xref: /rk3399_ARM-atf/docs/design/cpu-specific-build-macros.rst (revision 0d41e17400ba55ff007154dfd55ea59fd838c360)
1Arm CPU Specific Build Macros
2=============================
3
4This document describes the various build options present in the CPU specific
5operations framework to enable errata workarounds and to enable optimizations
6for a specific CPU on a platform.
7
8Security Vulnerability Workarounds
9----------------------------------
10
11TF-A exports a series of build flags which control which security
12vulnerability workarounds should be applied at runtime.
13
14-  ``WORKAROUND_CVE_2017_5715``: Enables the security workaround for
15   `CVE-2017-5715`_. This flag can be set to 0 by the platform if none
16   of the PEs in the system need the workaround. Setting this flag to 0 provides
17   no performance benefit for non-affected platforms, it just helps to comply
18   with the recommendation in the spec regarding workaround discovery.
19   Defaults to 1.
20
21-  ``WORKAROUND_CVE_2018_3639``: Enables the security workaround for
22   `CVE-2018-3639`_. Defaults to 1. The TF-A project recommends to keep
23   the default value of 1 even on platforms that are unaffected by
24   CVE-2018-3639, in order to comply with the recommendation in the spec
25   regarding workaround discovery.
26
27-  ``DYNAMIC_WORKAROUND_CVE_2018_3639``: Enables dynamic mitigation for
28   `CVE-2018-3639`_. This build option should be set to 1 if the target
29   platform contains at least 1 CPU that requires dynamic mitigation.
30   Defaults to 0.
31
32-  ``WORKAROUND_CVE_2022_23960``: Enables mitigation for `CVE-2022-23960`_.
33   This build option should be set to 1 if the target platform contains at
34   least 1 CPU that requires this mitigation. Defaults to 1.
35
36.. _arm_cpu_macros_errata_workarounds:
37
38CPU Errata Workarounds
39----------------------
40
41TF-A exports a series of build flags which control the errata workarounds that
42are applied to each CPU by the reset handler. The errata details can be found
43in the CPU specific errata documents published by Arm:
44
45-  `Cortex-A53 MPCore Software Developers Errata Notice`_
46-  `Cortex-A57 MPCore Software Developers Errata Notice`_
47-  `Cortex-A72 MPCore Software Developers Errata Notice`_
48
49The errata workarounds are implemented for a particular revision or a set of
50processor revisions. This is checked by the reset handler at runtime. Each
51errata workaround is identified by its ``ID`` as specified in the processor's
52errata notice document. The format of the define used to enable/disable the
53errata workaround is ``ERRATA_<Processor name>_<ID>``, where the ``Processor name``
54is for example ``A57`` for the ``Cortex_A57`` CPU.
55
56Refer to :ref:`firmware_design_cpu_errata_reporting` for information on how to
57write errata workaround functions.
58
59All workarounds are disabled by default. The platform is responsible for
60enabling these workarounds according to its requirement by defining the
61errata workaround build flags in the platform specific makefile. In case
62these workarounds are enabled for the wrong CPU revision then the errata
63workaround is not applied. In the DEBUG build, this is indicated by
64printing a warning to the crash console.
65
66In the current implementation, a platform which has more than 1 variant
67with different revisions of a processor has no runtime mechanism available
68for it to specify which errata workarounds should be enabled or not.
69
70The value of the build flags is 0 by default, that is, disabled. A value of 1
71will enable it.
72
73For Cortex-A9, the following errata build flags are defined :
74
75-  ``ERRATA_A9_794073``: This applies errata 794073 workaround to Cortex-A9
76   CPU. This needs to be enabled for all revisions of the CPU.
77
78For Cortex-A15, the following errata build flags are defined :
79
80-  ``ERRATA_A15_816470``: This applies errata 816470 workaround to Cortex-A15
81   CPU. This needs to be enabled only for revision >= r3p0 of the CPU.
82
83-  ``ERRATA_A15_827671``: This applies errata 827671 workaround to Cortex-A15
84   CPU. This needs to be enabled only for revision >= r3p0 of the CPU.
85
86For Cortex-A17, the following errata build flags are defined :
87
88-  ``ERRATA_A17_852421``: This applies errata 852421 workaround to Cortex-A17
89   CPU. This needs to be enabled only for revision <= r1p2 of the CPU.
90
91-  ``ERRATA_A17_852423``: This applies errata 852423 workaround to Cortex-A17
92   CPU. This needs to be enabled only for revision <= r1p2 of the CPU.
93
94For Cortex-A35, the following errata build flags are defined :
95
96-  ``ERRATA_A35_855472``: This applies errata 855472 workaround to Cortex-A35
97   CPUs. This needs to be enabled only for revision r0p0 of Cortex-A35.
98
99For Cortex-A53, the following errata build flags are defined :
100
101-  ``ERRATA_A53_819472``: This applies errata 819472 workaround to all
102   CPUs. This needs to be enabled only for revision <= r0p1 of Cortex-A53.
103
104-  ``ERRATA_A53_824069``: This applies errata 824069 workaround to all
105   CPUs. This needs to be enabled only for revision <= r0p2 of Cortex-A53.
106
107-  ``ERRATA_A53_826319``: This applies errata 826319 workaround to Cortex-A53
108   CPU. This needs to be enabled only for revision <= r0p2 of the CPU.
109
110-  ``ERRATA_A53_827319``: This applies errata 827319 workaround to all
111   CPUs. This needs to be enabled only for revision <= r0p2 of Cortex-A53.
112
113-  ``ERRATA_A53_835769``: This applies erratum 835769 workaround at compile and
114   link time to Cortex-A53 CPU. This needs to be enabled for some variants of
115   revision <= r0p4. This workaround can lead the linker to create ``*.stub``
116   sections.
