ARM Trusted Firmware - version 1.1
==================================
New features
------------
* A prototype implementation of Trusted Board Boot has been added. Boot
loader images are verified by BL1 and BL2 during the cold boot path. BL1 and
BL2 use the PolarSSL SSL library to verify certificates and images. The
OpenSSL library is used to create the X.509 certificates. Support has been
added to `fip_create` tool to package the certificates in a FIP.
* Support for calling CPU and platform specific reset handlers upon entry into
BL3-1 during the cold and warm boot paths has been added. This happens after
another Boot ROM `reset_handler()` has already run. This enables a developer
to perform additional actions or undo actions already performed during the
first call of the reset handlers e.g. apply additional errata workarounds.
* Support has been added to demonstrate routing of IRQs to EL3 instead of
S-EL1 when execution is in secure world.
* The PSCI implementation now conforms to version 1.0 of the PSCI
specification. All the mandatory APIs and selected optional APIs are
supported. In particular, support for the `PSCI_FEATURES` API has been
added. A capability variable is constructed during initialization by
examining the `plat_pm_ops` and `spd_pm_ops` exported by the platform and
the Secure Payload Dispatcher. This is used by the PSCI FEATURES function
to determine which PSCI APIs are supported by the platform.
* Improvements have been made to the PSCI code as follows.
* The code has been refactored to remove redundant parameters from
internal functions.
* Changes have been made to the code for PSCI `CPU_SUSPEND`, `CPU_ON` and
`CPU_OFF` calls to facilitate an early return to the caller in case a
failure condition is detected. For example, a PSCI `CPU_SUSPEND` call
returns `SUCCESS` to the caller if a pending interrupt is detected early
in the code path.
* Optional platform APIs have been added to validate the `power_state` and
`entrypoint` parameters early in PSCI `CPU_ON` and `CPU_SUSPEND` code
paths.
* PSCI migrate APIs have been reworked to invoke the SPD hook to determine
the type of Trusted OS and the CPU it is resident on (if
applicable). Also, during a PSCI `MIGRATE` call, the SPD hook to migrate
the Trusted OS is invoked.
* It is now possible to build Trusted Firmware without marking at least an
extra page of memory as coherent. The build flag `USE_COHERENT_MEM` can be
used to choose between the two implementations. This has been made possible
through these changes.
* An implementation of Bakery locks, where the locks are not allocated in
coherent memory has been added.
* Memory which was previously marked as coherent is now kept coherent
through the use of software cache maintenance operations.
Approximately, 4K worth of memory is saved for each boot loader stage when
`USE_COHERENT_MEM=0`. Enabling this option increases the latencies
associated with acquire and release of locks. It also requires changes to
the platform ports.
* It is now possible to specify the name of the FIP at build time by defining
the `FIP_NAME` variable.
* Issues with depedencies on the 'fiptool' makefile target have been
rectified. The `fip_create` tool is now rebuilt whenever its source files
change.
* The BL3-1 runtime console is now also used as the crash console. The crash
console is changed to SoC UART0 (UART2) from the previous FPGA UART0 (UART0)
on Juno. In FVP, it is changed from UART0 to UART1.
* CPU errata workarounds are applied only when the revision and part number
match. This behaviour has been made consistent across the debug and release
builds. The debug build additionally prints a warning if a mismatch is
detected.
* It is now possible to issue cache maintenance operations by set/way for a
particular level of data cache. Levels 1-3 are currently supported.
* The following improvements have been made to the FVP port.
* The build option `FVP_SHARED_DATA_LOCATION` which allowed relocation of
shared data into the Trusted DRAM has been deprecated. Shared data is
now always located at the base of Trusted SRAM.
* BL2 Translation tables have been updated to map only the region of
DRAM which is accessible to normal world. This is the region of the 2GB
DDR-DRAM memory at 0x80000000 excluding the top 16MB. The top 16MB is
accessible to only the secure world.
* BL3-2 can now reside in the top 16MB of DRAM which is accessible only to
the secure world. This can be done by setting the build flag
`FVP_TSP_RAM_LOCATION` to the value `dram`.
* Separate transation tables are created for each boot loader image. The
`IMAGE_BLx` build options are used to do this. This allows each stage to
create mappings only for areas in the memory map that it needs.
