Merge pull request #179 from jcastillo-arm/jc/tf-issues/219 ...

Call platform_is_primary_cpu() only from reset handler

Merge pull request #178 from soby-mathew/sm/optmize_el3_context ...

Optimize EL3 register state stored in cpu_context structure

Support asynchronous method for BL3-2 initialization ...

This patch adds support for BL3-2 initialization by asynchronous
method where BL3-1 transfers control to BL3-2 using world switch.
After BL3-2 initialization, it transfers control to BL3-3 via SPD
service handler. The SPD service handler initializes the CPU context
to BL3-3 entrypoint depending on the return function indentifier from
TSP initialization.

Fixes ARM-software/TF-issues#184

Change-Id: I7b135c2ceeb356d3bb5b6a287932e96ac67c7a34

Call platform_is_primary_cpu() only from reset handler ...

The purpose of platform_is_primary_cpu() is to determine after reset
(BL1 or BL3-1 with reset handler) if the current CPU must follow the
cold boot path (primary CPU), or wait in a safe state (secondary CPU)
until the primary CPU has finished the system initialization.

This patch removes redundant calls to platform_is_primary_cpu() in
subsequent bootloader entrypoints since the reset handler already
guarantees that code is executed exclusively on the primary CPU.

Additionally, this patch removes the weak definition of
platform_is_primary_cpu(), so the implementation of this function
becomes mandatory. Removing the weak symbol avoids other
bootloaders accidentally picking up an invalid definition in case the
porting layer makes the real function available only to BL1.

The define PRIMARY_CPU is no longer mandatory in the platform porting
because platform_is_primary_cpu() hides the implementation details
(for instance, there may be platforms that report the primary CPU in
a system register). The primary CPU definition in FVP has been moved
to fvp_def.h.

The porting guide has been updated accordingly.

Fixes ARM-software/tf-issues#219

Change-Id: If675a1de8e8d25122b7fef147cb238d939f90b5e

Optimize EL3 register state stored in cpu_context structure ...

This patch further optimizes the EL3 register state stored in
cpu_context. The 2 registers which are removed from cpu_context are:

  * cntfrq_el0 is the system timer register which is writable
    only in EL3 and it can be programmed during cold/warm boot. Hence
    it need not be saved to cpu_context.

  * cptr_el3 controls access to Trace, Floating-point, and Advanced
    SIMD functionality and it is programmed every time during cold
    and warm boot. The current BL3-1 implementation does not need to
    modify the access controls during normal execution and hence
    they are expected to remain static.

Fixes ARM-software/tf-issues#197

Change-Id: I599ceee3b73a7dcfd37069fd41b60e3d397a7b18

Merge pull request #177 from jcastillo-arm/jc/tf-issues/096 ...

Rework incorrect use of assert() and panic() in codebase

Merge pull request #172 from soby-mathew/sm/asm_assert ...

Introduce asm assert and optimize crash reporting

Merge pull request #170 from achingupta/ag/tf-issues#226 ...

Simplify management of SCTLR_EL3 and SCTLR_EL1

Merge pull request #169 from achingupta/ag/tf-issues#198 ...

Ag/tf issues#198

Rework incorrect use of assert() and panic() in codebase ...

Assert a valid security state using the macro sec_state_is_valid().
Replace assert() with panic() in those cases that might arise
because of runtime errors and not programming errors.
Replace panic() with assert() in those cases that might arise
because of programming errors.

Fixes ARM-software/tf-issues#96

Change-Id: I51e9ef0439fd5ff5e0edfef49050b69804bf14d5

Add CPUECTLR_EL1 and Snoop Control register to crash reporting ...

This patch adds the CPUECTLR_EL1 register and the CCI Snoop Control
register to the list of registers being reported when an unhandled
exception occurs.

Change-Id: I2d997f2d6ef3d7fa1fad5efe3364dc9058f9f22c

Rework the crash reporting in BL3-1 to use less stack ...

This patch reworks the crash reporting mechanism to further
optimise the stack and code size. The reporting makes use
of assembly console functions to avoid calling C Runtime
to report the CPU state. The crash buffer requirement is
reduced to 64 bytes with this implementation. The crash
buffer is now part of per-cpu data which makes retrieving
the crash buffer trivial.

