xref: /rk3399_ARM-atf/docs/design/cpu-specific-build-macros.rst (revision 2757da06149238041308060e5cb51f0870a02a15)
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
283 -  ``ERRATA_A77_2743100``: This applies errata 2743100 workaround to Cortex-A77
284    CPU. This needs to be enabled for r0p0, r1p0, and r1p1, it is still open.
285
286For Cortex-A78, the following errata build flags are defined :
287
288-  ``ERRATA_A78_1688305``: This applies errata 1688305 workaround to Cortex-A78
289   CPU. This needs to be enabled only for revision r0p0 - r1p0 of the CPU.
290
291-  ``ERRATA_A78_1941498``: This applies errata 1941498 workaround to Cortex-A78
292   CPU. This needs to be enabled for revisions r0p0, r1p0, and r1p1 of the CPU.
293
294-  ``ERRATA_A78_1951500``: This applies errata 1951500 workaround to Cortex-A78
295   CPU. This needs to be enabled for revisions r1p0 and r1p1, r0p0 has the same
296   issue but there is no workaround for that revision.
297
298-  ``ERRATA_A78_1821534``: This applies errata 1821534 workaround to Cortex-A78
299   CPU. This needs to be enabled for revisions r0p0 and r1p0.
300
301-  ``ERRATA_A78_1952683``: This applies errata 1952683 workaround to Cortex-A78
302   CPU. This needs to be enabled for revision r0p0, it is fixed in r1p0.
303
304-  ``ERRATA_A78_2132060``: This applies errata 2132060 workaround to Cortex-A78
305   CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1, and r1p2. It
306   is still open.
307
308-  ``ERRATA_A78_2242635``: This applies errata 2242635 workaround to Cortex-A78
309   CPU. This needs to be enabled for revisions r1p0, r1p1, and r1p2. The issue
310   is present in r0p0 but there is no workaround. It is still open.
311
312-  ``ERRATA_A78_2376745``: This applies errata 2376745 workaround to Cortex-A78
313   CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1, and r1p2, and
314   it is still open.
315
316-  ``ERRATA_A78_2395406``: This applies errata 2395406 workaround to Cortex-A78
317   CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1, and r1p2, and
318   it is still open.
319
320-  ``ERRATA_A78_2772019``: This applies errata 2772019 workaround to Cortex-A78
321   CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1, and r1p2, and
322   it is still open.
323
324-  ``ERRATA_A78_2779479``: This applies erratum 2779479 workaround to Cortex-A78
325   CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1 and r1p2 and
326   it is still open.
327
328For Cortex-A78 AE, the following errata build flags are defined :
329
330- ``ERRATA_A78_AE_1941500`` : This applies errata 1941500 workaround to
331   Cortex-A78 AE CPU. This needs to be enabled for revisions r0p0 and r0p1.
332   This erratum is still open.
333
334- ``ERRATA_A78_AE_1951502`` : This applies errata 1951502 workaround to
335  Cortex-A78 AE CPU. This needs to be enabled for revisions r0p0 and r0p1. This
336  erratum is still open.
337
338- ``ERRATA_A78_AE_2376748`` : This applies errata 2376748 workaround to
339  Cortex-A78 AE CPU. This needs to be enabled for revisions r0p0 and r0p1. This
340  erratum is still open.
341
342- ``ERRATA_A78_AE_2395408`` : This applies errata 2395408 workaround to
343  Cortex-A78 AE CPU. This needs to be enabled for revisions r0p0 and r0p1. This
344  erratum is still open.
345
346For Cortex-A78C, the following errata build flags are defined :
347
348- ``ERRATA_A78C_2132064`` : This applies errata 2132064 workaround to
349  Cortex-A78C CPU. This needs to be enabled for revisions r0p1, r0p2 and
350  it is still open.
351
352- ``ERRATA_A78C_2242638`` : This applies errata 2242638 workaround to
353  Cortex-A78C CPU. This needs to be enabled for revisions r0p1, r0p2 and
354  it is still open.