117
118-  ``ERRATA_A53_836870``: This applies errata 836870 workaround to Cortex-A53
119   CPU. This needs to be enabled only for revision <= r0p3 of the CPU. From
120   r0p4 and onwards, this errata is enabled by default in hardware.
121
122-  ``ERRATA_A53_843419``: This applies erratum 843419 workaround at link time
123   to Cortex-A53 CPU.  This needs to be enabled for some variants of revision
124   <= r0p4. This workaround can lead the linker to emit ``*.stub`` sections
125   which are 4kB aligned.
126
127-  ``ERRATA_A53_855873``: This applies errata 855873 workaround to Cortex-A53
128   CPUs. Though the erratum is present in every revision of the CPU,
129   this workaround is only applied to CPUs from r0p3 onwards, which feature
130   a chicken bit in CPUACTLR_EL1 to enable a hardware workaround.
131   Earlier revisions of the CPU have other errata which require the same
132   workaround in software, so they should be covered anyway.
133
134-  ``ERRATA_A53_1530924``: This applies errata 1530924 workaround to all
135   revisions of Cortex-A53 CPU.
136
137For Cortex-A55, the following errata build flags are defined :
138
139-  ``ERRATA_A55_768277``: This applies errata 768277 workaround to Cortex-A55
140   CPU. This needs to be enabled only for revision r0p0 of the CPU.
141
142-  ``ERRATA_A55_778703``: This applies errata 778703 workaround to Cortex-A55
143   CPU. This needs to be enabled only for revision r0p0 of the CPU.
144
145-  ``ERRATA_A55_798797``: This applies errata 798797 workaround to Cortex-A55
146   CPU. This needs to be enabled only for revision r0p0 of the CPU.
147
148-  ``ERRATA_A55_846532``: This applies errata 846532 workaround to Cortex-A55
149   CPU. This needs to be enabled only for revision <= r0p1 of the CPU.
150
151-  ``ERRATA_A55_903758``: This applies errata 903758 workaround to Cortex-A55
152   CPU. This needs to be enabled only for revision <= r0p1 of the CPU.
153
154-  ``ERRATA_A55_1221012``: This applies errata 1221012 workaround to Cortex-A55
155   CPU. This needs to be enabled only for revision <= r1p0 of the CPU.
156
157-  ``ERRATA_A55_1530923``: This applies errata 1530923 workaround to all
158   revisions of Cortex-A55 CPU.
159
160For Cortex-A57, the following errata build flags are defined :
161
162-  ``ERRATA_A57_806969``: This applies errata 806969 workaround to Cortex-A57
163   CPU. This needs to be enabled only for revision r0p0 of the CPU.
164
165-  ``ERRATA_A57_813419``: This applies errata 813419 workaround to Cortex-A57
166   CPU. This needs to be enabled only for revision r0p0 of the CPU.
167
168-  ``ERRATA_A57_813420``: This applies errata 813420 workaround to Cortex-A57
169   CPU. This needs to be enabled only for revision r0p0 of the CPU.
170
171-  ``ERRATA_A57_814670``: This applies errata 814670 workaround to Cortex-A57
172   CPU. This needs to be enabled only for revision r0p0 of the CPU.
173
174-  ``ERRATA_A57_817169``: This applies errata 817169 workaround to Cortex-A57
175   CPU. This needs to be enabled only for revision <= r0p1 of the CPU.
176
177-  ``ERRATA_A57_826974``: This applies errata 826974 workaround to Cortex-A57
178   CPU. This needs to be enabled only for revision <= r1p1 of the CPU.
179
180-  ``ERRATA_A57_826977``: This applies errata 826977 workaround to Cortex-A57
181   CPU. This needs to be enabled only for revision <= r1p1 of the CPU.
182
183-  ``ERRATA_A57_828024``: This applies errata 828024 workaround to Cortex-A57
184   CPU. This needs to be enabled only for revision <= r1p1 of the CPU.
185
186-  ``ERRATA_A57_829520``: This applies errata 829520 workaround to Cortex-A57
187   CPU. This needs to be enabled only for revision <= r1p2 of the CPU.
188
189-  ``ERRATA_A57_833471``: This applies errata 833471 workaround to Cortex-A57
190   CPU. This needs to be enabled only for revision <= r1p2 of the CPU.
191
192-  ``ERRATA_A57_859972``: This applies errata 859972 workaround to Cortex-A57
193   CPU. This needs to be enabled only for revision <= r1p3 of the CPU.
194
195-  ``ERRATA_A57_1319537``: This applies errata 1319537 workaround to all
196   revisions of Cortex-A57 CPU.
