diff --git a/docs/draw.io/ehf.svg b/docs/draw.io/ehf.svg
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@@ -0,0 +1,2 @@
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diff --git a/docs/draw.io/ehf.xml b/docs/draw.io/ehf.xml
new file mode 100644
index 0000000..db1f91d
--- /dev/null
+++ b/docs/draw.io/ehf.xml
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diff --git a/docs/draw.io/ras.svg b/docs/draw.io/ras.svg
new file mode 100644
index 0000000..ff58198
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font-size: 12px; font-family: Helvetica; color: rgb(0, 0, 0); line-height: 1.2; vertical-align: top; width: 46px; white-space: normal; overflow-wrap: normal; text-align: center;"><div xmlns="http://www.w3.org/1999/xhtml" style="display:inline-block;text-align:inherit;text-decoration:inherit;">Interrupt Priority</div></div></foreignObject><text x="23" y="20" fill="#000000" text-anchor="middle" font-size="12px" font-family="Helvetica">Interrupt Priority</text></switch></g><path d="M 138 110 L 138 150 L 138 261.76" fill="none" stroke="#000000" stroke-width="2" stroke-miterlimit="10" stroke-dasharray="6 6" pointer-events="none"/><path d="M 138 267.76 L 134 259.76 L 138 261.76 L 142 259.76 Z" fill="#000000" stroke="#000000" stroke-width="2" stroke-miterlimit="10" pointer-events="none"/><g transform="translate(140.5,176.5)"><switch><foreignObject style="overflow:visible;" pointer-events="all" width="38" height="27" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"><div xmlns="http://www.w3.org/1999/xhtml" style="display: inline-block; 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diff --git a/docs/draw.io/ras.xml b/docs/draw.io/ras.xml
new file mode 100644
index 0000000..ce6df3a
--- /dev/null
+++ b/docs/draw.io/ras.xml
@@ -0,0 +1 @@
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diff --git a/docs/exception-handling.rst b/docs/exception-handling.rst
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--- /dev/null
+++ b/docs/exception-handling.rst
@@ -0,0 +1,636 @@
+Exception Handling Framework in Trusted Firmware-A
+==================================================
+
+
+.. section-numbering::
+    :suffix: .
+
+.. contents::
+    :depth: 2
+
+.. |EHF| replace:: Exception Handling Framework
+.. |TF-A| replace:: Trusted Firmware-A
+
+This document describes various aspects of handling exceptions by Runtime
+Firmware (BL31) that are targeted at EL3, other than SMCs. The |EHF| takes care
+of the following exceptions when targeted at EL3:
+
+-  Interrupts
+-  Synchronous External Aborts
+-  Asynchronous External Aborts
+
+|TF-A|'s handling of synchronous ``SMC`` exceptions raised from lower ELs is
+described in the `Firmware Design document`__. However, the |EHF| changes the
+semantics of `interrupt handling`__ and `synchronous exceptions`__ other than
+SMCs.
+
+.. __: firmware-design.rst#handling-an-smc
+.. __: `Interrupt handling`_
+.. __: `Effect on SMC calls`_
+
+The |EHF| is selected by setting the build option ``EL3_EXCEPTION_HANDLING`` to
+``1``, and is only available for AArch64 systems.
+
+Introduction
+------------
+
+Through various control bits in the ``SCR_EL3`` register, the Arm architecture
+allows for asynchronous exceptions to be routed to EL3. As described in the
+`Interrupt Framework Design`_ document, depending on the chosen interrupt
+routing model, TF-A appropriately sets the ``FIQ`` and ``IRQ`` bits of
+``SCR_EL3`` register to effect this routing. For most use cases, other than for
+the purpose of facilitating context switch between Normal and Secure worlds,
+FIQs and IRQs routed to EL3 are not required to be handled in EL3.
+
+However, the evolving system and standards landscape demands that various
+exceptions are targeted at and handled in EL3. For instance:
+
+-  Starting with ARMv8.2 architecture extension, many RAS features have been
+   introduced to the Arm architecture. With RAS features implemented, various
+   components of the system may use one of the asynchronous exceptions to signal
+   error conditions to PEs. These error conditions are of critical nature, and
+   it's imperative that corrective or remedial actions are taken at the earliest
+   opportunity. Therefore, a *Firmware-first Handling* approach is generally
+   followed in response to RAS events in the system.
+
+-  The Arm `SDEI specification`_ defines interfaces through which Normal world
+   interacts with the Runtime Firmware in order to request notification of
+   system events. The SDEI specification requires that these events are notified
+   even when the Normal world executes with the exceptions masked. This too
+   implies that firmware-first handling is required, where the events are first
+   received by the EL3 firmware, and then dispatched to Normal world through
+   purely software mechanism.
+
+For |TF-A|, firmware-first handling means that asynchronous exceptions are
+suitably routed to EL3, and the Runtime Firmware (BL31) is extended to include
+software components that are capable of handling those exceptions that target
+EL3. These components—referred to as *dispatchers* [#spd]_ in general—may
+choose to:
+
+.. _delegation-use-cases:
+
+-  Receive and handle exceptions entirely in EL3, meaning the exceptions
+   handling terminates in EL3.
+
+-  Receive exceptions, but handle part of the exception in EL3, and delegate the
+   rest of the handling to a dedicated software stack running at lower Secure
+   ELs. In this scheme, the handling spans various secure ELs.
+
+-  Receive exceptions, but handle part of the exception in EL3, and delegate
+   processing of the error to dedicated software stack running at lower secure
+   ELs (as above); additionally, the Normal world may also be required to
+   participate in the handling, or be notified of such events (for example, as
+   an SDEI event). In this scheme, exception handling potentially and maximally
+   spans all ELs in both Secure and Normal worlds.
+
+On any given system, all of the above handling models may be employed
+independently depending on platform choice and the nature of the exception
+received.
+
+.. [#spd] Not to be confused with `Secure Payload Dispatcher`__, which is an
+   EL3 component that operates in EL3 on behalf of Secure OS.
+
+.. __: firmware-design.rst#secure-el1-payloads-and-dispatchers
+
+The role of Exception Handling Framework
+----------------------------------------
+
+Corollary to the use cases cited above, the primary role of the |EHF| is to
+facilitate firmware-first handling of exceptions on Arm systems. The |EHF| thus
+enables multiple exception dispatchers in runtime firmware to co-exist, register
+for, and handle exceptions targeted at EL3. This section outlines the basics,
+and the rest of this document expands the various aspects of the |EHF|.
+
+In order to arbitrate exception handling among dispatchers, the |EHF| operation
+is based on a priority scheme. This priority scheme is closely tied to how the
+Arm GIC architecture defines it, although it's applied to non-interrupt
+exceptions too (SErrors, for example).
+
+The platform is required to `partition`__ the Secure priority space into
+priority levels as applicable for the Secure software stack. It then assigns the
+dispatchers to one or more priority levels. The dispatchers then register
+handlers for the priority levels at runtime. A dispatcher can register handlers
+for more than one priority level.
+
+.. __: `Partitioning priority levels`_
+
+
+.. _ehf-figure:
+
+.. image:: draw.io/ehf.svg
+
+A priority level is *active* when a handler at that priority level is currently
+executing in EL3, or has delegated the execution to a lower EL. For interrupts,
+this is implicit when an interrupt is targeted and acknowledged at EL3, and the
+priority of the acknowledged interrupt is used to match its registered handler.
+The priority level is likewise implicitly deactivated when the interrupt
+handling concludes by EOIing the interrupt.
+
+Non-interrupt exceptions (SErrors, for example) don't have a notion of priority.
+In order for the priority arbitration to work, the |EHF| provides APIs in order
+for these non-interrupt exceptions to assume a priority, and to interwork with
+interrupts. Dispatchers handling such exceptions must therefore explicitly
+activate and deactivate the respective priority level as and when they're
+handled or delegated.
+
+Because priority activation and deactivation for interrupt handling is implicit
+and involves GIC priority masking, it's impossible for a lower priority
+interrupt to preempt a higher priority one. By extension, this means that a
+lower priority dispatcher cannot preempt a higher-priority one. Priority
+activation and deactivation for non-interrupt exceptions, however, has to be
+explicit. The |EHF| therefore disallows for lower priority level to be activated
+whilst a higher priority level is active, and would result in a panic.
+Likewise, a panic would result if it's attempted to deactivate a lower priority
+level when a higher priority level is active.
+
+In essence, priority level activation and deactivation conceptually works like a
+stack—priority levels stack up in strictly increasing fashion, and need to be
+unstacked in strictly the reverse order. For interrupts, the GIC ensures this is
+the case; for non-interrupts, the |EHF| monitors and asserts this. See
+`Transition of priority levels`_.
+
+Interrupt handling
+------------------
+
+The |EHF| is a client of *Interrupt Management Framework*, and registers the
+top-level handler for interrupts that target EL3, as described in the `Interrupt
+Framework Design`_ document. This has the following implications.
+
+-  On GICv3 systems, when executing in S-EL1, pending Non-secure interrupts of
+   sufficient priority are signalled as FIQs, and therefore will be routed to
+   EL3. As a result, S-EL1 software cannot expect to handle Non-secure
+   interrupts at S-EL1. Essentially, this deprecates the routing mode described
+   as `CSS=0, TEL3=0`__.
+
+   .. __: interrupt-framework-design.rst#el3-interrupts
+
+   In order for S-EL1 software to handle Non-secure interrupts while having
+   |EHF| enabled, the dispatcher must adopt a model where Non-secure interrupts
+   are received at EL3, but are then `synchronously`__ handled over to S-EL1.
+
+   .. __: interrupt-framework-design.rst#secure-payload
+
+-  On GICv2 systems, it's required that the build option ``GICV2_G0_FOR_EL3`` is
+   set to ``1`` so that *Group 0* interrupts target EL3.
+
+-  While executing in Secure world, |EHF| sets GIC Priority Mask Register to the
+   lowest Secure priority. This means that no Non-secure interrupts can preempt
+   Secure execution. See `Effect on SMC calls`_ for more details.
+
+As mentioned above, with |EHF|, the platform is required to partition *Group 0*
+interrupts into distinct priority levels. A dispatcher that chooses to receive
+interrupts can then *own* one or more priority levels, and register interrupt
+handlers for them. A given priority level can be assigned to only one handler. A
+dispatcher may register more than one priority level.
+
+Dispatchers are assigned interrupt priority levels in two steps:
+
+Partitioning priority levels
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Interrupts are associated to dispatchers by way of grouping and assigning
+interrupts to a priority level. In other words, all interrupts that are to
+target a particular dispatcher should fall in a particular priority level. For
+priority assignment:
+
+-  Of the 8 bits of priority that Arm GIC architecture permits, bit 7 must be 0
+   (secure space).
+
+-  Depending on the number of dispatchers to support, the platform must choose
+   to use the top *n* of the 7 remaining bits to identify and assign interrupts
+   to individual dispatchers. Choosing *n* bits supports up to 2\ :sup:`n`
+   distinct dispatchers. For example, by choosing 2 additional bits (i.e., bits
+   6 and 5), the platform can partition into 4 secure priority ranges: ``0x0``,
+   ``0x20``, ``0x40``, and ``0x60``. See `Interrupt handling example`_.
+
+Note:
+
+   The Arm GIC architecture requires that a GIC implementation that supports two
+   security states must implement at least 32 priority levels; i.e., at least 5
+   upper bits of the 8 bits are writeable. In the scheme described above, when
+   choosing *n* bits for priority range assignment, the platform must ensure
+   that at least ``n+1`` top bits of GIC priority are writeable.
+
+The priority thus assigned to an interrupt is also used to determine the
+priority of delegated execution in lower ELs. Delegated execution in lower EL is
+associated with a priority level chosen with ``ehf_activate_priority()`` API
+(described `later`__). The chosen priority level also determines the interrupts
+masked while executing in a lower EL, therefore controls preemption of delegated
+execution.
+
+.. __: `ehf-apis`_
+
+The platform expresses the chosen priority levels by declaring an array of
+priority level descriptors. Each entry in the array is of type
+``ehf_pri_desc_t``, and declares a priority level, and shall be populated by the
+``EHF_PRI_DESC()`` macro.
+
+Note:
+
+   The macro ``EHF_PRI_DESC()`` installs the descriptors in the array at a
+   computed index, and not necessarily where the macro is placed in the array.
