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So far the ARM platform Makefile would require that RESET_TO_BL31 is set
when we ask for the ARM_LINUX_KERNEL_AS_BL33 feature.
There is no real technical reason for that, and the one place in the
code where this was needed has been fixed.

Remove the requirement of those two options to be always enabled
together.
This enables the direct kernel boot feature for the Foundation FVP
(as described in the documentation), which requires a BL1/FIP
combination to boot, so cannot use RESET_TO_BL31.

Change-Id: I6814797b6431b6614d684bab3c5830bfd9481851
Signed-off-by: Andre Przywara <andre.przywara@arm.com>

At the moment we have the somewhat artifical limitation of
ARM_LINUX_KERNEL_AS_BL33 only being used together with RESET_TO_BL31.

However there does not seem to be a good technical reason for that,
it was probably just to differentate between two different boot flows.

Move the initial register setup for ARM_LINUX_KERNEL_AS_BL33 out of the
RESET_TO_BL31 #ifdef, so that we initialise the registers in any case.

This allows to use a preloaded kernel image when using BL1 and FIP.

Change-Id: I832df272d3829f077661f4ee6d3dd9a276a0118f
Signed-off-by: Andre Przywara <andre.przywara@arm.com>

Currently, when RECLAIM_INIT_CODE is set, the
stacks are scaled to ensure that the entirety
of the init section can be reclaimed as stack.

This causes an issue in lib/psci/aarch64/psci_helpers.S,
where the stack size is used for cache operations in
psci_do_pwrdown_cache_maintenance(). If the stacks
are scaled, then the PSCI code may fail to invalidate
some of the stack memory before power down.

Resizing stacks is also not good for stability in general,
since code that works with a small number of cores may
overflow the stack when the number of cores is increased.

Change to make every stack be PLATFORM_STACK_SIZE big,
and allow the total stack to be smaller than the
init section.

Any pages of the init section not reclaimed as
stack will be set to read-only and execute-never,
for security.

Change-Id: I10b3884981006431f2fcbec3864c81d4a8c246e8
Signed-off-by: David Horstmann <david.horstmann@arm.com>

Usually, C has no problem up-converting types to larger bit sizes. MISRA
rule 10.7 requires that you not do this, or be very explicit about this.
This resolves the following required rule:

    bl1/aarch64/bl1_context_mgmt.c:81:[MISRA C-2012 Rule 10.7 (required)]<None>
    The width of the composite expression "0U | ((mode & 3U) << 2U) | 1U |
    0x3c0U" (32 bits) is less that the right hand operand
    "18446744073709547519ULL" (64 bits).

This also resolves MISRA defects such as:

    bl2/aarch64/bl2arch_setup.c:18:[MISRA C-2012 Rule 12.2 (required)]
    In the expression "3U << 20", shifting more than 7 bits, the number
    of bits in the essential type of the left expression, "3U", is
    not allowed.

Further, MISRA requires that all shifts don't overflow. The definition of
PAGE_SIZE was (1U << 12), and 1U is 8 bits. This caused about 50 issues.
This fixes the violation by changing the definition to 1UL << 12. Since
this uses 32bits, it should not create any issues for aarch32.

This patch also contains a fix for a build failure in the sun50i_a64
platform. Specifically, these misra fixes removed a single and
instruction,

    92407e73        and     x19, x19, #0xffffffff

from the cm_setup_context function caused a relocation in
psci_cpus_on_start to require a linker-generated stub. This increased the
size of the .text section and caused an alignment later on to go over a
page boundary and round up to the end of RAM before placing the .data
section. This sectionn is of non-zero size and therefore causes a link
error.

The fix included in this reorders the functions during link time
without changing their ording with respect to alignment.

Change-Id: I76b4b662c3d262296728a8b9aab7a33b02087f16
Signed-off-by: Jimmy Brisson <jimmy.brisson@arm.com>

And from crash_console_flush.

We ignore the error information return by console_flush in _every_
place where we call it, and casting the return type to void does not
work around the MISRA violation that this causes. Instead, we collect
the error information from the driver (to avoid changing that API), and
don't return it to the caller.

Change-Id: I1e35afe01764d5c8f0efd04f8949d333ffb688c1
Signed-off-by: Jimmy Brisson <jimmy.brisson@arm.com>

Implemented a parser which populates the properties of
the CoT descriptors as per the binding document [1].
'COT_DESC_IN_DTB' build option is disabled by default and can
be enabled in future for all Arm platforms by making necessary
changes in the memory map.
Currently, this parser is tested only for FVP platform.