197
198For Cortex-A72, the following errata build flags are defined :
199
200-  ``ERRATA_A72_859971``: This applies errata 859971 workaround to Cortex-A72
201   CPU. This needs to be enabled only for revision <= r0p3 of the CPU.
202
203-  ``ERRATA_A72_1319367``: This applies errata 1319367 workaround to all
204   revisions of Cortex-A72 CPU.
205
206For Cortex-A73, the following errata build flags are defined :
207
208-  ``ERRATA_A73_852427``: This applies errata 852427 workaround to Cortex-A73
209   CPU. This needs to be enabled only for revision r0p0 of the CPU.
210
211-  ``ERRATA_A73_855423``: This applies errata 855423 workaround to Cortex-A73
212   CPU. This needs to be enabled only for revision <= r0p1 of the CPU.
213
214For Cortex-A75, the following errata build flags are defined :
215
216-  ``ERRATA_A75_764081``: This applies errata 764081 workaround to Cortex-A75
217   CPU. This needs to be enabled only for revision r0p0 of the CPU.
218
219-  ``ERRATA_A75_790748``: This applies errata 790748 workaround to Cortex-A75
220    CPU. This needs to be enabled only for revision r0p0 of the CPU.
221
222For Cortex-A76, the following errata build flags are defined :
223
224-  ``ERRATA_A76_1073348``: This applies errata 1073348 workaround to Cortex-A76
225   CPU. This needs to be enabled only for revision <= r1p0 of the CPU.
226
227-  ``ERRATA_A76_1130799``: This applies errata 1130799 workaround to Cortex-A76
228   CPU. This needs to be enabled only for revision <= r2p0 of the CPU.
229
230-  ``ERRATA_A76_1220197``: This applies errata 1220197 workaround to Cortex-A76
231   CPU. This needs to be enabled only for revision <= r2p0 of the CPU.
232
233-  ``ERRATA_A76_1257314``: This applies errata 1257314 workaround to Cortex-A76
234   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
235
236-  ``ERRATA_A76_1262606``: This applies errata 1262606 workaround to Cortex-A76
237   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
238
239-  ``ERRATA_A76_1262888``: This applies errata 1262888 workaround to Cortex-A76
240   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
241
242-  ``ERRATA_A76_1275112``: This applies errata 1275112 workaround to Cortex-A76
243   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
244
245-  ``ERRATA_A76_1791580``: This applies errata 1791580 workaround to Cortex-A76
246   CPU. This needs to be enabled only for revision <= r4p0 of the CPU.
247
248-  ``ERRATA_A76_1165522``: This applies errata 1165522 workaround to all
249   revisions of Cortex-A76 CPU. This errata is fixed in r3p0 but due to
250   limitation of errata framework this errata is applied to all revisions
251   of Cortex-A76 CPU.
252
253-  ``ERRATA_A76_1868343``: This applies errata 1868343 workaround to Cortex-A76
254   CPU. This needs to be enabled only for revision <= r4p0 of the CPU.
255
256-  ``ERRATA_A76_1946160``: This applies errata 1946160 workaround to Cortex-A76
257   CPU. This needs to be enabled only for revisions r3p0 - r4p1 of the CPU.
258
259-  ``ERRATA_A76_2743102``: This applies errata 2743102 workaround to Cortex-A76
260   CPU. This needs to be enabled for all revisions <= r4p1 of the CPU and is
261   still open.
262
263For Cortex-A77, the following errata build flags are defined :
264
265-  ``ERRATA_A77_1508412``: This applies errata 1508412 workaround to Cortex-A77
266   CPU. This needs to be enabled only for revision <= r1p0 of the CPU.
267
268-  ``ERRATA_A77_1925769``: This applies errata 1925769 workaround to Cortex-A77
269   CPU. This needs to be enabled only for revision <= r1p1 of the CPU.
270
271-  ``ERRATA_A77_1946167``: This applies errata 1946167 workaround to Cortex-A77
272   CPU. This needs to be enabled only for revision <= r1p1 of the CPU.
273
274-  ``ERRATA_A77_1791578``: This applies errata 1791578 workaround to Cortex-A77
275   CPU. This needs to be enabled for r0p0, r1p0, and r1p1, it is still open.
276
277-  ``ERRATA_A77_2356587``: This applies errata 2356587 workaround to Cortex-A77
278   CPU. This needs to be enabled for r0p0, r1p0, and r1p1, it is still open.
279
280 -  ``ERRATA_A77_1800714``: This applies errata 1800714 workaround to Cortex-A77
281    CPU. This needs to be enabled for revisions <= r1p1 of the CPU.
282
283For Cortex-A78, the following errata build flags are defined :
284
285-  ``ERRATA_A78_1688305``: This applies errata 1688305 workaround to Cortex-A78
286   CPU. This needs to be enabled only for revision r0p0 - r1p0 of the CPU.
287
288-  ``ERRATA_A78_1941498``: This applies errata 1941498 workaround to Cortex-A78
289   CPU. This needs to be enabled for revisions r0p0, r1p0, and r1p1 of the CPU.
290
291-  ``ERRATA_A78_1951500``: This applies errata 1951500 workaround to Cortex-A78
292   CPU. This needs to be enabled for revisions r1p0 and r1p1, r0p0 has the same
293   issue but there is no workaround for that revision.