+   The size of the array might therefore be larger than what it appears to be.
+   The ``ARRAY_SIZE()`` macro therefore should be used to determine the size of
+   array.
+
+Finally, this array of descriptors is exposed to |EHF| via. the
+``EHF_REGISTER_PRIORITIES()`` macro.
+
+Refer to the `Interrupt handling example`_ for usage. See also: `Interrupt
+Prioritisation Considerations`_.
+
+Programming priority
+~~~~~~~~~~~~~~~~~~~~
+
+The text in `Partitioning priority levels`_ only describes how the platform
+expresses the required levels of priority. It however doesn't choose interrupts
+nor program the required priority in GIC.
+
+The `Firmware Design guide`__ explains methods for configuring secure
+interrupts. |EHF| requires the platform to enumerate interrupt properties (as
+opposed to just numbers) of Secure interrupts. The priority of secure interrupts
+must match that as determined in the `Partitioning priority levels`_ section above.
+
+.. __: firmware-design.rst#configuring-secure-interrupts
+
+See `Limitations`_, and also refer to `Interrupt handling example`_ for
+illustration.
+
+Registering handler
+-------------------
+
+Dispatchers register handlers for their priority levels through the following
+API:
+
+.. code:: c
+
+   int ehf_register_priority_handler(int pri, ehf_handler_t handler)
+
+The API takes two arguments:
+
+-  The priority level for which the handler is being registered;
+
+-  The handler to be registered. The handler must be aligned to 4 bytes.
+
+If a dispatcher owns more than one priority levels, it has to call the API for
+each of them.
+
+The API will succeed, and return ``0``, only if:
+
+-  There exists a descriptor with the priority level requested.
+
+-  There are no handlers already registered by a previous call to the API.
+
+Otherwise, the API returns ``-1``.
+
+The interrupt handler should have the following signature:
+
+.. code:: c
+
+   typedef int (*ehf_handler_t)(uint32_t intr_raw, uint32_t flags, void *handle,
+                   void *cookie);
+
+The parameters are as obtained from the top-level `EL3 interrupt handler`__.
+
+.. __: interrupt-framework-design.rst#el3-runtime-firmware
+
+The `SDEI dispatcher`__, for example, expects the platform to allocate two
+different priority levels—``PLAT_SDEI_CRITICAL_PRI``, and
+``PLAT_SDEI_NORMAL_PRI``—and registers the same handler to handle both levels.
+
+.. __: sdei.rst
+
+Interrupt handling example
+--------------------------
+
+The following annotated snippet demonstrates how a platform might choose to
+assign interrupts to fictitious dispatchers:
+
+.. code:: c
+
+   #include <exception_mgmt.h>
+   #include <gic_common.h>
+   #include <interrupt_props.h>
+
+   ...
+
+   /*
+    * This platform uses 2 bits for interrupt association. In total, 3 upper
+    * bits are in use.
+    *
+    *  7 6 5   3      0
+    * .-.-.-.----------.
+    * |0|b|b|  ..0..   |
+    * '-'-'-'----------'
+    */
+   #define PLAT_PRI_BITS        2
+
+   /* Priorities for individual dispatchers */
+   #define DISP0_PRIO           0x00 /* Not used */
+   #define DISP1_PRIO           0x20
+   #define DISP2_PRIO           0x40
+   #define DISP3_PRIO           0x60
+
+   /* Install priority level descriptors for each dispatcher */
+   ehf_pri_desc_t plat_exceptions[] = {
+        EHF_PRI_DESC(PLAT_PRI_BITS, DISP1_PRIO),
+        EHF_PRI_DESC(PLAT_PRI_BITS, DISP2_PRIO),
+        EHF_PRI_DESC(PLAT_PRI_BITS, DISP3_PRIO),
+   };
+
+   /* Expose priority descriptors to Exception Handling Framework */
+   EHF_REGISTER_PRIORITIES(plat_exceptions, ARRAY_SIZE(plat_exceptions),
+        PLAT_PRI_BITS);
+
+   ...
+
+   /* List interrupt properties for GIC driver. All interrupts target EL3 */
+   const interrupt_prop_t plat_interrupts[] = {
+        /* Dispatcher 1 owns interrupts d1_0 and d1_1, so assigns priority DISP1_PRIO */
+        INTR_PROP_DESC(d1_0, DISP1_PRIO, INTR_TYPE_EL3, GIC_INTR_CFG_LEVEL),
+        INTR_PROP_DESC(d1_1, DISP1_PRIO, INTR_TYPE_EL3, GIC_INTR_CFG_LEVEL),
+
+        /* Dispatcher 2 owns interrupts d2_0 and d2_1, so assigns priority DISP2_PRIO */
+        INTR_PROP_DESC(d2_0, DISP2_PRIO, INTR_TYPE_EL3, GIC_INTR_CFG_LEVEL),
+        INTR_PROP_DESC(d2_1, DISP2_PRIO, INTR_TYPE_EL3, GIC_INTR_CFG_LEVEL),
+
+        /* Dispatcher 3 owns interrupts d3_0 and d3_1, so assigns priority DISP3_PRIO */
+        INTR_PROP_DESC(d3_0, DISP3_PRIO, INTR_TYPE_EL3, GIC_INTR_CFG_LEVEL),
+        INTR_PROP_DESC(d3_1, DISP3_PRIO, INTR_TYPE_EL3, GIC_INTR_CFG_LEVEL),
+   };
+
+   ...
+
+   /* Dispatcher 1 registers its handler */
+   ehf_register_priority_handler(DISP1_PRIO, disp1_handler);
+
+   /* Dispatcher 2 registers its handler */
+   ehf_register_priority_handler(DISP2_PRIO, disp2_handler);
+
+   /* Dispatcher 3 registers its handler */
+   ehf_register_priority_handler(DISP3_PRIO, disp3_handler);
+
+   ...
+
+See also the `Build-time flow`_ and the `Run-time flow`_.
+
+Activating and Deactivating priorities
+--------------------------------------
+
+A priority level is said to be *active* when an exception of that priority is
+being handled: for interrupts, this is implied when the interrupt is
+acknowledged; for non-interrupt exceptions, viz. SErrors or `SDEI explicit
+dispatches`__, this has to be done via. calling ``ehf_activate_priority()``. See
+`Run-time flow`_.
+
+.. __: sdei.rst#explicit-dispatch-of-events
+
+Conversely, when the dispatcher has reached a logical resolution for the cause
+of the exception, the corresponding priority level ought to be deactivated. As
+above, for interrupts, this is implied when the interrupt is EOId in the GIC;
+for other exceptions, this has to be done via. calling
+``ehf_deactivate_priority()``.
+
+Thanks to `different provisions`__ for exception delegation, there are
+potentially more than one work flow for deactivation:
+
+.. __: `delegation-use-cases`_
+
+.. _deactivation workflows:
+
+-  The dispatcher has addressed the cause of the exception, and decided to take
+   no further action. In this case, the dispatcher's handler deactivates the
+   priority level before returning to the |EHF|. Runtime firmware, upon exit
+   through an ``ERET``, resumes execution before the interrupt occurred.
+
+-  The dispatcher has to delegate the execution to lower ELs, and the cause of
+   the exception can be considered resolved only when the lower EL returns
+   signals complete (via. an ``SMC``) at a future point in time. The following
+   sequence ensues:
+
+   #. The dispatcher calls ``setjmp()`` to setup a jump point, and arranges to
+      enter a lower EL upon the next ``ERET``.
+
+   #. Through the ensuing ``ERET`` from runtime firmware, execution is delegated
+      to a lower EL.
+
+   #. The lower EL completes its execution, and signals completion via. an
+      ``SMC``.
+
+   #. The ``SMC`` is handled by the same dispatcher that handled the exception
+      previously. Noticing the conclusion of exception handling, the dispatcher
+      does ``longjmp()`` to resume beyond the previous jump point.
+
+As mentioned above, the |EHF| provides the following APIs for activating and
+deactivating interrupt:
+
+.. _ehf-apis:
+
+-  ``ehf_activate_priority()`` activates the supplied priority level, but only
+   if the current active priority is higher than the given one; otherwise
+   panics. Also, to prevent interruption by physical interrupts of lower
+   priority, the |EHF| programs the *Priority Mask Register* corresponding to
+   the PE to the priority being activated.  Dispatchers typically only need to
+   call this when handling exceptions other than interrupts, and it needs to
+   delegate execution to a lower EL at a desired priority level.
+
+-  ``ehf_deactivate_priority()`` deactivates a given priority, but only if the
+   current active priority is equal to the given one; otherwise panics. |EHF|
+   also restores the *Priority Mask Register* corresponding to the PE to the
+   priority before the call to ``ehf_activate_priority()``. Dispatchers
+   typically only need to call this after handling exceptions other than
+   interrupts.
+
+The calling of APIs are subject to allowed `transitions`__. See also the
+`Run-time flow`_.
+
+.. __: `Transition of priority levels`_
+
+Transition of priority levels
+-----------------------------
+
+The |EHF| APIs ``ehf_activate_priority()`` and ``ehf_deactivate_priority()`` can
+be called to transition the current priority level on a PE. A given sequence of
+calls to these APIs are subject to the following conditions:
+
+-  For activation, the |EHF| only allows for the priority to increase (i.e.
+   numeric value decreases);
+
+-  For deactivation, the |EHF| only allows for the priority to decrease (i.e.
+   numeric value increases). Additionally, the priority being deactivated is
+   required to be the current priority.
+
+If these are violated, a panic will result.
+
+Effect on SMC calls
+-------------------
+
+In general, Secure execution is regarded as more important than Non-secure
+execution. As discussed elsewhere in this document, EL3 execution, and any
+delegated execution thereafter, has the effect of raising GIC's priority
+mask—either implicitly by acknowledging Secure interrupts, or when dispatchers
+call ``ehf_activate_priority()``. As a result, Non-secure interrupts cannot
+preempt any Secure execution.
+
+SMCs from Non-secure world are synchronous exceptions, and are mechanisms for
+Non-secure world to request Secure services. They're broadly classified as
+*Fast* or *Yielding* (see `SMCCC`__).
+
+.. __: `http://infocenter.arm.com/help/topic/com.arm.doc.den0028a/index.html`
+
+-  *Fast* SMCs are atomic from the caller's point of view. I.e., they return
+   to the caller only when the Secure world has finished serving the request.
+   Any Non-secure interrupts that become pending meanwhile cannot preempt Secure
+   execution.
+
+-  *Yielding* SMCs carry the semantics of a preemptible, lower-priority request.
+   A pending Non-secure interrupt can preempt Secure execution handling a
+   Yielding SMC. I.e., the caller might observe a Yielding SMC returning when
+   either:
+
+   #. Secure world completes the request, and the caller would find ``SMC_OK``
+      as the return code.
+
+   #. A Non-secure interrupt preempts Secure execution. Non-secure interrupt is
+      handled, and Non-secure execution resumes after ``SMC`` instruction.
+
+   The dispatcher handling a Yielding SMC must provide a different return code
+   to the Non-secure caller to distinguish the latter case. This return code,
+   however, is not standardised (unlike ``SMC_UNKNOWN`` or ``SMC_OK``, for
+   example), so will vary across dispatchers that handle the request.
+
+For the latter case above, dispatchers before |EHF| expect Non-secure interrupts
+to be taken to S-EL1 [#irq]_, so would get a chance to populate the designated
+preempted error code before yielding to Non-secure world.
+
+The introduction of |EHF| changes the behaviour as described in `Interrupt
+handling`_.
+
+When |EHF| is enabled, in order to allow Non-secure interrupts to preempt
+Yielding SMC handling, the dispatcher must call ``ehf_allow_ns_preemption()``
+API. The API takes one argument, the error code to be returned to the Non-secure
+world upon getting preempted.
+
+.. [#irq] In case of GICv2, Non-secure interrupts while in S-EL1 were signalled
+          as IRQs, and in case of GICv3, FIQs.
+
+Build-time flow
+---------------
+
+Please refer to the `figure`__ above.
+
+.. __: `ehf-figure`_
+
+The build-time flow involves the following steps:
+
+#. Platform assigns priorities by installing priority level descriptors for
+   individual dispatchers, as described in `Partitioning priority levels`_.
