Rework BL3-1 unhandled exception handling and reporting ...

This patch implements the register reporting when unhandled exceptions are
taken in BL3-1. Unhandled exceptions will result in a dump of registers
to the console, before halting execution by that CPU. The Crash Stack,
previously called the Exception Stack, is used for this activity.
This stack is used to preserve the CPU context and runtime stack
contents for debugging and analysis.

This also introduces the per_cpu_ptr_cache, referenced by tpidr_el3,
to provide easy access to some of BL3-1 per-cpu data structures.
Initially, this is used to provide a pointer to the Crash stack.

panic() now prints the the error file and line number in Debug mode
and prints the PC value in release mode.

The Exception Stack is renamed to Crash Stack with this patch.
The original intention of exception stack is no longer valid
since we intend to support several valid exceptions like IRQ
and FIQ in the trusted firmware context. This stack is now
utilized for dumping and reporting the system state when a
crash happens and hence the rename.

Fixes ARM-software/tf-issues#79 Improve reporting of unhandled exception

Change-Id: I260791dc05536b78547412d147193cdccae7811a

Merge pull request #63 from soby-mathew/sm/save_callee_saved_registers_in_cpu_context-1 ...

Preserve x19-x29 across world switch for exception handling

Merge pull request #62 from athoelke/set-little-endian-v2 ...

Set processor endianness immediately after RESET v2

Preserve x19-x29 across world switch for exception handling ...

Previously exception handlers in BL3-1, X19-X29 were not saved
and restored on every SMC/trap into EL3. Instead these registers
were 'saved as needed' as a side effect of the A64 ABI used by the C
compiler.

That approach failed when world switching but was not visible
with the TSP/TSPD code because the TSP is 64-bit, did not
clobber these registers when running and did not support pre-emption
by normal world interrupts. These scenarios showed
that the values in these registers can be passed through a world
switch, which broke the normal and trusted world assumptions
about these registers being preserved.

The Ideal solution saves and restores these registers when a
world switch occurs - but that type of implementation is more complex.
So this patch always saves and restores these registers on entry and
exit of EL3.

Fixes ARM-software/tf-issues#141

Change-Id: I9a727167bbc594454e81cf78a97ca899dfb11c27

Access system registers directly in assembler ...

Instead of using the system register helper functions to read
or write system registers, assembler coded functions should
use MRS/MSR instructions. This results in faster and more
compact code.

This change replaces all usage of the helper functions with
direct register accesses.

Change-Id: I791d5f11f257010bb3e6a72c6c5ab8779f1982b3

Correct usage of data and instruction barriers ...

The current code does not always use data and instruction
barriers as required by the architecture and frequently uses
barriers excessively due to their inclusion in all of the
write_*() helper functions.

Barriers should be used explicitly in assembler or C code
when modifying processor state that requires the barriers in
order to enable review of correctness of the code.

This patch removes the barriers from the helper functions and
introduces them as necessary elsewhere in the code.

PORTING NOTE: check any port of Trusted Firmware for use of
system register helper functions for reliance on the previous
barrier behaviour and add explicit barriers as necessary.

Fixes ARM-software/tf-issues#92

Change-Id: Ie63e187404ff10e0bdcb39292dd9066cb84c53bf

Set processor endianness immediately after RESET ...

SCTLR_EL3.EE is being configured too late in bl1_arch_setup() and
bl31_arch_setup() after data accesses have already occured on
the cold and warm boot paths.

This control bit must be configured immediately on CPU reset to
match the endian state of the firmware (little endian).

Fixes ARM-software/tf-issues#145

Change-Id: Ie12e46fbbed6baf024c30beb50751591bb8c8655

Remove variables from .data section ...

Update code base to remove variables from the .data section,
mainly by using const static data where possible and adding
the const specifier as required. Most changes are to the IO
subsystem, including the framework APIs. The FVP power
management code is also affected.

Delay initialization of the global static variable,
next_image_type in bl31_main.c, until it is realy needed.
Doing this moves the variable from the .data to the .bss
section.

Also review the IO interface for inconsistencies, using
uintptr_t where possible instead of void *. Remove the
io_handle and io_dev_handle typedefs, which were
unnecessary, replacing instances with uintptr_t.

