Rationalize reset handling code ...

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

Remove FIRST_RESET_HANDLER_CALL build option ...

This patch removes the FIRST_RESET_HANDLER_CALL build flag and its
use in ARM development platforms. If a different reset handling
behavior is required between the first and subsequent invocations
of the reset handling code, this should be detected at runtime.

On Juno, the platform reset handler is now always compiled in.
This means it is now executed twice on the cold boot path, first in
BL1 then in BL3-1, and it has the same behavior in both cases. It is
also executed twice on the warm boot path, first in BL1 then in the
PSCI entrypoint code.

Also update the documentation to reflect this change.

NOTE: THIS PATCH MAY FORCE PLATFORM PORTS THAT USE THE
FIRST_RESET_HANDLER_CALL BUILD OPTION TO FIX THEIR RESET HANDLER.

Change-Id: Ie5c17dbbd0932f5fa3b446efc6e590798a5beae2

Always enable CCI coherency in BL3-1 ...

On ARM standard platforms, snoop and DVM requests used to be enabled
for the primary CPU's cluster only in the first EL3 bootloader.
In other words, if the platform reset into BL1 then CCI coherency
would be enabled by BL1 only, and not by BL3-1 again.

However, this doesn't cater for platforms that use BL3-1 along with
a non-TF ROM bootloader that doesn't enable snoop and DVM requests.
In this case, CCI coherency is never enabled.

This patch modifies the function bl31_early_platform_setup() on
ARM standard platforms so that it always enables snoop and DVM
requests regardless of whether earlier bootloader stages have
already done it. There is no harm in executing this code twice.

ARM Trusted Firmware Design document updated accordingly.

Change-Id: Idf1bdeb24d2e1947adfbb76a509f10beef224e1c

Merge pull request #303 from danh-arm/dh/fix-fvp-setup-topology ...

Fix return type of FVP plat_arm_topology_setup

Fix return type of FVP plat_arm_topology_setup ...

Fix the return type of the FVP `plat_arm_topology_setup` function
to be `void` instead of `int` to match the declaration in
`plat_arm.h`.

This does not result in any change in behavior.

Change-Id: I62edfa7652b83bd26cffb7d167153959b38e37e7

Merge pull request #301 from soby-mathew/sm/cpu_on_pend_state_fix ...

PSCI: Set ON_PENDING state early during CPU_ON

PSCI: Set ON_PENDING state early during CPU_ON ...

In the debug build of the function get_power_on_target_afflvl(), there is a
check to ensure that the CPU is emerging from a SUSPEND or ON_PENDING state.
The state is checked without acquiring the lock for the CPU node. The state
could be updated to ON_PENDING in psci_afflvl_on() after the target CPU has
been powered up. This results in a race condition which could cause the
check for the ON_PENDING state in get_power_on_target_afflvl() to fail.
This patch resolves this race condition by setting the state of the target
CPU to ON_PENDING before the platform port attempts to power it on. The
target CPU is thus guaranteed to read the correct the state. In case
the power on operation fails, the state of the CPU is restored to OFF.

Fixes ARM-software/tf-issues#302

Change-Id: I3f2306a78c58d47b1a0fb7e33ab04f917a2d5044

Merge pull request #297 from sandrine-bailleux/sb/move-up-deps ...

Move up dependency versions

Merge pull request #296 from danh-arm/sb/scpi-min-changes ...

Move to the new ARM SCP Messaging Interfaces v2

Merge pull request #295 from danh-arm/dh/plat-port-reorg ...

ARM platform port reorganization

FVP: update device tree idle state entries ...

Device tree idle state bindings changed in kernel v3.18. This patch
updates the FVP DT files to use PSCI suspend as idle state.

The patch also updates the 'compatible' property in the PSCI node
and the 'entry-method' property in the idle-states node in the FVP
Foundation GICv2-legacy device tree.

Change-Id: Ie921d497c579f425c03d482f9d7b90e166106e2f

Move up dependency versions in user guide ...

Move up the version numbers in the user guide of:

 * DS-5 (to v5.21)
 * EDK2 (to v3.0)
 * Linux Kernel (to 1.6-Juno)
 * Linaro file-system (to 15.03)
 * Juno SCP binary (to v1.7.0 within board recovery image 0.11.3).

Change-Id: Ieb09e633acc2b33823ddf35f77f44e7da60b99ba

Detect SCP version incompatibility ...