* A Secure Payload Dispatcher (OPTEED) for the OP-TEE Trusted OS has been
added. Details of using it with ARM Trusted Firmware can be found in
[OP-TEE Dispatcher]
Issues resolved since last release
----------------------------------
* The Juno port has been aligned with the FVP port as follows.
* Support for reclaiming all BL1 RW memory and BL2 memory by overlaying
the BL3-1/BL3-2 NOBITS sections on top of them has been added to the
Juno port.
* The top 16MB of the 2GB DDR-DRAM memory at 0x80000000 is configured
using the TZC-400 controller to be accessible only to the secure world.
* The ARM GIC driver is used to configure the GIC-400 instead of using a
GIC driver private to the Juno port.
* PSCI `CPU_SUSPEND` calls that target a standby state are now supported.
* The TZC-400 driver is used to configure the controller instead of direct
accesses to the registers.
* The Linux kernel version referred to in the user guide has DVFS and HMP
support enabled.
* DS-5 v5.19 did not detect Version 5.8 of the Cortex-A57-A53 Base FVPs in
CADI server mode. This issue is not seen with DS-5 v5.20 and Version 6.2 of
the Cortex-A57-A53 Base FVPs.
Known issues
------------
* The Trusted Board Boot implementation is a prototype. There are issues with
the modularity and scalability of the design. Support for a Trusted
Watchdog, firmware update mechanism, recovery images and Trusted debug is
absent. These issues will be addressed in future releases.
* The FVP and Juno ports do not use the hash of the ROTPK stored in the
Trusted Key Storage registers to verify the ROTPK in the
`plat_match_rotpk()` function. This prevents the correct establishment of
the Chain of Trust at the first step in the Trusted Board Boot process.
* The version of the AEMv8 Base FVP used in this release resets the model
instead of terminating its execution in response to a shutdown request using
the PSCI `SYSTEM_OFF` API. This issue will be fixed in a future version of
the model.
* GICv3 support is experimental. There are known issues with GICv3
initialization in the ARM Trusted Firmware.
* While this version greatly reduces the on-chip RAM requirements, there are
further RAM usage enhancements that could be made.
* The firmware design documentation for the Test Secure-EL1 Payload (TSP) and
its dispatcher (TSPD) is incomplete. Similarly for the PSCI section.
* The Juno-specific firmware design documentation is incomplete.
ARM Trusted Firmware - version 1.0
==================================
New features
------------
* It is now possible to map higher physical addresses using non-flat virtual
to physical address mappings in the MMU setup.
* Wider use is now made of the per-CPU data cache in BL3-1 to store:
* Pointers to the non-secure and secure security state contexts.
* A pointer to the CPU-specific operations.
* A pointer to PSCI specific information (for example the current power
state).
* A crash reporting buffer.
* The following RAM usage improvements result in a BL3-1 RAM usage reduction
from 96KB to 56KB (for FVP with TSPD), and a total RAM usage reduction
across all images from 208KB to 88KB, compared to the previous release.
* Removed the separate `early_exception` vectors from BL3-1 (2KB code size
saving).
* Removed NSRAM from the FVP memory map, allowing the removal of one
(4KB) translation table.
* Eliminated the internal `psci_suspend_context` array, saving 2KB.
* Correctly dimensioned the PSCI `aff_map_node` array, saving 1.5KB in the
FVP port.
* Removed calling CPU mpidr from the bakery lock API, saving 160 bytes.
* Removed current CPU mpidr from PSCI common code, saving 160 bytes.
* Inlined the mmio accessor functions, saving 360 bytes.
* Fully reclaimed all BL1 RW memory and BL2 memory on the FVP port by
overlaying the BL3-1/BL3-2 NOBITS sections on top of these at runtime.
* Made storing the FP register context optional, saving 0.5KB per context
(8KB on the FVP port, with TSPD enabled and running on 8 CPUs).
* Implemented a leaner `tf_printf()` function, allowing the stack to be
greatly reduced.
* Removed coherent stacks from the codebase. Stacks allocated in normal
memory are now used before and after the MMU is enabled. This saves 768
bytes per CPU in BL3-1.
* Reworked the crash reporting in BL3-1 to use less stack.
* Optimized the EL3 register state stored in the `cpu_context` structure
so that registers that do not change during normal execution are
re-initialized each time during cold/warm boot, rather than restored
from memory. This saves about 1.2KB.
* As a result of some of the above, reduced the runtime stack size in all
BL images. For BL3-1, this saves 1KB per CPU.