[1]:
https://trustedfirmware-a.readthedocs.io/en/latest/components/cot-binding.html



Change-Id: I2f911206087a1a2942aa728de151d2ac269d27cc
Signed-off-by: Manish V Badarkhe <Manish.Badarkhe@arm.com>

UUID's in the device tree files were stored in little endian. So
to keep all entries in these files RFC 4122 compliant, store them in
big endian then convert it to little endian when they are read so they
can be used in the UUID data structure.
Signed-off-by: Ruari Phipps <ruari.phipps@arm.com>
Change-Id: I5674159b82b245104381df10a4e3291160d9b3b5

Trace analysis of FVP_Base_AEMv8A 0.0/6063 model
running in Aarch32 mode with the build options
listed below:
TRUSTED_BOARD_BOOT=1 GENERATE_COT=1
ARM_ROTPK_LOCATION=devel_ecdsa KEY_ALG=ecdsa
ROT_KEY=plat/arm/board/common/rotpk/arm_rotprivk_ecdsa.pem
shows that when auth_signature() gets called
71.99% of CPU execution time is spent in memset() function
written in C using single byte write operations,
see lib\libc\memset.c.
This patch introduces new libc_asm.mk makefile which
replaces C memset() implementation with assembler
version giving the following results:
- for Aarch32 in auth_signature() call memset() CPU time
reduced to 20.56%.
The number of CPU instructions (Inst) executed during
TF-A boot stage before start of BL33 in RELEASE builds
for different versions is presented in the tables below,
where:
- C TF-A: existing TF-A C code;
- C musl: "lightweight code" C "implementation of the
  standard library for Linux-based systems"
https://git.musl-libc.org/cgit/musl/tree/src/string/memset.c
- Asm Opt: assemler version from "Arm Optimized Routines"
  project
https://github.com/ARM-software/optimized-routines/blob/
master/string/arm/memset.S
- Asm Linux: assembler version from Linux kernel
https://github.com/torvalds/linux/blob/master/arch/arm/lib/memset.S


- Asm TF-A: assembler version from this patch

Aarch32:
+-----------+------+------+--------------+----------+
| Variant   | Set  | Size |    Inst 	 |  Ratio   |
+-----------+------+------+--------------+----------+
| C TF-A    | T32  | 16   | 2122110003   | 1.000000 |
| C musl    | T32  | 156  | 1643917668   | 0.774662 |
| Asm Opt   | T32  | 84   | 1604810003   | 0.756233 |
| Asm Linux | A32  | 168  | 1566255018   | 0.738065 |
| Asm TF-A  | A32  | 160  | 1525865101   | 0.719032 |
+-----------+------+------+--------------+----------+

AArch64:
+-----------+------+------------+----------+
| Variant   | Size |    Inst    |  Ratio   |
+-----------+------+------------+----------+
| C TF-A    | 28   | 2732497518 | 1.000000 |
| C musl    | 212  | 1802999999 | 0.659836 |
| Asm TF-A  | 140  | 1680260003 | 0.614917 |
+-----------+------+------------+----------+

This patch modifies 'plat\arm\common\arm_common.mk'
by overriding libc.mk makefile with libc_asm.mk and
does not effect other platforms.

Change-Id: Ie89dd0b74ba1079420733a0d76b7366ad0157c2e
Signed-off-by: Alexei Fedorov <Alexei.Fedorov@arm.com>

In the case of Juno AArch32, platform security configuration
gets done from both BL2 and SP_MIN(BL32) components when
JUNO_AARCH32_EL3_RUNTIME and RESET_TO_SP_MIN build options
are set.
Fix is provided to avoid Platform security configuration from
SP_MIN when it is already done in BL2.
Signed-off-by: Manish V Badarkhe <Manish.Badarkhe@arm.com>
Change-Id: I702e91dacb4cdd2d10e339ddeaea91289bef3229

Using the Fconf, register base address of the various nv-counters
(currently, trusted, non-trusted nv-counters) are moved to the
device tree and retrieved during run-time. This feature is
enabled using the build option COT_DESC_IN_DTB.
Signed-off-by: Manish V Badarkhe <Manish.Badarkhe@arm.com>
Change-Id: I236f532e63cea63b179f60892cb406fc05cd5830