There has been a breaking change in the communication protocols used
between the AP cores and the SCP on CSS based platforms like Juno.
This means both the AP Trusted Firmware and SCP firmware must be
updated at the same time.

In case the user forgets to update the SCP ROM firmware, this patch
detects when it still uses the previous version of the communication
protocol. It will then output a comprehensive error message that helps
trouble-shoot the issue.

Change-Id: I7baf8f05ec0b7d8df25e0ee53df61fe7be0207c2

Move to the new ARM SCP Messaging Interfaces ...

The communication protocol used between the AP cores and the SCP
in CSS-based platforms like Juno has undergone a number of changes.
This patch makes the required modifications to the SCP Boot Protocol,
SCPI Protocol and MHU driver code in shared CSS platform code so that
the AP cores are still able to communicate with the SCP.

This patch focuses on the mandatory changes to make it work. The
design of this code needs to be improved but this will come in
a subsequent patch.

The main changes are:

 - MHU communication protocol

   - The command ID and payload size are no longer written into the
     MHU registers directly. Instead, they are stored in the payload
     area. The MHU registers are now used only as a doorbell to kick
     off messages. Same goes for any command result, the AP has to
     pick it up from the payload area.

 - SCP Boot Protocol

   - The BL3-0 image is now expected to embed a checksum. This
     checksum must be passed to the SCP, which uses it to check the
     integrity of the image it received.

   - The BL3-0 image used to be transferred a block (4KB)
     at a time. The SCP now supports receiving up to 128KB at a
     time, which is more than the size of the BL3-0 image.
     Therefore, the image is now sent in one go.

   - The command IDs have changed.

 - SCPI Protocol

   - The size of the SCPI payload has been reduced down from 512
     bytes to 256 bytes. This changes the base address of the
     AP-to-SCP payload area.

   - For commands that have a response, the response is the same SCPI
     header that was sent, except for the size and the status, which
     both must be updated appropriately. Success/Failure of a command
     is determined by looking at the updated status code.

   - Some command IDs have changed.

NOTE: THIS PATCH BREAKS COMPATIBILITY WITH FORMER VERSIONS OF THE SCP
FIRMWARE AND THUS REQUIRES AN UPDATE OF THIS BINARY. THE LATEST SCP
BINARY CAN BE OBTAINED FROM THE ARM CONNECTED COMMUNITY WEBSITE.

Change-Id: Ia5f6b95fe32401ee04a3805035748e8ef6718da7

Doc updates following platform port reorganization ...

Update the User Guide, Porting Guide and Firmware Design documents
to align them with the recent changes made to the FVP and Juno
platform ports.

Also fix some other historical inaccuracies.

Change-Id: I37aba4805f9044b1a047996d3e396c75f4a09176

Move Juno port to plat/arm/board/juno ...

Move the Juno port from plat/juno to plat/arm/board/juno. Also rename
some of the files so they are consistently prefixed with juno_.
Update the platform makefiles accordingly.

Change-Id: I0af6cb52a5fee7ef209107a1188b76a3c33a2a9f

Migrate Juno port to use common code ...

Major update to the Juno platform port to use the common platform code
in (include/)plat/arm/* and (include/)plat/common/*. This mainly
consists of removing duplicated code but also introduces some small
behavioural changes where there was unnecessary variation between the
FVP and Juno ports. See earlier commit titled `Add common ARM and CSS
platform code` for details.

Also move the ARM SoC specific security setup (i.e. NIC-400 and PCIe
initialization) from BL1 to `plat_arm_security_setup()` in BL2,
where the other security setup is done.

Change-Id: Ic9fe01bae8ed382bfb04fc5839a4cfff332eb124

Move FVP port to plat/arm/board/fvp ...

Move the FVP port from plat/fvp to plat/arm/board/fvp. Also rename
some of the files so they are consistently prefixed with fvp_.
Update the platform makefiles accordingly.

Change-Id: I7569affc3127d66405f1548fc81b878a858e61b7

Migrate FVP port to use common code ...

Major update to the FVP platform port to use the common platform code
in (include/)plat/arm/* and (include/)plat/common/*. This mainly
consists of removing duplicated code but also introduces some small
behavioural changes where there was unnecessary variation between the
FVP and Juno ports. See earlier commit titled `Add common ARM and CSS
platform code` for details.

Also add support for Foundation FVP version 9.1 during FVP config
setup to prevent a warning being emitted in the console.

Change-Id: I254ca854987642ce09d1b924c9fd410a6e13e3bc

Add common ARM and CSS platform code ...