355
356- ``ERRATA_A78C_2376749`` : This applies errata 2376749 workaround to
357  Cortex-A78C CPU. This needs to be enabled for revisions r0p1 and r0p2. This
358  erratum is still open.
359
360- ``ERRATA_A78C_2395411`` : This applies errata 2395411 workaround to
361  Cortex-A78C CPU. This needs to be enabled for revisions r0p1 and r0p2. This
362  erratum is still open.
363
364For Cortex-X1 CPU, the following errata build flags are defined:
365
366- ``ERRATA_X1_1821534`` : This applies errata 1821534 workaround to Cortex-X1
367   CPU. This needs to be enabled only for revision <= r1p0 of the CPU.
368
369- ``ERRATA_X1_1688305`` : This applies errata 1688305 workaround to Cortex-X1
370   CPU. This needs to be enabled only for revision <= r1p0 of the CPU.
371
372- ``ERRATA_X1_1827429`` : This applies errata 1827429 workaround to Cortex-X1
373   CPU. This needs to be enabled only for revision <= r1p0 of the CPU.
374
375For Neoverse N1, the following errata build flags are defined :
376
377-  ``ERRATA_N1_1073348``: This applies errata 1073348 workaround to Neoverse-N1
378   CPU. This needs to be enabled only for revision r0p0 and r1p0 of the CPU.
379
380-  ``ERRATA_N1_1130799``: This applies errata 1130799 workaround to Neoverse-N1
381   CPU. This needs to be enabled only for revision <= r2p0 of the CPU.
382
383-  ``ERRATA_N1_1165347``: This applies errata 1165347 workaround to Neoverse-N1
384   CPU. This needs to be enabled only for revision <= r2p0 of the CPU.
385
386-  ``ERRATA_N1_1207823``: This applies errata 1207823 workaround to Neoverse-N1
387   CPU. This needs to be enabled only for revision <= r2p0 of the CPU.
388
389-  ``ERRATA_N1_1220197``: This applies errata 1220197 workaround to Neoverse-N1
390   CPU. This needs to be enabled only for revision <= r2p0 of the CPU.
391
392-  ``ERRATA_N1_1257314``: This applies errata 1257314 workaround to Neoverse-N1
393   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
394
395-  ``ERRATA_N1_1262606``: This applies errata 1262606 workaround to Neoverse-N1
396   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
397
398-  ``ERRATA_N1_1262888``: This applies errata 1262888 workaround to Neoverse-N1
399   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
400
401-  ``ERRATA_N1_1275112``: This applies errata 1275112 workaround to Neoverse-N1
402   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
403
404-  ``ERRATA_N1_1315703``: This applies errata 1315703 workaround to Neoverse-N1
405   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
406
407-  ``ERRATA_N1_1542419``: This applies errata 1542419 workaround to Neoverse-N1
408   CPU. This needs to be enabled only for revisions r3p0 - r4p0 of the CPU.
409
410-  ``ERRATA_N1_1868343``: This applies errata 1868343 workaround to Neoverse-N1
411   CPU. This needs to be enabled only for revision <= r4p0 of the CPU.
412
413-  ``ERRATA_N1_1946160``: This applies errata 1946160 workaround to Neoverse-N1
414   CPU. This needs to be enabled for revisions r3p0, r3p1, r4p0, and r4p1, for
415   revisions r0p0, r1p0, and r2p0 there is no workaround.
416
417-  ``ERRATA_N1_2743102``: This applies errata 2743102 workaround to Neoverse-N1
418   CPU. This needs to be enabled for all revisions <= r4p1 of the CPU and is
419   still open.
420
421For Neoverse V1, the following errata build flags are defined :
422
423-  ``ERRATA_V1_1618635``: This applies errata 1618635 workaround to Neoverse-V1
424   CPU. This needs to be enabled for revision r0p0 of the CPU, it is fixed in
425   r1p0.
426
427-  ``ERRATA_V1_1774420``: This applies errata 1774420 workaround to Neoverse-V1
428   CPU. This needs to be enabled only for revisions r0p0 and r1p0, it is fixed
429   in r1p1.