294
295-  ``ERRATA_A78_1821534``: This applies errata 1821534 workaround to Cortex-A78
296   CPU. This needs to be enabled for revisions r0p0 and r1p0.
297
298-  ``ERRATA_A78_1952683``: This applies errata 1952683 workaround to Cortex-A78
299   CPU. This needs to be enabled for revision r0p0, it is fixed in r1p0.
300
301-  ``ERRATA_A78_2132060``: This applies errata 2132060 workaround to Cortex-A78
302   CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1, and r1p2. It
303   is still open.
304
305-  ``ERRATA_A78_2242635``: This applies errata 2242635 workaround to Cortex-A78
306   CPU. This needs to be enabled for revisions r1p0, r1p1, and r1p2. The issue
307   is present in r0p0 but there is no workaround. It is still open.
308
309-  ``ERRATA_A78_2376745``: This applies errata 2376745 workaround to Cortex-A78
310   CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1, and r1p2, and
311   it is still open.
312
313-  ``ERRATA_A78_2395406``: This applies errata 2395406 workaround to Cortex-A78
314   CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1, and r1p2, and
315   it is still open.
316
317For Cortex-A78 AE, the following errata build flags are defined :
318
319- ``ERRATA_A78_AE_1941500`` : This applies errata 1941500 workaround to
320   Cortex-A78 AE CPU. This needs to be enabled for revisions r0p0 and r0p1.
321   This erratum is still open.
322
323- ``ERRATA_A78_AE_1951502`` : This applies errata 1951502 workaround to
324  Cortex-A78 AE CPU. This needs to be enabled for revisions r0p0 and r0p1. This
325  erratum is still open.
326
327- ``ERRATA_A78_AE_2376748`` : This applies errata 2376748 workaround to
328  Cortex-A78 AE CPU. This needs to be enabled for revisions r0p0 and r0p1. This
329  erratum is still open.
330
331- ``ERRATA_A78_AE_2395408`` : This applies errata 2395408 workaround to
332  Cortex-A78 AE CPU. This needs to be enabled for revisions r0p0 and r0p1. This
333  erratum is still open.
334
335For Cortex-A78C, the following errata build flags are defined :
336
337- ``ERRATA_A78C_2132064`` : This applies errata 2132064 workaround to
338  Cortex-A78C CPU. This needs to be enabled for revisions r0p1, r0p2 and
339  it is still open.
340
341- ``ERRATA_A78C_2242638`` : This applies errata 2242638 workaround to
342  Cortex-A78C CPU. This needs to be enabled for revisions r0p1, r0p2 and
343  it is still open.
344
345- ``ERRATA_A78C_2376749`` : This applies errata 2376749 workaround to
346  Cortex-A78C CPU. This needs to be enabled for revisions r0p1 and r0p2. This
347  erratum is still open.
348
349- ``ERRATA_A78C_2395411`` : This applies errata 2395411 workaround to
350  Cortex-A78C CPU. This needs to be enabled for revisions r0p1 and r0p2. This
351  erratum is still open.
352
353For Cortex-X1 CPU, the following errata build flags are defined:
354
355- ``ERRATA_X1_1821534`` : This applies errata 1821534 workaround to Cortex-X1
356   CPU. This needs to be enabled only for revision <= r1p0 of the CPU.
357
358- ``ERRATA_X1_1688305`` : This applies errata 1688305 workaround to Cortex-X1
359   CPU. This needs to be enabled only for revision <= r1p0 of the CPU.
360
361- ``ERRATA_X1_1827429`` : This applies errata 1827429 workaround to Cortex-X1
362   CPU. This needs to be enabled only for revision <= r1p0 of the CPU.
363
364For Neoverse N1, the following errata build flags are defined :
365
366-  ``ERRATA_N1_1073348``: This applies errata 1073348 workaround to Neoverse-N1
367   CPU. This needs to be enabled only for revision r0p0 and r1p0 of the CPU.
368
369-  ``ERRATA_N1_1130799``: This applies errata 1130799 workaround to Neoverse-N1
370   CPU. This needs to be enabled only for revision <= r2p0 of the CPU.
371
372-  ``ERRATA_N1_1165347``: This applies errata 1165347 workaround to Neoverse-N1
373   CPU. This needs to be enabled only for revision <= r2p0 of the CPU.
374
375-  ``ERRATA_N1_1207823``: This applies errata 1207823 workaround to Neoverse-N1
