GitLab

The pre-processor directives make it hard to read the non-TBB version of
this function. Refactor the code to improve readability. No functional
change introduced.

In particular, introduce a new helper function load_image_flush(),
that simply loads an image and flushes it out to main memory. This is
the only thing load_auth_image_internal() needs to do when TBB is
disabled or when authentication is dynamically disabled.

In other cases, we need to recursively authenticate the parent images up
to the root of trust. To make this clearer, this code gets moved to a
TBB-specific helper function called load_auth_image_recursive().

As a result, load_auth_image_internal() now boils down to calling the
right helper function (depending on TBB enablement and dynamic
authentication status).

Change-Id: I20a39a3b833810b97ecf4219358e7d2cac263890
Signed-off-by: Sandrine Bailleux <sandrine.bailleux@arm.com>

This patch provides the following features and makes modifications
listed below:
- Individual APIAKey key generation for each CPU.
- New key generation on every BL31 warm boot and TSP CPU On event.
- Per-CPU storage of APIAKey added in percpu_data[]
  of cpu_data structure.
- `plat_init_apiakey()` function replaced with `plat_init_apkey()`
  which returns 128-bit value and uses Generic timer physical counter
  value to increase the randomness of the generated key.
  The new function can be used for generation of all ARMv8.3-PAuth keys
- ARMv8.3-PAuth specific code placed in `lib\extensions\pauth`.
- New `pauth_init_enable_el1()` and `pauth_init_enable_el3()` functions
  generate, program and enable APIAKey_EL1 for EL1 and EL3 respectively;
  pauth_disable_el1()` and `pauth_disable_el3()` functions disable
  PAuth for EL1 and EL3 respectively;
  `pauth_load_bl31_apiakey()` loads saved per-CPU APIAKey_EL1 from
  cpu-data structure.
- Combined `save_gp_pauth_registers()` function replaces calls to
  `save_gp_registers()` and `pauth_context_save()`;
  `restore_gp_pauth_registers()` replaces `pauth_context_restore()`
  and `restore_gp_registers()` calls.
- `restore_gp_registers_eret()` function removed with corresponding
  code placed in `el3_exit()`.
- Fixed the issue when `pauth_t pauth_ctx` structure allocated space
  for 12 uint64_t PAuth registers instead of 10 by removal of macro
  CTX_PACGAKEY_END from `include/lib/el3_runtime/aarch64/context.h`
  and assigning its value to CTX_PAUTH_REGS_END.
- Use of MODE_SP_ELX and MODE_SP_EL0 macro definitions
  in `msr	spsel`  instruction instead of hard-coded values.
- Changes in documentation related to ARMv8.3-PAuth and ARMv8.5-BTI.

Change-Id: Id18b81cc46f52a783a7e6a09b9f149b6ce803211
Signed-off-by: Alexei Fedorov <Alexei.Fedorov@arm.com>

NOTE: AARCH32/AARCH64 macros are now deprecated in favor of __aarch64__.

All common C compilers pre-define the same macros to signal which
architecture the code is being compiled for: __arm__ for AArch32 (or
earlier versions) and __aarch64__ for AArch64. There's no need for TF-A
to define its own custom macros for this. In order to unify code with
the export headers (which use __aarch64__ to avoid another dependency),
let's deprecate the AARCH32 and AARCH64 macros and switch the code base
over to the pre-defined standard macro. (Since it is somewhat
unintuitive that __arm__ only means AArch32, let's standardize on only
using __aarch64__.)

Change-Id: Ic77de4b052297d77f38fc95f95f65a8ee70cf200
Signed-off-by: Julius Werner <jwerner@chromium.org>

Check for both IMPLEMENTATION_DEFINED and Architected algorithms of
Address Authentication.

Change-Id: I209dcc6087172cfef7baf8d09e0454628f02cbd0
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

The previous commit added the infrastructure to load and save
ARMv8.3-PAuth registers during Non-secure <-> Secure world switches, but
didn't actually enable pointer authentication in the firmware.

This patch adds the functionality needed for platforms to provide
authentication keys for the firmware, and a new option (ENABLE_PAUTH) to
enable pointer authentication in the firmware itself. This option is
disabled by default, and it requires CTX_INCLUDE_PAUTH_REGS to be
enabled.

Change-Id: I35127ec271e1198d43209044de39fa712ef202a5
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

Commit ed51b51f

 ("Remove build option LOAD_IMAGE_V2") intended
to remove all code related to LOAD_IMAGE_V2=0 but missed a few things.

