diff options
author | Paul Beesley <paul.beesley@arm.com> | 2019-02-11 17:54:45 +0000 |
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committer | Paul Beesley <paul.beesley@arm.com> | 2019-05-21 15:05:56 +0100 |
commit | 40d553cfde38d4f68449c62967cd1ce0d6478750 (patch) | |
tree | 1fafd4701066cdf0e5fb15aee2d842279a67b611 /docs/cpu-specific-build-macros.rst | |
parent | 12b67439e93a78a4b756e987e1bd1b6e22cc4bf8 (diff) |
doc: Move documents into subdirectories
This change creates the following directories under docs/
in order to provide a grouping for the content:
- components
- design
- getting_started
- perf
- process
In each of these directories an index.rst file is created
and this serves as an index / landing page for each of the
groups when the pages are compiled. Proper layout of the
top-level table of contents relies on this directory/index
structure.
Without this patch it is possible to build the documents
correctly with Sphinx but the output looks messy because
there is no overall hierarchy.
Change-Id: I3c9f4443ec98571a56a6edf775f2c8d74d7f429f
Signed-off-by: Paul Beesley <paul.beesley@arm.com>
Diffstat (limited to 'docs/cpu-specific-build-macros.rst')
-rw-r--r-- | docs/cpu-specific-build-macros.rst | 299 |
1 files changed, 0 insertions, 299 deletions
diff --git a/docs/cpu-specific-build-macros.rst b/docs/cpu-specific-build-macros.rst deleted file mode 100644 index 493e07e9..00000000 --- a/docs/cpu-specific-build-macros.rst +++ /dev/null @@ -1,299 +0,0 @@ -Arm CPU Specific Build Macros -============================= - - -.. section-numbering:: - :suffix: . - -.. contents:: - -This document describes the various build options present in the CPU specific -operations framework to enable errata workarounds and to enable optimizations -for a specific CPU on a platform. - -Security Vulnerability Workarounds ----------------------------------- - -TF-A exports a series of build flags which control which security -vulnerability workarounds should be applied at runtime. - -- ``WORKAROUND_CVE_2017_5715``: Enables the security workaround for - `CVE-2017-5715`_. This flag can be set to 0 by the platform if none - of the PEs in the system need the workaround. Setting this flag to 0 provides - no performance benefit for non-affected platforms, it just helps to comply - with the recommendation in the spec regarding workaround discovery. - Defaults to 1. - -- ``WORKAROUND_CVE_2018_3639``: Enables the security workaround for - `CVE-2018-3639`_. Defaults to 1. The TF-A project recommends to keep - the default value of 1 even on platforms that are unaffected by - CVE-2018-3639, in order to comply with the recommendation in the spec - regarding workaround discovery. - -- ``DYNAMIC_WORKAROUND_CVE_2018_3639``: Enables dynamic mitigation for - `CVE-2018-3639`_. This build option should be set to 1 if the target - platform contains at least 1 CPU that requires dynamic mitigation. - Defaults to 0. - -CPU Errata Workarounds ----------------------- - -TF-A exports a series of build flags which control the errata workarounds that -are applied to each CPU by the reset handler. The errata details can be found -in the CPU specific errata documents published by Arm: - -- `Cortex-A53 MPCore Software Developers Errata Notice`_ -- `Cortex-A57 MPCore Software Developers Errata Notice`_ -- `Cortex-A72 MPCore Software Developers Errata Notice`_ - -The errata workarounds are implemented for a particular revision or a set of -processor revisions. This is checked by the reset handler at runtime. Each -errata workaround is identified by its ``ID`` as specified in the processor's -errata notice document. The format of the define used to enable/disable the -errata workaround is ``ERRATA_<Processor name>_<ID>``, where the ``Processor name`` -is for example ``A57`` for the ``Cortex_A57`` CPU. - -Refer to the section *CPU errata status reporting* in -`Firmware Design guide`_ for information on how to write errata workaround -functions. - -All workarounds are disabled by default. The