430
431-  ``ERRATA_V1_1791573``: This applies errata 1791573 workaround to Neoverse-V1
432   CPU. This needs to be enabled only for revisions r0p0 and r1p0, it is fixed
433   in r1p1.
434
435-  ``ERRATA_V1_1852267``: This applies errata 1852267 workaround to Neoverse-V1
436   CPU. This needs to be enabled only for revisions r0p0 and r1p0, it is fixed
437   in r1p1.
438
439-  ``ERRATA_V1_1925756``: This applies errata 1925756 workaround to Neoverse-V1
440   CPU. This needs to be enabled for r0p0, r1p0, and r1p1, it is still open.
441
442-  ``ERRATA_V1_1940577``: This applies errata 1940577 workaround to Neoverse-V1
443   CPU. This needs to be enabled only for revision r1p0 and r1p1 of the
444   CPU.
445
446-  ``ERRATA_V1_1966096``: This applies errata 1966096 workaround to Neoverse-V1
447   CPU. This needs to be enabled for revisions r1p0 and r1p1 of the CPU, the
448   issue is present in r0p0 as well but there is no workaround for that
449   revision.  It is still open.
450
451-  ``ERRATA_V1_2139242``: This applies errata 2139242 workaround to Neoverse-V1
452   CPU. This needs to be enabled for revisions r0p0, r1p0, and r1p1 of the
453   CPU.  It is still open.
454
455-  ``ERRATA_V1_2108267``: This applies errata 2108267 workaround to Neoverse-V1
456   CPU. This needs to be enabled for revisions r0p0, r1p0, and r1p1 of the CPU.
457   It is still open.
458
459-  ``ERRATA_V1_2216392``: This applies errata 2216392 workaround to Neoverse-V1
460   CPU. This needs to be enabled for revisions r1p0 and r1p1 of the CPU, the
461   issue is present in r0p0 as well but there is no workaround for that
462   revision.  It is still open.
463
464-  ``ERRATA_V1_2294912``: This applies errata 2294912 workaround to Neoverse-V1
465   CPU. This needs to be enabled for revisions r0p0, r1p0, and r1p1 of the CPU.
466
467-  ``ERRATA_V1_2372203``: This applies errata 2372203 workaround to Neoverse-V1
468   CPU. This needs to be enabled for revisions r0p0, r1p0 and r1p1 of the CPU.
469   It is still open.
470
471-  ``ERRATA_V1_2743093``: This applies errata 2743093 workaround to Neoverse-V1
472   CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1 and r1p2 of the
473   CPU. It is still open.
474
475-  ``ERRATA_V1_2779461``: This applies erratum 2779461 workaround to Neoverse-V1
476   CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1, r1p2 of the
477   CPU. It is still open.
478
479For Cortex-A710, the following errata build flags are defined :
480
481-  ``ERRATA_A710_1987031``: This applies errata 1987031 workaround to
482   Cortex-A710 CPU. This needs to be enabled only for revisions r0p0, r1p0 and
483   r2p0 of the CPU. It is still open.
484
485-  ``ERRATA_A710_2081180``: This applies errata 2081180 workaround to
486   Cortex-A710 CPU. This needs to be enabled only for revisions r0p0, r1p0 and
487   r2p0 of the CPU. It is still open.
488
489-  ``ERRATA_A710_2055002``: This applies errata 2055002 workaround to
490   Cortex-A710 CPU. This needs to be enabled for revisions r1p0, r2p0 of the CPU
491   and is still open.
492
493-  ``ERRATA_A710_2017096``: This applies errata 2017096 workaround to
494   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
495   of the CPU and is still open.
496
497-  ``ERRATA_A710_2083908``: This applies errata 2083908 workaround to
498   Cortex-A710 CPU. This needs to be enabled for revision r2p0 of the CPU and
499   is still open.
500
501-  ``ERRATA_A710_2058056``: This applies errata 2058056 workaround to
502   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
503   of the CPU and is still open.
504
505-  ``ERRATA_A710_2267065``: This applies errata 2267065 workaround to
506   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
507   of the CPU and is fixed in r2p1.