Change-Id: I16aaf52779dd4af1e134e682731328c5f1e5d622
Signed-off-by: Sandrine Bailleux <sandrine.bailleux@arm.com>

Enforce full include path for includes. Deprecate old paths.

The following folders inside include/lib have been left unchanged:

- include/lib/cpus/${ARCH}
- include/lib/el3_runtime/${ARCH}

The reason for this change is that having a global namespace for
includes isn't a good idea. It defeats one of the advantages of having
folders and it introduces problems that are sometimes subtle (because
you may not know the header you are actually including if there are two
of them).

For example, this patch had to be created because two headers were
called the same way: e0ea0928 ("Fix gpio includes of mt8173 platform
to avoid collision."). More recently, this patch has had similar
problems: 46f9b2c3 ("drivers: add tzc380 support").

This problem was introduced in commit 4ecca339

 ("Move include and
source files to logical locations"). At that time, there weren't too
many headers so it wasn't a real issue. However, time has shown that
this creates problems.

Platforms that want to preserve the way they include headers may add the
removed paths to PLAT_INCLUDES, but this is discouraged.

Change-Id: I39dc53ed98f9e297a5966e723d1936d6ccf2fc8f
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

No functional changes.

Change-Id: I9638e02acb9b22eb794ebf45aad84348a710287e
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

The code of LOAD_IMAGE_V2=0 has been removed.

Change-Id: Iea03e5bebb90c66889bdb23f85c07d0c9717fffe
Co-authored-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

Conflict with function name and variable name within that function.
Change the name of the function from image_size to get_image_size
to remove conflict and make the function fit the normal project
naming convention.

Rule 5.3:  An identifier declared in an inner scope shall not
           hide an identifier declared in an outer scope

Fixed For:
    make LOG_LEVEL=50 PLAT=fvp

Change-Id: I1a63d2730113e2741fffa79730459c584b0224d7
Signed-off-by: Daniel Boulby <daniel.boulby@arm.com>

This patch allows platforms to dynamically disable authentication of
images during cold boot. This capability is controlled via the
DYN_DISABLE_AUTH build flag and is only meant for development
purposes.

Change-Id: Ia3df8f898824319bb76d5cc855b5ad6c3d227260
Signed-off-by: Soby Mathew <soby.mathew@arm.com>

Previously the cache flush happened in 2 different places in code
depending on whether TRUSTED_BOARD_BOOT is enabled or not. This
patch unifies this code path for both the cases. The `load_image()`
function is now made an internal static function.

Change-Id: I96a1da29d29236bbc34b1c95053e6a9a7fc98a54
Signed-off-by: Soby Mathew <soby.mathew@arm.com>

These hooks are intended to allow one platform to try load
images from alternative places. There is a hook to initialize
the sequence of boot locations and a hook to pass to the next
sequence.

Change-Id: Ia0f84c415208dc4fa4f9d060d58476db23efa5b2
Signed-off-by: Roberto Vargas <roberto.vargas@arm.com>

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>

The files affected by this patch don't really depend on `xlat_tables.h`.
By changing the included file it becomes easier to switch between the
two versions of the translation tables library.

Change-Id: Idae9171c490e0865cb55883b19eaf942457c4ccc
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

Introduce zeromem_dczva function on AArch64 that can handle unaligned
addresses and make use of DC ZVA instruction to zero a whole block at a
time. This zeroing takes place directly in the cache to speed it up
without doing external memory access.

Remove the zeromem16 function on AArch64 and replace it with an alias to
zeromem. This zeromem16 function is now deprecated.

Remove the 16-bytes alignment constraint on __BSS_START__ in
firmware-design.md as it is now not mandatory anymore (it used to comply
with zeromem16 requirements).

Change the 16-bytes alignment constraints in SP min's linker script to a
8-bytes alignment constraint as the AArch32 zeromem implementation is now
more efficient on 8-bytes aligned addresses.

Introduce zero_normalmem and zeromem helpers in platform agnostic header
that are implemented this way:
* AArch32:
	* zero_normalmem: zero using usual data access
	* zeromem: alias for zero_normalmem
* AArch64:
	* zero_normalmem: zero normal memory  using DC ZVA instruction
	                  (needs MMU enabled)
	* zeromem: zero using usual data access

Usage guidelines: in most cases, zero_normalmem should be preferred.