platform is responsible for -enabling these workarounds according to its requirement by defining the -errata workaround build flags in the platform specific makefile. In case -these workarounds are enabled for the wrong CPU revision then the errata -workaround is not applied. In the DEBUG build, this is indicated by -printing a warning to the crash console. - -In the current implementation, a platform which has more than 1 variant -with different revisions of a processor has no runtime mechanism available -for it to specify which errata workarounds should be enabled or not. - -The value of the build flags is 0 by default, that is, disabled. A value of 1 -will enable it. - -For Cortex-A9, the following errata build flags are defined : - -- ``ERRATA_A9_794073``: This applies errata 794073 workaround to Cortex-A9 - CPU. This needs to be enabled for all revisions of the CPU. - -For Cortex-A15, the following errata build flags are defined : - -- ``ERRATA_A15_816470``: This applies errata 816470 workaround to Cortex-A15 - CPU. This needs to be enabled only for revision >= r3p0 of the CPU. - -- ``ERRATA_A15_827671``: This applies errata 827671 workaround to Cortex-A15 - CPU. This needs to be enabled only for revision >= r3p0 of the CPU. - -For Cortex-A17, the following errata build flags are defined : - -- ``ERRATA_A17_852421``: This applies errata 852421 workaround to Cortex-A17 - CPU. This needs to be enabled only for revision <= r1p2 of the CPU. - -- ``ERRATA_A17_852423``: This applies errata 852423 workaround to Cortex-A17 - CPU. This needs to be enabled only for revision <= r1p2 of the CPU. - -For Cortex-A35, the following errata build flags are defined : - -- ``ERRATA_A35_855472``: This applies errata 855472 workaround to Cortex-A35 - CPUs. This needs to be enabled only for revision r0p0 of Cortex-A35. - -For Cortex-A53, the following errata build flags are defined : - -- ``ERRATA_A53_819472``: This applies errata 819472 workaround to all - CPUs. This needs to be enabled only for revision <= r0p1 of Cortex-A53. - -- ``ERRATA_A53_824069``: This applies errata 824069 workaround to all - CPUs. This needs to be enabled only for revision <= r0p2 of Cortex-A53. - -- ``ERRATA_A53_826319``: This applies errata 826319 workaround to Cortex-A53 - CPU. This needs to be enabled only for revision <= r0p2 of the CPU. - -- ``ERRATA_A53_827319``: This applies errata 827319 workaround to all - CPUs. This needs to be enabled only for revision <= r0p2 of Cortex-A53. - -- ``ERRATA_A53_835769``: This applies erratum 835769 workaround at compile and - link time to Cortex-A53 CPU. This needs to be enabled for some variants of - revision <= r0p4. This workaround can lead the linker to create ``*.stub`` - sections. - -- ``ERRATA_A53_836870``: This applies errata 836870 workaround to Cortex-A53 - CPU. This needs to be enabled only for revision <= r0p3 of the CPU. From - r0p4 and onwards, this errata is enabled by default in hardware. - -- ``ERRATA_A53_843419``: This applies erratum 843419 workaround at link time - to Cortex-A53 CPU. This needs to be enabled for some variants of revision - <= r0p4. This workaround can lead the linker to emit ``*.stub`` sections - which are 4kB aligned. - -- ``ERRATA_A53_855873``: This applies errata 855873 workaround to Cortex-A53 - CPUs. Though the erratum is present in every revision of the CPU, - this workaround is only applied to CPUs from r0p3 onwards, which feature - a chicken bit in CPUACTLR_EL1 to enable a hardware workaround. - Earlier revisions of the CPU have other errata which require the same - workaround in software, so they should be covered anyway. - -For Cortex-A55, the following errata build flags are defined : - -- ``ERRATA_A55_768277``: This applies errata 768277 workaround to Cortex-A55 - CPU. This needs to be enabled only for revision r0p0 of the CPU. - -- ``ERRATA_A55_778703``: This applies errata 778703 workaround to Cortex-A55 - CPU. This needs to be enabled only for revision r0p0 of the CPU. - -- ``ERRATA_A55_798797``: This applies errata 798797 workaround to Cortex-A55 - CPU. This needs to be enabled only for revision r0p0 of the CPU. - -- ``ERRATA_A55_846532``: This applies errata 846532 workaround to Cortex-A55 - CPU. This needs to be enabled only for revision <= r0p1 of the CPU. - -- ``ERRATA_A55_903758``: This applies errata 903758 workaround to Cortex-A55 - CPU. This needs to be enabled only for revision <= r0p1 of the CPU. - -For Cortex-A57, the following errata build flags are defined : - -- ``ERRATA_A57_806969``: This applies errata 806969 workaround to Cortex-A57 - CPU. This needs to be enabled only for revision r0p0 of the CPU. - -- ``ERRATA_A57_813419``: This applies errata 813419 workaround to Cortex-A57 - CPU. This needs to be enabled only for revision r0p0 of the CPU. - -- ``ERRATA_A57_813420``: This applies errata 813420 workaround to Cortex-A57 - CPU. This needs to be enabled only for revision r0p0 of the CPU. - -- ``ERRATA_A57_814670``: This applies errata 814670 workaround to Cortex-A57 - CPU. This needs to be enabled only for revision r0p0 of the CPU. - -- ``ERRATA_A57_817169``: This applies errata 817169 workaround to Cortex-A57 - CPU. This needs to be enabled only for revision <= r0p1 of the CPU. - -- ``ERRATA_A57_826974``: This applies errata 826974 workaround to Cortex-A57 - CPU. This needs to be enabled only for revision <= r1p1 of the CPU. - -- ``ERRATA_A57_826977``: This applies errata 826977 workaround to Cortex-A57 - CPU. This needs to be enabled only for revision <= r1p1 of the CPU. - -- ``ERRATA_A57_828024``: This applies errata 828024 workaround to Cortex-A57 - CPU. This needs to be enabled only for revision <= r1p1 of the CPU. - -- ``ERRATA_A57_829520``: This applies errata 829520 workaround to Cortex-A57 - CPU. This needs to be enabled only for revision <= r1p2 of the CPU. - -- ``ERRATA_A57_833471``: This applies errata 833471 workaround to Cortex-A57 - CPU. This needs to be enabled only for revision <= r1p2 of the CPU. - -- ``ERRATA_A57_859972``: This applies errata 859972 workaround to Cortex-A57 - CPU. This needs to be enabled only for revision <= r1p3 of the CPU. - - -For Cortex-A72, the following errata build flags are defined : - -- ``ERRATA_A72_859971``: This applies errata 859971 workaround to Cortex-A72 - CPU. This needs to be enabled only for revision <= r0p3 of the CPU. - -For Cortex-A73, the following errata build flags are defined : - -- ``ERRATA_A73_852427``: This applies errata 852427 workaround to Cortex-A73 - CPU. This needs to be enabled only for revision r0p0 of the CPU. - -- ``ERRATA_A73_855423``: This applies errata 855423 workaround to Cortex-A73 - CPU. This needs to be enabled only for revision <= r0p1 of the CPU. - -For Cortex-A75, the following errata build flags are defined : - -- ``ERRATA_A75_764081``: This applies errata 764081 workaround to Cortex-A75 - CPU. This needs to be enabled only for revision r0p0 of the CPU. - -- ``ERRATA_A75_790748``: This applies errata 790748 workaround to Cortex-A75 - CPU. This needs to be enabled only for revision r0p0 of the CPU. - -For Cortex-A76, the following errata build flags are defined : - -- ``ERRATA_A76_1073348``: This applies errata 1073348 workaround to Cortex-A76 - CPU. This needs to be enabled only for revision <= r1p0 of the CPU. - -- ``ERRATA_A76_1130799``: This applies errata 1130799 workaround to Cortex-A76 - CPU. This needs to be enabled only for revision <= r2p0 of the CPU. - -- ``ERRATA_A76_1220197``: This applies errata 1220197 workaround to Cortex-A76 - CPU. This needs to be enabled only for revision <= r2p0 of the CPU. - -- ``ERRATA_A76_1257314``: This applies errata 1257314 workaround to Cortex-A76 - CPU. This needs to be enabled only for revision <= r3p0 of the CPU. - -- ``ERRATA_A76_1262606``: This applies errata 1262606 workaround to Cortex-A76 - CPU. This needs to be enabled only for revision <= r3p0 of the CPU. - -- ``ERRATA_A76_1262888``: This applies errata 1262888 workaround to Cortex-A76 - CPU. This needs to be enabled only