376   CPU. This needs to be enabled only for revision <= r2p0 of the CPU.
377
378-  ``ERRATA_N1_1220197``: This applies errata 1220197 workaround to Neoverse-N1
379   CPU. This needs to be enabled only for revision <= r2p0 of the CPU.
380
381-  ``ERRATA_N1_1257314``: This applies errata 1257314 workaround to Neoverse-N1
382   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
383
384-  ``ERRATA_N1_1262606``: This applies errata 1262606 workaround to Neoverse-N1
385   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
386
387-  ``ERRATA_N1_1262888``: This applies errata 1262888 workaround to Neoverse-N1
388   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
389
390-  ``ERRATA_N1_1275112``: This applies errata 1275112 workaround to Neoverse-N1
391   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
392
393-  ``ERRATA_N1_1315703``: This applies errata 1315703 workaround to Neoverse-N1
394   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
395
396-  ``ERRATA_N1_1542419``: This applies errata 1542419 workaround to Neoverse-N1
397   CPU. This needs to be enabled only for revisions r3p0 - r4p0 of the CPU.
398
399-  ``ERRATA_N1_1868343``: This applies errata 1868343 workaround to Neoverse-N1
400   CPU. This needs to be enabled only for revision <= r4p0 of the CPU.
401
402-  ``ERRATA_N1_1946160``: This applies errata 1946160 workaround to Neoverse-N1
403   CPU. This needs to be enabled for revisions r3p0, r3p1, r4p0, and r4p1, for
404   revisions r0p0, r1p0, and r2p0 there is no workaround.
405
406-  ``ERRATA_N1_2743102``: This applies errata 2743102 workaround to Neoverse-N1
407   CPU. This needs to be enabled for all revisions <= r4p1 of the CPU and is
408   still open.
409
410For Neoverse V1, the following errata build flags are defined :
411
412-  ``ERRATA_V1_1618635``: This applies errata 1618635 workaround to Neoverse-V1
413   CPU. This needs to be enabled for revision r0p0 of the CPU, it is fixed in
414   r1p0.
415
416-  ``ERRATA_V1_1774420``: This applies errata 1774420 workaround to Neoverse-V1
417   CPU. This needs to be enabled only for revisions r0p0 and r1p0, it is fixed
418   in r1p1.
419
420-  ``ERRATA_V1_1791573``: This applies errata 1791573 workaround to Neoverse-V1
421   CPU. This needs to be enabled only for revisions r0p0 and r1p0, it is fixed
422   in r1p1.
423
424-  ``ERRATA_V1_1852267``: This applies errata 1852267 workaround to Neoverse-V1
425   CPU. This needs to be enabled only for revisions r0p0 and r1p0, it is fixed
426   in r1p1.
427
428-  ``ERRATA_V1_1925756``: This applies errata 1925756 workaround to Neoverse-V1
429   CPU. This needs to be enabled for r0p0, r1p0, and r1p1, it is still open.
430
431-  ``ERRATA_V1_1940577``: This applies errata 1940577 workaround to Neoverse-V1
432   CPU. This needs to be enabled only for revision r1p0 and r1p1 of the
433   CPU.
434
435-  ``ERRATA_V1_1966096``: This applies errata 1966096 workaround to Neoverse-V1
436   CPU. This needs to be enabled for revisions r1p0 and r1p1 of the CPU, the
437   issue is present in r0p0 as well but there is no workaround for that
438   revision.  It is still open.
439
440-  ``ERRATA_V1_2139242``: This applies errata 2139242 workaround to Neoverse-V1
441   CPU. This needs to be enabled for revisions r0p0, r1p0, and r1p1 of the
442   CPU.  It is still open.
443
444-  ``ERRATA_V1_2108267``: This applies errata 2108267 workaround to Neoverse-V1
445   CPU. This needs to be enabled for revisions r0p0, r1p0, and r1p1 of the CPU.
446   It is still open.
447
448-  ``ERRATA_V1_2216392``: This applies errata 2216392 workaround to Neoverse-V1
449   CPU. This needs to be enabled for revisions r1p0 and r1p1 of the CPU, the
450   issue is present in r0p0 as well but there is no workaround for that
451   revision.  It is still open.
452
453-  ``ERRATA_V1_2294912``: This applies errata 2294912 workaround to Neoverse-V1
454   CPU. This needs to be enabled for revisions r0p0, r1p0, and r1p1 of the CPU.
455
456-  ``ERRATA_V1_2372203``: This applies errata 2372203 workaround to Neoverse-V1
457   CPU. This needs to be enabled for revisions r0p0, r1p0 and r1p1 of the CPU.
458   It is still open.
459
460For Cortex-A710, the following errata build flags are defined :
461
462-  ``ERRATA_A710_1987031``: This applies errata 1987031 workaround to
463   Cortex-A710 CPU. This needs to be enabled only for revisions r0p0, r1p0 and
464   r2p0 of the CPU. It is still open.
465
466-  ``ERRATA_A710_2081180``: This applies errata 2081180 workaround to
467   Cortex-A710 CPU. This needs to be enabled only for revisions r0p0, r1p0 and
468   r2p0 of the CPU. It is still open.