Fixes ARM-software/tf-issues#107.

Change-Id: I085a62197c82410b566e4698e5590063563ed304

Reduce deep nesting of header files ...

Reduce the number of header files included from other header
files as much as possible without splitting the files. Use forward
declarations where possible. This allows removal of some unnecessary
"#ifndef __ASSEMBLY__" statements.

Also, review the .c and .S files for which header files really need
including and reorder the #include statements alphabetically.

Fixes ARM-software/tf-issues#31

Change-Id: Iec92fb976334c77453e010b60bcf56f3be72bd3e

Always use named structs in header files ...

Add tag names to all unnamed structs in header files. This
allows forward declaration of structs, which is necessary to
reduce header file nesting (to be implemented in a subsequent
commit).

Also change the typedef names across the codebase to use the _t
suffix to be more conformant with the Linux coding style. The
coding style actually prefers us not to use typedefs at all but
this is considered a step too far for Trusted Firmware.

Also change the IO framework structs defintions to use typedef'd
structs to be consistent with the rest of the codebase.

Change-Id: I722b2c86fc0d92e4da3b15e5cab20373dd26786f

Remove vpath usage in makefiles ...

Remove all usage of the vpath keyword in makefiles as it was prone
to mistakes. Specify the relative paths to source files instead.

Also reorder source files in makefiles alphabetically.

Fixes ARM-software/tf-issues#121

Change-Id: Id15f60655444bae60e0e2165259efac71a50928b

Make use of user/system includes more consistent ...

Make codebase consistent in its use of #include "" syntax for
user includes and #include <> syntax for system includes.

Fixes ARM-software/tf-issues#65

Change-Id: If2f7c4885173b1fd05ac2cde5f1c8a07000c7a33

Move include and source files to logical locations ...

Move almost all system include files to a logical sub-directory
under ./include. The only remaining system include directories
not under ./include are specific to the platform. Move the
corresponding source files to match the include directory
structure.

Also remove pm.h as it is no longer used.

Change-Id: Ie5ea6368ec5fad459f3e8a802ad129135527f0b3

Allocate single stacks for BL1 and BL2 ...

The BL images share common stack management code which provides
one coherent and one cacheable stack for every CPU. BL1 and BL2
just execute on the primary CPU during boot and do not require
the additional CPU stacks. This patch provides separate stack
support code for UP and MP images, substantially reducing the
RAM usage for BL1 and BL2 for the FVP platform.

This patch also provides macros for declaring stacks and
calculating stack base addresses to improve consistency where
this has to be done in the firmware.

The stack allocation source files are now included via
platform.mk rather than the common BLx makefiles. This allows
each platform to select the appropriate MP/UP stack support
for each BL image.

Each platform makefile must be updated when including this
commit.

Fixes ARM-software/tf-issues#76

Change-Id: Ia251f61b8148ffa73eae3f3711f57b1ffebfa632

Merge pull request #36 from athoelke/at/gc-sections-80 ...

Using GCC --gc-sections to eliminate unused code and data

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.

It properly fixes ARM-software/tf-issues#24

Change-Id: If95639b279f75d66ac0576c48a6614b5ccb0e84b

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.

Fixes ARM-software/tf-issues#125

Conflicts:

	docs/firmware-design.md
	plat/fvp/bl31_plat_setup.c

Change-Id: Ib584ad7ed069707ac04cf86717f836136ad3ab54

Place assembler functions in separate sections ...

This extends the --gc-sections behaviour to the many assembler
support functions in the firmware images by placing each function
into its own code section. This is achieved by creating a 'func'
macro used to declare each function label.

Fixes ARM-software/tf-issues#80

Change-Id: I301937b630add292d2dec6d2561a7fcfa6fec690

Use --gc-sections during link ...

All common functions are being built into all binary images,
whether or not they are actually used. This change enables the
use of -ffunction-sections, -fdata-sections and --gc-sections
in the compiler and linker to remove unused code and data from
the images.

Change-Id: Ia9f78c01054ac4fa15d145af38b88a0d6fb7d409

Separate out BL2, BL3-1 and BL3-2 early exception vectors from BL1 ...

bl1/aarch64/early_exceptions.S used to be re-used by BL2, BL3-1 and
BL3-2.  There was some early SMC handling code in there that was not
required by the other bootloader stages.  Therefore this patch
introduces an even simpler exception vector source file for BL2,
BL3-1 and BL3-2.