+
+#. Platform provides interrupt properties to GIC driver, as described in
+   `Programming priority`_.
+
+#. Dispatcher calling ``ehf_register_priority_handler()`` to register an
+   interrupt handler.
+
+Also refer to the `Interrupt handling example`_.
+
+Run-time flow
+-------------
+
+.. _interrupt-flow:
+
+The following is an example flow for interrupts:
+
+#. The GIC driver, during initialization, iterates through the platform-supplied
+   interrupt properties (see `Programming priority`_), and configures the
+   interrupts. This programs the appropriate priority and group (Group 0) on
+   interrupts belonging to different dispatchers.
+
+#. The |EHF|, during its initialisation, registers a top-level interrupt handler
+   with the `Interrupt Management Framework`__ for EL3 interrupts. This also
+   results in setting the routing bits in ``SCR_EL3``.
+
+   .. __: interrupt-framework-design.rst#el3-runtime-firmware
+
+#. When an interrupt belonging to a dispatcher fires, GIC raises an EL3/Group 0
+   interrupt, and is taken to EL3.
+
+#. The top-level EL3 interrupt handler executes. The handler acknowledges the
+   interrupt, reads its *Running Priority*, and from that, determines the
+   dispatcher handler.
+
+#. The |EHF| programs the *Priority Mask Register* of the PE to the priority of
+   the interrupt received.
+
+#. The |EHF| marks that priority level *active*, and jumps to the dispatcher
+   handler.
+
+#. Once the dispatcher handler finishes its job, it has to immediately
+   *deactivate* the priority level before returning to the |EHF|. See
+   `deactivation workflows`_.
+
+.. _non-interrupt-flow:
+
+The following is an example flow for exceptions that targets EL3 other than
+interrupt:
+
+#. The platform provides handlers for the specific kind of exception.
+
+#. The exception arrives, and the corresponding handler is executed.
+
+#. The handler calls ``ehf_activate_priority()`` to activate the required
+   priority level. This also has the effect of raising GIC priority mask, thus
+   preventing interrupts of lower priority from preempting the handling. The
+   handler may choose to do the handling entirely in EL3 or delegate to a lower
+   EL.
+
+#. Once exception handling concludes, the handler calls
+   ``ehf_deactivate_priority()`` to deactivate the priority level activated
+   earlier. This also has the effect of lowering GIC priority mask to what it
+   was before.
+
+Interrupt Prioritisation Considerations
+---------------------------------------
+
+The GIC priority scheme, by design, prioritises Secure interrupts over Normal
+world ones. The platform further assigns relative priorities amongst Secure
+dispatchers through |EHF|.
+
+As mentioned in `Partitioning priority levels`_, interrupts targeting distinct
+dispatchers fall in distinct priority levels. Because they're routed via. the
+GIC, interrupt delivery to the PE is subject to GIC prioritisation rules. In
+particular, when an interrupt is being handled by the PE (i.e., the interrupt is
+in *Active* state), only interrupts of higher priority are signalled to the PE,
+even if interrupts of same or lower priority are pending. This has the side
+effect of one dispatcher being starved of interrupts by virtue of another
+dispatcher handling its (higher priority) interrupts.
+
+The |EHF| doesn't enforce a particular prioritisation policy, but the platform
+should carefully consider the assignment of priorities to dispatchers integrated
+into runtime firmware. The platform should sensibly delineate priority to
+various dispatchers according to their nature. In particular, dispatchers of
+critical nature (RAS, for example) should be assigned higher priority than
+others (SDEI, for example); and within SDEI, Critical priority SDEI should be
+assigned higher priority than Normal ones.
+
+Limitations
+-----------
+
+The |EHF| has the following limitations:
+
+-  Although there could be up to 128 Secure dispatchers supported by the GIC
+   priority scheme, the size of descriptor array exposed with
+   ``EHF_REGISTER_PRIORITIES()`` macro is currently limited to 32. This serves most
+   expected use cases. This may be expanded in the future, should use cases
+   demand so.
+
+-  The platform must ensure that the priority assigned to the dispatcher in the
+   exception descriptor and the programmed priority of interrupts handled by the
+   dispatcher match. The |EHF| cannot verify that this has been followed.
+
+----
+
+*Copyright (c) 2018, Arm Limited and Contributors. All rights reserved.*
+
+.. _Interrupt Framework Design: interrupt-framework-design.rst
+.. _SDEI specification: http://infocenter.arm.com/help/topic/com.arm.doc.den0054a/ARM_DEN0054A_Software_Delegated_Exception_Interface.pdf
diff --git a/docs/firmware-design.rst b/docs/firmware-design.rst
index 051b92b..21a4d53 100644
--- a/docs/firmware-design.rst
+++ b/docs/firmware-design.rst
@@ -981,6 +981,11 @@
 On return from the handler the result registers are populated in X0-X3 before
 restoring the stack and CPU state and returning from the original SMC.
 
+Exception Handling Framework
+----------------------------
+
+Please refer to the `Exception Handling Framework`_ document.
+
 Power State Coordination Interface
 ----------------------------------
 
@@ -2641,5 +2646,6 @@
 .. _SMC Calling Convention PDD: http://infocenter.arm.com/help/topic/com.arm.doc.den0028b/ARM_DEN0028B_SMC_Calling_Convention.pdf
 .. _TF-A Interrupt Management Design guide: ./interrupt-framework-design.rst
 .. _Xlat_tables design: xlat-tables-lib-v2-design.rst
+.. _Exception Handling Framework: exception-handling.rst
 
 .. |Image 1| image:: diagrams/rt-svc-descs-layout.png?raw=true
diff --git a/docs/interrupt-framework-design.rst b/docs/interrupt-framework-design.rst
index b5c7d21..4247f1f 100644
--- a/docs/interrupt-framework-design.rst
+++ b/docs/interrupt-framework-design.rst
@@ -153,7 +153,10 @@
 
    However, when ``EL3_EXCEPTION_HANDLING`` is ``1``, this routing model is
    invalid as EL3 interrupts are unconditionally routed to EL3, and EL3
-   interrupts will always preempt Secure EL1/EL0 execution.
+   interrupts will always preempt Secure EL1/EL0 execution. See `exception
+   handling`__ documentation.
+
+   .. __: exception-handling.rst#interrupt-handling
 
 #. **CSS=0, TEL3=1**. Interrupt is routed to EL3 when execution is in
    Secure-EL1/Secure-EL0. This is a valid routing model as secure software
diff --git a/docs/porting-guide.rst b/docs/porting-guide.rst
index bef4af6..4f1638a 100644
--- a/docs/porting-guide.rst
+++ b/docs/porting-guide.rst
@@ -2646,8 +2646,8 @@
 If you're trying to debug crashes in BL1, you can call the console_xx_core_flush
 function exported by some console drivers from here.
 
-Extternal Abort handling and RAS Support
-----------------------------------------
+External Abort handling and RAS Support
+---------------------------------------
 
 Function : plat_ea_handler
 ~~~~~~~~~~~~~~~~~~~~~~~~~~
diff --git a/docs/ras.rst b/docs/ras.rst
new file mode 100644
index 0000000..4c82022
--- /dev/null
+++ b/docs/ras.rst
@@ -0,0 +1,258 @@
+RAS support in Trusted Firmware-A
+=================================
+
+.. section-numbering::
+    :suffix: .
+
+.. contents::
+    :depth: 2
+
+.. |EHF| replace:: Exception Handling Framework
+.. |TF-A| replace:: Trusted Firmware-A
+
+This document describes |TF-A| support for Arm Reliability, Availability, and
+Serviceability (RAS) extensions. RAS is a mandatory extension for Armv8.2 and
+later CPUs, and also an optional extension to the base Armv8.0 architecture.
+
+In conjunction with the |EHF|, support for RAS extension enables firmware-first
+paradigm for handling platform errors, in which exceptions resulting from
+errors—viz. Synchronous External Abort (SEA), Asynchronous External Abort
+(signalled as SErrors), Fault Handling and Error Recovery interrupts are routed
+to and handled in EL3. The |EHF| document mentions various `error handling
+use-cases`__.
+
+.. __: exception-handling.rst#delegation-use-cases
+
+For the description of Arm RAS extensions, Standard Error Records, and the
+precise definition of RAS terminology, please refer to the Arm Architecture
+Reference Manual. The rest of this document assumes familiarity with
+architecture and terminology.
+
+Overview
+--------
+
+As mentioned above, the RAS support in |TF-A| enables routing to and handling of
+exceptions resulting from platform errors in EL3. It allows the platform to
+define an External Abort handler, and to register RAS nodes and interrupts. RAS
+framework also provides `helpers`__ for accessing Standard Error Records as
+introduced by the RAS extensions.
+
+.. __: `Standard Error Record helpers`_
+
+The build option ``RAS_EXTENSION`` when set to ``1`` includes the RAS in run
+time firmware; ``EL3_EXCEPTION_HANDLING`` and ``HANDLE_EA_EL3_FIRST`` must also
+be set ``1``.
+
+.. _ras-figure:
+
+.. image:: draw.io/ras.svg
+
+See more on `Engaging the RAS framework`_.
+
+Platform APIs
+-------------
+
+The RAS framework allows the platform to define handlers for External Abort,
+Uncontainable Errors, Double Fault, and errors rising from EL3 execution. Please
+refer to the porting guide for the `RAS platform API descriptions`__.
+
+.. __: porting-guide.rst#external-abort-handling-and-ras-support
+
+Registering RAS error records
+-----------------------------
+
+RAS nodes are components in the system capable of signalling errors to PEs
+through one one of the notification mechanisms—SEAs, SErrors, or interrupts. RAS
+nodes contain one or more error records, which are registers through which the
+nodes advertise various properties of the signalled error. Arm recommends that
+error records are implemented in the Standard Error Record format. The RAS
+architecture allows for error records to be accessible via. system or
+memory-mapped registers.
+
+The platform should enumerate the error records providing for each of them:
+
+-  A handler to probe error records for errors;
+-  When the probing identifies an error, a handler to handle it;
+-  For memory-mapped error record, its base address and size in KB; for a system
+   register-accessed record, the start index of the record and number of
+   continuous records from that index;
+-  Any node-specific auxiliary data.
+
+With this information supplied, when the run time firmware receives one of the
+notification mechanisms, the RAS framework can iterate through and probe error
+records for error, and invoke the appropriate handler to handle it.
+
+The RAS framework provides the macros to populate error record information. The
+macros are versioned, and the latest version as of this writing is 1. These
+macros create a structure of type ``struct err_record_info`` from its arguments,
+which are later passed to probe and error handlers.
+
+For memory-mapped error records:
+
+.. code:: c
+
+    ERR_RECORD_MEMMAP_V1(base_addr, size_num_k, probe, handler, aux)
+
+And, for system register ones:
+
+.. code:: c
+
+    ERR_RECORD_SYSREG_V1(idx_start, num_idx, probe, handler, aux)
+
+The probe handler must have the following prototype:
+
+.. code:: c
+
+    typedef int (*err_record_probe_t)(const struct err_record_info *info,
+                    int *probe_data);
+
+The probe handler must return a non-zero value if an error was detected, or 0
+otherwise. The ``probe_data`` output parameter can be used to pass any useful
+information resulting from probe to the error handler (see `below`__). For
+example, it could return the index of the record.
+
+.. __: `Standard Error Record helpers`_
+
+The error handler must have the following prototype:
+
+.. code:: c
+
+    typedef int (*err_record_handler_t)(const struct err_record_info *info,
+               int probe_data, const struct err_handler_data *const data);
+
+The ``data`` constant parameter describes the various properties of the error,
+viz. the reason for the error, exception syndrome, and also ``flags``,
+``cookie``, and ``handle`` parameters from the `top-level exception handler`__.
+
+.. __: interrupt-framework-design.rst#el3-interrupts
+
+The platform is expected populate an array using the macros above, and register
+the it with the RAS framework using the macro ``REGISTER_ERR_RECORD_INFO()``,
+passing it the name of the array describing the records. Note that the macro
+must be used in the same file where the array is defined.