469
470-  ``ERRATA_A710_2055002``: This applies errata 2055002 workaround to
471   Cortex-A710 CPU. This needs to be enabled for revisions r1p0, r2p0 of the CPU
472   and is still open.
473
474-  ``ERRATA_A710_2017096``: This applies errata 2017096 workaround to
475   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
476   of the CPU and is still open.
477
478-  ``ERRATA_A710_2083908``: This applies errata 2083908 workaround to
479   Cortex-A710 CPU. This needs to be enabled for revision r2p0 of the CPU and
480   is still open.
481
482-  ``ERRATA_A710_2058056``: This applies errata 2058056 workaround to
483   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
484   of the CPU and is still open.
485
486-  ``ERRATA_A710_2267065``: This applies errata 2267065 workaround to
487   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
488   of the CPU and is fixed in r2p1.
489
490-  ``ERRATA_A710_2136059``: This applies errata 2136059 workaround to
491   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
492   of the CPU and is fixed in r2p1.
493
494-  ``ERRATA_A710_2147715``: This applies errata 2147715 workaround to
495   Cortex-A710 CPU. This needs to be enabled for revision r2p0 of the CPU
496   and is fixed in r2p1.
497
498-  ``ERRATA_A710_2216384``: This applies errata 2216384 workaround to
499   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
500   of the CPU and is fixed in r2p1.
501
502-  ``ERRATA_A710_2282622``: This applies errata 2282622 workaround to
503   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
504   of the CPU and is fixed in r2p1.
505
506- ``ERRATA_A710_2291219``: This applies errata 2291219 workaround to
507   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
508   of the CPU and is fixed in r2p1.
509
510-  ``ERRATA_A710_2008768``: This applies errata 2008768 workaround to
511   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
512   of the CPU and is fixed in r2p1.
513
514-  ``ERRATA_A710_2371105``: This applies errata 2371105 workaround to
515   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
516   of the CPU and is fixed in r2p1.
517
518For Neoverse N2, the following errata build flags are defined :
519
520-  ``ERRATA_N2_2002655``: This applies errata 2002655 workaround to Neoverse-N2
521   CPU. This needs to be enabled for revision r0p0 of the CPU, it is still open.
522
523-  ``ERRATA_N2_2067956``: This applies errata 2067956 workaround to Neoverse-N2
524   CPU. This needs to be enabled for revision r0p0 of the CPU and is still open.
525
526-  ``ERRATA_N2_2025414``: This applies errata 2025414 workaround to Neoverse-N2
527   CPU. This needs to be enabled for revision r0p0 of the CPU and is still open.
528
529-  ``ERRATA_N2_2189731``: This applies errata 2189731 workaround to Neoverse-N2
530   CPU. This needs to be enabled for revision r0p0 of the CPU and is still open.
531
532-  ``ERRATA_N2_2138956``: This applies errata 2138956 workaround to Neoverse-N2
533   CPU. This needs to be enabled for revision r0p0 of the CPU and is still open.
534
535-  ``ERRATA_N2_2138953``: This applies errata 2138953 workaround to Neoverse-N2
536   CPU. This needs to be enabled for revision r0p0 of the CPU and is still open.
537
538-  ``ERRATA_N2_2242415``: This applies errata 2242415 workaround to Neoverse-N2
539   CPU. This needs to be enabled for revision r0p0 of the CPU and is still open.
540
541-  ``ERRATA_N2_2138958``: This applies errata 2138958 workaround to Neoverse-N2
542   CPU. This needs to be enabled for revision r0p0 of the CPU and is still open.
543
544-  ``ERRATA_N2_2242400``: This applies errata 2242400 workaround to Neoverse-N2
545   CPU. This needs to be enabled for revision r0p0 of the CPU and is still open.
546
547-  ``ERRATA_N2_2280757``: This applies errata 2280757 workaround to Neoverse-N2
548   CPU. This needs to be enabled for revision r0p0 of the CPU and is still open.
549
550-  ``ERRATA_N2_2326639``: This applies errata 2326639 workaround to Neoverse-N2
551   CPU. This needs to be enabled for revision r0p0 of the CPU, it is fixed in
552   r0p1.
553
554-  ``ERRATA_N2_2376738``: This applies errata 2376738 workaround to Neoverse-N2
555   CPU. This needs to be enabled for revision r0p0 of the CPU, it is fixed in
556   r0p1.
557
558-  ``ERRATA_N2_2388450``: This applies errata 2388450 workaround to Neoverse-N2
559   CPU. This needs to be enabled for revision r0p0 of the CPU, it is fixed in
560   r0p1.
561
562For Cortex-X2, the following errata build flags are defined :
563
564-  ``ERRATA_X2_2002765``: This applies errata 2002765 workaround to Cortex-X2
565   CPU. This needs to be enabled for revisions r0p0, r1p0, and r2p0 of the CPU,
566   it is still open.
567
568-  ``ERRATA_X2_2058056``: This applies errata 2058056 workaround to Cortex-X2
569   CPU. This needs to be enabled for revisions r0p0, r1p0, and r2p0 of the CPU,
570   it is still open.