'EHF' is used by RAS, SDEI, SPM_MM common frameworks.
If platform needs to plug-in specific handlers then
'PLAT_EHF_DESC' can be used to populate platform specific
priority levels.
Signed-off-by: Sandeep Tripathy <sandeep.tripathy@broadcom.com>
Change-Id: I37af7e0e48111f87b6982604bf5c15db3e05755d

In case of AT speculative workaround applied, page table walk
is disabled for lower ELs (EL1 and EL0) in EL3.
Hence added a wrapper function which temporarily enables page
table walk to execute AT instruction for lower ELs and then
disables page table walk.

Execute AT instructions directly for lower ELs (EL1 and EL0)
assuming page table walk is enabled always when AT speculative
workaround is not applied.

Change-Id: I4ad4c0bcbb761448af257e9f72ae979473c0dde8
Signed-off-by: Manish V Badarkhe <Manish.Badarkhe@arm.com>

Removed common code for soc-id feature which is applicable
for all arm platforms.

In subsequent patches, added a platform based functions
for FVP and Juno to retrieve the soc-id information.

Change-Id: Idb632a935758a6caff2ca03a6eab8f663da8a93a
Signed-off-by: Manish V Badarkhe <Manish.Badarkhe@arm.com>

For Arm platforms SPs are loaded by parsing tb_fw_config.dts and
adding them to SP structure sequentially, which in-turn is appended to
loadable image list.

With recently introduced dualroot CoT for SPs where they are owned
either by SiP or by Platform. SiP owned SPs index starts at SP_PKG1_ID
and Plat owned SPs index starts at SP_PKG5_ID. As the start index of SP
depends on the owner, there should be a mechanism to parse owner of a SP
and put it at the correct index in SP structure.

This patch adds support for parsing a new optional field "owner" and
based on it put SP details(UUID & Load-address) at the correct index in
SP structure.

Change-Id: Ibd255b60d5c45023cc7fdb10971bef6626cb560b
Signed-off-by: Manish Pandey <manish.pandey2@arm.com>

There was a collision between the name of the typedef in the CASSERT and
something else, so we make the name of the typedef unique to the
invocation of DEFFINE_SVC_UUID2 by appending the name that's passed into
the macro. This eliminates the following MISRA violation:

    bl1/bl1_main.c:233:[MISRA C-2012 Rule 5.6 (required)] Identifier
    "invalid_svc_uuid" is already used to represent a typedef.

This also resolves MISRA rule 5.9.

These renamings are as follows:
  * tzram -> secram. This matches the function call name as it has
  sec_mem in it's  name
  * fw_config_base -> config_base. This file does not mess with
  hw_conig, so there's little chance of confusion

Change-Id: I8734ba0956140c8e29b89d0596d10d61a6ef351e
Signed-off-by: Jimmy Brisson <jimmy.brisson@arm.com>

BL31 binary size is aligned to 4KB because of the
code in include\plat\arm\common\arm_reclaim_init.ld.S:
    __INIT_CODE_UNALIGNED__ = .;
    . = ALIGN(PAGE_SIZE);
    __INIT_CODE_END__ = .;
with all the zero data after the last instruction of
BL31 code to the end of the page.
This causes increase in size of BL31 binary stored in FIP
and its loading time by BL2.
This patch reduces the size of BL31 image by moving
page alignment from __INIT_CODE_END__ to __STACKS_END__
which also increases the stack size for secondary CPUs.

Change-Id: Ie2ec503fc774c22c12ec506d74fd3ef2b0b183a9
Signed-off-by: Alexei Fedorov <Alexei.Fedorov@arm.com>

Currently only single signing domain is supported for SP packages but
there is plan to support dual signing domains if CoT is dualroot.

SP_CONTENT_CERT_ID is the certificate file which is currently generated
and signed with trusted world key which in-turn is derived from Silicon
provider RoT key.
To allow dual signing domain for SP packages, other certificate file
will be derived from Platform owned RoT key.

This patch renames "SP_CONTENT_CERT_ID" to "SIP_SP_CONTENT_CERT_ID" and
does other related changes.
Signed-off-by: Manish Pandey <manish.pandey2@arm.com>
Change-Id: I0bc445a3ab257e2dac03faa64f46e36a9fed5e93

This patch fixes a bug where wrong panic was caused when the number
of SP was same as max limit.
Signed-off-by: Manish Pandey <manish.pandey2@arm.com>
Change-Id: I9ace62d8d5bcdc410eeacdd9d33d55a7be5fcc8e

Currently, soc-revision information is not available for arm
platforms hence disabled 'SMCCC_ARCH_SOC_ID' feature for all arm
platforms.