* PSCI SMC handler improvements to correctly handle calls from secure states
and from AArch32.
* CPU contexts are now initialized from the `entry_point_info`. BL3-1 fully
determines the exception level to use for the non-trusted firmware (BL3-3)
based on the SPSR value provided by the BL2 platform code (or otherwise
provided to BL3-1). This allows platform code to directly run non-trusted
firmware payloads at either EL2 or EL1 without requiring an EL2 stub or OS
loader.
* Code refactoring improvements:
* Refactored `fvp_config` into a common platform header.
* Refactored the fvp gic code to be a generic driver that no longer has an
explicit dependency on platform code.
* Refactored the CCI-400 driver to not have dependency on platform code.
* Simplified the IO driver so it's no longer necessary to call `io_init()`
and moved all the IO storage framework code to one place.
* Simplified the interface the the TZC-400 driver.
* Clarified the platform porting interface to the TSP.
* Reworked the TSPD setup code to support the alternate BL3-2
intialization flow where BL3-1 generic code hands control to BL3-2,
rather than expecting the TSPD to hand control directly to BL3-2.
* Considerable rework to PSCI generic code to support CPU specific
operations.
* Improved console log output, by:
* Adding the concept of debug log levels.
* Rationalizing the existing debug messages and adding new ones.
* Printing out the version of each BL stage at runtime.
* Adding support for printing console output from assembler code,
including when a crash occurs before the C runtime is initialized.
* Moved up to the latest versions of the FVPs, toolchain, EDK2, kernel, Linaro
file system and DS-5.
* On the FVP port, made the use of the Trusted DRAM region optional at build
time (off by default). Normal platforms will not have such a "ready-to-use"
DRAM area so it is not a good example to use it.
* Added support for PSCI `SYSTEM_OFF` and `SYSTEM_RESET` APIs.
* Added support for CPU specific reset sequences, power down sequences and
register dumping during crash reporting. The CPU specific reset sequences
include support for errata workarounds.
* Merged the Juno port into the master branch. Added support for CPU hotplug
and CPU idle. Updated the user guide to describe how to build and run on the
Juno platform.
Issues resolved since last release
----------------------------------
* Removed the concept of top/bottom image loading. The image loader now
automatically detects the position of the image inside the current memory
layout and updates the layout to minimize fragementation. This resolves the
image loader limitations of previously releases. There are currently no
plans to support dynamic image loading.
* CPU idle now works on the publicized version of the Foundation FVP.
* All known issues relating to the compiler version used have now been
resolved. This TF version uses Linaro toolchain 14.07 (based on GCC 4.9).
Known issues
------------
* GICv3 support is experimental. The Linux kernel patches to support this are
not widely available. There are known issues with GICv3 initialization in
the ARM Trusted Firmware.
* While this version greatly reduces the on-chip RAM requirements, there are
further RAM usage enhancements that could be made.
* The firmware design documentation for the Test Secure-EL1 Payload (TSP) and
its dispatcher (TSPD) is incomplete. Similarly for the PSCI section.
* The Juno-specific firmware design documentation is incomplete.
* Some recent enhancements to the FVP port have not yet been translated into
the Juno port. These will be tracked via the tf-issues project.
* The Linux kernel version referred to in the user guide has DVFS and HMP
support disabled due to some known instabilities at the time of this
release. A future kernel version will re-enable these features.
* DS-5 v5.19 does not detect Version 5.8 of the Cortex-A57-A53 Base FVPs in
CADI server mode. This is because the `<SimName>` reported by the FVP in
this version has changed. For example, for the Cortex-A57x4-A53x4 Base FVP,
the `<SimName>` reported by the FVP is `FVP_Base_Cortex_A57x4_A53x4`, while
DS-5 expects it to be `FVP_Base_A57x4_A53x4`.
The temporary fix to this problem is to change the name of the FVP in
`sw/debugger/configdb/Boards/ARM FVP/Base_A57x4_A53x4/cadi_config.xml`.
Change the following line:
<SimName>System Generator:FVP_Base_A57x4_A53x4</SimName>
to
<SimName>System Generator:FVP_Base_Cortex-A57x4_A53x4</SimName>
A similar change can be made to the other Cortex-A57-A53 Base FVP variants.
ARM Trusted Firmware - version 0.4
==================================
New features
------------
* Makefile improvements:
* Improved dependency checking when building.