508
509-  ``ERRATA_A710_2136059``: This applies errata 2136059 workaround to
510   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
511   of the CPU and is fixed in r2p1.
512
513-  ``ERRATA_A710_2147715``: This applies errata 2147715 workaround to
514   Cortex-A710 CPU. This needs to be enabled for revision r2p0 of the CPU
515   and is fixed in r2p1.
516
517-  ``ERRATA_A710_2216384``: This applies errata 2216384 workaround to
518   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
519   of the CPU and is fixed in r2p1.
520
521-  ``ERRATA_A710_2282622``: This applies errata 2282622 workaround to
522   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and
523   r2p1 of the CPU and is still open.
524
525- ``ERRATA_A710_2291219``: This applies errata 2291219 workaround to
526   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
527   of the CPU and is fixed in r2p1.
528
529-  ``ERRATA_A710_2008768``: This applies errata 2008768 workaround to
530   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
531   of the CPU and is fixed in r2p1.
532
533-  ``ERRATA_A710_2371105``: This applies errata 2371105 workaround to
534   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
535   of the CPU and is fixed in r2p1.
536
537-  ``ERRATA_A710_2768515``: This applies errata 2768515 workaround to
538   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and
539   r2p1 of the CPU and is still open.
540
541For Neoverse N2, the following errata build flags are defined :
542
543-  ``ERRATA_N2_2002655``: This applies errata 2002655 workaround to Neoverse-N2
544   CPU. This needs to be enabled for revision r0p0 of the CPU, it is still open.
545
546-  ``ERRATA_N2_2067956``: This applies errata 2067956 workaround to Neoverse-N2
547   CPU. This needs to be enabled for revision r0p0 of the CPU and is still open.
548
549-  ``ERRATA_N2_2025414``: This applies errata 2025414 workaround to Neoverse-N2
550   CPU. This needs to be enabled for revision r0p0 of the CPU and is still open.
551
552-  ``ERRATA_N2_2189731``: This applies errata 2189731 workaround to Neoverse-N2
553   CPU. This needs to be enabled for revision r0p0 of the CPU and is still open.
554
555-  ``ERRATA_N2_2138956``: This applies errata 2138956 workaround to Neoverse-N2
556   CPU. This needs to be enabled for revision r0p0 of the CPU and is still open.
557
558-  ``ERRATA_N2_2138953``: This applies errata 2138953 workaround to Neoverse-N2
559   CPU. This needs to be enabled for revision r0p0 of the CPU and is still open.
560
561-  ``ERRATA_N2_2242415``: This applies errata 2242415 workaround to Neoverse-N2
562   CPU. This needs to be enabled for revision r0p0 of the CPU and is still open.
563
564-  ``ERRATA_N2_2138958``: This applies errata 2138958 workaround to Neoverse-N2
565   CPU. This needs to be enabled for revision r0p0 of the CPU and is still open.
566
567-  ``ERRATA_N2_2242400``: This applies errata 2242400 workaround to Neoverse-N2
568   CPU. This needs to be enabled for revision r0p0 of the CPU and is still open.
569
570-  ``ERRATA_N2_2280757``: This applies errata 2280757 workaround to Neoverse-N2
571   CPU. This needs to be enabled for revision r0p0 of the CPU and is still open.
572
573-  ``ERRATA_N2_2326639``: This applies errata 2326639 workaround to Neoverse-N2
574   CPU. This needs to be enabled for revision r0p0 of the CPU, it is fixed in
575   r0p1.
576
577-  ``ERRATA_N2_2376738``: This applies errata 2376738 workaround to Neoverse-N2
578   CPU. This needs to be enabled for revision r0p0 of the CPU, it is fixed in
579   r0p1.
580
581-  ``ERRATA_N2_2388450``: This applies errata 2388450 workaround to Neoverse-N2
582   CPU. This needs to be enabled for revision r0p0 of the CPU, it is fixed in
583   r0p1.