Also now panic() will use crash reporting if
invoked from BL3-1.

Fixes ARM-software/tf-issues#199

Change-Id: I79d27a4524583d723483165dc40801f45e627da5

Simplify management of SCTLR_EL3 and SCTLR_EL1 ...

This patch reworks the manner in which the M,A, C, SA, I, WXN & EE bits of
SCTLR_EL3 & SCTLR_EL1 are managed. The EE bit is cleared immediately after reset
in EL3. The I, A and SA bits are set next in EL3 and immediately upon entry in
S-EL1. These bits are no longer managed in the blX_arch_setup() functions. They
do not have to be saved and restored either. The M, WXN and optionally the C
bit are set in the enable_mmu_elX() function. This is done during both the warm
and cold boot paths.

Fixes ARM-software/tf-issues#226

Change-Id: Ie894d1a07b8697c116960d858cd138c50bc7a069

Add support for printing version at runtime ...

Print out Trusted Firmware version at runtime at each BL stage.
Message consists of TF version as defined statically in the Makefile
(e.g. v0.4), build mode (debug|release) and a customizable build
string:

  1. By defining BUILD_STRING in command line when building TF
  2. Default string is git commit ID
  3. Empty if git meta-data is not available

Fixes ARM-software/tf-issues#203

Change-Id: I5c5ba438f66ab68810427d76b49c5b9177a957d6

Implement a leaner printf for Trusted Firmware ...

This patch implements a "tf_printf" which supports only the commonly
used format specifiers in Trusted Firmware, which uses a lot less
stack space than the stdlib printf function.

Fixes ARM-software/tf-issues#116

Change-Id: I7dfa1944f4c1e634b3e2d571f49afe02d109a351

Remove coherent stack usage from the warm boot path ...

This patch uses stacks allocated in normal memory to enable the MMU early in the
warm boot path thus removing the dependency on stacks allocated in coherent
memory. Necessary cache and stack maintenance is performed when a cpu is being
powered down and up. This avoids any coherency issues that can arise from
reading speculatively fetched stale stack memory from another CPUs cache. These
changes affect the warm boot path in both BL3-1 and BL3-2.

The EL3 system registers responsible for preserving the MMU state are not saved
and restored any longer. Static values are used to program these system
registers when a cpu is powered on or resumed from suspend.

Change-Id: I8357e2eb5eb6c5f448492c5094b82b8927603784

Remove coherent stack usage from the cold boot path ...

This patch reworks the cold boot path across the BL1, BL2, BL3-1 and BL3-2 boot
loader stages to not use stacks allocated in coherent memory for early platform
setup and enabling the MMU. Stacks allocated in normal memory are used instead.

Attributes for stack memory change from nGnRnE when the MMU is disabled to
Normal WBWA Inner-shareable when the MMU and data cache are enabled. It is
possible for the CPU to read stale stack memory after the MMU is enabled from
another CPUs cache. Hence, it is unsafe to turn on the MMU and data cache while
using normal stacks when multiple CPUs are a part of the same coherency
domain. It is safe to do so in the cold boot path as only the primary cpu
executes it. The secondary cpus are in a quiescent state.

This patch does not remove the allocation of coherent stack memory. That is done
in a subsequent patch.

Change-Id: I12c80b7c7ab23506d425c5b3a8a7de693498f830

Merge pull request #162 from jcastillo-arm/jc/tf-issues/194 ...

Allow FP register context to be optional at build time

Merge pull request #163 from sandrine-bailleux/sb/tf-issue-117-v2 ...

fvp: Reuse BL1 and BL2 memory through image overlaying (v2)

fvp: Reuse BL1 and BL2 memory through image overlaying ...

This patch re-organizes the memory layout on FVP as to give the
BL3-2 image as much memory as possible.

Considering these two facts:
 - not all images need to live in memory at the same time. Once
   in BL3-1, the memory used by BL1 and BL2 can be reclaimed.
 - when BL2 loads the BL3-1 and BL3-2 images, it only considers the
   PROGBITS sections of those 2 images. The memory occupied by the
   NOBITS sections will be touched only at execution of the BL3-x
   images;
Then it is possible to choose the different base addresses such that
the NOBITS sections of BL3-1 and BL3-2 overlay BL1 and BL2.