* Removed `dump` target (build now always produces dump files).
* Enabled platform ports to optionally make use of parts of the Trusted
Firmware (e.g. BL3-1 only), rather than being forced to use all parts.
Also made the `fip` target optional.
* Specified the full path to source files and removed use of the `vpath`
keyword.
* Provided translation table library code for potential re-use by platforms
other than the FVPs.
* Moved architectural timer setup to platform-specific code.
* Added standby state support to PSCI cpu_suspend implementation.
* SRAM usage improvements:
* Started using the `-ffunction-sections`, `-fdata-sections` and
`--gc-sections` compiler/linker options to remove unused code and data
from the images. Previously, all common functions were being built into
all binary images, whether or not they were actually used.
* Placed all assembler functions in their own section to allow more unused
functions to be removed from images.
* Updated BL1 and BL2 to use a single coherent stack each, rather than one
per CPU.
* Changed variables that were unnecessarily declared and initialized as
non-const (i.e. in the .data section) so they are either uninitialized
(zero init) or const.
* Moved the Test Secure-EL1 Payload (BL3-2) to execute in Trusted SRAM by
default. The option for it to run in Trusted DRAM remains.
* Implemented a TrustZone Address Space Controller (TZC-400) driver. A
default configuration is provided for the Base FVPs. This means the model
parameter `-C bp.secure_memory=1` is now supported.
* Started saving the PSCI cpu_suspend 'power_state' parameter prior to
suspending a CPU. This allows platforms that implement multiple power-down
states at the same affinity level to identify a specific state.
* Refactored the entire codebase to reduce the amount of nesting in header
files and to make the use of system/user includes more consistent. Also
split platform.h to separate out the platform porting declarations from the
required platform porting definitions and the definitions/declarations
specific to the platform port.
* Optimized the data cache clean/invalidate operations.
* Improved the BL3-1 unhandled exception handling and reporting. Unhandled
exceptions now result in a dump of registers to the console.
* Major rework to the handover interface between BL stages, in particular the
interface to BL3-1. The interface now conforms to a specification and is
more future proof.
* Added support for optionally making the BL3-1 entrypoint a reset handler
(instead of BL1). This allows platforms with an alternative image loading
architecture to re-use BL3-1 with fewer modifications to generic code.
* Reserved some DDR DRAM for secure use on FVP platforms to avoid future
compatibility problems with non-secure software.
* Added support for secure interrupts targeting the Secure-EL1 Payload (SP)
(using GICv2 routing only). Demonstrated this working by adding an interrupt
target and supporting test code to the TSP. Also demonstrated non-secure
interrupt handling during TSP processing.
Issues resolved since last release
----------------------------------
* Now support use of the model parameter `-C bp.secure_memory=1` in the Base
FVPs (see **New features**).
* Support for secure world interrupt handling now available (see **New
features**).
* Made enough SRAM savings (see **New features**) to enable the Test Secure-EL1
Payload (BL3-2) to execute in Trusted SRAM by default.
* The tested filesystem used for this release (Linaro AArch64 OpenEmbedded
14.04) now correctly reports progress in the console.
* Improved the Makefile structure to make it easier to separate out parts of
the Trusted Firmware for re-use in platform ports. Also, improved target
dependency checking.
Known issues
------------
* GICv3 support is experimental. The Linux kernel patches to support this are
not widely available. There are known issues with GICv3 initialization in
the ARM Trusted Firmware.
* Dynamic image loading is not available yet. The current image loader
implementation (used to load BL2 and all subsequent images) has some
limitations. Changing BL2 or BL3-1 load addresses in certain ways can lead
to loading errors, even if the images should theoretically fit in memory.
* The ARM Trusted Firmware still uses too much on-chip Trusted SRAM. A number
of RAM usage enhancements have been identified to rectify this situation.
* CPU idle does not work on the advertised version of the Foundation FVP.
Some FVP fixes are required that are not available externally at the time
of writing. This can be worked around by disabling CPU idle in the Linux
kernel.
* Various bugs in ARM Trusted Firmware, UEFI and the Linux kernel have been
observed when using Linaro toolchain versions later than 13.11. Although
most of these have been fixed, some remain at the time of writing. These
mainly seem to relate to a subtle change in the way the compiler converts
between 64-bit and 32-bit values (e.g. during casting operations), which
reveals previously hidden bugs in client code.