584
585-  ``ERRATA_N2_2743089``: This applies errata 2743089 workaround to Neoverse-N2
586   CPU. This needs to be enabled for revisions r0p0, r0p1 and r0p2. It is fixed
587   in r0p3.
588
589For Cortex-X2, the following errata build flags are defined :
590
591-  ``ERRATA_X2_2002765``: This applies errata 2002765 workaround to Cortex-X2
592   CPU. This needs to be enabled for revisions r0p0, r1p0, and r2p0 of the CPU,
593   it is still open.
594
595-  ``ERRATA_X2_2058056``: This applies errata 2058056 workaround to Cortex-X2
596   CPU. This needs to be enabled for revisions r0p0, r1p0, and r2p0 of the CPU,
597   it is still open.
598
599-  ``ERRATA_X2_2083908``: This applies errata 2083908 workaround to Cortex-X2
600   CPU. This needs to be enabled for revision r2p0 of the CPU, it is still open.
601
602-  ``ERRATA_X2_2017096``: This applies errata 2017096 workaround to Cortex-X2
603   CPU. This needs to be enabled only for revisions r0p0, r1p0 and r2p0 of the
604   CPU, it is fixed in r2p1.
605
606-  ``ERRATA_X2_2081180``: This applies errata 2081180 workaround to Cortex-X2
607   CPU. This needs to be enabled only for revisions r0p0, r1p0 and r2p0 of the
608   CPU, it is fixed in r2p1.
609
610-  ``ERRATA_X2_2216384``: This applies errata 2216384 workaround to Cortex-X2
611   CPU. This needs to be enabled only for revisions r0p0, r1p0 and r2p0 of the
612   CPU, it is fixed in r2p1.
613
614-  ``ERRATA_X2_2147715``: This applies errata 2147715 workaround to Cortex-X2
615   CPU. This needs to be enabled only for revision r2p0 of the CPU, it is fixed
616   in r2p1.
617
618-  ``ERRATA_X2_2282622``: This applies errata 2282622 workaround to Cortex-X2
619   CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and r2p1 of the
620   CPU and is still open.
621
622-  ``ERRATA_X2_2371105``: This applies errata 2371105 workaround to Cortex-X2
623   CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0 of the CPU
624   and is fixed in r2p1.
625
626-  ``ERRATA_X2_2768515``: This applies errata 2768515 workaround to Cortex-X2
627   CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and r2p1 of the
628   CPU and is still open.
629
630For Cortex-X3, the following errata build flags are defined :
631
632- ``ERRATA_X3_2313909``: This applies errata 2313909 workaround to
633  Cortex-X3 CPU. This needs to be enabled only for revisions r0p0 and r1p0
634  of the CPU, it is fixed in r1p1.
635
636- ``ERRATA_X3_2615812``: This applies errata 2615812 workaround to Cortex-X3
637  CPU. This needs to be enabled only for revisions r0p0, r1p0 and r1p1 of the
638  CPU, it is still open.
639
640For Cortex-A510, the following errata build flags are defined :
641
642-  ``ERRATA_A510_1922240``: This applies errata 1922240 workaround to
643   Cortex-A510 CPU. This needs to be enabled only for revision r0p0, it is
644   fixed in r0p1.
645
646-  ``ERRATA_A510_2288014``: This applies errata 2288014 workaround to
647   Cortex-A510 CPU. This needs to be enabled only for revisions r0p0, r0p1,
648   r0p2, r0p3 and r1p0, it is fixed in r1p1.
649
650-  ``ERRATA_A510_2042739``: This applies errata 2042739 workaround to
651   Cortex-A510 CPU. This needs to be enabled only for revisions r0p0, r0p1 and
652   r0p2, it is fixed in r0p3.
653
654-  ``ERRATA_A510_2041909``: This applies errata 2041909 workaround to
655   Cortex-A510 CPU. This needs to be enabled only for revision r0p2 and is fixed
656   in r0p3. The issue is also present in r0p0 and r0p1 but there is no
657   workaround for those revisions.