There are 2 scenarios where zeromem (or memset) must be used instead:
* Code that must run with MMU disabled (which means all memory is
  considered device memory for data accesses).
* Code that fills device memory with null bytes.

Optionally, the following rule can be applied if performance is
important:
* Code zeroing small areas (few bytes) that are not secrets should use
  memset to take advantage of compiler optimizations.

  Note: Code zeroing security-related critical information should use
  zero_normalmem/zeromem instead of memset to avoid removal by
  compilers' optimizations in some cases or misbehaving versions of GCC.

Fixes ARM-software/tf-issues#408

Change-Id: Iafd9663fc1070413c3e1904e54091cf60effaa82
Signed-off-by: Douglas Raillard <douglas.raillard@arm.com>

The is_mem_free() function used to be local to bl_common.c.
This patch exports it so that it can be used outside of bl_common.c.

Change-Id: I01dcb4229f3a36f56a4724b567c5e6c416dc5e98
Signed-off-by: Sandrine Bailleux <sandrine.bailleux@arm.com>

When loading and authenticating an image, all parent images must also
be authenticated. The parent images are just certificates that don't
need to be used by any other CPU except the one loading the image, and
so there is no need to flush the cache of memory regions where they
are loaded.

Change-Id: Ice8d6979d1c02eabf1a543281ae1a07d098e4a99
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

This patch adds capability to load BL images based on image
descriptors instead of hard coded way of loading BL images.
This framework is designed such that it can be readily adapted
by any BL stage that needs to load images.

In order to provide the above capability the following new
platform functions are introduced:

  bl_load_info_t *plat_get_bl_image_load_info(void);
    This function returns pointer to the list of images that the
    platform has populated to load.

  bl_params_t *plat_get_next_bl_params(void);
    This function returns a pointer to the shared memory that the
    platform has kept aside to pass trusted firmware related
    information that next BL image needs.

  void plat_flush_next_bl_params(void);
    This function flushes to main memory all the params that
    are passed to next image.

  int bl2_plat_handle_post_image_load(unsigned int image_id)
    This function can be used by the platforms to update/use
    image information for given `image_id`.

`desc_image_load.c` contains utility functions which can be used
by the platforms to generate, load and executable, image list
based on the registered image descriptors.

This patch also adds new version of `load_image/load_auth_image`
functions in-order to achieve the above capability.

Following are the changes for the new version as compared to old:
  - Refactor the signature and only keep image_id and image_info_t
    arguments. Removed image_base argument as it is already passed
    through image_info_t. Given that the BL image base addresses and
    limit/size are already provided by the platforms, the meminfo_t
    and entry_point_info arguments are not needed to provide/reserve
    the extent of free memory for the given BL image.

  - Added check for the image size against the defined max size.
    This is needed because the image size could come from an
    unauthenticated source (e.g. the FIP header).
    To make this check, new member is added to the image_info_t
    struct for identifying the image maximum size.

New flag `LOAD_IMAGE_V2` is added in the Makefile.
Default value is 0.

NOTE: `TRUSTED_BOARD_BOOT` is currently not supported when
      `LOAD_IMAGE_V2` is enabled.

Change-Id: Ia7b643f4817a170d5a2fbf479b9bc12e63112e79

This patch resolves a build error in Trusted Firmware when `ARCH=aarch32`
and LOG_LEVEL >= 50.

Change-Id: I62a23ded4a25304533cdcc5ff11442aee041709b

At the end of successful image authentication in load_auth_image(),
the data cache for the virtual address range corresponding to the
image is invalidated (by a call to inv_dcache_range()). The intent
seems to be to ensure the data caches do not contain any sensitive
data used during authentication, which subsequent code can read.
However, this same address range is already flushed (cleaned and
invalidated by a call to flush_dcache_range()) at the end of
load_image(), and the subsequent invalidate has no functional
effect.

This patch removes the redundant call to inv_dcache_range(). It
also moves the flush_dcache_range() call from the end of load_image()
to the end of load_auth_image(), so the image data will remain in
the caches during authentication, improving performance.

This also improves the comments that explain the rationale for
calling flush_dcache_range() after image loading/authentication.

Change-Id: I14f17ad2935075ef6f3d1327361c5088bfb2d284

This patch adds some runtime checks to prevent some potential
pointer overflow issues in the is_mem_free() function. The overflow
could happen in the case where the end addresses, computed as the
sum of a base address and a size, results in a value large enough
to wrap around. This, in turn, could lead to unpredictable behaviour.