On FVP we choose to put:
 - BL1 and BL3-1 at the top of the Trusted RAM, with BL3-1 NOBITS
   sections overlaying BL1;
 - BL3-2 at the bottom of the Trusted RAM, with its NOBITS sections
   overlaying BL2;

This is illustrated by the following diagram:

0x0404_0000 ------------    ------------------
            |   BL1    | <= |  BL3-1 NOBITS  |
            ------------ <= ------------------
            |          | <= | BL3-1 PROGBITS |
            ------------    ------------------
            |   BL2    | <= |  BL3-2 NOBITS  |
            ------------ <= ------------------
            |          | <= | BL3-2 PROGBITS |
0x0400_0000 ------------    ------------------

New platform-specific constants have been introduced to easily check
at link time that BL3-1 and BL3-2 PROGBITS sections don't overwrite
BL1 and BL2. These are optional and the platform code is free to define
them or not. If not defined, the linker won't attempt to check
image overlaying.

Fixes ARM-software/tf-issues#117

Change-Id: I5981d1c3d66ee70eaac8bd052630c9ac6dd8b042

Allow FP register context to be optional at build time ...

CTX_INCLUDE_FPREGS make variable allows us to include or exclude FP
registers from context structure, in case FP is not used by TSPD.

Fixes ARM-software/tf-issues#194

Change-Id: Iee41af382d691340c7ae21830ad1bbf95dad1f4b

Merge pull request #151 from vikramkanigiri/vk/t133-code-readability ...

Simplify entry point information generation code on FVP

Remove all checkpatch errors from codebase ...

Exclude stdlib files because they do not follow kernel code style.

Fixes ARM-software/tf-issues#73

Change-Id: I4cfafa38ab436f5ab22c277cb38f884346a267ab

Simplify entry point information generation code on FVP ...

This patch reworks FVP specific code responsible for determining
the entry point information for BL3-2 and BL3-3 stages when BL3-1
is configured as the reset handler.

Change-Id: Ia661ff0a6a44c7aabb0b6c1684b2e8d3642d11ec

Initialise CPU contexts from entry_point_info ...

Consolidate all BL3-1 CPU context initialization for cold boot, PSCI
and SPDs into two functions:
*  The first uses entry_point_info to initialize the relevant
   cpu_context for first entry into a lower exception level on a CPU
*  The second populates the EL1 and EL2 system registers as needed
   from the cpu_context to ensure correct entry into the lower EL

This patch alters the way that BL3-1 determines which exception level
is used when first entering EL1 or EL2 during cold boot - this is now
fully determined by the SPSR value in the entry_point_info for BL3-3,
as set up by the platform code in BL2 (or otherwise provided to BL3-1).

In the situation that EL1 (or svc mode) is selected for a processor
that supports EL2, the context management code will now configure all
essential EL2 register state to ensure correct execution of EL1. This
allows the platform code to run non-secure EL1 payloads directly
without requiring a small EL2 stub or OS loader.

Change-Id: If9fbb2417e82d2226e47568203d5a369f39d3b0f

Merge pull request #138 from athoelke/at/cpu-context ...

Move CPU context pointers into cpu_data

Remove early_exceptions from BL3-1 ...

The crash reporting support and early initialisation of the
cpu_data allow the runtime_exception vectors to be used from
the start in BL3-1, removing the need for the additional
early_exception vectors and 2KB of code from BL3-1.

Change-Id: I5f8997dabbaafd8935a7455910b7db174a25d871

Move CPU context pointers into cpu_data ...

Moving the context pointers for each CPU into the per-cpu data
allows for much more efficient access to the contexts for the
current CPU.

Change-Id: Id784e210d63cbdcddb44ac1591617ce668dbc29f

Per-cpu data cache restructuring ...

This patch prepares the per-cpu pointer cache for wider use by:
* renaming the structure to cpu_data and placing in new header
* providing accessors for this CPU, or other CPUs
* splitting the initialization of the TPIDR pointer from the
  initialization of the cpu_data content
* moving the crash stack initialization to a crash stack function
* setting the TPIDR pointer very early during boot

Change-Id: Icef9004ff88f8eb241d48c14be3158087d7e49a3

Merge pull request #133 from athoelke/at/crash-reporting-opt ...

Make the BL3-1 crash reporting optional