+
+Standard Error Record helpers
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+The |TF-A| RAS framework provides probe handlers for Standard Error Records, for
+both memory-mapped and System Register accesses:
+
+.. code:: c
+
+    int ras_err_ser_probe_memmap(const struct err_record_info *info,
+                int *probe_data);
+
+    int ras_err_ser_probe_sysreg(const struct err_record_info *info,
+                int *probe_data);
+
+When the platform enumerates error records, for those records in the Standard
+Error Record format, these helpers maybe used instead of rolling out their own.
+Both helpers above:
+
+-  Return non-zero value when an error is detected in a Standard Error Record;
+-  Set ``probe_data`` to the index of the error record upon detecting an error.
+
+Registering RAS interrupts
+--------------------------
+
+RAS nodes can signal errors to the PE by raising Fault Handling and/or Error
+Recovery interrupts. For the firmware-first handling paradigm for interrupts to
+work, the platform must setup and register with |EHF|. See `Interaction with
+Exception Handling Framework`_.
+
+For each RAS interrupt, the platform has to provide structure of type ``struct
+ras_interrupt``:
+
+-  Interrupt number;
+-  The associated error record information (pointer to the corresponding
+   ``struct err_record_info``);
+-  Optionally, a cookie.
+
+The platform is expected to define an array of ``struct ras_interrupt``, and
+register it with the RAS framework using the macro
+``REGISTER_RAS_INTERRUPTS()``, passing it the name of the array. Note that the
+macro must be used in the same file where the array is defined.
+
+The array of ``struct ras_interrupt`` must be sorted in the increasing order of
+interrupt number. This allows for fast look of handlers in order to service RAS
+interrupts.
+
+Double-fault handling
+---------------------
+
+A Double Fault condition arises when an error is signalled to the PE while
+handling of a previously signalled error is still underway. When a Double Fault
+condition arises, the Arm RAS extensions only require for handler to perform
+orderly shutdown of the system, as recovery may be impossible.
+
+The RAS extensions part of Armv8.4 introduced new architectural features to deal
+with Double Fault conditions, specifically, the introduction of ``NMEA`` and
+``EASE`` bits to ``SCR_EL3`` register. These were introduced to assist EL3
+software which runs part of its entry/exit routines with exceptions momentarily
+masked—meaning, in such systems, External Aborts/SErrors are not immediately
+handled when they occur, but only after the exceptions are unmasked again.
+
+|TF-A|, for legacy reasons, executes entire EL3 with all exceptions unmasked.
+This means that all exceptions routed to EL3 are handled immediately. |TF-A|
+thus is able to detect a Double Fault conditions in software, without needing
+the intended advantages of Armv8.4 Double Fault architecture extensions.
+
+Double faults are fatal, and terminate at the platform double fault handler, and
+doesn't return.
+
+Engaging the RAS framework
+--------------------------
+
+Enabling RAS support is a platform choice conjunctional of three distinct but
+related build options:
+
+-  ``RAS_EXTENSION=1`` includes the RAS framework in the run time firmware;
+
+-  ``EL3_EXCEPTION_HANDLING=1`` enables handling of exceptions at EL3. See
+   `Interaction with Exception Handling Framework`_;
+
+-  ``HANDLE_EA_EL3_FIRST=1`` enables routing of External Aborts and SErrors to
+   EL3.
+
+The RAS support in |TF-A| introduces a default implementation of
+``plat_ea_handler``, the External Abort handler in EL3. When ``RAS_EXTENSION``
+is set to ``1``, it'll first call ``ras_ea_handler()`` function, which is the
+top-level RAS exception handler. ``ras_ea_handler`` is responsible for iterating
+to through platform-supplied error records, probe them, and when an error is
+identified, look up and invoke the corresponding error handler.
+
+Note that, if the platform chooses to override the ``plat_ea_handler`` function
+and intend to use the RAS framework, it must explicitly call
+``ras_ea_handler()`` from within.
+
+Similarly, for RAS interrupts, the framework defines
+``ras_interrupt_handler()``. The RAS framework arranges for it to be invoked
+when  a RAS interrupt taken at EL3. The function bisects the platform-supplied
+sorted array of interrupts to look up the error record information associated
+with the interrupt number. That error handler for that record is then invoked to
+handle the error.
+
+Interaction with Exception Handling Framework
+---------------------------------------------
+
+As mentioned in earlier sections, RAS framework interacts with the |EHF| to
+arbitrate handling of RAS exceptions with others that are routed to EL3. This
+means that the platform must partition a `priority level`__ for handling RAS
+exceptions. The platform must then define the macro ``PLAT_RAS_PRI`` to the
+priority level used for RAS exceptions. Platforms would typically want to
+allocate the highest secure priority for RAS handling.
+
+.. __: exception-handling.rst#partitioning-priority-levels
+
+Handling of both `interrrupt`__ and `non-interrupt`__ exceptions follow the
+sequences outlined in the |EHF| documentation. I.e., for interrupts, the
+priority management is implicit; but for non-interrupt exceptions, they're
+explicit using `EHF APIs`__.
+
+.. __: exception-handling.rst#interrupt-flow
+.. __: exception-handling.rst#non-interrupt-flow
+.. __: exception-handling.rst#activating-and-deactivating-priorities
+
+----
+
+*Copyright (c) 2018, Arm Limited and Contributors. All rights reserved.*
diff --git a/drivers/arm/ccn/ccn.c b/drivers/arm/ccn/ccn.c
index 910cd7c..59a7576 100644
--- a/drivers/arm/ccn/ccn.c
+++ b/drivers/arm/ccn/ccn.c
@@ -11,6 +11,7 @@
 #include <debug.h>
 #include <errno.h>
 #include <mmio.h>
+#include <stdbool.h>
 #include "ccn_private.h"
 
 static const ccn_desc_t *ccn_plat_desc;
@@ -490,3 +491,123 @@
 	return (int)(mmio_read_64(periphbase
 			+ MN_PERIPH_ID_0_1_OFFSET) & 0xFF);
 }
+
+/*******************************************************************************
+ * This function returns the region id corresponding to a node_id of node_type.
+ ******************************************************************************/
+static unsigned int get_region_id_for_node(node_types_t node_type,
+						unsigned int node_id)
+{
+	unsigned int mn_reg_off, region_id;
+	unsigned long long node_bitmap;
+	unsigned int loc_node_id, node_pos_in_map = 0;
+
+	assert(node_type < NUM_NODE_TYPES);
+	assert(node_id < MAX_RN_NODES);
+
+	switch (node_type) {
+	case NODE_TYPE_RNI:
+		region_id = RNI_REGION_ID_START;
+		break;
+	case NODE_TYPE_HNF:
+		region_id = HNF_REGION_ID_START;
+		break;
+	case NODE_TYPE_HNI:
+		region_id = HNI_REGION_ID_START;
+		break;
+	case NODE_TYPE_SN:
+		region_id = SBSX_REGION_ID_START;
+		break;
+	default:
+		ERROR("Un-supported Node Type = %d.\n", node_type);
+		assert(false);
+		return REGION_ID_LIMIT;
+	}
+	/*
+	 * RN-I, HN-F, HN-I, SN node registers in the MN region
+	 * occupy contiguous 16 byte apart offsets.
+	 *
+	 * RN-F and RN-D node are not supported as
+	 * none of them exposes any memory map to
+	 * configure any of their offset registers.
+	 */
+
+	mn_reg_off = MN_RNF_NODEID_OFFSET + (node_type << 4);
+	node_bitmap = ccn_reg_read(ccn_plat_desc->periphbase,
+					MN_REGION_ID, mn_reg_off);
+
+	assert((node_bitmap & (1ULL << (node_id))) != 0U);
+
+
+	FOR_EACH_PRESENT_NODE_ID(loc_node_id, node_bitmap) {
+		INFO("Index = %u with loc_nod=%u and input nod=%u\n",
+					node_pos_in_map, loc_node_id, node_id);
+		if (loc_node_id == node_id)
+			break;
+		node_pos_in_map++;
+	}
+
+	if (node_pos_in_map == CCN_MAX_RN_MASTERS) {
+		ERROR("Node Id = %d, is not found.\n", node_id);
+		assert(false);
+		return REGION_ID_LIMIT;
+	}
+
+	region_id += node_pos_in_map;
+
+	return region_id;
+}
+
+/*******************************************************************************
+ * This function sets the value 'val' to the register at register_offset from
+ * the base address pointed to by the region_id.
+ * where, region id is mapped to a node_id of node_type.
+ ******************************************************************************/
+void ccn_write_node_reg(node_types_t node_type, unsigned int node_id,
+			unsigned int reg_offset, unsigned long long val)
+{
+	unsigned int region_id = get_region_id_for_node(node_type, node_id);
+
+	if (reg_offset > REGION_ID_OFFSET) {
+		ERROR("Invalid Register offset 0x%x is provided.\n",
+								reg_offset);
+		assert(false);
+		return;
+	}
+
+	/* Setting the value of Auxilary Control Register of the Node */
+	ccn_reg_write(ccn_plat_desc->periphbase, region_id, reg_offset, val);
+	VERBOSE("Value is successfully written at address 0x%lx.\n",
+			(ccn_plat_desc->periphbase
+			+ region_id_to_base(region_id))
+			+ reg_offset);
+}
+
+/*******************************************************************************
+ * This function read the value 'val' stored in the register at register_offset
+ * from the base address pointed to by the region_id.
+ * where, region id is mapped to a node_id of node_type.
+ ******************************************************************************/
+unsigned long long ccn_read_node_reg(node_types_t node_type,
+					unsigned int node_id,
+					unsigned int reg_offset)
+{
+	unsigned long long val;
+	unsigned int region_id = get_region_id_for_node(node_type, node_id);
+
+	if (reg_offset > REGION_ID_OFFSET) {
+		ERROR("Invalid Register offset 0x%x is provided.\n",
+								reg_offset);
+		assert(false);
+		return ULL(0);
+	}
+
+	/* Setting the value of Auxilary Control Register of the Node */
+	val = ccn_reg_read(ccn_plat_desc->periphbase, region_id, reg_offset);
+	VERBOSE("Value is successfully read from address 0x%lx.\n",
+			(ccn_plat_desc->periphbase
+			+ region_id_to_base(region_id))
+			+ reg_offset);
+
+	return val;
+}
diff --git a/include/drivers/arm/ccn.h b/include/drivers/arm/ccn.h
index eba974d..9c3abac 100644
--- a/include/drivers/arm/ccn.h
+++ b/include/drivers/arm/ccn.h
@@ -76,6 +76,16 @@
 	uintptr_t periphbase;
 } ccn_desc_t;
 
+/* Enum used to loop through all types of nodes in CCN*/
+typedef enum node_types {
+	NODE_TYPE_RNF = 0,
+	NODE_TYPE_RNI,
+	NODE_TYPE_RND,
+	NODE_TYPE_HNF,
+	NODE_TYPE_HNI,
+	NODE_TYPE_SN,
+	NUM_NODE_TYPES
+} node_types_t;
 
 void ccn_init(const ccn_desc_t *plat_ccn_desc);
 void ccn_enter_snoop_dvm_domain(unsigned long long master_iface_map);
@@ -92,5 +102,12 @@
 unsigned int ccn_get_l3_run_mode(void);
 int ccn_get_part0_id(uintptr_t periphbase);
 
+void ccn_write_node_reg(node_types_t node_type, unsigned int node_id,
+				unsigned int reg_offset,
+				unsigned long long val);
+unsigned long long ccn_read_node_reg(node_types_t node_type,
+					unsigned int node_id,
+					unsigned int reg_offset);
+
 #endif /* __ASSEMBLY__ */
 #endif /* CCN_H */
diff --git a/include/lib/aarch32/arch.h b/include/lib/aarch32/arch.h
index 38e01bd..3e5e3fb 100644
--- a/include/lib/aarch32/arch.h
+++ b/include/lib/aarch32/arch.h
@@ -33,10 +33,12 @@
 #define MPIDR_AFF0_SHIFT	U(0)
 #define MPIDR_AFF1_SHIFT	U(8)
 #define MPIDR_AFF2_SHIFT	U(16)
+#define MPIDR_AFF_SHIFT(_n)	MPIDR_AFF##_n##_SHIFT
 #define MPIDR_AFFINITY_MASK	U(0x00ffffff)
 #define MPIDR_AFFLVL0		U(0)
 #define MPIDR_AFFLVL1		U(1)
 #define MPIDR_AFFLVL2		U(2)
+#define MPIDR_AFFLVL(_n)	MPIDR_AFFLVL##_n
 
 #define MPIDR_AFFLVL0_VAL(mpidr) \
 		(((mpidr) >> MPIDR_AFF0_SHIFT) & MPIDR_AFFLVL_MASK)
@@ -46,6 +48,20 @@
 		(((mpidr) >> MPIDR_AFF2_SHIFT) & MPIDR_AFFLVL_MASK)
 #define MPIDR_AFFLVL3_VAL(mpidr)	U(0)
 
+#define MPIDR_AFF_ID(mpid, n)					\
+	(((mpid) >> MPIDR_AFF_SHIFT(n)) & MPIDR_AFFLVL_MASK)
+
+#define MPID_MASK		(MPIDR_MT_MASK				|\
+				 (MPIDR_AFFLVL_MASK << MPIDR_AFF2_SHIFT)|\
+				 (MPIDR_AFFLVL_MASK << MPIDR_AFF1_SHIFT)|\
+				 (MPIDR_AFFLVL_MASK << MPIDR_AFF0_SHIFT))
+
+/*
+ * An invalid MPID. This value can be used by functions that return an MPID to
+ * indicate an error.
