This patch adds the authentication framework that will be used as
the base to implement Trusted Board Boot in the Trusted Firmware.
The framework comprises the following modules:
- Image Parser Module (IPM)
This module is responsible for interpreting images, check
their integrity and extract authentication information from
them during Trusted Board Boot.
The module currently supports three types of images i.e.
raw binaries, X509v3 certificates and any type specific to
a platform. An image parser library must be registered for
each image type (the only exception is the raw image parser,
which is included in the main module by default).
Each parser library (if used) must export a structure in a
specific linker section which contains function pointers to:
1. Initialize the library
2. Check the integrity of the image type supported by
the library
3. Extract authentication information from the image
- Cryptographic Module (CM)
This module is responsible for verifying digital signatures
and hashes. It relies on an external cryptographic library
to perform the cryptographic operations.
To register a cryptographic library, the library must use the
REGISTER_CRYPTO_LIB macro, passing function pointers to:
1. Initialize the library
2. Verify a digital signature
3. Verify a hash
Failing to register a cryptographic library will generate
a build time error.
- Authentication Module (AM)
This module provides methods to authenticate an image, like
hash comparison or digital signatures. It uses the image parser
module to extract authentication parameters, the crypto module
to perform cryptographic operations and the Chain of Trust to
authenticate the images.
The Chain of Trust (CoT) is a data structure that defines the
dependencies between images and the authentication methods
that must be followed to authenticate an image.
The Chain of Trust, when added, must provide a header file named
cot_def.h with the following definitions:
- COT_MAX_VERIFIED_PARAMS
Integer value indicating the maximum number of authentication
parameters an image can present. This value will be used by the
authentication module to allocate the memory required to load
the parameters in the image descriptor.
Change-Id: Ied11bd5cd410e1df8767a1df23bb720ce7e58178
The Trusted firmware code identifies BL images by name. The platform
port defines a name for each image e.g. the IO framework uses this
mechanism in the platform function plat_get_image_source(). For
a given image name, it returns the handle to the image file which
involves comparing images names. In addition, if the image is
packaged in a FIP, a name comparison is required to find the UUID
for the image. This method is not optimal.
This patch changes the interface between the generic and platform
code with regard to identifying images. The platform port must now
allocate a unique number (ID) for every image. The generic code will
use the image ID instead of the name to access its attributes.
As a result, the plat_get_image_source() function now takes an image
ID as an input parameter. The organisation of data structures within
the IO framework has been rationalised to use an image ID as an index
into an array which contains attributes of the image such as UUID and
name. This prevents the name comparisons.
A new type 'io_uuid_spec_t' has been introduced in the IO framework
to specify images identified by UUID (i.e. when the image is contained
in a FIP file). There is no longer need to maintain a look-up table
[iname_name --> uuid] in the io_fip driver code.
Because image names are no longer mandatory in the platform port, the
debug messages in the generic code will show the image identifier
instead of the file name. The platforms that support semihosting to
load images (i.e. FVP) must provide the file names as definitions
private to the platform.
The ARM platform ports and documentation have been updated accordingly.
All ARM platforms reuse the image IDs defined in the platform common
code. These IDs will be used to access other attributes of an image in
subsequent patches.
IMPORTANT: applying this patch breaks compatibility for platforms that
use TF BL1 or BL2 images or the image loading code. The platform port
must be updated to match the new interface.
Change-Id: I9c1b04cb1a0684c6ee65dee66146dd6731751ea5
Add a delay timer driver for the ARM SP804 dual timer.
This driver only uses the first timer, called timer 1 in the
SP804 Technical Reference Manual (ARM DDI 0271D).
To use this driver, the BSP must provide three constants:
* The base address of the SP804 dual timer
* The clock multiplier
* The clock divider
The BSP is responsible for calling sp804_timer_init(). The SP804
driver instantiates a constant timer_ops_t and calls the generic
timer_init().
Change-Id: I49ba0a52bdf6072f403d1d0a20e305151d4bc086
Co-authored-by: Dan Handley <dan.handley@arm.com>
The API is simple. The BSP or specific timer driver creates an
instance of timer_ops_t, fills in the timer specific data, then calls
timer_init(). The timer specific data includes a function pointer
to return the timer value and a clock multiplier/divider. The ratio
of the multiplier and the divider is the clock frequency in MHz.
After that, mdelay() or udelay() can be called to delay execution for
the specified time (milliseconds or microseconds, respectively).
Change-Id: Icf8a295e1d25874f789bf28b7412156329dc975c
Co-authored-by: Dan Handley <dan.handley@arm.com>
This patch adds driver for the 16550 UART interface. The driver is exposed
as a console, which platforms can use to dump their boot/crash logs.
