ARM Trusted Firmware

Detailed changes since last release

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 FVPs, as well as the Foundation FVP. NOTE: The software will not work on Version 1.0 of the Foundation FVP.
Regression-checked against latest Base FVPs (Version 5.2).
The supplied FDTs expose the Interrupt Translation Service (ITS) available in GICv3.
Fixed various GCC compiler warnings.
Unmask SError and Debug exceptions in the trusted firmware. Also route external abort and SError interrupts to EL3.
The amount of physical RAM available to Linux as specified in the FDTs for Base FVPs have been increased from 2GB to 4GB. This resolves the issue of failing to start user-space when using a RAM-disk file-system.
Build products are now created in a separate build directory tree.
Analyze at link-time whether bootloader images will fit in memory and won't overlap each other at run time. If it is not the case then image linking will now fail.
Reduce the size of the bootloader images by cutting some sections out of their disk images and allocating them at load time, whenever possible.
Properly initialise the C runtime environment. C code can now safely assume that global variables are initialised to 0 and that initialised data holds the correct value.
General changes on the memory layout: some sections have been moved, some of them have been merged together, and some alignment constraints on sections have changed.
Enable third party contributions. Add a new contributing.md containing instructions for how to contribute and update copyright text in all files to acknowledge contributors.
The wake up enable bit in the FVP power controller is cleared when a cpu is physically powered up to prevent a spurious wake up from a subsequent cpu off state.
Definitions of some constants related to the PSCI api calls AFFINITY_INFO and CPU_SUSPEND have been corrected.
A bug which triggered an error condition in the code executed after a cpu is powered on, if a non zero context id parameter was passed in the PSCI CPU_ON and CPU_SUSPEND api calls has been corrected.
A restriction in the FVP code which did not allow the non-secure entrypoint to lie outside the DRAM has been removed.
The PSCI CPU_SUSPEND api has been stabilised to an 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 Base FVP.
The PSCI AFFINITY_INFO api has undergone limited testing on the AEMv8 Base FVP to allow experimental use.
Locks corresponding to each affinity level are acquired and released in the correct sequence in the PSCI implementation. Invocation of the PSCI CPU_SUSPEND and CPU_OFF apis simultaneously across cpus & clusters should not result in unexpected behaviour.
The API to return the memory layout structures for each bootloader stage has undergone change. A pointer to these structures is returned instead of their copy.

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.

Detailed changes since last release

First source release - not applicable.