Change-Id: I1ab878c6a4c8fecfff63bc6dde83e3ecefe20279
Signed-off-by: Manish V Badarkhe <Manish.Badarkhe@arm.com>

SPM(BL32) and hafnium(BL33) expect their manifest base address in x0
register, which is updated during BL2 stage by parsing fw_config.
In case of RESET_TO_BL31 it has to be updated while populating
entry point information.
Signed-off-by: Manish Pandey <manish.pandey2@arm.com>
Change-Id: I6f4a97f3405029bd6ba25f0935e2d1f74bb95517

In BL2, fw_config's population happened before the cache gets
enabled.
Hence to boost the performance, moved fw_config's population
after cache gets enabled (i.e. after MMU gets enabled).
Signed-off-by: Manish V Badarkhe <Manish.Badarkhe@arm.com>
Change-Id: I2e75cabd76b1cb7a660f6b72f409ab40d2877284

Updated the function 'set_fw_config_info' to make it generic
by doing below changes:

1. Rename function name from 'set_fw_config_info' to 'set_config_info'
2. Take image_id as an argument so that this function can set any
   config information.
Signed-off-by: Manish V Badarkhe <Manish.Badarkhe@arm.com>
Change-Id: Icf29e19d3e9996d8154d84dbbbc76712fab0f0c1

Update the data type of the member 'config_max_size' present in the
structure 'dyn_cfg_dtb_info_t' to uint32_t.

This change is being done so that dyn_cfg_dtb_info_t and image_info
structure should use same data type for maximum size.

Change-Id: I9b5927a47eb8351bbf3664b8b1e047ae1ae5a260
Signed-off-by: Manish V Badarkhe <Manish.Badarkhe@arm.com>

Currently, the need for firmware update is being checked twice
in the code hence modifications are done to do this check only
once and set the global variable.
Then this global variable helps to decide whether to go for
normal boot or firmware update flow.

Change-Id: I8469284555a8039786f34670f9dc4830f87aecc1
Signed-off-by: Manish V Badarkhe <Manish.Badarkhe@arm.com>

This patch adds support for Event Log generation required
for Measured Boot functionality.

Change-Id: I34f05a33565e6659e78499d62cc6fb00b7d6c2dc
Signed-off-by: Alexei Fedorov <Alexei.Fedorov@arm.com>

This patch adds support for Measured Boot driver functionality
in common Arm platform code.

Change-Id: If049dcf8d847c39023b77c0d805a8cf5b8bcaa3e
Signed-off-by: Alexei Fedorov <Alexei.Fedorov@arm.com>

Added assert in the code to check valid address of dtb information
structure retrieved from fw_config device tree.
This patch fixes coverity defect:360213.

Also, removed conditional calling of "fconf_populate" as "fconf_populate"
function already checks the validity of the device tree address received
and go to panic in case of address is NULL.
Signed-off-by: Manish V Badarkhe <Manish.Badarkhe@arm.com>
Change-Id: Ib83e4e84a95e2456a12c7a2bb3fe70461d882cba

Modified the code to do below changes:

1. Load tb_fw_config along with fw_config by BL1.
2. Populate fw_config device tree information in the
   BL1 to load tb_fw_config.
3. In BL2, populate fw_config information to retrieve
   the address of tb_fw_config and then tb_fw_config
   gets populated using retrieved address.
4. Avoid processing of configuration file in case of error
   value returned from "fw_config_load" function.
5. Updated entrypoint information for BL2 image so
   that it's arg0 should point to fw_config address.
Signed-off-by: Manish V Badarkhe <Manish.Badarkhe@arm.com>
Signed-off-by: Louis Mayencourt <louis.mayencourt@arm.com>
Change-Id: Ife6f7b673a074e7f544ee3d1bda7645fd5b2886c

Modified the code to do below changes:

