AArch32: Add generic changes in BL1 ...

This patch adds generic changes in BL1 to support AArch32 state.
New AArch32 specific assembly/C files are introduced and
some files are moved to AArch32/64 specific folders.
BL1 for AArch64 is refactored but functionally identical.
BL1 executes in Secure Monitor mode in AArch32 state.

NOTE: BL1 in AArch32 state ONLY handles BL1_RUN_IMAGE SMC.

Change-Id: I6e2296374c7efbf3cf2aa1a0ce8de0732d8c98a5

BL1: Add linker symbol identifying end of ROM content ...

This patch adds a new linker symbol in BL1's linker script named
'__BL1_ROM_END__', which marks the end of BL1's ROM content. This
covers BL1's code, read-only data and read-write data to relocate
in Trusted SRAM. The address of this new linker symbol is exported
to C code through the 'BL1_ROM_END' macro.

The section related to linker symbols in the Firmware Design guide
has been updated and improved.

Change-Id: I5c442ff497c78d865ffba1d7d044511c134e11c7

FWU: Add Generic Firmware Update framework support in BL1 ...

Firmware update(a.k.a FWU) feature is part of the TBB architecture.
BL1 is responsible for carrying out the FWU process if platform
specific code detects that it is needed.

This patch adds support for FWU feature support in BL1 which is
included by enabling `TRUSTED_BOARD_BOOT` compile time flag.

This patch adds bl1_fwu.c which contains all the core operations
of FWU, which are; SMC handler, image copy, authentication, execution
and resumption. It also adds bl1.h introducing #defines for all
BL1 SMCs.

Following platform porting functions are introduced:

int bl1_plat_mem_check(uintptr_t mem_base, unsigned int mem_size,
unsigned int flags);
	This function can be used to add platform specific memory checks
	for the provided base/size for the given security state.
	The weak definition will invoke `assert()` and return -ENOMEM.

__dead2 void bl1_plat_fwu_done(void *cookie, void *reserved);
	This function can be used to initiate platform specific procedure
	to mark completion of the FWU process.
	The weak definition waits forever calling `wfi()`.

plat_bl1_common.c contains weak definitions for above functions.

FWU process starts when platform detects it and return the image_id
other than BL2_IMAGE_ID by using `bl1_plat_get_next_image_id()` in
`bl1_main()`.

NOTE: User MUST provide platform specific real definition for
bl1_plat_mem_check() in order to use it for Firmware update.

Change-Id: Ice189a0885d9722d9e1dd03f76cac1aceb0e25ed

Add descriptor based image management support in BL1 ...

As of now BL1 loads and execute BL2 based on hard coded information
provided in BL1. But due to addition of support for upcoming Firmware
Update feature, BL1 now require more flexible approach to load and
run different images using information provided by the platform.

This patch adds new mechanism to load and execute images based on
platform provided image id's. BL1 now queries the platform to fetch
the image id of the next image to be loaded and executed. In order
to achieve this, a new struct image_desc_t was added which holds the
information about images, such as: ep_info and image_info.

This patch introduces following platform porting functions:

unsigned int bl1_plat_get_next_image_id(void);
	This is used to identify the next image to be loaded
	and executed by BL1.

struct image_desc *bl1_plat_get_image_desc(unsigned int image_id);
	This is used to retrieve the image_desc for given image_id.

void bl1_plat_set_ep_info(unsigned int image_id,
struct entry_point_info *ep_info);
	This function allows platforms to update ep_info for given
	image_id.

The plat_bl1_common.c file provides default weak implementations of
all above functions, the `bl1_plat_get_image_desc()` always return
BL2 image descriptor, the `bl1_plat_get_next_image_id()` always return
BL2 image ID and `bl1_plat_set_ep_info()` is empty and just returns.
These functions gets compiled into all BL1 platforms by default.

Platform setup in BL1, using `bl1_platform_setup()`, is now done
_after_ the initialization of authentication module. This change
provides the opportunity to use authentication while doing the
platform setup in BL1.

In order to store secure/non-secure context, BL31 uses percpu_data[]
to store context pointer for each core. In case of BL1 only the
primary CPU will be active hence percpu_data[] is not required to
store the context pointer.

This patch introduce bl1_cpu_context[] and bl1_cpu_context_ptr[] to
store the context and context pointers respectively. It also also
re-defines cm_get_context() and cm_set_context() for BL1 in
bl1/bl1_context_mgmt.c.

BL1 now follows the BL31 pattern of using SP_EL0 for the C runtime
environment, to support resuming execution from a previously saved
context.

NOTE: THE `bl1_plat_set_bl2_ep_info()` PLATFORM PORTING FUNCTION IS
      NO LONGER CALLED BY BL1 COMMON CODE. PLATFORMS THAT OVERRIDE
      THIS FUNCTION MAY NEED TO IMPLEMENT `bl1_plat_set_ep_info()`
      INSTEAD TO MAINTAIN EXISTING BEHAVIOUR.

Change-Id: Ieee4c124b951c2e9bc1c1013fa2073221195d881

Remove concept of top/bottom image loading ...

This concept is no longer required since we now support loading of
images at fixed addresses only.

The image loader now automatically detects the position of the image
inside the current memory layout and updates the layout such that
memory fragmentation is minimised.

The 'attr' field of the meminfo data structure, which used to hold
the bottom/top loading information, has been removed. Also the 'next'
field has been removed as it wasn't used anywhere.

The 'init_bl2_mem_layout()' function has been moved out of common
code and put in BL1-specific code. It has also been renamed into
'bl1_init_bl2_mem_layout'.

Fixes ARM-software/tf-issues#109

Change-Id: I3f54642ce7b763d5ee3b047ad0ab59eabbcf916d

Remove extern keyword from function declarations ...

Function declarations implicitly have external linkage so do not
need the extern keyword.

Change-Id: Ia0549786796d8bf5956487e8996450a0b3d79f32

Separate BL functions out of arch.h ...

Move the BL function prototypes out of arch.h and into the
appropriate header files to allow more efficient header file
inclusion. Create new BL private header files where there is no
sensible existing header file.

Change-Id: I45f3e10b72b5d835254a6f25a5e47cf4cfb274c3