571
572-  ``ERRATA_X2_2083908``: This applies errata 2083908 workaround to Cortex-X2
573   CPU. This needs to be enabled for revision r2p0 of the CPU, it is still open.
574
575-  ``ERRATA_X2_2017096``: This applies errata 2017096 workaround to
576   Cortex-X2 CPU. This needs to be enabled only for revisions r0p0, r1p0 and
577   r2p0 of the CPU, it is fixed in r2p1.
578
579-  ``ERRATA_X2_2081180``: This applies errata 2081180 workaround to
580   Cortex-X2 CPU. This needs to be enabled only for revisions r0p0, r1p0 and
581   r2p0 of the CPU, it is fixed in r2p1.
582
583-  ``ERRATA_X2_2216384``: This applies errata 2216384 workaround to
584   Cortex-X2 CPU. This needs to be enabled only for revisions r0p0, r1p0 and
585   r2p0 of the CPU, it is fixed in r2p1.
586
587-  ``ERRATA_X2_2147715``: This applies errata 2147715 workaround to
588   Cortex-X2 CPU. This needs to be enabled only for revision r2p0 of the CPU,
589   it is fixed in r2p1.
590
591-  ``ERRATA_X2_2371105``: This applies errata 2371105 workaround to
592   Cortex-X2 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
593   of the CPU and is fixed in r2p1.
594
595For Cortex-X3, the following errata build flags are defined :
596
597- ``ERRATA_X3_2313909``: This applies errata 2313909 workaround to
598  Cortex-X3 CPU. This needs to be enabled only for revisions r0p0 and r1p0
599  of the CPU, it is fixed in r1p1.
600
601For Cortex-A510, the following errata build flags are defined :
602
603-  ``ERRATA_A510_1922240``: This applies errata 1922240 workaround to
604   Cortex-A510 CPU. This needs to be enabled only for revision r0p0, it is
605   fixed in r0p1.
606
607-  ``ERRATA_A510_2288014``: This applies errata 2288014 workaround to
608   Cortex-A510 CPU. This needs to be enabled only for revisions r0p0, r0p1,
609   r0p2, r0p3 and r1p0, it is fixed in r1p1.
610
611-  ``ERRATA_A510_2042739``: This applies errata 2042739 workaround to
612   Cortex-A510 CPU. This needs to be enabled only for revisions r0p0, r0p1 and
613   r0p2, it is fixed in r0p3.
614
615-  ``ERRATA_A510_2041909``: This applies errata 2041909 workaround to
616   Cortex-A510 CPU. This needs to be enabled only for revision r0p2 and is fixed
617   in r0p3. The issue is also present in r0p0 and r0p1 but there is no
618   workaround for those revisions.
619
620-  ``ERRATA_A510_2250311``: This applies errata 2250311 workaround to
621   Cortex-A510 CPU. This needs to be enabled for revisions r0p0, r0p1, r0p2,
622   r0p3 and r1p0, it is fixed in r1p1. This workaround disables MPMM even if
623   ENABLE_MPMM=1.
624
625-  ``ERRATA_A510_2218950``: This applies errata 2218950 workaround to
626   Cortex-A510 CPU. This needs to be enabled for revisions r0p0, r0p1, r0p2,
627   r0p3 and r1p0, it is fixed in r1p1.
628
629-  ``ERRATA_A510_2172148``: This applies errata 2172148 workaround to
630   Cortex-A510 CPU. This needs to be enabled for revisions r0p0, r0p1, r0p2,
631   r0p3 and r1p0, it is fixed in r1p1.
632
633- ``ERRATA_A510_2347730``: This applies errata 2347730 workaround to
634   Cortex-A510 CPU. This needs to be enabled for revisions r0p0, r0p1, r0p2,
635   r0p3, r1p0 and r1p1. It is fixed in r1p2.
636
637-  ``ERRATA_A510_2371937``: This applies errata 2371937 workaround to
638   Cortex-A510 CPU. This needs to applied for revisions r0p0, r0p1, r0p2,
639   r0p3, r1p0, r1p1, and is fixed in r1p2.
640
641-  ``ERRATA_A510_2666669``: This applies errata 2666669 workaround to
642   Cortex-A510 CPU. This needs to applied for revisions r0p0, r0p1, r0p2,
643   r0p3, r1p0, r1p1. It is fixed in r1p2.
644
645DSU Errata Workarounds
646----------------------
647
648Similar to CPU errata, TF-A also implements workarounds for DSU (DynamIQ
649Shared Unit) errata. The DSU errata details can be found in the respective Arm
650documentation:
651
652- `Arm DSU Software Developers Errata Notice`_.
653
654Each erratum is identified by an ``ID``, as defined in the DSU errata notice
655document. Thus, the build flags which enable/disable the errata workarounds
656have the format ``ERRATA_DSU_<ID>``. The implementation and application logic
657of DSU errata workarounds are similar to `CPU errata workarounds`_.