1. Migrates the Arm platforms to the API changes introduced in the
   previous patches by fixing the fconf_load_config() call.
2. Retrieve dynamically the address of tb_fw_config using fconf
   getter api which is subsequently used to write mbedTLS heap
   address and BL2 hash data in the tb_fw_config DTB.
Signed-off-by: Manish V Badarkhe <Manish.Badarkhe@arm.com>
Signed-off-by: Louis Mayencourt <louis.mayencourt@arm.com>
Change-Id: I3c9d9345dcbfb99127c61d5589b4aa1532fbf4be

Cleaned up confused naming between TB_FW and FW_CONFIG.
Signed-off-by: Louis Mayencourt <louis.mayencourt@arm.com>
Signed-off-by: Manish V Badarkhe <Manish.Badarkhe@arm.com>
Change-Id: I9e9f6e6ca076d38fee0388f97d370431ae067f08

fw_config image is authenticated using secure boot framework by
adding it into the single root and dual root chain of trust.

The COT for fw_config image looks as below:

+------------------+       +-------------------+
| ROTPK/ROTPK Hash |------>| Trusted Boot fw   |
+------------------+       | Certificate       |
                           | (Auth Image)      |
                          /+-------------------+
                         /                   |
                        /                    |
                       /                     |
                      /                      |
                     L                       v
+------------------+       +-------------------+
| fw_config hash   |------>| fw_config         |
|                  |       | (Data Image)      |
+------------------+       +-------------------+
Signed-off-by: Louis Mayencourt <louis.mayencourt@arm.com>
Signed-off-by: Manish V Badarkhe <Manish.Badarkhe@arm.com>
Change-Id: I08fc8ee95c29a95bb140c807dd06e772474c7367

Using the fconf framework, the Group 0 and Group 1 secure interrupt
descriptors are moved to device tree and retrieved in runtime. This
feature is enabled by the build flag SEC_INT_DESC_IN_FCONF.

Change-Id: I360c63a83286c7ecc2426cd1ff1b4746d61e633c
Signed-off-by: Madhukar Pappireddy <madhukar.pappireddy@arm.com>

A new certificate "sip-sp-cert" has been added for Silicon Provider(SiP)
owned Secure Partitions(SP). A similar support for Platform owned SP can
be added in future. The certificate is also protected against anti-
rollback using the trusted Non-Volatile counter.

To avoid deviating from TBBR spec, support for SP CoT is only provided
in dualroot.
Secure Partition content certificate is assigned image ID 31 and SP
images follows after it.

The CoT for secure partition look like below.
+------------------+       +-------------------+
| ROTPK/ROTPK Hash |------>| Trusted Key       |
+------------------+       | Certificate       |
                           | (Auth Image)      |
                          /+-------------------+
                         /                   |
                        /                    |
                       /                     |
                      /                      |
                     L                       v
+------------------+       +-------------------+
| Trusted World    |------>| SiP owned SPs     |
| Public Key       |       | Content Cert      |
+------------------+       | (Auth Image)      |
                        /   +-------------------+
                       /                      |
                      /                      v|
+------------------+ L     +-------------------+
| SP_PKG1 Hash     |------>| SP_PKG1           |
|                  |       | (Data Image)      |
+------------------+       +-------------------+
        .                           .
        .                           .
        .                           .
+------------------+       +-------------------+
| SP_PKG8 Hash     |------>| SP_PKG8           |
|                  |       | (Data Image)      |
+------------------+       +-------------------+
Signed-off-by: Manish Pandey <manish.pandey2@arm.com>
Change-Id: Ia31546bac1327a3e0b5d37e8b99c808442d5e53f

Fixed build error for dualroot chain of trust.
Build error were thrown as below while compiling the code for
dualroot chain of trust:

aarch64-none-elf-ld.bfd: ./build/fvp/debug/bl1/tbbr_cot_bl1.o:
(.bss.auth_img_flags+0x0): multiple definition of `auth_img_flags';
./build/fvp/debug/bl1/cot.o:(.bss.auth_img_flags+0x0): first defined here

aarch64-none-elf-ld.bfd: ./build/fvp/debug/bl1/tbbr_cot_bl1.o:
(.rodata.cot_desc_size+0x0): multiple definition of `cot_desc_size';
./build/fvp/debug/bl1/cot.o:(.rodata.cot_desc_size+0x0): first defined here

aarch64-none-elf-ld.bfd: ./build/fvp/debug/bl1/tbbr_cot_bl1.o:
(.rodata.cot_desc_ptr+0x0): multiple definition of `cot_desc_ptr';
./build/fvp/debug/bl1/cot.o:(.rodata.cot_desc_ptr+0x0): first defined here
Signed-off-by: Manish V Badarkhe <Manish.Badarkhe@arm.com>
Change-Id: I1a426c4e7f5f8013d71dafc176c7467c1b329757

We query the UART base address and clk frequency in runtime
using fconf getter APIs.

