Define frequency of system counter in platform code ...

BL3-1 architecture setup code programs the system counter frequency
into the CNTFRQ_EL0 register. This frequency is defined by the
platform, though. This patch introduces a new platform hook that
the architecture setup code can call to retrieve this information.
In the ARM FVP port, this returns the first entry of the frequency
modes table from the memory mapped generic timer.

All system counter setup code has been removed from BL1 as some
platforms may not have initialized the system counters at this stage.
The platform specific settings done exclusively in BL1 have been moved
to BL3-1. In the ARM FVP port, this consists in enabling and
initializing the System level generic timer. Also, the frequency change
request in the counter control register has been set to 0 to make it
explicit it's using the base frequency. The CNTCR_FCREQ() macro has been
fixed in this context to give an entry number rather than a bitmask.

In future, when support for firmware update is implemented, there
is a case where BL1 platform specific code will need to program
the counter frequency. This should be implemented at that time.

This patch also updates the relevant documentation.

Revert "Move architecture timer setup to platform-specific code" ...

This reverts commit 1c297bf
because it introduced a bug: the CNTFRQ_EL0 register was no
longer programmed by all CPUs.  bl31_platform_setup() function
is invoked only in the cold boot path and consequently only
on the primary cpu.

A subsequent commit will correctly implement the necessary changes
to the counter frequency setup code.

Move architecture timer setup to platform-specific code ...

At present, bl1_arch_setup() and bl31_arch_setup() program the counter
frequency using a value from the memory mapped generic timer. The
generic timer however is not necessarily present on all ARM systems
(although it is architected to be present on all server systems).

This patch moves the timer setup to platform-specific code and updates
the relevant documentation. Also, CNTR.FCREQ is set as the specification
requires the bit corresponding to the counter's frequency to be set when
enabling. Since we intend to use the base frequency, set bit 8.

Fixes ARM-software/tf-issues#24

Change-Id: I32c52cf882253e01f49056f47c58c23e6f422652

Consolidate design and porting documentation ...

Consolidate firmware-design.md and porting-guide.pm so
that recently added sections fit better with
pre-existing sections. Make the documentation more
consistent in use of terminology.

Change-Id: Id87050b096122fbd845189dc2fe1cd17c3003468

fvp: Initialise UART earlier ...

The UART used to be initialised in bl1_platform_setup(). This is too
late because there are some calls to the assert() macro, which needs
to print some messages on the console, before that.

This patch moves the UART initialisation code to
bl1_early_platform_setup().

Fixes ARM-software/tf-issues#49

Change-Id: I98c83a803866372806d2a9c2e1ed80f2ef5b3bcc

Add support for BL3-2 in BL3-1 ...

This patch adds the following support to the BL3-1 stage:

1. BL3-1 allows runtime services to specify and determine the security
   state of the next image after BL3-1. This has been done by adding
   the `bl31_set_next_image_type()` & `bl31_get_next_image_type()`
   apis. The default security state is non-secure. The platform api
   `bl31_get_next_image_info()` has been modified to let the platform
   decide which is the next image in the desired security state.

2. BL3-1 exports the `bl31_prepare_next_image_entry()` function to
   program entry into the target security state. It uses the apis
   introduced in 1. to do so.

3. BL3-1 reads the information populated by BL2 about the BL3-2 image
   into its internal data structures.

4. BL3-1 introduces a weakly defined reference `bl32_init()` to allow
   initialisation of a BL3-2 image. A runtime service like the Secure
   payload dispatcher will define this function if present.

Change-Id: Icc46dcdb9e475ce6575dd3f9a5dc7a48a83d21d1

Add support for BL3-2 in BL2 ...

This patch adds support for loading a BL3-2 image in BL2. In case a
BL3-2 image is found, it also passes information to BL3-1 about where it
is located and the extents of memory available to it. Information about
memory extents is populated by platform specific code.

The documentation has also been updated to reflect the above changes.

Change-Id: I526b2efb80babebab1318f2b02e319a86d6758b0
Co-authored-by: Jeenu Viswambharan <jeenu.viswambharan@arm.com>

Rework BL2 to BL3-1 hand over interface ...

This patch reworks BL2 to BL3-1 hand over interface by introducing a
composite structure (bl31_args) that holds the superset of information
that needs to be passed from BL2 to BL3-1.