for revision <= r3p0 of the CPU. - -- ``ERRATA_A76_1275112``: This applies errata 1275112 workaround to Cortex-A76 - CPU. This needs to be enabled only for revision <= r3p0 of the CPU. - -DSU Errata Workarounds ----------------------- - -Similar to CPU errata, TF-A also implements workarounds for DSU (DynamIQ -Shared Unit) errata. The DSU errata details can be found in the respective Arm -documentation: - -- `Arm DSU Software Developers Errata Notice`_. - -Each erratum is identified by an ``ID``, as defined in the DSU errata notice -document. Thus, the build flags which enable/disable the errata workarounds -have the format ``ERRATA_DSU_<ID>``. The implementation and application logic -of DSU errata workarounds are similar to `CPU errata workarounds`_. - -For DSU errata, the following build flags are defined: - -- ``ERRATA_DSU_798953``: This applies errata 798953 workaround for the - affected DSU configurations. This errata applies only for those DSUs that - revision is r0p0 (on r0p1 it is fixed). However, please note that this - workaround results in increased DSU power consumption on idle. - -- ``ERRATA_DSU_936184``: This applies errata 936184 workaround for the - affected DSU configurations. This errata applies only for those DSUs that - contain the ACP interface **and** the DSU revision is older than r2p0 (on - r2p0 it is fixed). However, please note that this workaround results in - increased DSU power consumption on idle. - -CPU Specific optimizations --------------------------- - -This section describes some of the optimizations allowed by the CPU micro -architecture that can be enabled by the platform as desired. - -- ``SKIP_A57_L1_FLUSH_PWR_DWN``: This flag enables an optimization in the - Cortex-A57 cluster power down sequence by not flushing the Level 1 data - cache. The L1 data cache and the L2 unified cache are inclusive. A flush - of the L2 by set/way flushes any dirty lines from the L1 as well. This - is a known safe deviation from the Cortex-A57 TRM defined power down - sequence. Each Cortex-A57 based platform must make its own decision on - whether to use the optimization. - -- ``A53_DISABLE_NON_TEMPORAL_HINT``: This flag disables the cache non-temporal - hint. The LDNP/STNP instructions as implemented on Cortex-A53 do not behave - in a way most programmers expect, and will most probably result in a - significant speed degradation to any code that employs them. The Armv8-A - architecture (see Arm DDI 0487A.h, section D3.4.3) allows cores to ignore - the non-temporal hint and treat LDNP/STNP as LDP/STP instead. Enabling this - flag enforces this behaviour. This needs to be enabled only for revisions - <= r0p3 of the CPU and is enabled by default. - -- ``A57_DISABLE_NON_TEMPORAL_HINT``: This flag has the same behaviour as - ``A53_DISABLE_NON_TEMPORAL_HINT`` but for Cortex-A57. This needs to be - enabled only for revisions <= r1p2 of the CPU and is enabled by default, - as recommended in section "4.7 Non-Temporal Loads/Stores" of the - `Cortex-A57 Software Optimization Guide`_. - --------------- - -*Copyright (c) 2014-2019, Arm Limited and Contributors. All rights reserved.* - -.. _CVE-2017-5715: http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-5715 -.. _CVE-2018-3639: http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-3639 -.. _Cortex-A53 MPCore Software Developers Errata Notice: http://infocenter.arm.com/help/topic/com.arm.doc.epm048406/index.html -.. _Cortex-A57 MPCore Software Developers Errata Notice: http://infocenter.arm.com/help/topic/com.arm.doc.epm049219/index.html -.. _Cortex-A72 MPCore Software Developers Errata Notice: http://infocenter.arm.com/help/topic/com.arm.doc.epm012079/index.html -.. _Firmware Design guide: firmware-design.rst -.. _Cortex-A57 Software Optimization Guide: http://infocenter.arm.com/help/topic/com.arm.doc.uan0015b/Cortex_A57_Software_Optimization_Guide_external.pdf -.. _Arm DSU Software Developers Errata Notice: http://infocenter.arm.com/help/topic/com.arm.doc.epm138168/index.html |