+ */
+#define INVALID_MPID		U(0xFFFFFFFF)
+
 /*
  * The MPIDR_MAX_AFFLVL count starts from 0. Take care to
  * add one while using this macro to define array sizes.
@@ -127,7 +143,7 @@
 #define SDCR_RESET_VAL		U(0x0)
 
 /* HSCTLR definitions */
-#define HSCTLR_RES1 	((U(1) << 29) | (U(1) << 28) | (U(1) << 23) | \
+#define HSCTLR_RES1	((U(1) << 29) | (U(1) << 28) | (U(1) << 23) | \
 			 (U(1) << 22) | (U(1) << 18) | (U(1) << 16) | \
 			 (U(1) << 11) | (U(1) << 4) | (U(1) << 3))
 
@@ -167,6 +183,7 @@
 #define GET_NS_BIT(scr)		((scr) & SCR_NS_BIT)
 
 /* HCR definitions */
+#define HCR_TGE_BIT		(U(1) << 27)
 #define HCR_AMO_BIT		(U(1) << 5)
 #define HCR_IMO_BIT		(U(1) << 4)
 #define HCR_FMO_BIT		(U(1) << 3)
@@ -212,10 +229,9 @@
 /* CNTHP_CTL definitions */
 #define CNTHP_CTL_RESET_VAL	U(0x0)
 
-/* NASCR definitions */
+/* NSACR definitions */
 #define NSASEDIS_BIT		(U(1) << 15)
 #define NSTRCDIS_BIT		(U(1) << 20)
-/* NOTE: correct typo in the definitions */
 #define NSACR_CP11_BIT		(U(1) << 11)
 #define NSACR_CP10_BIT		(U(1) << 10)
 #define NSACR_IMP_DEF_MASK	(U(0x7) << 16)
@@ -262,7 +278,6 @@
 /*
  * TTBCR definitions
  */
-/* The ARM Trusted Firmware uses the long descriptor format */
 #define TTBCR_EAE_BIT		(U(1) << 31)
 
 #define TTBCR_SH1_NON_SHAREABLE		(U(0x0) << 28)
@@ -407,14 +422,30 @@
 #define CNTACR_RWPT_SHIFT	U(0x5)
 
 /*******************************************************************************
- * Definitions of register offsets in the CNTBaseN Frame of the
+ * Definitions of register offsets and fields in the CNTBaseN Frame of the
  * system level implementation of the Generic Timer.
  ******************************************************************************/
-#define CNTBASE_CNTFRQ		U(0x10)
+/* Physical Count register. */
+#define CNTPCT_LO		U(0x0)
+/* Counter Frequency register. */
+#define CNTBASEN_CNTFRQ		U(0x10)
+/* Physical Timer CompareValue register. */
+#define CNTP_CVAL_LO		U(0x20)
+/* Physical Timer Control register. */
+#define CNTP_CTL		U(0x2c)
+
+/* Physical timer control register bit fields shifts and masks */
+#define CNTP_CTL_ENABLE_SHIFT   0
+#define CNTP_CTL_IMASK_SHIFT    1
+#define CNTP_CTL_ISTATUS_SHIFT  2
+
+#define CNTP_CTL_ENABLE_MASK    U(1)
+#define CNTP_CTL_IMASK_MASK     U(1)
+#define CNTP_CTL_ISTATUS_MASK   U(1)
 
 /* MAIR macros */
-#define MAIR0_ATTR_SET(attr, index)	((attr) << ((index) << 3))
-#define MAIR1_ATTR_SET(attr, index)	((attr) << (((index) - U(3)) << 3))
+#define MAIR0_ATTR_SET(attr, index)	((attr) << ((index) << U(3)))
+#define MAIR1_ATTR_SET(attr, index)	((attr) << (((index) - U(3)) << U(3)))
 
 /* System register defines The format is: coproc, opt1, CRn, CRm, opt2 */
 #define SCR		p15, 0, c1, c1, 0
@@ -423,6 +454,7 @@
 #define SDCR		p15, 0, c1, c3, 1
 #define MPIDR		p15, 0, c0, c0, 5
 #define MIDR		p15, 0, c0, c0, 0
+#define HVBAR		p15, 4, c12, c0, 0
 #define VBAR		p15, 0, c12, c0, 0
 #define MVBAR		p15, 0, c12, c0, 1
 #define NSACR		p15, 0, c1, c1, 2
@@ -443,6 +475,7 @@
 #define TTBR0		p15, 0, c2, c0, 0
 #define TTBR1		p15, 0, c2, c0, 1
 #define TLBIALL		p15, 0, c8, c7, 0
+#define TLBIALLH	p15, 4, c8, c7, 0
 #define TLBIALLIS	p15, 0, c8, c3, 0
 #define TLBIMVA		p15, 0, c8, c7, 1
 #define TLBIMVAA	p15, 0, c8, c7, 3
@@ -472,6 +505,7 @@
 /* Debug register defines. The format is: coproc, opt1, CRn, CRm, opt2 */
 #define HDCR		p15, 4, c1, c1, 1
 #define PMCR		p15, 0, c9, c12, 0
+#define CNTHP_TVAL	p15, 4, c14, c2, 0
 #define CNTHP_CTL	p15, 4, c14, c2, 1
 
 /* AArch32 coproc registers for 32bit MMU descriptor support */
@@ -507,6 +541,7 @@
 #define VTTBR_64	p15, 6, c2
 #define CNTPCT_64	p15, 0, c14
 #define HTTBR_64	p15, 4, c2
+#define CNTHP_CVAL_64	p15, 6, c14
 #define PAR_64		p15, 0, c7
 
 /* 64 bit GICv3 CPU Interface system register defines. The format is: coproc, opt1, CRm */
diff --git a/include/lib/aarch32/arch_helpers.h b/include/lib/aarch32/arch_helpers.h
index 03f0e86..7d1944c 100644
--- a/include/lib/aarch32/arch_helpers.h
+++ b/include/lib/aarch32/arch_helpers.h
@@ -7,7 +7,7 @@
 #ifndef ARCH_HELPERS_H
 #define ARCH_HELPERS_H
 
-#include <arch.h>	/* for additional register definitions */
+#include <arch.h>
 #include <cdefs.h>
 #include <stdint.h>
 #include <string.h>
@@ -33,13 +33,8 @@
 
 /*
  *  The undocumented %Q and %R extended asm are used to implemented the below
- *  64 bit `mrrc` and `mcrr` instructions. It works only on Little Endian
- *  systems for GCC versions < 4.6. Above GCC 4.6, both Little Endian and
- *  Big Endian systems generate the right instruction encoding.
+ *  64 bit `mrrc` and `mcrr` instructions.
  */
-#if !(__clang__ || __GNUC__ > (4) || __GNUC__ == (4) && __GNUC_MINOR__ >= (6))
-#error "clang or GCC 4.6 or above is required to build AArch32 Trusted Firmware"
-#endif
 
 #define _DEFINE_COPROCR_WRITE_FUNC_64(_name, coproc, opc1, CRm)		\
 static inline void write64_## _name(uint64_t v)				\
@@ -78,6 +73,10 @@
 #define DEFINE_COPROCR_READ_FUNC(_name, ...) 				\
 	_DEFINE_COPROCR_READ_FUNC(_name, __VA_ARGS__)
 
+/* Define write function for coproc register */
+#define DEFINE_COPROCR_WRITE_FUNC(_name, ...) 				\
+	_DEFINE_COPROCR_WRITE_FUNC(_name, __VA_ARGS__)
+
 /* Define read & write function for coproc register */
 #define DEFINE_COPROCR_RW_FUNCS(_name, ...) 				\
 	_DEFINE_COPROCR_READ_FUNC(_name, __VA_ARGS__)			\
@@ -87,6 +86,10 @@
 #define DEFINE_COPROCR_READ_FUNC_64(_name, ...) 			\
 	_DEFINE_COPROCR_READ_FUNC_64(_name, __VA_ARGS__)
 
+/* Define 64 bit write function for coproc register */
+#define DEFINE_COPROCR_WRITE_FUNC_64(_name, ...) 			\
+	_DEFINE_COPROCR_WRITE_FUNC_64(_name, __VA_ARGS__)
+
 /* Define 64 bit read & write function for coproc register */
 #define DEFINE_COPROCR_RW_FUNCS_64(_name, ...) 				\
 	_DEFINE_COPROCR_READ_FUNC_64(_name, __VA_ARGS__)		\
@@ -101,30 +104,15 @@
  * Macros to create inline functions for tlbi operations
  *********************************************************************/
 
-#if ERRATA_A57_813419
-/*
- * Define function for TLBI instruction with type specifier that
- * implements the workaround for errata 813419 of Cortex-A57
- */
 #define _DEFINE_TLBIOP_FUNC(_op, coproc, opc1, CRn, CRm, opc2)		\
 static inline void tlbi##_op(void)					\
 {									\
 	u_register_t v = 0;						\
 	__asm__ volatile ("mcr "#coproc","#opc1",%0,"#CRn","#CRm","#opc2 : : "r" (v));\
-	__asm__ volatile ("dsb ish");\
-	__asm__ volatile ("mcr "#coproc","#opc1",%0,"#CRn","#CRm","#opc2 : : "r" (v));\
 }
 
-#define _DEFINE_TLBIOP_PARAM_FUNC(_op, coproc, opc1, CRn, CRm, opc2)	\
-static inline void tlbi##_op(u_register_t v)				\
-{									\
-	__asm__ volatile ("mcr "#coproc","#opc1",%0,"#CRn","#CRm","#opc2 : : "r" (v));\
-	__asm__ volatile ("dsb ish");\
-	__asm__ volatile ("mcr "#coproc","#opc1",%0,"#CRn","#CRm","#opc2 : : "r" (v));\
-}
-#else
-#define _DEFINE_TLBIOP_FUNC(_op, coproc, opc1, CRn, CRm, opc2)		\
-static inline void tlbi##_op(void)					\
+#define _DEFINE_BPIOP_FUNC(_op, coproc, opc1, CRn, CRm, opc2)		\
+static inline void bpi##_op(void)					\
 {									\
 	u_register_t v = 0;						\
 	__asm__ volatile ("mcr "#coproc","#opc1",%0,"#CRn","#CRm","#opc2 : : "r" (v));\
@@ -135,14 +123,6 @@
 {									\
 	__asm__ volatile ("mcr "#coproc","#opc1",%0,"#CRn","#CRm","#opc2 : : "r" (v));\
 }
-#endif /* ERRATA_A57_813419 */
-
-#define _DEFINE_BPIOP_FUNC(_op, coproc, opc1, CRn, CRm, opc2)		\
-static inline void bpi##_op(void)					\
-{									\
-	u_register_t v = 0;						\
-	__asm__ volatile ("mcr "#coproc","#opc1",%0,"#CRn","#CRm","#opc2 : : "r" (v));\
-}
 
 /* Define function for simple TLBI operation */
 #define DEFINE_TLBIOP_FUNC(_op, ...)					\
@@ -250,10 +230,13 @@
 DEFINE_COPROCR_RW_FUNCS(cnthctl, CNTHCTL)
 DEFINE_COPROCR_RW_FUNCS(mair0, MAIR0)
 DEFINE_COPROCR_RW_FUNCS(mair1, MAIR1)
+DEFINE_COPROCR_RW_FUNCS(hmair0, HMAIR0)
 DEFINE_COPROCR_RW_FUNCS(ttbcr, TTBCR)
+DEFINE_COPROCR_RW_FUNCS(htcr, HTCR)
 DEFINE_COPROCR_RW_FUNCS(ttbr0, TTBR0)
 DEFINE_COPROCR_RW_FUNCS_64(ttbr0, TTBR0_64)
 DEFINE_COPROCR_RW_FUNCS(ttbr1, TTBR1)