658
659For DSU errata, the following build flags are defined:
660
661-  ``ERRATA_DSU_798953``: This applies errata 798953 workaround for the
662   affected DSU configurations. This errata applies only for those DSUs that
663   revision is r0p0 (on r0p1 it is fixed). However, please note that this
664   workaround results in increased DSU power consumption on idle.
665
666-  ``ERRATA_DSU_936184``: This applies errata 936184 workaround for the
667   affected DSU configurations. This errata applies only for those DSUs that
668   contain the ACP interface **and** the DSU revision is older than r2p0 (on
669   r2p0 it is fixed). However, please note that this workaround results in
670   increased DSU power consumption on idle.
671
672-  ``ERRATA_DSU_2313941``: This applies errata 2313941 workaround for the
673   affected DSU configurations. This errata applies for those DSUs with
674   revisions r0p0, r1p0, r2p0, r2p1, r3p0, r3p1 and is still open. However,
675   please note that this workaround results in increased DSU power consumption
676   on idle.
677
678CPU Specific optimizations
679--------------------------
680
681This section describes some of the optimizations allowed by the CPU micro
682architecture that can be enabled by the platform as desired.
683
684-  ``SKIP_A57_L1_FLUSH_PWR_DWN``: This flag enables an optimization in the
685   Cortex-A57 cluster power down sequence by not flushing the Level 1 data
686   cache. The L1 data cache and the L2 unified cache are inclusive. A flush
687   of the L2 by set/way flushes any dirty lines from the L1 as well. This
688   is a known safe deviation from the Cortex-A57 TRM defined power down
689   sequence. Each Cortex-A57 based platform must make its own decision on
690   whether to use the optimization.
691
692-  ``A53_DISABLE_NON_TEMPORAL_HINT``: This flag disables the cache non-temporal
693   hint. The LDNP/STNP instructions as implemented on Cortex-A53 do not behave
694   in a way most programmers expect, and will most probably result in a
695   significant speed degradation to any code that employs them. The Armv8-A
696   architecture (see Arm DDI 0487A.h, section D3.4.3) allows cores to ignore
697   the non-temporal hint and treat LDNP/STNP as LDP/STP instead. Enabling this
698   flag enforces this behaviour. This needs to be enabled only for revisions
699   <= r0p3 of the CPU and is enabled by default.
700
701-  ``A57_DISABLE_NON_TEMPORAL_HINT``: This flag has the same behaviour as
702   ``A53_DISABLE_NON_TEMPORAL_HINT`` but for Cortex-A57. This needs to be
703   enabled only for revisions <= r1p2 of the CPU and is enabled by default,
704   as recommended in section "4.7 Non-Temporal Loads/Stores" of the
705   `Cortex-A57 Software Optimization Guide`_.
706
707- ''A57_ENABLE_NON_CACHEABLE_LOAD_FWD'': This flag enables non-cacheable
708   streaming enhancement feature for Cortex-A57 CPUs. Platforms can set
709   this bit only if their memory system meets the requirement that cache
710   line fill requests from the Cortex-A57 processor are atomic. Each
711   Cortex-A57 based platform must make its own decision on whether to use
712   the optimization. This flag is disabled by default.
713
714-  ``NEOVERSE_Nx_EXTERNAL_LLC``: This flag indicates that an external last
715   level cache(LLC) is present in the system, and that the DataSource field
716   on the master CHI interface indicates when data is returned from the LLC.
717   This is used to control how the LL_CACHE* PMU events count.
718   Default value is 0 (Disabled).
719
720GIC Errata Workarounds
721----------------------
722-  ``GIC600_ERRATA_WA_2384374``: This flag applies part 2 of errata 2384374
723   workaround for the affected GIC600 and GIC600-AE implementations. It applies
724   to implementations of GIC600 and GIC600-AE with revisions less than or equal
725   to r1p6 and r0p2 respectively. If the platform sets GICV3_SUPPORT_GIC600,
726   then this flag is enabled; otherwise, it is 0 (Disabled).
727
728--------------
729
730*Copyright (c) 2014-2022, Arm Limited and Contributors. All rights reserved.*
731
732.. _CVE-2017-5715: http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-5715
733.. _CVE-2018-3639: http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-3639
734.. _CVE-2022-23960: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-23960
735.. _Cortex-A53 MPCore Software Developers Errata Notice: http://infocenter.arm.com/help/topic/com.arm.doc.epm048406/index.html
736.. _Cortex-A57 MPCore Software Developers Errata Notice: http://infocenter.arm.com/help/topic/com.arm.doc.epm049219/index.html
737.. _Cortex-A72 MPCore Software Developers Errata Notice: http://infocenter.arm.com/help/topic/com.arm.doc.epm012079/index.html
738.. _Cortex-A57 Software Optimization Guide: http://infocenter.arm.com/help/topic/com.arm.doc.uan0015b/Cortex_A57_Software_Optimization_Guide_external.pdf
739.. _Arm DSU Software Developers Errata Notice: http://infocenter.arm.com/help/topic/com.arm.doc.epm138168/index.html
740