Fixes ARM-software/tf-issues#38

Change-Id: I0244b80e9930b0f8035156a0bf91cc3e9a8f995d

Move per cpu exception stack in BL31 to tzfw_normal_stacks ...

Fixes ARM-software/tf-issues#70

Change-Id: I7f024f173fbdecd315076f528b05d6295aff7276

Remove partially qualified asm helper functions ...

Each ARM Trusted Firmware image should know in which EL it is running
and it should use the corresponding register directly instead of reading
currentEL and knowing which asm register to read/write

Change-Id: Ief35630190b6f07c8fbb7ba6cb20db308f002945

Specify image entry in linker script ...

At present, the entry point for each BL image is specified via the
Makefiles and provided on the command line to the linker. When using a
link script the entry point should rather be specified via the ENTRY()
directive in the link script.

This patch updates linker scripts of all BL images to specify the entry
point using the ENTRY() directive. It also removes the --entry flag
passed to the linker through Makefile.

Fixes issue ARM-software/tf-issues#66

Change-Id: I1369493ebbacea31885b51185441f6b628cf8da0

Implement ARM Standard Service ...

This patch implements ARM Standard Service as a runtime service and adds
support for call count, UID and revision information SMCs. The existing
PSCI implementation is subsumed by the Standard Service calls and all
PSCI calls are therefore dispatched by the Standard Service to the PSCI
handler.

At present, PSCI is the only specification under Standard Service. Thus
call count returns the number of PSCI calls implemented. As this is the
initial implementation, a revision number of 0.1 is returned for call
revision.

Fixes ARM-software/tf-issues#62

Change-Id: I6d4273f72ad6502636efa0f872e288b191a64bc1

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

Generate build time and date message at link time. ...

So it updates each time a bootloader changes, not just when bl*_main.c
files are recompiled.

Fixes ARM-software/tf-issues#33

Change-Id: Ie8e1a7bd7e1913d2e96ac268606284f76af8c5ab
Signed-off-by: Jon Medhurst <tixy@linaro.org>

Update Makefiles to get proper dependency checking working. ...

This change requires all platforms to now specify a list of source files
rather than object files.

New source files should preferably be specified by using the path as
well and we should add this in the future for all files so we can remove
use of vpath. This is desirable because vpath hides issues like the fact
that BL2 currently pulls in a BL1 file bl1/aarch64/early_exceptions.S
and if in the future we added bl2/aarch64/early_exceptions.S then it's
likely only one of the two version would be used for both bootloaders.

This change also removes the 'dump' build target and simply gets
bootloaders to always generate a dump file. At the same time the -x
option is added so the section headers and symbols table are listed.

Fixes ARM-software/tf-issues#11

Change-Id: Ie38f7be76fed95756c8576cf3f3ea3b7015a18dc
Signed-off-by: Jon Medhurst <tixy@linaro.org>

Remove duplicate xlat_table descriptions ...

The BL31 and BL2 linker scripts ended up having duplicate descriptions
for xlat_tables section. This patch removes those duplicate
descriptions.

Change-Id: Ibbdda0902c57fca5ea4e91e0baefa6df8f0a9bb1

Implement late binding for runtime hooks ...

At present SPD power management hooks and BL3-2 entry are implemented
using weak references. This would have the handlers bound and registered
with the core framework at build time, but leaves them dangling if a
service fails to initialize at runtime.

This patch replaces implementation by requiring runtime handlers to
register power management and deferred initialization hooks with the
core framework at runtime. The runtime services are to register the
hooks only as the last step, after having all states successfully
initialized.

Change-Id: Ibe788a2a381ef39aec1d4af5ba02376e67269782

Add power management support in the SPD ...

This patch implements a set of handlers in the SPD which are called by
the PSCI runtime service upon receiving a power management
operation. These handlers in turn pass control to the Secure Payload
image if required before returning control to PSCI. This ensures that
the Secure Payload has complete visibility of all power transitions in
the system and can prepare accordingly.

Change-Id: I2d1dba5629b7cf2d53999d39fe807dfcf3f62fe2