+DEFINE_COPROCR_RW_FUNCS_64(httbr, HTTBR_64)
 DEFINE_COPROCR_RW_FUNCS(vpidr, VPIDR)
 DEFINE_COPROCR_RW_FUNCS(vmpidr, VMPIDR)
 DEFINE_COPROCR_RW_FUNCS_64(vttbr, VTTBR_64)
@@ -261,6 +244,9 @@
 DEFINE_COPROCR_RW_FUNCS_64(cntvoff, CNTVOFF_64)
 DEFINE_COPROCR_RW_FUNCS(csselr, CSSELR)
 DEFINE_COPROCR_RW_FUNCS(hstr, HSTR)
+DEFINE_COPROCR_RW_FUNCS(cnthp_ctl_el2, CNTHP_CTL)
+DEFINE_COPROCR_RW_FUNCS(cnthp_tval_el2, CNTHP_TVAL)
+DEFINE_COPROCR_RW_FUNCS_64(cnthp_cval_el2, CNTHP_CVAL_64)
 
 DEFINE_COPROCR_RW_FUNCS(icc_sre_el1, ICC_SRE)
 DEFINE_COPROCR_RW_FUNCS(icc_sre_el2, ICC_HSRE)
@@ -268,6 +254,7 @@
 DEFINE_COPROCR_RW_FUNCS(icc_pmr_el1, ICC_PMR)
 DEFINE_COPROCR_RW_FUNCS(icc_rpr_el1, ICC_RPR)
 DEFINE_COPROCR_RW_FUNCS(icc_igrpen1_el3, ICC_MGRPEN1)
+DEFINE_COPROCR_RW_FUNCS(icc_igrpen1_el1, ICC_IGRPEN1)
 DEFINE_COPROCR_RW_FUNCS(icc_igrpen0_el1, ICC_IGRPEN0)
 DEFINE_COPROCR_RW_FUNCS(icc_hppir0_el1, ICC_HPPIR0)
 DEFINE_COPROCR_RW_FUNCS(icc_hppir1_el1, ICC_HPPIR1)
@@ -276,13 +263,17 @@
 DEFINE_COPROCR_RW_FUNCS(icc_eoir0_el1, ICC_EOIR0)
 DEFINE_COPROCR_RW_FUNCS(icc_eoir1_el1, ICC_EOIR1)
 DEFINE_COPROCR_RW_FUNCS_64(icc_sgi0r_el1, ICC_SGI0R_EL1_64)
+DEFINE_COPROCR_WRITE_FUNC_64(icc_sgi1r, ICC_SGI1R_EL1_64)
 
 DEFINE_COPROCR_RW_FUNCS(hdcr, HDCR)
 DEFINE_COPROCR_RW_FUNCS(cnthp_ctl, CNTHP_CTL)
 DEFINE_COPROCR_READ_FUNC(pmcr, PMCR)
 
-DEFINE_COPROCR_RW_FUNCS(ats1cpr, ATS1CPR)
-DEFINE_COPROCR_RW_FUNCS(ats1hr, ATS1HR)
+/*
+ * Address translation
+ */
+DEFINE_COPROCR_WRITE_FUNC(ats1cpr, ATS1CPR)
+DEFINE_COPROCR_WRITE_FUNC(ats1hr, ATS1HR)
 DEFINE_COPROCR_RW_FUNCS_64(par, PAR_64)
 
 DEFINE_COPROCR_RW_FUNCS(nsacr, NSACR)
@@ -340,9 +331,7 @@
 #define IS_IN_SVC()	(GET_M32(read_cpsr()) == MODE32_svc)
 #define IS_IN_MON()	(GET_M32(read_cpsr()) == MODE32_mon)
 #define IS_IN_EL2()	IS_IN_HYP()
- /*
-  * If EL3 is AArch32, then secure PL1 and monitor mode correspond to EL3
-  */
+/* If EL3 is AArch32, then secure PL1 and monitor mode correspond to EL3 */
 #define IS_IN_EL3() \
 	((GET_M32(read_cpsr()) == MODE32_mon) ||	\
 		(IS_IN_SECURE() && (GET_M32(read_cpsr()) != MODE32_usr)))
@@ -378,7 +367,15 @@
 
 #define read_ctr_el0()		read_ctr()
 
-#define write_icc_sgi0r_el1(_v) \
-		write64_icc_sgi0r_el1(_v)
+#define write_icc_sgi0r_el1(_v)	write64_icc_sgi0r_el1(_v)
+
+#define read_daif()		read_cpsr()
+#define write_daif(flags)	write_cpsr(flags)
+
+#define read_cnthp_cval_el2()	read64_cnthp_cval_el2()
+#define write_cnthp_cval_el2(v)	write64_cnthp_cval_el2(v)
+
+#define read_amcntenset0_el0()	read_amcntenset0()
+#define read_amcntenset1_el0()	read_amcntenset1()
 
 #endif /* ARCH_HELPERS_H */
diff --git a/include/lib/aarch64/arch.h b/include/lib/aarch64/arch.h
index e6842e1..d7867bc 100644
--- a/include/lib/aarch64/arch.h
+++ b/include/lib/aarch64/arch.h
@@ -35,12 +35,14 @@
 #define MPIDR_AFF1_SHIFT	U(8)
 #define MPIDR_AFF2_SHIFT	U(16)
 #define MPIDR_AFF3_SHIFT	U(32)
+#define MPIDR_AFF_SHIFT(_n)	MPIDR_AFF##_n##_SHIFT
 #define MPIDR_AFFINITY_MASK	ULL(0xff00ffffff)
 #define MPIDR_AFFLVL_SHIFT	U(3)
-#define MPIDR_AFFLVL0		U(0x0)
-#define MPIDR_AFFLVL1		U(0x1)
-#define MPIDR_AFFLVL2		U(0x2)
-#define MPIDR_AFFLVL3		U(0x3)
+#define MPIDR_AFFLVL0		ULL(0x0)
+#define MPIDR_AFFLVL1		ULL(0x1)
+#define MPIDR_AFFLVL2		ULL(0x2)
+#define MPIDR_AFFLVL3		ULL(0x3)
+#define MPIDR_AFFLVL(_n)	MPIDR_AFFLVL##_n
 #define MPIDR_AFFLVL0_VAL(mpidr) \
 		(((mpidr) >> MPIDR_AFF0_SHIFT) & MPIDR_AFFLVL_MASK)
 #define MPIDR_AFFLVL1_VAL(mpidr) \
@@ -56,28 +58,42 @@
  */
 #define MPIDR_MAX_AFFLVL	U(2)
 
-/* Constant to highlight the assumption that MPIDR allocation starts from 0 */
-#define FIRST_MPIDR		ULL(0)
+#define MPID_MASK		(MPIDR_MT_MASK				 | \
+				 (MPIDR_AFFLVL_MASK << MPIDR_AFF3_SHIFT) | \
+				 (MPIDR_AFFLVL_MASK << MPIDR_AFF2_SHIFT) | \
+				 (MPIDR_AFFLVL_MASK << MPIDR_AFF1_SHIFT) | \
+				 (MPIDR_AFFLVL_MASK << MPIDR_AFF0_SHIFT))
+
+#define MPIDR_AFF_ID(mpid, n)					\
+	(((mpid) >> MPIDR_AFF_SHIFT(n)) & MPIDR_AFFLVL_MASK)
+
+/*
+ * An invalid MPID. This value can be used by functions that return an MPID to
+ * indicate an error.
+ */
+#define INVALID_MPID		U(0xFFFFFFFF)
 
 /*******************************************************************************
  * Definitions for CPU system register interface to GICv3
  ******************************************************************************/
-#define ICC_SRE_EL1     S3_0_C12_C12_5
-#define ICC_SRE_EL2     S3_4_C12_C9_5
-#define ICC_SRE_EL3     S3_6_C12_C12_5
-#define ICC_CTLR_EL1    S3_0_C12_C12_4
-#define ICC_CTLR_EL3    S3_6_C12_C12_4
-#define ICC_PMR_EL1     S3_0_C4_C6_0
-#define ICC_RPR_EL1     S3_0_C12_C11_3
-#define ICC_IGRPEN1_EL3 S3_6_c12_c12_7
-#define ICC_IGRPEN0_EL1 S3_0_c12_c12_6
-#define ICC_HPPIR0_EL1  S3_0_c12_c8_2
-#define ICC_HPPIR1_EL1  S3_0_c12_c12_2
-#define ICC_IAR0_EL1    S3_0_c12_c8_0
-#define ICC_IAR1_EL1    S3_0_c12_c12_0
-#define ICC_EOIR0_EL1   S3_0_c12_c8_1
-#define ICC_EOIR1_EL1   S3_0_c12_c12_1
-#define ICC_SGI0R_EL1	S3_0_c12_c11_7
+#define ICC_IGRPEN1_EL1		S3_0_C12_C12_7
+#define ICC_SGI1R		S3_0_C12_C11_5
+#define ICC_SRE_EL1		S3_0_C12_C12_5
+#define ICC_SRE_EL2		S3_4_C12_C9_5
+#define ICC_SRE_EL3		S3_6_C12_C12_5
+#define ICC_CTLR_EL1		S3_0_C12_C12_4
+#define ICC_CTLR_EL3		S3_6_C12_C12_4
+#define ICC_PMR_EL1		S3_0_C4_C6_0
+#define ICC_RPR_EL1		S3_0_C12_C11_3
+#define ICC_IGRPEN1_EL3		S3_6_c12_c12_7
+#define ICC_IGRPEN0_EL1		S3_0_c12_c12_6
+#define ICC_HPPIR0_EL1		S3_0_c12_c8_2
+#define ICC_HPPIR1_EL1		S3_0_c12_c12_2
+#define ICC_IAR0_EL1		S3_0_c12_c8_0
+#define ICC_IAR1_EL1		S3_0_c12_c12_0
+#define ICC_EOIR0_EL1		S3_0_c12_c8_1
+#define ICC_EOIR1_EL1		S3_0_c12_c12_1
+#define ICC_SGI0R_EL1		S3_0_c12_c11_7
 
 /*******************************************************************************
  * Generic timer memory mapped registers & offsets
@@ -140,6 +156,25 @@
 #define ID_AA64MMFR0_EL1_PARANGE_SHIFT	U(0)
 #define ID_AA64MMFR0_EL1_PARANGE_MASK	ULL(0xf)
 
+/* ID_AA64ISAR1_EL1 definitions */
+#define ID_AA64ISAR1_GPI_SHIFT	U(28)
+#define ID_AA64ISAR1_GPI_WIDTH	U(4)
+#define ID_AA64ISAR1_GPA_SHIFT	U(24)
+#define ID_AA64ISAR1_GPA_WIDTH	U(4)
+#define ID_AA64ISAR1_API_SHIFT	U(8)
+#define ID_AA64ISAR1_API_WIDTH	U(4)
+#define ID_AA64ISAR1_APA_SHIFT	U(4)
+#define ID_AA64ISAR1_APA_WIDTH	U(4)
+
+#define ID_AA64ISAR1_GPI_MASK \
+	(((ULL(1) << ID_AA64ISAR1_GPI_WIDTH) - ULL(1)) << ID_AA64ISAR1_GPI_SHIFT)
+#define ID_AA64ISAR1_GPA_MASK \
+	(((ULL(1) << ID_AA64ISAR1_GPA_WIDTH) - ULL(1)) << ID_AA64ISAR1_GPA_SHIFT)
+#define ID_AA64ISAR1_API_MASK \
+	(((ULL(1) << ID_AA64ISAR1_API_WIDTH) - ULL(1)) << ID_AA64ISAR1_API_SHIFT)
+#define ID_AA64ISAR1_APA_MASK \
+	(((ULL(1) << ID_AA64ISAR1_APA_WIDTH) - ULL(1)) << ID_AA64ISAR1_APA_SHIFT)
+
 #define PARANGE_0000	U(32)
 #define PARANGE_0001	U(36)
 #define PARANGE_0010	U(40)
@@ -278,6 +313,7 @@
 /* HCR definitions */
 #define HCR_API_BIT		(ULL(1) << 41)
 #define HCR_APK_BIT		(ULL(1) << 40)
+#define HCR_TGE_BIT		(ULL(1) << 27)
 #define HCR_RW_SHIFT		U(31)
 #define HCR_RW_BIT		(ULL(1) << HCR_RW_SHIFT)
 #define HCR_AMO_BIT		(ULL(1) << 5)
@@ -351,6 +387,8 @@
 #define DISABLE_ALL_EXCEPTIONS \
 		(DAIF_FIQ_BIT | DAIF_IRQ_BIT | DAIF_ABT_BIT | DAIF_DBG_BIT)
 
+#define DISABLE_INTERRUPTS	(DAIF_FIQ_BIT | DAIF_IRQ_BIT)
+
 /*
  * RMR_EL3 definitions
  */
@@ -360,12 +398,12 @@
 /*
  * HI-VECTOR address for AArch32 state
  */
-#define HI_VECTOR_BASE	U(0xFFFF0000)
+#define HI_VECTOR_BASE		U(0xFFFF0000)
 
 /*
  * TCR defintions
  */
-#define TCR_EL3_RES1		((U(1) << 31) | (U(1) << 23))
+#define TCR_EL3_RES1		((ULL(1) << 31) | (ULL(1) << 23))
 #define TCR_EL2_RES1		((ULL(1) << 31) | (ULL(1) << 23))
 #define TCR_EL1_IPS_SHIFT	U(32)
 #define TCR_EL2_PS_SHIFT	U(16)
@@ -571,10 +609,17 @@
 #define CNTACR_RWPT_SHIFT	U(0x5)
 
 /*******************************************************************************
- * Definitions of register offsets in the CNTBaseN Frame of the
+ * Definitions of register offsets and fields in the CNTBaseN Frame of the
  * system level implementation of the Generic Timer.
