Standardise header guards across codebase ...

All identifiers, regardless of use, that start with two underscores are
reserved. This means they can't be used in header guards.

The style that this project is now to use the full name of the file in
capital letters followed by 'H'. For example, for a file called
"uart_example.h", the header guard is UART_EXAMPLE_H.

The exceptions are files that are imported from other projects:

- CryptoCell driver
- dt-bindings folders
- zlib headers

Change-Id: I50561bf6c88b491ec440d0c8385c74650f3c106e
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

Remove .func and .endfunc assembler directives ...

These directives are only used when stabs debugging information
is used, but we use ELF which uses DWARF debugging information.
Clang assembler doesn't support these directives, and removing
them makes the code more compatible with clang.

Change-Id: I2803f22ebd24c0fe248e04ef1b17de9cec5f89c4
Signed-off-by: Roberto Vargas <roberto.vargas@arm.com>

Mark functions defined in assembly files ...

This patch change the name of the section containing the functions
defined in assembly files from text.* to text.asm.*. This change
makes possible to select in the linker script the functions
defined in those files.

Change-Id: If35e44ef1b43ffd951dfac5e052db75d7198e2e0
Signed-off-by: Roberto Vargas <roberto.vargas@arm.com>

asm_macros: set the default assembly code alignment to 4 byte ...

Assembly routines are usually defined by using "func" and "endfunc":

    func foo
      ...
    endfunc foo

Currently, the "func" macro does not specify ".align" directive
by default.  It causes unaligned instruction under some circumstances.

As far as I tested, this problem happens for GCC 5 or older.  It did
not happen for GCC 6 or newer.  Taking into account that GCC 4.x / 5.x
is still used, make sure that assembly code is at least 4 byte aligned.

[ How to reproduce the problem ]

For example, use GCC 5.3 downloaded from Linaro:
http://releases.linaro.org/components/toolchain/binaries/5.3-2016.05/
aarch64-linux-gnu/gcc-linaro-5.3.1-2016.05-x86_64_aarch64-linux-gnu.tar.xz

Expand mbedtls-2.4.2 to the current directory.

Try the following:

  $ git log --oneline -1
  77544ef Merge pull request #1071 from jeenu-arm/syntax-fix
  $ aarch64-linux-gnu-gcc --version | head -1
  aarch64-linux-gnu-gcc (Linaro GCC 5.3-2016.05) 5.3.1 20160412
  $ make CROSS_COMPILE=aarch64-linux-gnu- PLAT=uniphier \
    TRUSTED_BOARD_BOOT=1 MBEDTLS_DIR=mbedtls-2.4.2
    ( snip build log )
  $ aarch64-linux-gnu-nm build/uniphier/release/bl1/bl1.elf | grep handler
  00000000800088f4 T bl1_fwu_smc_handler
  00000000800084c8 T bl1_smc_handler
  000000008000a6e0 t _panic_handler
  000000008000a8e0 W plat_error_handler
  000000008000a8e8 W plat_panic_handler
  000000008000a8d8 W plat_reset_handler
  000000008000a39f T reset_handler
  000000008000a367 t smc_handler
  000000008000a2ef t smc_handler64

You will notice "smc_handler64", "reset_handler", etc. are not properly
aligned.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

Add new alignment parameter to func assembler macro ...

Assembler programmers are used to being able to define functions with a
specific aligment with a pattern like this:

    .align X
  myfunction:

However, this pattern is subtly broken when instead of a direct label
like 'myfunction:', you use the 'func myfunction' macro that's standard
in Trusted Firmware. Since the func macro declares a new section for the
function, the .align directive written above it actually applies to the
*previous* section in the assembly file, and the function it was
supposed to apply to is linked with default alignment.

An extreme case can be seen in Rockchip's plat_helpers.S which contains
this code:

  [...]
  endfunc plat_crash_console_putc

  .align 16
  func platform_cpu_warmboot
  [...]

This assembles into the following plat_helpers.o:

  Sections:
  Idx Name                             Size  [...]  Algn
   9 .text.plat_crash_console_putc 00010000  [...]  2**16
  10 .text.platform_cpu_warmboot   00000080  [...]  2**3

As can be seen, the *previous* function actually got the alignment
constraint, and it is also 64KB big even though it contains only two
instructions, because the .align directive at the end of its section
forces the assembler to insert a giant sled of NOPs. The function we
actually wanted to align has the default constraint. This code only
works at all because the linker just happens to put the two functions
right behind each other when linking the final image, and since the end
of plat_crash_console_putc is aligned the start of platform_cpu_warmboot
will also be. But it still wastes almost 64KB of image space
unnecessarily, and it will break under certain circumstances (e.g. if
the plat_crash_console_putc function becomes unused and its section gets
garbage-collected out).

There's no real way to fix this with the existing func macro. Code like

 func myfunc
 .align X

happens to do the right thing, but is still not really correct code
(because the function label is inserted before the .align directive, so
the assembler is technically allowed to insert padding at the beginning
of the function which would then get executed as instructions if the
function was called). Therefore, this patch adds a new parameter with a
default value to the func macro that allows overriding its alignment.

Also fix up all existing instances of this dangerous antipattern.

Change-Id: I5696a07e2fde896f21e0e83644c95b7b6ac79a10
Signed-off-by: Julius Werner <jwerner@chromium.org>

Use SPDX license identifiers ...

To make software license auditing simpler, use SPDX[0] license
identifiers instead of duplicating the license text in every file.

NOTE: Files that have been imported by FreeBSD have not been modified.

[0]: https://spdx.org/

Change-Id: I80a00e1f641b8cc075ca5a95b10607ed9ed8761a
Signed-off-by: dp-arm <dimitris.papastamos@arm.com>

Add CFI debug frame information for ASM functions ...

This allows the debugger to print the callstack when there is an
assembly function in the callstack.

It will work as long as the CFA pointer (frame pointer) location is not
modified (i.e. x29 is not touched in AArch64 state). It is the case in
almost all assembly functions, so this patch improves the average
debugging experience. Call stacks from the debugger should still be
interpreted with care. In more complex functions, one could use .cfi*
directives to inform the debugger about the new location of the CFA
pointer.

Change-Id: I9dabfbc033b45e8528e67f4823c17de7bf02fa24
Signed-off-by: Douglas Raillard <douglas.raillard@arm.com>

AArch32: Add assembly helpers ...

This patch adds various assembly helpers for AArch32 like :

* cache management : Functions to flush, invalidate and clean
cache by MVA. Also helpers to do cache operations by set-way
are also added.

* stack management: Macros to declare stack and get the current
stack corresponding to current CPU.

* Misc: Macros to access co processor registers in AArch32,
macros to define functions in assembly, assert macros, generic
`do_panic()` implementation and function to zero block of memory.

Change-Id: I7b78ca3f922c0eda39beb9786b7150e9193425be

Rearrange assembly helper macros ...

This patch moves assembler macros which are not architecture specific
to a new file `asm_macros_common.S` and moves the `el3_common_macros.S`
into `aarch64` specific folder.

Change-Id: I444a1ee3346597bf26a8b827480cd9640b38c826