Signed-off-by: Varun Wadekar <vwadekar@nvidia.com>
The ARM GIC driver treats the entire contents of the GICC_HPPIR as the interrupt
ID instead of just bits[9:0]. This could result in an SGI being treated as a
Group 1 interrupt on a GICv2 system.
This patch introduces a mask to retrieve only the ID from a read of GICC_HPPIR,
GICC_IAR and similar registers. The value read from these registers is masked
with this constant prior to use as an interrupt ID.
FixesARM-software/tf-issues#306
Change-Id: Ie3885157de33b71df9781a41f6ef015a30c4608d
Separate out the common console functionality in
`drivers/arm/pl011/pl011_console.S` into a new source file
`drivers/console/console.S`. The former includes the latter to
provide backwards compatibility for platform make files.
Also add a skeleton console implementation for platforms that do not
want to use PL011.
Change-Id: I1ff963b2b54a872fbcf1eb0700797b9e9afa2538
Region 0 is special in TZC-400. It is possible to set the access
permissions for this but not the address range or filters to which
the permissions apply. Add a function for setting the region 0
access permissions.
Also add some VERBOSE logging and allow assembly files to include
the TZC header.
Change-Id: I4389261ba10a6e5e2e43ee93d55318dc507b6648
In order for the symbol table in the ELF file to contain the size of
functions written in assembly, it is necessary to report it to the
assembler using the .size directive.
To fulfil the above requirements, this patch introduces an 'endfunc'
macro which contains the .endfunc and .size directives. It also adds
a .func directive to the 'func' assembler macro.
The .func/.endfunc have been used so the assembler can fail if
endfunc is omitted.
FixesARM-Software/tf-issues#295
Change-Id: If8cb331b03d7f38fe7e3694d4de26f1075b278fc
Signed-off-by: Kévin Petit <kevin.petit@arm.com>
On a GICv2 system, the group status of PPIs and SGIs is set in the GICD_IGROUPR0
register. On a GICv3 system, if affinity routing is enabled for the non-secure
state, then the group status of PPIs and SGIs should be set in the GICR_IGROUPR0
register. ARM Trusted firmware sets the group status using the GICv2
sequence. On a GICv3 system, if the group status of an interrupt is set to Group
1 through a write to the GICD_IGROUPR0, then the GICR_IGROUPR0 is updated as
well.
The current sequence is incorrect since it first marks all PPIs and SGIs as
Group 1. It then clears the bits in GICD_IGROUPR0 corresponding to secure
interrupts to set their group status to Group 0. This operation is a no-op. It
leaves the secure generic timer interrupt (#29) used by the TSP marked as Group
1. This causes the interrupt to interfere with the execution of non-secure
software. Once an interrupt has been marked as Group 1, the GICR_IGROUPR0 should
be programmed to change its group status.
This patch rectifies this issue by setting the group status of only the
non-secure PPI and SGIs to Group 1 in the first place. GICD_IGROUPR0 resets to
0. So secure interrupts are marked as Group 0 by default.
Change-Id: I958b4b15f3e2b2444ce4c17764def36216498d00
Even though both CCI-400 and CCI-500 IPs have different configurations
with respect to the number and types of supported interfaces, their
register offsets and programming sequences are similar. This patch
creates a common driver for enabling and disabling snoop transactions
and DVMs with both the IPs.
New platform ports which implement one of these IPs should use this
common driver. Existing platform ports which implement CCI-400 should
migrate to the common driver as the standalone CCI-400 will be
deprecated in the future.
Change-Id: I3ccd0eb7b062922d2e4a374ff8c21e79fa357556
This patch defines the ARRAY_SIZE macro for calculating number of elements
in an array and uses it where appropriate.
Change-Id: I72746a9229f0b259323972b498b9a3999731bc9b
This patch adds support to authenticate the Trusted Key certificate
and the BL3-x certificates and images at BL2.
Change-Id: I69a8c13a14c8da8b75f93097d3a4576aed71c5dd
This patch adds support to authenticate the BL2 content certificate
and image using the authentication module in BL1.
The FIP driver has been extended to include the BL2 certificate
UUID.
FVP and Juno ports include the BL2 certificate FIP file
definition.
Change-Id: I32680e9bd123c8db4a4193c14448c9b32b0e9325
This patch introduces several improvements to the ARM GIC driver:
* In function gicd_set_itargetsr(), target CPU is specified using
the same bit mask detailed in the GICD_ITARGETSRn register instead
of the CPU linear ID, removing the dependency between bit position
and linear ID in the platform porting. The current CPU bit mask
may be obtained by reading GICD_ITARGETSR0.