* The firmware design documentation for the Test Secure-EL1 Payload (TSP) and
its dispatcher (TSPD) is incomplete. Similarly for the PSCI section.
ARM Trusted Firmware - version 0.3
==================================
New features
------------
* Support for Foundation FVP Version 2.0 added.
The documented UEFI configuration disables some devices that are unavailable
in the Foundation FVP, including MMC and CLCD. The resultant UEFI binary can
be used on the AEMv8 and Cortex-A57-A53 Base FVPs, as well as the Foundation
FVP.
NOTE: The software will not work on Version 1.0 of the Foundation FVP.
* Enabled third party contributions. Added a new contributing.md containing
instructions for how to contribute and updated copyright text in all files
to acknowledge contributors.
* The PSCI CPU_SUSPEND API has been stabilised to the extent where it can be
used for entry into power down states with the following restrictions:
- Entry into standby states is not supported.
- The API is only supported on the AEMv8 and Cortex-A57-A53 Base FVPs.
* The PSCI AFFINITY_INFO api has undergone limited testing on the Base FVPs to
allow experimental use.
* Required C library and runtime header files are now included locally in ARM
Trusted Firmware instead of depending on the toolchain standard include
paths. The local implementation has been cleaned up and reduced in scope.
* Added I/O abstraction framework, primarily to allow generic code to load
images in a platform-independent way. The existing image loading code has
been reworked to use the new framework. Semi-hosting and NOR flash I/O
drivers are provided.
* Introduced Firmware Image Package (FIP) handling code and tools. A FIP
combines multiple firmware images with a Table of Contents (ToC) into a
single binary image. The new FIP driver is another type of I/O driver. The
Makefile builds a FIP by default and the FVP platform code expect to load a
FIP from NOR flash, although some support for image loading using semi-
hosting is retained.
NOTE: Building a FIP by default is a non-backwards-compatible change.
NOTE: Generic BL2 code now loads a BL3-3 (non-trusted firmware) image into
DRAM instead of expecting this to be pre-loaded at known location. This is
also a non-backwards-compatible change.
NOTE: Some non-trusted firmware (e.g. UEFI) will need to be rebuilt so that
it knows the new location to execute from and no longer needs to copy
particular code modules to DRAM itself.
* Reworked BL2 to BL3-1 handover interface. A new composite structure
(bl31_args) holds the superset of information that needs to be passed from
BL2 to BL3-1, including information on how handover execution control to
BL3-2 (if present) and BL3-3 (non-trusted firmware).
* Added library support for CPU context management, allowing the saving and
restoring of
- Shared system registers between Secure-EL1 and EL1.
- VFP registers.
- Essential EL3 system registers.
* Added a framework for implementing EL3 runtime services. Reworked the PSCI
implementation to be one such runtime service.
* Reworked the exception handling logic, making use of both SP_EL0 and SP_EL3
stack pointers for determining the type of exception, managing general
purpose and system register context on exception entry/exit, and handling
SMCs. SMCs are directed to the correct EL3 runtime service.
* Added support for a Test Secure-EL1 Payload (TSP) and a corresponding
Dispatcher (TSPD), which is loaded as an EL3 runtime service. The TSPD
implements Secure Monitor functionality such as world switching and
EL1 context management, and is responsible for communication with the TSP.
NOTE: The TSPD does not yet contain support for secure world interrupts.
NOTE: The TSP/TSPD is not built by default.
Issues resolved since last release
----------------------------------
* Support has been added for switching context between secure and normal
worlds in EL3.
* PSCI API calls `AFFINITY_INFO` & `PSCI_VERSION` have now been tested (to
a limited extent).
* The ARM Trusted Firmware build artifacts are now placed in the `./build`
directory and sub-directories instead of being placed in the root of the
project.
* The ARM Trusted Firmware is now free from build warnings. Build warnings
are now treated as errors.
* The ARM Trusted Firmware now provides C library support locally within the
project to maintain compatibility between toolchains/systems.
* The PSCI locking code has been reworked so it no longer takes locks in an
incorrect sequence.
* The RAM-disk method of loading a Linux file-system has been confirmed to
work with the ARM Trusted Firmware and Linux kernel version (based on
version 3.13) used in this release, for both Foundation and Base FVPs.
Known issues
------------
The following is a list of issues which are expected to be fixed in the future
releases of the ARM Trusted Firmware.
