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| author | Jeenu Viswambharan <jeenu.viswambharan@arm.com> | 2017-09-22 08:32:10 +0100 |
|---|---|---|
| committer | Jeenu Viswambharan <jeenu.viswambharan@arm.com> | 2017-11-13 07:49:30 +0000 |
| commit | 21b818c05fa4ec8cec468aad690267c5be930ccd (patch) | |
| tree | 8fe600879542720ded4eed9a546c75fcfe5ed5be /docs | |
| parent | 4ee8d0becddd65b27206cc01ed0d896a6605b82b (diff) | |
| download | platform_external_arm-trusted-firmware-21b818c05fa4ec8cec468aad690267c5be930ccd.tar.gz platform_external_arm-trusted-firmware-21b818c05fa4ec8cec468aad690267c5be930ccd.tar.bz2 platform_external_arm-trusted-firmware-21b818c05fa4ec8cec468aad690267c5be930ccd.zip | |
BL31: Introduce Exception Handling Framework
EHF is a framework that allows dispatching of EL3 interrupts to their
respective handlers in EL3.
This framework facilitates the firmware-first error handling policy in
which asynchronous exceptions may be routed to EL3. Such exceptions may
be handed over to respective exception handlers. Individual handlers
might further delegate exception handling to lower ELs.
The framework associates the delegated execution to lower ELs with a
priority value. For interrupts, this corresponds to the priorities
programmed in GIC; for other types of exceptions, viz. SErrors or
Synchronous External Aborts, individual dispatchers shall explicitly
associate delegation to a secure priority. In order to prevent lower
priority interrupts from preempting higher priority execution, the
framework provides helpers to control preemption by virtue of
programming Priority Mask register in the interrupt controller.
This commit allows for handling interrupts targeted at EL3. Exception
handlers own interrupts by assigning them a range of secure priorities,
and registering handlers for each priority range it owns.
Support for exception handling in BL31 image is enabled by setting the
build option EL3_EXCEPTION_HANDLING=1.
Documentation to follow.
NOTE: The framework assumes the priority scheme supported by platform
interrupt controller is compliant with that of ARM GIC architecture (v2
or later).
Change-Id: I7224337e4cea47c6ca7d7a4ca22a3716939f7e42
Signed-off-by: Jeenu Viswambharan <jeenu.viswambharan@arm.com>
Diffstat (limited to 'docs')
| -rw-r--r-- | docs/user-guide.rst | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/docs/user-guide.rst b/docs/user-guide.rst index 4df75908c..8ae5e9eaa 100644 --- a/docs/user-guide.rst +++ b/docs/user-guide.rst @@ -361,6 +361,11 @@ Common build options Firmware as error. It can take the value 1 (flag the use of deprecated APIs as error) or 0. The default is 0. +- ``EL3_EXCEPTION_HANDLING``: When set to ``1``, enable handling of exceptions + targeted at EL3. When set ``0`` (default), no exceptions are expected or + handled at EL3, and a panic will result. This is supported only for AArch64 + builds. + - ``FIP_NAME``: This is an optional build option which specifies the FIP filename for the ``fip`` target. Default is ``fip.bin``. |