Merge "refactor(console): disable getc() by default" into integration

refactor(console): disable getc() by default

The ability to read a character from the console constitutes an attack
vector into TF-A, as it gives attackers a means to inject arbitrary
data into TF-A

refactor(console): disable getc() by default

The ability to read a character from the console constitutes an attack
vector into TF-A, as it gives attackers a means to inject arbitrary
data into TF-A. It is dangerous to keep that feature enabled if not
strictly necessary, especially in production firmware builds.

Thus, we need a way to disable this feature. Moreover, when it is
disabled, all related code should be eliminated from the firmware
binaries, such that no remnant/dead getc() code remains in memory,
which could otherwise be used as a gadget as part of a bigger security
attack.

This patch disables getc() feature by default. For legitimate getc()
use cases [1], it can be explicitly enabled by building TF-A with
ENABLE_CONSOLE_GETC=1.

The following changes are introduced when getc() is disabled:

- The multi-console framework no longer provides the console_getc()
function.

- If the console driver selected by the platform attempts to register
a getc() callback into the multi-console framework then TF-A will
now fail to build.

If registered through the assembly function finish_console_register():
- On AArch64, you'll get:
Error: undefined symbol CONSOLE_T_GETC used as an immediate value.
- On AArch32, you'll get:
Error: internal_relocation (type: OFFSET_IMM) not fixed up

If registered through the C function console_register(), this requires
populating a struct console with a getc field, which will trigger:
error: 'console_t' {aka 'struct console'} has no member named 'getc'

- All console drivers which previously registered a getc() callback
have been modified to do so only when ENABLE_CONSOLE_GETC=1.

[1] Example of such use cases would be:
- Firmware recovery: retrieving a golden BL2 image over the console in
order to repair a broken firmware on a bricked board.
- Factory CLI tool: Drive some soak tests through the console.

Discussed on TF-A mailing list here:
https://lists.trustedfirmware.org/archives/list/tf-a@lists.trustedfirmware.org/thread/YS7F6RCNTWBTEOBLAXIRTXWIOYINVRW7/

Change-Id: Icb412304cd23dbdd7662df7cf8992267b7975cc5
Signed-off-by: Sandrine Bailleux <sandrine.bailleux@arm.com>
Acked-by: Baruch Siach <baruch@tkos.co.il>

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Merge changes from topic "bk/warnings" into integration

* changes:
docs: describe the new warning levels
build: add -Wunused-const-variable=2 to W=2
build: include -Wextra in generic builds

Merge changes from topic "bk/warnings" into integration

* changes:
docs: describe the new warning levels
build: add -Wunused-const-variable=2 to W=2
build: include -Wextra in generic builds
docs(porting-guide): update a reference
fix(st-usb): replace redundant checks with asserts
fix(brcm): add braces around bodies of conditionals
fix(renesas): align incompatible function pointers
fix(zynqmp): remove redundant api_version check
fix: remove old-style declarations
fix: unify fallthrough annotations

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docs: describe the new warning levels

When -Wextra was added, the warning levels changed their meaning. Add a
description in the build option section and leave the security hardening
section as most

docs: describe the new warning levels

When -Wextra was added, the warning levels changed their meaning. Add a
description in the build option section and leave the security hardening
section as mostly a pointer to it.

Signed-off-by: Boyan Karatotev <boyan.karatotev@arm.com>
Change-Id: Iabf2f598d0bf3e865c9b991c5d44d2acb9572bd5

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Merge "Update docs with PMU security information" into integration

Update docs with PMU security information

This patch adds information on the PMU configuration registers
and security considerations related to the PMU.

Signed-off-by: Petre-Ionut Tudor <petre-ionu

Update docs with PMU security information

This patch adds information on the PMU configuration registers
and security considerations related to the PMU.

Signed-off-by: Petre-Ionut Tudor <petre-ionut.tudor@arm.com>
Change-Id: I36b15060b9830a77d3f47f293c0a6dafa3c581fb

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Merge "doc: Split and expand coding style documentation" into integration

doc: Split and expand coding style documentation

This patch expands the coding style documentation, splitting it
into two documents: the core style rules and extended guidelines.
Note that it does n

doc: Split and expand coding style documentation

This patch expands the coding style documentation, splitting it
into two documents: the core style rules and extended guidelines.
Note that it does not redefine or change the coding style (aside
from section 4.6.2) - generally, it is only documenting the
existing style in more detail.

The aim is for the coding style to be more readable and, in turn,
for it to be followed by more people. We can use this as a more
concrete reference when discussing the accepted style with external
contributors.