  ******************************************************************************/
-#define CNTBASE_CNTFRQ		U(0x10)
+/* Physical Count register. */
+#define CNTPCT_LO		U(0x0)
+/* Counter Frequency register. */
+#define CNTBASEN_CNTFRQ		U(0x10)
+/* Physical Timer CompareValue register. */
+#define CNTP_CVAL_LO		U(0x20)
+/* Physical Timer Control register. */
+#define CNTP_CTL		U(0x2c)
 
 /* PMCR_EL0 definitions */
 #define PMCR_EL0_RESET_VAL	U(0x0)
@@ -753,7 +798,22 @@
 #define ERXCTLR_EL1		S3_0_C5_C4_1
 #define ERXSTATUS_EL1		S3_0_C5_C4_2
 #define ERXADDR_EL1		S3_0_C5_C4_3
+#define ERXPFGF_EL1		S3_0_C5_C4_4
+#define ERXPFGCTL_EL1		S3_0_C5_C4_5
+#define ERXPFGCDN_EL1		S3_0_C5_C4_6
 #define ERXMISC0_EL1		S3_0_C5_C5_0
 #define ERXMISC1_EL1		S3_0_C5_C5_1
 
+#define ERXCTLR_ED_BIT		(U(1) << 0)
+#define ERXCTLR_UE_BIT		(U(1) << 4)
+
+#define ERXPFGCTL_UC_BIT	(U(1) << 1)
+#define ERXPFGCTL_UEU_BIT	(U(1) << 2)
+#define ERXPFGCTL_CDEN_BIT	(U(1) << 31)
+
+/*******************************************************************************
+ * Armv8.3 Pointer Authentication Registers
+ *******************************************************************************/
+#define APGAKeyLo_EL1		S3_0_C2_C3_0
+
 #endif /* ARCH_H */
diff --git a/include/lib/aarch64/arch_helpers.h b/include/lib/aarch64/arch_helpers.h
index 61f9830..8b3d53a 100644
--- a/include/lib/aarch64/arch_helpers.h
+++ b/include/lib/aarch64/arch_helpers.h
@@ -7,8 +7,8 @@
 #ifndef ARCH_HELPERS_H
 #define ARCH_HELPERS_H
 
-#include <arch.h>	/* for additional register definitions */
-#include <cdefs.h>	/* For __dead2 */
+#include <arch.h>
+#include <cdefs.h>
 #include <stdbool.h>
 #include <stdint.h>
 #include <string.h>
@@ -179,11 +179,13 @@
 #define write_daifclr(val) SYSREG_WRITE_CONST(daifclr, val)
 #define write_daifset(val) SYSREG_WRITE_CONST(daifset, val)
 
-DEFINE_SYSREG_READ_FUNC(par_el1)
+DEFINE_SYSREG_RW_FUNCS(par_el1)
 DEFINE_SYSREG_READ_FUNC(id_pfr1_el1)
+DEFINE_SYSREG_READ_FUNC(id_aa64isar1_el1)
 DEFINE_SYSREG_READ_FUNC(id_aa64pfr0_el1)
 DEFINE_SYSREG_READ_FUNC(id_aa64dfr0_el1)
 DEFINE_SYSREG_READ_FUNC(CurrentEl)
+DEFINE_SYSREG_READ_FUNC(ctr_el0)
 DEFINE_SYSREG_RW_FUNCS(daif)
 DEFINE_SYSREG_RW_FUNCS(spsr_el1)
 DEFINE_SYSREG_RW_FUNCS(spsr_el2)
@@ -202,14 +204,20 @@
 DEFINE_SYSOP_TYPE_FUNC(dsb, ish)
 DEFINE_SYSOP_TYPE_FUNC(dsb, nsh)
 DEFINE_SYSOP_TYPE_FUNC(dsb, ishst)
-DEFINE_SYSOP_TYPE_FUNC(dmb, ish)
+DEFINE_SYSOP_TYPE_FUNC(dmb, oshld)
+DEFINE_SYSOP_TYPE_FUNC(dmb, oshst)
+DEFINE_SYSOP_TYPE_FUNC(dmb, osh)
+DEFINE_SYSOP_TYPE_FUNC(dmb, nshld)
+DEFINE_SYSOP_TYPE_FUNC(dmb, nshst)
+DEFINE_SYSOP_TYPE_FUNC(dmb, nsh)
+DEFINE_SYSOP_TYPE_FUNC(dmb, ishld)
 DEFINE_SYSOP_TYPE_FUNC(dmb, ishst)
+DEFINE_SYSOP_TYPE_FUNC(dmb, ish)
 DEFINE_SYSOP_FUNC(isb)
 
 uint32_t get_afflvl_shift(uint32_t);
 uint32_t mpidr_mask_lower_afflvls(uint64_t, uint32_t);
 
-
 void __dead2 eret(uint64_t x0, uint64_t x1, uint64_t x2, uint64_t x3,
 		  uint64_t x4, uint64_t x5, uint64_t x6, uint64_t x7);
 void __dead2 smc(uint64_t x0, uint64_t x1, uint64_t x2, uint64_t x3,
@@ -286,9 +294,15 @@
 
 DEFINE_SYSREG_RW_FUNCS(cpacr_el1)
 DEFINE_SYSREG_RW_FUNCS(cntfrq_el0)
+DEFINE_SYSREG_RW_FUNCS(cnthp_ctl_el2)
+DEFINE_SYSREG_RW_FUNCS(cnthp_tval_el2)
+DEFINE_SYSREG_RW_FUNCS(cnthp_cval_el2)
 DEFINE_SYSREG_RW_FUNCS(cntps_ctl_el1)
 DEFINE_SYSREG_RW_FUNCS(cntps_tval_el1)
 DEFINE_SYSREG_RW_FUNCS(cntps_cval_el1)
+DEFINE_SYSREG_RW_FUNCS(cntp_ctl_el0)
+DEFINE_SYSREG_RW_FUNCS(cntp_tval_el0)
+DEFINE_SYSREG_RW_FUNCS(cntp_cval_el0)
 DEFINE_SYSREG_READ_FUNC(cntpct_el0)
 DEFINE_SYSREG_RW_FUNCS(cnthctl_el2)
 
@@ -298,24 +312,23 @@
 
 DEFINE_SYSREG_RW_FUNCS(vpidr_el2)
 DEFINE_SYSREG_RW_FUNCS(vmpidr_el2)
-DEFINE_SYSREG_RW_FUNCS(cntp_ctl_el0)
 
 DEFINE_SYSREG_READ_FUNC(isr_el1)
 
-DEFINE_SYSREG_READ_FUNC(ctr_el0)
-
 DEFINE_SYSREG_RW_FUNCS(mdcr_el2)
 DEFINE_SYSREG_RW_FUNCS(mdcr_el3)
 DEFINE_SYSREG_RW_FUNCS(hstr_el2)
-DEFINE_SYSREG_RW_FUNCS(cnthp_ctl_el2)
 DEFINE_SYSREG_RW_FUNCS(pmcr_el0)
 
+/* GICv3 System Registers */
+
 DEFINE_RENAME_SYSREG_RW_FUNCS(icc_sre_el1, ICC_SRE_EL1)
 DEFINE_RENAME_SYSREG_RW_FUNCS(icc_sre_el2, ICC_SRE_EL2)
 DEFINE_RENAME_SYSREG_RW_FUNCS(icc_sre_el3, ICC_SRE_EL3)
 DEFINE_RENAME_SYSREG_RW_FUNCS(icc_pmr_el1, ICC_PMR_EL1)
 DEFINE_RENAME_SYSREG_READ_FUNC(icc_rpr_el1, ICC_RPR_EL1)
 DEFINE_RENAME_SYSREG_RW_FUNCS(icc_igrpen1_el3, ICC_IGRPEN1_EL3)
+DEFINE_RENAME_SYSREG_RW_FUNCS(icc_igrpen1_el1, ICC_IGRPEN1_EL1)
 DEFINE_RENAME_SYSREG_RW_FUNCS(icc_igrpen0_el1, ICC_IGRPEN0_EL1)
 DEFINE_RENAME_SYSREG_READ_FUNC(icc_hppir0_el1, ICC_HPPIR0_EL1)
 DEFINE_RENAME_SYSREG_READ_FUNC(icc_hppir1_el1, ICC_HPPIR1_EL1)
@@ -324,6 +337,7 @@
 DEFINE_RENAME_SYSREG_WRITE_FUNC(icc_eoir0_el1, ICC_EOIR0_EL1)
 DEFINE_RENAME_SYSREG_WRITE_FUNC(icc_eoir1_el1, ICC_EOIR1_EL1)
 DEFINE_RENAME_SYSREG_WRITE_FUNC(icc_sgi0r_el1, ICC_SGI0R_EL1)
+DEFINE_RENAME_SYSREG_RW_FUNCS(icc_sgi1r, ICC_SGI1R)
 
 DEFINE_RENAME_SYSREG_RW_FUNCS(amcgcr_el0, AMCGCR_EL0)
 DEFINE_RENAME_SYSREG_RW_FUNCS(amcntenclr0_el0, AMCNTENCLR0_EL0)
@@ -351,11 +365,14 @@
 DEFINE_RENAME_SYSREG_READ_FUNC(erxmisc0_el1, ERXMISC0_EL1)
 DEFINE_RENAME_SYSREG_READ_FUNC(erxmisc1_el1, ERXMISC1_EL1)
 
+/* Armv8.3 Pointer Authentication Registers */
+DEFINE_RENAME_SYSREG_RW_FUNCS(apgakeylo_el1, APGAKeyLo_EL1)
+
 #define IS_IN_EL(x) \
 	(GET_EL(read_CurrentEl()) == MODE_EL##x)
 
 #define IS_IN_EL1() IS_IN_EL(1)
-#define IS_IN_EL3() IS_IN_EL(3)
+#define IS_IN_EL2() IS_IN_EL(2)
 #define IS_IN_EL3() IS_IN_EL(3)
 
 static inline unsigned int get_current_el(void)
diff --git a/include/lib/utils_def.h b/include/lib/utils_def.h
index fa13caa..02963ac 100644
--- a/include/lib/utils_def.h
+++ b/include/lib/utils_def.h
@@ -160,5 +160,6 @@
  */
 #define ASSERT_SYM_PTR_ALIGN(sym) assert(((size_t)(sym) % __alignof__(*(sym))) == 0)
 
+#define COMPILER_BARRIER() __asm__ volatile ("" ::: "memory")
 
 #endif /* UTILS_DEF_H */
diff --git a/lib/romlib/Makefile b/lib/romlib/Makefile
index 46b9206..00dde31 100644
--- a/lib/romlib/Makefile
+++ b/lib/romlib/Makefile
@@ -15,6 +15,7 @@
 INC         = $(INCLUDES:-I%=-I../../%)
 PPFLAGS     = $(INC) $(DEFINES) -P -D__ASSEMBLY__ -D__LINKER__ -MD -MP -MT $(BUILD_DIR)/romlib.ld
 OBJS        = $(BUILD_DIR)/jmptbl.o $(BUILD_DIR)/init.o
+MAPFILE     = ../../$(BUILD_PLAT)/romlib/romlib.map
 
 V ?= 0
 ifeq ($(V),0)
@@ -25,7 +26,7 @@
 
 ifeq ($(DEBUG),1)
    CFLAGS  := -g
-   LDFLAGS := -g
+   LDFLAGS := -g --gc-sections -O1 -Map=$(MAPFILE)
 endif
 
 
diff --git a/lib/romlib/gen_combined_bl1_romlib.sh b/lib/romlib/gen_combined_bl1_romlib.sh
new file mode 100755
index 0000000..1e3f73a
--- /dev/null
+++ b/lib/romlib/gen_combined_bl1_romlib.sh
@@ -0,0 +1,53 @@
+#!/bin/sh
+# Copyright (c) 2018, ARM Limited and Contributors. All rights reserved.