  - The extents of secure memory available to BL3-1
  - The extents of memory available to BL3-2 (not yet implemented) and
    BL3-3
  - Information to execute BL3-2 (not yet implemented) and BL3-3 images

This patch also introduces a new platform API (bl2_get_bl31_args_ptr)
that needs to be implemented by the platform code to export reference to
bl31_args structure which has been allocated in platform-defined memory.

The platform will initialize the extents of memory available to BL3-3
during early platform setup in bl31_args structure. This obviates the
need for bl2_get_ns_mem_layout platform API.

BL2 calls the bl2_get_bl31_args_ptr function to get a reference to
bl31_args structure. It uses the 'bl33_meminfo' field of this structure
to load the BL3-3 image. It sets the entry point information for the
BL3-3 image in the 'bl33_image_info' field of this structure. The
reference to this structure is passed to the BL3-1 image.

Also fixes issue ARM-software/tf-issues#25

Change-Id: Ic36426196dd5ebf89e60ff42643bed01b3500517

Add Firmware Image Package (FIP) documentation ...

This fixes ARM-software/tf-issues#9

Change-Id: Id57037115b8762efc9eaf5ff41887b71d6494c5d

fvp: rename fvp_* files to plat_* ...

The FVP platform has a few filenames that begin with fvp_.  These are
renamed to plat_ to make it easier to use the FVP port as a template.

Change-Id: I601e6256d5ef3bae81a2e1f5df6de56db5b27069
Signed-off-by: Ryan Harkin <ryan.harkin@linaro.org>

Update year in copyright text to 2014 ...

Change-Id: Ic7fb61aabae1d515b9e6baf3dd003807ff42da60

Local C library documentation updates ...

- Update porting guide to describe where files live and how to get
  FreeBSD source code.
- Update change-log to describe relocation and new functions.

Change-Id: Id8f30cc7bafdd1064b3a5c5aae958c5aa3fb79f3

Remove useless copies of meminfo structures ...

Platform setup code has to reserve some memory for storing the
memory layout information.  It is populated in early platform setup
code.

blx_get_sec_mem_layout() functions used to return a copy of this
structure.  This patch modifies blx_get_sec_mem_layout() functions
so that they now directly return a pointer to their memory layout
structure.  It ensures that the memory layout returned by
blx_get_sec_mem_layout() is always up-to-date and also avoids a
useless copy of the meminfo structure.

Also rename blx_get_sec_mem_layout() to blx_plat_sec_mem_layout()
to make it clear those functions are platform specific.

Change-Id: Ic7a6f9d6b6236b14865ab48a9f5eff545ce56551

psci: fix error due to a non zero context id ...

In the previous psci implementation, the psci_afflvl_power_on_finish()
function would run into an error condition if the value of the context
id parameter in the cpu_on and cpu_suspend psci calls was != 0. The
parameter was being restored as the return value of the affinity level
0 finisher function. A non zero context id would be treated as an
error condition. This would prevent successful wake up of the cpu from
a power down state. Also, the contents of the general purpose
registers were not being cleared upon return to the non-secure world
after a cpu power up. This could potentially allow the non-secure
world to view secure data.

This patch ensures that all general purpose registers are set to ~0
prior to the final eret that drops the execution to the non-secure
world. The context id is used to initialize the general purpose
register x0 prior to re-entry into the non-secure world and is no
longer restored as a function return value. A platform helper
(platform_get_stack()) has been introduced to facilitate this change.

Change-Id: I2454911ffd75705d6aa8609a5d250d9b26fa097c

Enable third party contributions ...

- Add instructions for contributing to ARM Trusted Firmware.

- Update copyright text in all files to acknowledge contributors.

Change-Id: I9311aac81b00c6c167d2f8c889aea403b84450e5

Update user guide further to linker scripts changes ...

This patch updates the user guide section about the memory layout.
  - Explain the verifications that the linker scripts does on the
    global memory layout.
  - Refer to the new linker symbols.
  - Describe the linker symbols exported to the trusted firmware code.

Change-Id: I033ab2b867e8b9776deb4185b9986bcb8218f286

Fix documentation issues in v0.2 release ...

Change-Id: I4e2a9daa97e3be3d2f53894f2ec7947ba6bb3a16

ARMv8 Trusted Firmware release v0.2