BL2 issues the SMC to transfer
execution to BL3-1 through BL1 directly. Only x0 and x1 are used
to pass arguments to BL31. These arguments and parameters for
running BL3-1 are passed through a reference to a
'el_change_info_t' structure. They were being passed value in
general purpose registers earlier.
Change-Id: Id4fd019a19a9595de063766d4a66295a2c9307e1
At present, non-secure timer register contents are saved and restored as
part of world switch by BL3-1. This effectively means that the
non-secure timer stops, and non-secure timer interrupts are prevented
from asserting until BL3-1 switches back, introducing latency for
non-secure services. Often, secure world might depend on alternate
sources for secure interrupts (secure timer or platform timer) instead
of non-secure timers, in which case this save and restore is
unnecessary.
This patch introduces a boolean build-time configuration NS_TIMER_SWITCH
to choose whether or not to save and restore non-secure timer registers
upon world switch. The default choice is made not to save and restore
them.
FixesARM-software/tf-issues#148
Change-Id: I1b9d623606acb9797c3e0b02fb5ec7c0a414f37e
This patch implements the register reporting when unhandled exceptions are
taken in BL3-1. Unhandled exceptions will result in a dump of registers
to the console, before halting execution by that CPU. The Crash Stack,
previously called the Exception Stack, is used for this activity.
This stack is used to preserve the CPU context and runtime stack
contents for debugging and analysis.
This also introduces the per_cpu_ptr_cache, referenced by tpidr_el3,
to provide easy access to some of BL3-1 per-cpu data structures.
Initially, this is used to provide a pointer to the Crash stack.
panic() now prints the the error file and line number in Debug mode
and prints the PC value in release mode.
The Exception Stack is renamed to Crash Stack with this patch.
The original intention of exception stack is no longer valid
since we intend to support several valid exceptions like IRQ
and FIQ in the trusted firmware context. This stack is now
utilized for dumping and reporting the system state when a
crash happens and hence the rename.
FixesARM-software/tf-issues#79 Improve reporting of unhandled exception
Change-Id: I260791dc05536b78547412d147193cdccae7811a
Previously exception handlers in BL3-1, X19-X29 were not saved
and restored on every SMC/trap into EL3. Instead these registers
were 'saved as needed' as a side effect of the A64 ABI used by the C
compiler.
That approach failed when world switching but was not visible
with the TSP/TSPD code because the TSP is 64-bit, did not
clobber these registers when running and did not support pre-emption
by normal world interrupts. These scenarios showed
that the values in these registers can be passed through a world
switch, which broke the normal and trusted world assumptions
about these registers being preserved.
The Ideal solution saves and restores these registers when a
world switch occurs - but that type of implementation is more complex.
So this patch always saves and restores these registers on entry and
exit of EL3.
FixesARM-software/tf-issues#141
Change-Id: I9a727167bbc594454e81cf78a97ca899dfb11c27
Instead of using the system register helper functions to read
or write system registers, assembler coded functions should
use MRS/MSR instructions. This results in faster and more
compact code.
This change replaces all usage of the helper functions with
direct register accesses.
Change-Id: I791d5f11f257010bb3e6a72c6c5ab8779f1982b3
The current code does not always use data and instruction
barriers as required by the architecture and frequently uses
barriers excessively due to their inclusion in all of the
write_*() helper functions.
Barriers should be used explicitly in assembler or C code
when modifying processor state that requires the barriers in
order to enable review of correctness of the code.
This patch removes the barriers from the helper functions and
introduces them as necessary elsewhere in the code.
PORTING NOTE: check any port of Trusted Firmware for use of
system register helper functions for reliance on the previous
barrier behaviour and add explicit barriers as necessary.
FixesARM-software/tf-issues#92
Change-Id: Ie63e187404ff10e0bdcb39292dd9066cb84c53bf
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).
FixesARM-software/tf-issues#145
Change-Id: Ie12e46fbbed6baf024c30beb50751591bb8c8655
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.
FixesARM-software/tf-issues#31
Change-Id: Iec92fb976334c77453e010b60bcf56f3be72bd3e
Make codebase consistent in its use of #include "" syntax for
user includes and #include <> syntax for system includes.
FixesARM-software/tf-issues#65
Change-Id: If2f7c4885173b1fd05ac2cde5f1c8a07000c7a33
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.
FixesARM-software/tf-issues#76
Change-Id: Ia251f61b8148ffa73eae3f3711f57b1ffebfa632
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 fixesARM-software/tf-issues#24
Change-Id: If95639b279f75d66ac0576c48a6614b5ccb0e84b
This reverts commit 1c297bf015
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.
FixesARM-software/tf-issues#125
Conflicts:
docs/firmware-design.md
plat/fvp/bl31_plat_setup.c
Change-Id: Ib584ad7ed069707ac04cf86717f836136ad3ab54
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.
FixesARM-software/tf-issues#80
Change-Id: I301937b630add292d2dec6d2561a7fcfa6fec690
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
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.
FixesARM-software/tf-issues#24
Change-Id: I32c52cf882253e01f49056f47c58c23e6f422652
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
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
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
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: Achin Gupta <achin.gupta@arm.com>
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
davidcunado-arm
Antonio Nino Diaz
Soby Mathew
Dimitris Papastamos
Julius Werner
Jeenu Viswambharan
Douglas Raillard
Sandrine Bailleux
Gerald Lejeune
Juan Castillo
Yatharth Kochar
danh-arm
Achin Gupta
Kévin Petit
Vikram Kanigiri
Andrew Thoelke