* PPIs and SGIs are initialized in arm_gic_pcpu_distif_setup().
SPIs are initialized in arm_gic_distif_setup().
* By default, non secure interrupts are assigned the maximum
priority allowed to a non secure interrupt (defined by
GIC_HIGHEST_NS_PRIORITY).
* GICR base address is allowed to be NULL for GICv1 and GICv2.
Change-Id: Ie2837fe860d43b2282e582dfdb13c39c6186f232
This patch configures the TrustZone Controller in Juno to split
the 2GB DDR-DRAM memory at 0x80000000 into Secure and Non-Secure
regions:
- Secure DDR-DRAM: top 16 MB, except for the last 2 MB which are
used by the SCP for DDR retraining
- Non-Secure DDR-DRAM: remaining DRAM starting at base address
Build option PLAT_TSP_LOCATION selects the location of the secure
payload (BL3-2):
- 'tsram' : Trusted SRAM (default option)
- 'dram' : Secure region in the DDR-DRAM (set by the TrustZone
controller)
The MMU memory map has been updated to give BL2 permission to load
BL3-2 into the DDR-DRAM secure region.
FixesARM-software/tf-issues#233
Change-Id: I6843fc32ef90aadd3ea6ac4c7f314f8ecbd5d07b
The TZC-400 driver previously allowed the possibility of multiple
controller instances to be present in the same executable. This
was unnecessary since there will only ever be one instance.
This change simplifies the tzc_init() function to only take the
base address argument needed by implementation, conforming to the
driver initialization model of other drivers. It also hides some
of the implementation details that were previously exposed by the
API.
The FVP port has been updated accordingly.
THIS CHANGE REQUIRES ALL PLATFORM PORTS THAT USE THE TZC-400
DRIVER TO BE UPDATED
FixesARM-software/tf-issues#181
Change-Id: I7b721edf947064989958d8f457d6462d92e742c8
Move the remaining IO storage source file (io_storage.c) from the
lib to the drivers directory. This requires that platform ports
explicitly add this file to the list of source files.
Also move the IO header files to a new sub-directory, include/io.
Change-Id: I862b1252a796b3bcac0d93e50b11e7fb2ded93d6
* Create cci_init() function in CCI-400 driver to allow platform
to provide arguments needed by the driver (i.e. base address
and cluster indices for the ACE slave interfaces).
* Rename cci_(en|dis)able_coherency to
cci_(en|dis)able_cluster_coherency to make it clear that
the driver only enables/disables the coherency of CPU
clusters and not other devices connected to the CCI-400.
* Update FVP port to use new cci_init() function and remove
unnecessary CCI defintions from platform_def.h. Also rename
fvp_cci_setup() to fvp_cci_enable() to more clearly
differentiate between CCI initialization and enabling.
THIS CHANGE REQUIRES PLATFORM PORTS THAT USE THE CCI-400 DRIVER
TO BE UPDATED
FixesARM-software/tf-issues#168
Change-Id: I1946a51409b91217b92285b6375082619f607fec
Fix the following issues with the console log output:
* Make sure the welcome string is the first thing in the log output
(during normal boot).
* Prefix each message with the BL image name so it's clear which
BL the output is coming from.
* Ensure all output is wrapped in one of the log output macros so it can
be easily compiled out if necessary. Change some of the INFO() messages
to VERBOSE(), especially in the TSP.
* Create some extra NOTICE() and INFO() messages during cold boot.
* Remove all usage of \r in log output.
FixesARM-software/tf-issues#231
Change-Id: Ib24f7acb36ce64bbba549f204b9cde2dbb46c8a3
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.
FixesARM-software/tf-issues#96
Change-Id: I51e9ef0439fd5ff5e0edfef49050b69804bf14d5
This patch adds baud rate and UART clock frequency as parameters
to the pl011 driver api console_init(). This allows each platform
to specify UART clock and baud rate according to their specific
hardware implementation.
FixesARM-software/tf-issues#215
Change-Id: Id13eef70a1c530e709b34dd1e6eb84db0797ced2
This patch replaces the pl011 console family of functions
with their equivalents defined in assembly. The baud rate is
defined by the PL011_BAUDRATE macro and IBRD and FBRD values
for pl011 are computed statically. This patch will enable
us to invoke the console functions without the C Runtime Stack.
Change-Id: Ic3f7b7370ded38bf9020bf746b362081b76642c7
- Add support for loading a BL3-0 image in BL2. Information about
memory extents is populated by platform-specific code. Subsequent
handling of BL3-0 is also platform specific.