If such an overflow is detected, the is_mem_free() function will now
declare the memory region as not free. The overflow is detected using
a new macro, called check_uptr_overflow().

This patch also modifies all other places in the 'bl_common.c' file
where an end address was computed as the sum of a base address and a
size and instead keeps the two values separate. This avoids the need
to handle pointer overflows everywhere. The code doesn't actually need
to compute any end address before the is_mem_free() function is called
other than to print information message to the serial output.

This patch also introduces 2 slight changes to the reserve_mem()
function:

 - It fixes the end addresses passed to choose_mem_pos(). It was
   incorrectly passing (base + size) instead of (base + size - 1).

 - When the requested allocation size is 0, the function now exits
   straight away and says so using a warning message.
   Previously, it used to actually reserve some memory. A zero-byte
   allocation was not considered as a special case so the function
   was using the same top/bottom allocation mechanism as for any
   other allocation. As a result, the smallest area of memory starting
   from the requested base address within the free region was
   reserved.

Change-Id: I0e695f961e24e56ffe000718014e0496dc6e1ec6

This patch reworks type usage in generic code, drivers and ARM platform files
to make it more portable. The major changes done with respect to
type usage are as listed below:

* Use uintptr_t for storing address instead of uint64_t or unsigned long.
* Review usage of unsigned long as it can no longer be assumed to be 64 bit.
* Use u_register_t for register values whose width varies depending on
  whether AArch64 or AArch32.
* Use generic C types where-ever possible.

In addition to the above changes, this patch also modifies format specifiers
in print invocations so that they are AArch64/AArch32 agnostic. Only files
related to upcoming feature development have been reworked.

Change-Id: I9f8c78347c5a52ba7027ff389791f1dad63ee5f8

- Fix the function documentation.
  Since commit 16948ae1, load_image() uses image IDs rather than image
  names.

- Clarify the consequences of a null entry point argument.

- Slightly reorganize the code to remove an unnecessary 'if' statement.

Change-Id: Iebea3149a37f23d3b847a37a206ed23f7e8ec717

The AArch32 long descriptor format and the AArch64 descriptor format
correspond to each other which allows possible sharing of xlat_tables
library code between AArch64 and AArch32. This patch refactors the
xlat_tables library code to seperate the common functionality from
architecture specific code. Prior to this patch, all of the xlat_tables
library code were in `lib/aarch64/xlat_tables.c` file. The refactored code
is now in `lib/xlat_tables/` directory. The AArch64 specific programming
for xlat_tables is in `lib/xlat_tables/aarch64/xlat_tables.c` and the rest
of the code common to AArch64 and AArch32 is in
`lib/xlat_tables/xlat_tables_common.c`. Also the data types used in
xlat_tables library APIs are reworked to make it compatible between AArch64
and AArch32.

The `lib/aarch64/xlat_tables.c` file now includes the new xlat_tables
library files to retain compatibility for existing platform ports.
The macros related to xlat_tables library are also moved from
`include/lib/aarch64/arch.h` to the header `include/lib/xlat_tables.h`.

NOTE: THE `lib/aarch64/xlat_tables.c` FILE IS DEPRECATED AND PLATFORM PORTS
ARE EXPECTED TO INCLUDE THE NEW XLAT_TABLES LIBRARY FILES IN THEIR MAKEFILES.

Change-Id: I3d17217d24aaf3a05a4685d642a31d4d56255a0f

This patch adds support for the `%p` format specifier in tf_printf()
following the example of the printf implementation of the stdlib used
in the trusted firmware.

Fixes ARM-software/tf-issues#292

Change-Id: I0b3230c783f735d3e039be25a9405f00023420da

Patch 7e26fe1f deprecates IO specific return definitions in favour
of standard errno codes. This patch removes those definitions
and its usage from the IO framework, IO drivers and IO platform
layer. Following this patch, standard errno codes must be used
when checking the return value of an IO function.

Change-Id: Id6e0e9d0a7daf15a81ec598cf74de83d5768650f

This patch introduces a new function called 'print_entry_point_info'
that prints an entry_point_t structure for debugging purposes.
As such, it can be used to display the entry point address, SPSR and
arguments passed from a firmware image to the next one.

This function is now called in the following images transitions:
 - BL1 to BL2
 - BL1 to BL31
 - BL31 to the next image (typically BL32 or BL33)

The following changes have been introduced:

 - Fix the output format of the SPSR value : SPSR is a 32-bit value,
   not a 64-bit one.