This major change pulls out the common functionality from the
FVP and Juno platform ports into the following categories:

*   (include/)plat/common. Common platform porting functionality that
typically may be used by all platforms.

*   (include/)plat/arm/common. Common platform porting functionality
that may be used by all ARM standard platforms. This includes all
ARM development platforms like FVP and Juno but may also include
non-ARM-owned platforms.

*   (include/)plat/arm/board/common. Common platform porting
functionality for ARM development platforms at the board
(off SoC) level.

*   (include/)plat/arm/css/common. Common platform porting
functionality at the ARM Compute SubSystem (CSS) level. Juno
is an example of a CSS-based platform.

*   (include/)plat/arm/soc/common. Common platform porting
functionality at the ARM SoC level, which is not already defined
at the ARM CSS level.

No guarantees are made about the backward compatibility of
functionality provided in (include/)plat/arm.

Also remove any unnecessary variation between the ARM development
platform ports, including:

*   Unify the way BL2 passes `bl31_params_t` to BL3-1. Use the
Juno implementation, which copies the information from BL2 memory
instead of expecting it to persist in shared memory.

*   Unify the TZC configuration. There is no need to add a region
for SCP in Juno; it's enough to simply not allow any access to
this reserved region. Also set region 0 to provide no access by
default instead of assuming this is the case.

*   Unify the number of memory map regions required for ARM
development platforms, although the actual ranges mapped for each
platform may be different. For the FVP port, this reduces the
mapped peripheral address space.

These latter changes will only be observed when the platform ports
are migrated to use the new common platform code in subsequent
patches.

Change-Id: Id9c269dd3dc6e74533d0e5116fdd826d53946dc8

Add linker symbol declarations to bl_common.h ...

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

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

Change-Id: I8ed0426bc815317c4536b588e4e78bc15b4fe91c

Allow deeper platform port directory structure ...

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

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

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

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

Change-Id: I213420164808c5ddb99a26144e8e3f141a7417b7

Separate out common console functionality ...

Separate out the common console functionality in
`drivers/arm/pl011/pl011_console.S` into a new source file
`drivers/console/console.S`. The former includes the latter to
provide backwards compatibility for platform make files.

Also add a skeleton console implementation for platforms that do not
want to use PL011.

Change-Id: I1ff963b2b54a872fbcf1eb0700797b9e9afa2538

Add header guards to asm macro files ...

Some assembly files containing macros are included like header files
into other assembly files. This will cause assembler errors if they
are included multiple times.

Add header guards to assembly macro files to avoid assembler errors.

Change-Id: Ia632e767ed7df7bf507b294982b8d730a6f8fe69

Remove use of PLATFORM_CACHE_LINE_SIZE ...

The required platform constant PLATFORM_CACHE_LINE_SIZE is
unnecessary since CACHE_WRITEBACK_GRANULE effectively provides the
same information. CACHE_WRITEBACK_GRANULE is preferred since this
is an architecturally defined term and allows comparison with the
corresponding hardware register value.

Replace all usage of PLATFORM_CACHE_LINE_SIZE with
CACHE_WRITEBACK_GRANULE.

Also, add a runtime assert in BL1 to check that the provided
CACHE_WRITEBACK_GRANULE matches the value provided in CTR_EL0.

Change-Id: If87286be78068424217b9f3689be358356500dcd

Fix type mismatches in verbose logging ...

Commit dad2504 adds support for type checking in printf-like
functions. Some of the VERBOSE logging statements were not updated
at that time.

Fix the type mismatches in the verbose logging statements.

Change-Id: Idd9a49e41cc0dc31f7698e220819d934e3d2d10e

Add TZC function to configure region 0 ...

Region 0 is special in TZC-400. It is possible to set the access
permissions for this but not the address range or filters to which
the permissions apply. Add a function for setting the region 0
access permissions.

Also add some VERBOSE logging and allow assembly files to include
the TZC header.

Change-Id: I4389261ba10a6e5e2e43ee93d55318dc507b6648

Merge pull request #290 from soby-mathew/sm/AEM_crash_report_fix ...

Fix recursive crash prints on FVP AEM model

Merge pull request #289 from danh-arm/vw/tlkd-args-via-cpu-regs-v4 ...

Pass arguments/results between EL3/S-EL1 via CPU registers (x0-x7) v4

Merge pull request #288 from danh-arm/sb/remove-arch-makefile ...

Remove the ARCH build configuration from the Makefile v2