Change-Id: I87405ace9a879d7f81e6b0b91b93ca69535e50ff
Signed-off-by: Paul Beesley <paul.beesley@arm.com>
Signed-off-by: Petre-Ionut Tudor <petre-ionut.tudor@arm.com>

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Merge "Remove -Wpadded warning" into integration

Remove -Wpadded warning

-Wpadded warns whenever the C compiler automatically includes any
padding in a structure. Because TF-A has a large number of structures,
this occurs fairly frequently and is

Remove -Wpadded warning

-Wpadded warns whenever the C compiler automatically includes any
padding in a structure. Because TF-A has a large number of structures,
this occurs fairly frequently and is incredibly verbose, and as such is
unlikely to ever be fixed.

The utility of this warning is also extremely limited - knowing that a
structure includes padding does not point to the existence of an error,
and is probably quite unlikely to indicate actually buggy behaviour.
Therefore, it's probably best to keep this warning off at all times.

Change-Id: I0797cb75f06b4fea0d2fdc16fd5ad978a31d76ec
Signed-off-by: Justin Chadwell <justin.chadwell@arm.com>

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Merge "Remove unnecessary warning options" into integration

Merge "doc: Split the User Guide into multiple files" into integration

doc: Split the User Guide into multiple files

The User Guide document has grown organically over time and
now covers a wide range of topics, making it difficult to
skim read and extract information

doc: Split the User Guide into multiple files

The User Guide document has grown organically over time and
now covers a wide range of topics, making it difficult to
skim read and extract information from. Currently, it covers
these topics and maybe a couple more:

- Requirements (hardware, tools, libs)
- Checking out the repo
- Basic build instructions
- A comprehensive list of build flags
- FIP packaging
- Building specifically for Juno
- Firmware update images
- EL3 payloads
- Preloaded BL33 boot flow
- Running on FVPs
- Running on Juno

I have separated these out into a few groups that become new
documents. Broadly speaking, build instructions for the tools,
for TF-A generally, and for specific scenarios are separated.
Content relating to specific platforms (Juno and the FVPs are
Arm-specific platforms, essentially) has been moved into the
documentation that is specific to those platforms, under
docs/plat/arm.

Change-Id: Ica87c52d8cd4f577332be0b0738998ea3ba3bbec
Signed-off-by: Paul Beesley <paul.beesley@arm.com>

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Remove unnecessary warning options

Both -Wmissing-field-initializers and -Wsign-compare are both covered by
-Wextra which is enabled at W=1 anyway. Therefore, the explicit options
are not required.

Remove unnecessary warning options

Both -Wmissing-field-initializers and -Wsign-compare are both covered by
-Wextra which is enabled at W=1 anyway. Therefore, the explicit options
are not required.

Change-Id: I2e7d95b5fc14af7c70895859a7ebbeac5bc0d2a4
Signed-off-by: Justin Chadwell <justin.chadwell@arm.com>

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Merge changes from topic "pb/readthedocs" into integration

* changes:
doc: Add guide for building the docs locally
doc: De-duplicate readme and license files
doc: Convert internal links to RST

Merge changes from topic "pb/readthedocs" into integration

* changes:
doc: Add guide for building the docs locally
doc: De-duplicate readme and license files
doc: Convert internal links to RST format

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doc: Convert internal links to RST format

Currently links between documents are using the format:

<path/to/><filename>.rst

This was required for services like GitHub because they render each
docum

doc: Convert internal links to RST format

Currently links between documents are using the format:

<path/to/><filename>.rst

This was required for services like GitHub because they render each
document in isolation - linking to another document is like linking
to any other file, just provide the full path.

However, with the new approach, the .rst files are only the raw
source for the documents. Once the documents have been rendered
the output is now in another format (HTML in our case) and so,
when linking to another document, the link must point to the
rendered version and not the .rst file.

The RST spec provides a few methods for linking between content.
The parent of this patch enabled the automatic creation of anchors
for document titles - we will use these anchors as the targets for
our links. Additional anchors can be added by hand if needed, on
section and sub-section titles, for example.

An example of this new format, for a document with the title
"Firmware Design" is :ref:`Firmware Design`.

One big advantage of this is that anchors are not dependent on
paths. We can then move documents around, even between directories,
without breaking any links between documents. Links will need to be
updated only if the title of a document changes.

Change-Id: I9e2340a61dd424cbd8fd1ecc2dc166f460d81703
Signed-off-by: Paul Beesley <paul.beesley@arm.com>

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Merge "doc: Isolate security-related build options" into integration

doc: Isolate security-related build options

Reference security specific build options from the user guide.

Change-Id: I0e1efbf47d914cf3c473104175c702ff1a80eb67
Signed-off-by: Ambroise Vincent <ambr

doc: Isolate security-related build options

Reference security specific build options from the user guide.

Change-Id: I0e1efbf47d914cf3c473104175c702ff1a80eb67
Signed-off-by: Ambroise Vincent <ambroise.vincent@arm.com>

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