* The TrustZone Address Space Controller (TZC-400) is not being programmed
yet. Use of model parameter `-C bp.secure_memory=1` is not supported.
* No support yet for secure world interrupt handling.
* GICv3 support is experimental. The Linux kernel patches to support this are
not widely available. There are known issues with GICv3 initialization in
the ARM Trusted Firmware.
* Dynamic image loading is not available yet. The current image loader
implementation (used to load BL2 and all subsequent images) has some
limitations. Changing BL2 or BL3-1 load addresses in certain ways can lead
to loading errors, even if the images should theoretically fit in memory.
* The ARM Trusted Firmware uses too much on-chip Trusted SRAM. Currently the
Test Secure-EL1 Payload (BL3-2) executes in Trusted DRAM since there is not
enough SRAM. A number of RAM usage enhancements have been identified to
rectify this situation.
* CPU idle does not work on the advertised version of the Foundation FVP.
Some FVP fixes are required that are not available externally at the time
of writing.
* Various bugs in ARM Trusted Firmware, UEFI and the Linux kernel have been
observed when using Linaro toolchain versions later than 13.11. Although
most of these have been fixed, some remain at the time of writing. These
mainly seem to relate to a subtle change in the way the compiler converts
between 64-bit and 32-bit values (e.g. during casting operations), which
reveals previously hidden bugs in client code.
* The tested filesystem used for this release (Linaro AArch64 OpenEmbedded
14.01) does not report progress correctly in the console. It only seems to
produce error output, not standard output. It otherwise appears to function
correctly. Other filesystem versions on the same software stack do not
exhibit the problem.
* The Makefile structure doesn't make it easy to separate out parts of the
Trusted Firmware for re-use in platform ports, for example if only BL3-1 is
required in a platform port. Also, dependency checking in the Makefile is
flawed.
* The firmware design documentation for the Test Secure-EL1 Payload (TSP) and
its dispatcher (TSPD) is incomplete. Similarly for the PSCI section.
ARM Trusted Firmware - version 0.2
==================================
New features
------------
* First source release.
* Code for the PSCI suspend feature is supplied, although this is not enabled
by default since there are known issues (see below).
Issues resolved since last release
----------------------------------
* The "psci" nodes in the FDTs provided in this release now fully comply
with the recommendations made in the PSCI specification.
Known issues
------------
The following is a list of issues which are expected to be fixed in the future
releases of the ARM Trusted Firmware.
* The TrustZone Address Space Controller (TZC-400) is not being programmed
yet. Use of model parameter `-C bp.secure_memory=1` is not supported.
* No support yet for secure world interrupt handling or for switching context
between secure and normal worlds in EL3.
* GICv3 support is experimental. The Linux kernel patches to support this are
not widely available. There are known issues with GICv3 initialization in
the ARM Trusted Firmware.
* Dynamic image loading is not available yet. The current image loader
implementation (used to load BL2 and all subsequent images) has some
limitations. Changing BL2 or BL3-1 load addresses in certain ways can lead
to loading errors, even if the images should theoretically fit in memory.
* Although support for PSCI `CPU_SUSPEND` is present, it is not yet stable
and ready for use.
* PSCI API calls `AFFINITY_INFO` & `PSCI_VERSION` are implemented but have not
been tested.
* The ARM Trusted Firmware make files result in all build artifacts being
placed in the root of the project. These should be placed in appropriate
sub-directories.
* The compilation of ARM Trusted Firmware is not free from compilation
warnings. Some of these warnings have not been investigated yet so they
could mask real bugs.
* The ARM Trusted Firmware currently uses toolchain/system include files like
stdio.h. It should provide versions of these within the project to maintain
compatibility between toolchains/systems.
* The PSCI code takes some locks in an incorrect sequence. This may cause
problems with suspend and hotplug in certain conditions.
* The Linux kernel used in this release is based on version 3.12-rc4. Using
this kernel with the ARM Trusted Firmware fails to start the file-system as
a RAM-disk. It fails to execute user-space `init` from the RAM-disk. As an
alternative, the VirtioBlock mechanism can be used to provide a file-system
to the kernel.
- - - - - - - - - - - - - - - - - - - - - - - - - -
_Copyright (c) 2013-2015, ARM Limited and Contributors. All rights reserved._
[OP-TEE Dispatcher]: ./optee-dispatcher.md