 - Print all arguments values.
   The entry_point_info_t structure allows to pass up to 8 arguments.
   In most cases, only the first 2 arguments were printed.
   print_entry_point_info() now prints all of them as 'VERBOSE'
   traces.

Change-Id: Ieb384bffaa7849e6cb95a01a47c0b7fc2308653a

This patch replaces custom definitions used as return values for
the load_auth_image() function with standard error codes defined
in errno.h. The custom definitions have been removed.

It also replaces the usage of IO framework error custom definitions,
which have been deprecated. Standard errno definitions are used
instead.

Change-Id: I1228477346d3876151c05b470d9669c37fd231be

BL2 loads secure runtime code(BL3-1, BL3-2) and hence it has to
run in secure world otherwise BL3-1/BL3-2 have to execute from
non-secure memory. Hence, This patch removes the change_security_state()
call in bl1_run_bl2() and replaces it with an assert to confirm
the BL2 as secure.

Fixes ARM-software/tf-issues#314

Change-Id: I611b83f5c4090e58a76a2e950b0d797b46df3c29

BL3-2 image (Secure Payload) is optional. If the image cannot be
loaded a warning message is printed and the boot process continues.
According to the TBBR document, this behaviour should not apply in
case of an authentication error, where the boot process should be
aborted.

This patch modifies the load_auth_image() function to distinguish
between a load error and an authentication error. The caller uses
the return value to abort the boot process or continue.

In case of authentication error, the memory region used to store
the image is wiped clean.

Change-Id: I534391d526d514b2a85981c3dda00de67e0e7992

This patch modifies the Trusted Board Boot implementation to use
the new authentication framework, making use of the authentication
module, the cryto module and the image parser module to
authenticate the images in the Chain of Trust.

A new function 'load_auth_image()' has been implemented. When TBB
is enabled, this function will call the authentication module to
authenticate parent images following the CoT up to the root of
trust to finally load and authenticate the requested image.

The platform is responsible for picking up the right makefiles to
build the corresponding cryptographic and image parser libraries.
ARM platforms use the mbedTLS based libraries.

The platform may also specify what key algorithm should be used
to sign the certificates. This is done by declaring the 'KEY_ALG'
variable in the platform makefile. FVP and Juno use ECDSA keys.

On ARM platforms, BL2 and BL1-RW regions have been increased 4KB
each to accommodate the ECDSA code.

REMOVED BUILD OPTIONS:

  * 'AUTH_MOD'

Change-Id: I47d436589fc213a39edf5f5297bbd955f15ae867

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

Commit dad25049 adds support for type checking in printf-like
functions. Some of the VERBOSE logging statements were not updated
at that time.

Fix the type mismatches in the verbose logging statements.

Change-Id: Idd9a49e41cc0dc31f7698e220819d934e3d2d10e

This patch adds support to not reserve the memory where an image is
loaded if the image is:

  1. A non-executable image e.g. a certificate
  2. An executable image which is not meant to run on the
     application CPU (e.g. BL3-0)

Both types of images are characterized by a NULL entrypoint argument
to the load_image() function. It is used to distinguish them from
other type of images.

Important: Use this feature carefully. The caller is responsible for
providing a valid entrypoint while loading images which will execute
on the application CPU to prevent a potential overwrite of the
corresponding memory region.

Change-Id: Ied482280d9db714c529ec12c33a6c1d918d77a4e

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.

Fixes ARM-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.

Fixes ARM-software/tf-issues#96

Change-Id: I51e9ef0439fd5ff5e0edfef49050b69804bf14d5

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

This concept is no longer required since we now support loading of
images at fixed addresses only.

The image loader now automatically detects the position of the image
inside the current memory layout and updates the layout such that
memory fragmentation is minimised.

The 'attr' field of the meminfo data structure, which used to hold
the bottom/top loading information, has been removed. Also the 'next'
field has been removed as it wasn't used anywhere.

The 'init_bl2_mem_layout()' function has been moved out of common
code and put in BL1-specific code. It has also been renamed into
'bl1_init_bl2_mem_layout'.

Fixes ARM-software/tf-issues#109

Change-Id: I3f54642ce7b763d5ee3b047ad0ab59eabbcf916d

There are cases where the entry point information is useless to the
caller, e.g. when an image just needs to be loaded in memory but won't
ever be executed.

This patch allows load_image() function to take a NULL pointer as the
entry point argument. In this case, it won't be populated.

Change-Id: Ie9394b054457706c6699926c5e0206e0c3851c56