Change-Id: I5f4e84953be5f384472bf90720b706d45cb86260
Signed-off-by: Madhukar Pappireddy <madhukar.pappireddy@arm.com>

CoT used for BL1 and BL2 are moved to tbbr_cot_bl1.c
and tbbr_cot_bl2.c respectively.
Common CoT used across BL1 and BL2 are moved to
tbbr_cot_common.c.
Signed-off-by: Manish V Badarkhe <Manish.Badarkhe@arm.com>
Change-Id: I2252ac8a6960b3431bcaafdb3ea4fb2d01b79cf5

This patch introduces dynamic configuration for SDEI setup and is supported
when the new build flag SDEI_IN_FCONF is enabled. Instead of using C arrays
and processing the configuration at compile time, the config is moved to
dts files. It will be retrieved at runtime during SDEI init, using the fconf
layer.

Change-Id: If5c35a7517ba00a9f258d7f3e7c8c20cee169a31
Signed-off-by: Balint Dobszay <balint.dobszay@arm.com>
Co-authored-by: Madhukar Pappireddy <madhukar.pappireddy@arm.com>

Our fdtw_read_cells() implementation goes to great lengths to
sanity-check every parameter and result, but leaves a big hole open:
The size of the storage the value pointer points at needs to match the
number of cells given. This can't be easily checked at compile time,
since we lose the size information by using a void pointer.
Regardless the current usage of this function is somewhat wrong anyways,
since we use it on single-element, fixed-length properties only, for
which the DT binding specifies the size.
Typically we use those functions dealing with a number of cells in DT
context to deal with *dynamically* sized properties, which depend on
other properties (#size-cells, #clock-cells, ...), to specify the number
of cells needed.

Another problem with the current implementation is the use of
ambiguously sized types (uintptr_t, size_t) together with a certain
expectation about their size. In general there is no relation between
the length of a DT property and the bitness of the code that parses the
DTB: AArch64 code could encounter 32-bit addresses (where the physical
address space is limited to 4GB [1]), while AArch32 code could read
64-bit sized properties (/memory nodes on LPAE systems, [2]).

To make this more clear, fix the potential issues and also align more
with other DT users (Linux and U-Boot), introduce functions to explicitly
read uint32 and uint64 properties. As the other DT consumers, we do this
based on the generic "read array" function.
Convert all users to use either of those two new functions, and make
sure we never use a pointer to anything other than uint32_t or uint64_t
variables directly.

This reveals (and fixes) a bug in plat_spmd_manifest.c, where we write
4 bytes into a uint16_t variable (passed via a void pointer).

Also we change the implementation of the function to better align with
other libfdt users, by using the right types (fdt32_t) and common
variable names (*prop, prop_names).

[1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi#n874
[2] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/arm/boot/dts/ecx-2000.dts



Change-Id: I718de960515117ac7a3331a1b177d2ec224a3890
Signed-off-by: Andre Przywara <andre.przywara@arm.com>

Currently our fdtw_read_array() implementation requires the length of
the property to exactly match the requested size, which makes it less
flexible for parsing generic device trees.
Also the name is slightly misleading, since we treat the cells of the
array as 32 bit unsigned integers, performing the endianess conversion.

To fix those issues and align the code more with other DT users (Linux
kernel or U-Boot), rename the function to "fdt_read_uint32_array", and
relax the length check to only check if the property covers at least the
number of cells we request.
This also changes the variable names to be more in-line with other DT
users, and switches to the proper data types.

This makes this function more useful in later patches.

Change-Id: Id86f4f588ffcb5106d4476763ecdfe35a735fa6c
Signed-off-by: Andre Przywara <andre.przywara@arm.com>

The platform io policies array is now always accessed through a fconf getter.
This gives us an ideal spot to check for out-of-bound accesses.

Remove the assertion in plat_get_image_source(), which is now redundant.

Change-Id: Iefe808d530229073b68cbd164d927b8b6662a217
Signed-off-by: Sandrine Bailleux <sandrine.bailleux@arm.com>