The BL2 main function has been broken down to improve readability.
The BL3-2 image is now loaded before the BL3-3 image to align with
the boot flow.
- Build system: Add support for specifying a BL3-0 image that will be
included into the FIP image.
- IO FIP driver: Add support for identifying a BL3-0 image inside a
FIP image.
- Update the documentation to reflect the above changes.
Change-Id: I067c184afd52ccaa86569f13664757570c86fc48
Refactor the FVP gic code in plat/fvp/fvp_gic.c to be a generic ARM
GIC driver in drivers/arm/gic/arm_gic.c. Provide the platform
specific inputs in the arm_gic_setup() function so that the driver
has no explicit dependency on platform code.
Provide weak implementations of the platform interrupt controller
API in a new file, plat/common/plat_gic.c. These simply call through
to the ARM GIC driver.
Move the only remaining FVP GIC function, fvp_gic_init() to
plat/fvp/aarch64/fvp_common.c and remove plat/fvp/fvp_gic.c
FixesARM-software/tf-issues#182
Change-Id: Iea82fe095fad62dd33ba9efbddd48c57717edd21
The assertion in console_putc() would trigger a recursion that
exhausts the stack and eventually aborts.
This patch replaces the assertion with an error return if the
console has not been initialized yet.
FixesARM-software/tf-issues#208
Change-Id: I95f736ff215d69655eb5ba7ceac70dc1409d986a
Replace the current out-of-line assembler implementations of
the system register and system instruction operations with
inline assembler.
This enables better compiler optimisation and code generation
when accessing system registers.
FixesARM-software/tf-issues#91
Change-Id: I149af3a94e1e5e5140a3e44b9abfc37ba2324476
Before attempting to write a character, the PL011 driver polls
the PL011_UARTFR_TXFF bit to know whether the UART FIFO is full.
However, the comparison with 1 was incorrect because
PL011_UARTFR_TXFF is not at bit 0. This patch fixes it.
Change-Id: If78892345bbdc8a5e4ae4a1b7159753c609681b0
Previously, platform.h contained many declarations and definitions
used for different purposes. This file has been split so that:
* Platform definitions used by common code that must be defined
by the platform are now in platform_def.h. The exact include
path is exported through $PLAT_INCLUDES in the platform makefile.
* Platform definitions specific to the FVP platform are now in
/plat/fvp/fvp_def.h.
* Platform API declarations specific to the FVP platform are now
in /plat/fvp/fvp_private.h.
* The remaining platform API declarations that must be ported by
each platform are still in platform.h but this file has been
moved to /include/plat/common since this can be shared by all
platforms.
Change-Id: Ieb3bb22fbab3ee8027413c6b39a783534aee474a
The generic image loading and IO FIP code no longer forces the
platform to create BL3-2 (Secure-EL1 Payload) specific
definitions. The BL3-2 loading code in bl2/bl2main.c is wrapped
by a #ifdef BL32_BASE blocks, allowing the BL3-2 definitions to
be optional. Similarly for the name_uuid array defintion in
drivers/io/io_fip.c.
Also update the porting guide to reflect this change.
The BL3-2 platform definitions remain non-configurably present
in the FVP port.
FixesARM-software/tf-issues#68
Change-Id: Iea28b4e94d87a31f5522f271e290919a8a955460
This patch introduces a framework for registering interrupts routed to
EL3. The interrupt routing model is governed by the SCR_EL3.IRQ and
FIQ bits and the security state an interrupt is generated in. The
framework recognizes three type of interrupts depending upon which
exception level and security state they should be handled in
i.e. Secure EL1 interrupts, Non-secure interrupts and EL3
interrupts. It provides an API and macros that allow a runtime service
to register an handler for a type of interrupt and specify the routing
model. The framework validates the routing model and uses the context
management framework to ensure that it is applied to the SCR_EL3 prior
to entry into the target security state. It saves the handler in
internal data structures. An API is provided to retrieve the handler
when an interrupt of a particular type is asserted. Registration is
expected to be done once by the primary CPU. The same handler and
routing model is used for all CPUs.
Support for EL3 interrupts will be added to the framework in the
future. A makefile flag has been added to allow the FVP port choose
between ARM GIC v2 and v3 support in EL3. The latter version is
currently unsupported.
A framework for handling interrupts in BL3-1 will be introduced in
subsequent patches. The default routing model in the absence of any
handlers expects no interrupts to be routed to EL3.
Change-Id: Idf7c023b34fcd4800a5980f2bef85e4b5c29e649
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.
