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

Add exception vector guards ...

This patch adds guards so that an exception vector exceeding 32
instructions will generate a compile-time error. This keeps the
exception handlers in check from spilling over.

Change-Id: I7aa56dd0071a333664e2814c656d3896032046fe

Setup VBAR_EL3 incrementally ...

This patch ensures that VBAR_EL3 points to the simple stack-less
'early_exceptions' when the C runtime stack is not correctly setup to
use the more complex 'runtime_exceptions'. It is initialised to
'runtime_exceptions' once this is done.

This patch also moves all exception vectors into a '.vectors' section
and modifies linker scripts to place all such sections together. This
will minimize space wastage from alignment restrictions.

Change-Id: I8c3e596ea3412c8bd582af9e8d622bb1cb2e049d

Fix spilled-over BL1 exception vector ...

The SynchronousExceptionA64 vector has gone beyond the 32-instruction
limit for individual exception vector. This patch splits and relocates
the exception handler so that it fits into the 32-instruction window.

Change-Id: Ic60c4fc3f09a1cb071d63ff0e58353ecaecbb62f

remove empty definition of display_boot_progress() ...

This patch replaces the empty definition of display_boot_progress() in
bl2_main.c with a weak definition. The former allowed bl2 to use the
early_exceptions(). It is possible to do that with a simple weak
definition as well.

Change-Id: Idb3f425a5e265f3579b638e3d26bd8c9bb78f80d

Change comments in assembler files to help ctags ...

Ctags seem to have a problem with generating tags for assembler symbols
when a comment immediately follows an assembly label.

This patch inserts a single space character between the label
definition and the following comments to help ctags.

The patch is generated by the command:

  git ls-files -- \*.S | xargs sed -i 's/^\([^:]\+\):;/\1: ;/1'

Change-Id: If7a3c9d0f51207ea033cc8b8e1b34acaa0926475

Do not trap access to floating point registers ...

Traps when accessing architectural features are disabled by clearing bits
in CPTR_EL3 during early boot, including accesses to floating point
registers. The value of this register was previously undetermined, causing
unwanted traps to EL3. Future EL3 code (for example, context save/restore
code) may use floating point registers, although they are not used by current
code.

Also, the '-mgeneral-regs-only' flag is enabled in the GCC settings to
prevent generation of code that uses floating point registers.

Change-Id: I9a03675f6387bbbee81a6f2c9ccf81150db03747

Update year in copyright text to 2014 ...

Change-Id: Ic7fb61aabae1d515b9e6baf3dd003807ff42da60

Enable third party contributions ...

- Add instructions for contributing to ARM Trusted Firmware.

- Update copyright text in all files to acknowledge contributors.

Change-Id: I9311aac81b00c6c167d2f8c889aea403b84450e5

Properly initialise the C runtime environment ...

This patch makes sure the C runtime environment is properly
initialised before executing any C code.

  - Zero-initialise NOBITS sections (e.g. the bss section).
  - Relocate BL1 data from ROM to RAM.

Change-Id: I0da81b417b2f0d1f7ef667cc5131b1e47e22571f

Various improvements/cleanups on the linker scripts ...

- Check at link-time that bootloader images will fit in memory
    at run time and that they won't overlap each other.
  - Remove text and rodata orphan sections.
  - Define new linker symbols to remove the need for platform setup
    code to know the order of sections.
  - Reduce the size of the raw binary images by cutting some sections
    out of the disk image and allocating them at load time, whenever
    possible.
  - Rework alignment constraints on sections.
  - Remove unused linker symbols.
  - Homogenize linker symbols names across all BLs.
  - Add some comments in the linker scripts.

Change-Id: I47a328af0ccc7c8ab47fcc0dc6e7dd26160610b9

Unmask SError and Debug exceptions. ...

Any asynchronous exception caused by the firmware should be handled
in the firmware itself.  For this reason, unmask SError exceptions
(and Debug ones as well) on all boot paths.  Also route external
abort and SError interrupts to EL3, otherwise they will target EL1.

Change-Id: I9c191d2d0dcfef85f265641c8460dfbb4d112092

Move generic architectural setup out of blx_plat_arch_setup(). ...

blx_plat_arch_setup() should only perform platform-specific
architectural setup, e.g. enabling the MMU.  This patch moves
generic architectural setup code out of blx_plat_arch_setup().

Change-Id: I4ccf56b8c4a2fa84909817779a2d97a14aaafab6

ARMv8 Trusted Firmware release v0.2