+#
+# SPDX-License-Identifier: BSD-3-Clause
+
+set -e
+
+output="bl1_romlib.bin"
+
+# Set trap for removing temporary file
+trap 'r=$?;rm -f $bin_path/$$.tmp;exit $r' EXIT HUP QUIT INT TERM
+
+# Read input parameters
+for i
+do
+	case $i in
+	-o)
+		output=$2
+		shift 2
+		;;
+	--)
+		shift
+		break
+		;;
+	-*)
+		echo usage: gen_combined_bl1_romlib.sh [-o output] path_to_build_directory >&2
+		;;
+	esac
+done
+
+
+bin_path=$1
+romlib_path=$1/romlib
+bl1_file="$1/bl1/bl1.elf"
+romlib_file="$1/romlib/romlib.elf"
+bl1_end=""
+romlib_begin=""
+
+# Get address of __BL1_ROM_END__
+bl1_end=`nm -a "$bl1_file" |
+awk '$3 == "__BL1_ROM_END__" {print "0x"$1}'`
+
+# Get start address of romlib "text" section
+romlib_begin=`nm -a "$romlib_file" |
+awk '$3 == ".text" {print "0x"$1}'`
+
+# Character "U" will be read as "55" in hex when it is
+# concatenated with bl1.bin. Generate combined BL1 and ROMLIB
+# binary with filler bytes for juno
+(cat $bin_path/bl1.bin
+ yes U | sed $(($romlib_begin - $bl1_end))q | tr -d '\n'
+ cat $bin_path/romlib/romlib.bin) > $bin_path/$$.tmp &&
+mv $bin_path/$$.tmp $bin_path/$output
diff --git a/lib/romlib/genwrappers.sh b/lib/romlib/genwrappers.sh
index bcf670b..48ee5a4 100755
--- a/lib/romlib/genwrappers.sh
+++ b/lib/romlib/genwrappers.sh
@@ -31,7 +31,7 @@
 done
 
 awk  '{sub(/[:blank:]*#.*/,"")}
-!/^$/ {print $1*4, $2, $3}' "$@" |
+!/^$/ && !/\\tpatch$/ {print $1*4, $2, $3}' "$@" |
 while read idx lib sym
 do
 	file=$build/${lib}_$sym
diff --git a/lib/romlib/jmptbl.i b/lib/romlib/jmptbl.i
index 338cd8a..5eca5aa 100644
--- a/lib/romlib/jmptbl.i
+++ b/lib/romlib/jmptbl.i
@@ -3,6 +3,10 @@
 #
 # SPDX-License-Identifier: BSD-3-Clause
 #
+# Format:
+# index	lib	function	[patch]
+# Add "patch" at the end of the line to patch a function. For example:
+# 14	mbedtls	mbedtls_memory_buffer_alloc_init	patch
 
 0	rom	rom_lib_init
 1	fdt	fdt_getprop_namelen
@@ -27,9 +31,10 @@
 20	mbedtls	mbedtls_pk_init
 21	mbedtls	mbedtls_pk_parse_subpubkey
 22	mbedtls	mbedtls_pk_verify_ext
-23	mbedtls	mbedtls_platform_set_snprintf
-24	mbedtls	mbedtls_x509_get_rsassa_pss_params
-25	mbedtls	mbedtls_x509_get_sig_alg
-26	mbedtls	mbedtls_md_info_from_type
-27	c	exit
-28	c	atexit
+23	mbedtls	mbedtls_platform_set_calloc_free
+24	mbedtls	mbedtls_platform_set_snprintf
+25	mbedtls	mbedtls_x509_get_rsassa_pss_params
+26	mbedtls	mbedtls_x509_get_sig_alg
+27	mbedtls	mbedtls_md_info_from_type
+28	c	exit
+29	c	atexit
\ No newline at end of file
diff --git a/make_helpers/build_macros.mk b/make_helpers/build_macros.mk
index e186fc1..d60a5bf 100644
--- a/make_helpers/build_macros.mk
+++ b/make_helpers/build_macros.mk
@@ -338,7 +338,7 @@
 LDLIBS += -l$(1)
 
 ifeq ($(USE_ROMLIB),1)
-LDLIBS := -lwrappers -lc
+LIBWRAPPER = -lwrappers
 endif
 
 all: ${LIB_DIR}/lib$(1).a
@@ -402,7 +402,7 @@
 endif
 	$$(Q)$$(LD) -o $$@ $$(TF_LDFLAGS) $$(LDFLAGS) -Map=$(MAPFILE) \
 		--script $(LINKERFILE) $(BUILD_DIR)/build_message.o \
-		$(OBJS) $(LDPATHS) $(LDLIBS) $(BL_LIBS)
+		$(OBJS) $(LDPATHS) $(LIBWRAPPER) $(LDLIBS) $(BL_LIBS)
 
 $(DUMP): $(ELF)
 	$${ECHO} "  OD      $$@"
diff --git a/plat/arm/board/juno/include/platform_def.h b/plat/arm/board/juno/include/platform_def.h
index 735e4a3..0bbe3e1 100644
--- a/plat/arm/board/juno/include/platform_def.h
+++ b/plat/arm/board/juno/include/platform_def.h
@@ -55,7 +55,8 @@
 #define PLAT_ARM_TRUSTED_SRAM_SIZE	UL(0x00040000)	/* 256 KB */
 
 /* Use the bypass address */
-#define PLAT_ARM_TRUSTED_ROM_BASE	V2M_FLASH0_BASE + BL1_ROM_BYPASS_OFFSET
+#define PLAT_ARM_TRUSTED_ROM_BASE	(V2M_FLASH0_BASE + \
+					BL1_ROM_BYPASS_OFFSET)
 
 #define NSRAM_BASE			UL(0x2e000000)
 #define NSRAM_SIZE			UL(0x00008000)	/* 32KB */
@@ -64,11 +65,22 @@
 #define PLAT_ARM_MEM_PROTEC_VA_FRAME	UL(0xc0000000)
 
 /*
+ * PLAT_ARM_MAX_ROMLIB_RW_SIZE is define to use a full page
+ */
+
+#if USE_ROMLIB
+#define PLAT_ARM_MAX_ROMLIB_RW_SIZE	UL(0x1000)
+#define PLAT_ARM_MAX_ROMLIB_RO_SIZE	UL(0xe000)
+#else
+#define PLAT_ARM_MAX_ROMLIB_RW_SIZE	UL(0)
+#define PLAT_ARM_MAX_ROMLIB_RO_SIZE	UL(0)
+#endif
+
+/*
  * Actual ROM size on Juno is 64 KB, but TBB currently requires at least 80 KB
  * in debug mode. We can test TBB on Juno bypassing the ROM and using 128 KB of
  * flash
  */
-#define PLAT_ARM_MAX_ROMLIB_RO_SIZE	0
 
 #if TRUSTED_BOARD_BOOT
 #define PLAT_ARM_TRUSTED_ROM_SIZE	UL(0x00020000)
@@ -121,15 +133,6 @@
 #endif
 
 /*
- * PLAT_ARM_MAX_ROMLIB_RW_SIZE is define to use a full page
- */
-#if USE_ROMLIB
-#define PLAT_ARM_MAX_ROMLIB_RW_SIZE	UL(0x1000)
-#else
-#define PLAT_ARM_MAX_ROMLIB_RW_SIZE	UL(0)
-#endif
-
-/*
  * PLAT_ARM_MAX_BL2_SIZE is calculated using the current BL2 debug size plus a
  * little space for growth.
  */
diff --git a/plat/arm/board/juno/platform.mk b/plat/arm/board/juno/platform.mk
index f28139d..ba1acd4 100644
--- a/plat/arm/board/juno/platform.mk
+++ b/plat/arm/board/juno/platform.mk
@@ -96,6 +96,14 @@
   Please set RESET_TO_BL31 to 0.")
 endif
 
+ifeq ($(USE_ROMLIB),1)
+all : bl1_romlib.bin
+endif
+
+bl1_romlib.bin : $(BUILD_PLAT)/bl1.bin $(BUILD_PLAT)/romlib/romlib.bin
+	@echo "Building combined BL1 and ROMLIB binary for Juno $@"
+	./lib/romlib/gen_combined_bl1_romlib.sh -o bl1_romlib.bin $(BUILD_PLAT)
+
 # Errata workarounds for Cortex-A53:
 ERRATA_A53_826319		:=	1
 ERRATA_A53_835769		:=	1
diff --git a/plat/arm/common/arm_common.c b/plat/arm/common/arm_common.c
index b72dd20..56ad8ae 100644
--- a/plat/arm/common/arm_common.c
+++ b/plat/arm/common/arm_common.c
@@ -128,10 +128,10 @@
 	/*
 	 * Initialize CNTFRQ register in Non-secure CNTBase frame.
 	 * This is only required for Juno, because it doesn't follow ARM ARM
-	 * in that the value updated in CNTFRQ is not reflected in CNTBASE_CNTFRQ.
-	 * Hence update the value manually.
+	 * in that the value updated in CNTFRQ is not reflected in
+	 * CNTBASEN_CNTFRQ. Hence update the value manually.
 	 */
-	mmio_write_32(ARM_SYS_CNT_BASE_NS + CNTBASE_CNTFRQ, freq_val);
+	mmio_write_32(ARM_SYS_CNT_BASE_NS + CNTBASEN_CNTFRQ, freq_val);
 #endif
 }
 #endif /* ARM_SYS_TIMCTL_BASE */
diff --git a/services/std_svc/sdei/sdei_intr_mgmt.c b/services/std_svc/sdei/sdei_intr_mgmt.c
index e834a2b..fa778c0 100644
--- a/services/std_svc/sdei/sdei_intr_mgmt.c
+++ b/services/std_svc/sdei/sdei_intr_mgmt.c
@@ -485,15 +485,14 @@
 	/*
 	 * We reach here when client completes the event.
 	 *
-	 * If the cause of dispatch originally interrupted the Secure world, and
-	 * if Non-secure world wasn't allowed to preempt Secure execution,
+	 * If the cause of dispatch originally interrupted the Secure world,
 	 * resume Secure.
 	 *
 	 * No need to save the Non-secure context ahead of a world switch: the
 	 * Non-secure context was fully saved before dispatch, and has been
 	 * returned to its pre-dispatch state.
 	 */
-	if ((sec_state == SECURE) && (ehf_is_ns_preemption_allowed() == 0U))
+	if (sec_state == SECURE)
 		restore_and_resume_secure_context();
 
 	/*