FixesARM-software/tf-issues#79 Improve reporting of unhandled exception
Change-Id: I260791dc05536b78547412d147193cdccae7811a
This patch fixes C accessors to GIC registers that follow a set/clear
semantic to change the state of an interrupt, instead of read/write/modify.
These registers are:
Set-Enable
Clear-Enable
Set-Pending
Clear-Pending
Set-Active
Clear-Active
For instance, to enable an interrupt we write a one to the corresponding bit
in the Set-Enable register, whereas to disable it we write a one to the
corresponding bit in the Clear-Enable register.
FixesARM-software/tf-issues#137
Change-Id: I3b66bad94d0b28e0fe08c9042bac0bf5ffa07944
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.
FixesARM-software/tf-issues#92
Change-Id: Ie63e187404ff10e0bdcb39292dd9066cb84c53bf
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.
FixesARM-software/tf-issues#107.
Change-Id: I085a62197c82410b566e4698e5590063563ed304
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.
FixesARM-software/tf-issues#31
Change-Id: Iec92fb976334c77453e010b60bcf56f3be72bd3e
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
Move the function prototypes from gic.h into either gic_v2.h or
gic_v3.h as appropriate. Update the source files to include the
correct headers.
Change-Id: I368cfda175cdcbd3a68f46e2332738ec49048e19
Make codebase consistent in its use of #include "" syntax for
user includes and #include <> syntax for system includes.
FixesARM-software/tf-issues#65
Change-Id: If2f7c4885173b1fd05ac2cde5f1c8a07000c7a33
Move the FVP power driver to a directory under the FVP platform
port as this is not a generically usable driver.
Change-Id: Ibc78bd88752eb3e3964336741488349ac345f4f0
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
The TZC-400 performs security checks on transactions to memory or
peripherals. Separate regions can be created in the address space each
with individual security settings.
Limitations:
This driver does not currently support raising an interrupt on access
violation.
Change-Id: Idf8ed64b4d8d218fc9b6f9d75acdb2cd441d2449
Rename drivers/console/console.c to
drivers/arm/peripherals/pl011/pl011_console.c. This makes it clear
that this is a pl011 specific console implementation.
FixesARM-software/tf-issues#129
Change-Id: Ie2f8109602134c5b86993e32452c70734c45a3ed
This patch reworks the console driver to ensure that each bootloader stage
initializes it independently. As a result, both BL3-1 and BL2 platform code
now calls console_init() instead of relying on BL1 to perform console setup
FixesARM-software/tf-issues#120
Change-Id: Ic4d66e0375e40a2fc7434afcabc8bbb4715c14ab
This commit isolates the accessor functions in pl011.c and builds
a wrapper layer for console functions.
This also modifies the console driver to use the pl011 FIFO.
FixesARM-software/tf-issues#63
Change-Id: I3b402171cd14a927831bf5e5d4bb310b6da0e9a8
This patch fixes a bug in the 'file_to_uuid()' function: it used
to cause an exception by dereferencing a null pointer when
a given UUID was not found in the UUID array. The fix is to delete
the final null entry in the UUID array, which is not needed because
the array is statically declared so its size is known at build time.
FixesARM-software/tf-issues#43
Change-Id: I0a003485b88134564c0d36f57c274215d9e16532
Fixes issues #10:
https://github.com/ARM-software/tf-issues/issues/10
This patch changes all/most variables of type int to be size_t or long
to fix the sizing and alignment problems found when building with the
newer toolchains such as Linaro GCC 13.12 or later.
Change-Id: Idc9d48eb2ff9b8c5bbd5b227e6907263d1ea188b
Signed-off-by: Ryan Harkin <ryan.harkin@linaro.org>
At present many recoverable failures are reported as errors. This patch
modifies all such failures to be reported as warnings instead.
Change-Id: I5141653c82498defcada9b90fdf7498ba496b2f2
If there is a request to open a file from FIP, and that file is not
found, the driver fails to reset the offset address. This causes
subsequent file loads to fail.
This patch resets the offset address to zero if a file is not found so
that subsequent file loads are unaffected.
Change-Id: I16418e35f92fb7c85fb12e2acc071990520cdef8
This patch adds the ability to specify the base address of a UART
device for initialising the console. This allows a boot loader stage
to use a different UART device from UART0 (default) for the console.
Change-Id: Ie60b927389ae26085cfc90d22a564ff83ba62955
Juan Castillo
Ryan Harkin
Varun Wadekar
Achin Gupta
Dan Handley
Kévin Petit
Vikram Kanigiri
Soby Mathew
Sandrine Bailleux
Andrew Thoelke
Harry Liebel
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