658
659-  ``ERRATA_A510_2250311``: This applies errata 2250311 workaround to
660   Cortex-A510 CPU. This needs to be enabled for revisions r0p0, r0p1, r0p2,
661   r0p3 and r1p0, it is fixed in r1p1. This workaround disables MPMM even if
662   ENABLE_MPMM=1.
663
664-  ``ERRATA_A510_2218950``: This applies errata 2218950 workaround to
665   Cortex-A510 CPU. This needs to be enabled for revisions r0p0, r0p1, r0p2,
666   r0p3 and r1p0, it is fixed in r1p1.
667
668-  ``ERRATA_A510_2172148``: This applies errata 2172148 workaround to
669   Cortex-A510 CPU. This needs to be enabled for revisions r0p0, r0p1, r0p2,
670   r0p3 and r1p0, it is fixed in r1p1.
671
672- ``ERRATA_A510_2347730``: This applies errata 2347730 workaround to
673   Cortex-A510 CPU. This needs to be enabled for revisions r0p0, r0p1, r0p2,
674   r0p3, r1p0 and r1p1. It is fixed in r1p2.
675
676-  ``ERRATA_A510_2371937``: This applies errata 2371937 workaround to
677   Cortex-A510 CPU. This needs to applied for revisions r0p0, r0p1, r0p2,
678   r0p3, r1p0, r1p1, and is fixed in r1p2.
679
680-  ``ERRATA_A510_2666669``: This applies errata 2666669 workaround to
681   Cortex-A510 CPU. This needs to applied for revisions r0p0, r0p1, r0p2,
682   r0p3, r1p0, r1p1. It is fixed in r1p2.
683
684DSU Errata Workarounds
685----------------------
686
687Similar to CPU errata, TF-A also implements workarounds for DSU (DynamIQ
688Shared Unit) errata. The DSU errata details can be found in the respective Arm
689documentation:
690
691- `Arm DSU Software Developers Errata Notice`_.
692
693Each erratum is identified by an ``ID``, as defined in the DSU errata notice
694document. Thus, the build flags which enable/disable the errata workarounds
695have the format ``ERRATA_DSU_<ID>``. The implementation and application logic
696of DSU errata workarounds are similar to `CPU errata workarounds`_.
697
698For DSU errata, the following build flags are defined:
699
700-  ``ERRATA_DSU_798953``: This applies errata 798953 workaround for the
701   affected DSU configurations. This errata applies only for those DSUs that
702   revision is r0p0 (on r0p1 it is fixed). However, please note that this
703   workaround results in increased DSU power consumption on idle.
704
705-  ``ERRATA_DSU_936184``: This applies errata 936184 workaround for the
706   affected DSU configurations. This errata applies only for those DSUs that
707   contain the ACP interface **and** the DSU revision is older than r2p0 (on
708   r2p0 it is fixed). However, please note that this workaround results in
709   increased DSU power consumption on idle.
710
711-  ``ERRATA_DSU_2313941``: This applies errata 2313941 workaround for the
712   affected DSU configurations. This errata applies for those DSUs with
713   revisions r0p0, r1p0, r2p0, r2p1, r3p0, r3p1 and is still open. However,
714   please note that this workaround results in increased DSU power consumption
715   on idle.
716
717CPU Specific optimizations
718--------------------------
719
720This section describes some of the optimizations allowed by the CPU micro
721architecture that can be enabled by the platform as desired.
722
723-  ``SKIP_A57_L1_FLUSH_PWR_DWN``: This flag enables an optimization in the
724   Cortex-A57 cluster power down sequence by not flushing the Level 1 data
725   cache. The L1 data cache and the L2 unified cache are inclusive. A flush
726   of the L2 by set/way flushes any dirty lines from the L1 as well. This
727   is a known safe deviation from the Cortex-A57 TRM defined power down
728   sequence. Each Cortex-A57 based platform must make its own decision on
729   whether to use the optimization.
730
731-  ``A53_DISABLE_NON_TEMPORAL_HINT``: This flag disables the cache non-temporal
732   hint. The LDNP/STNP instructions as implemented on Cortex-A53 do not behave
733   in a way most programmers expect, and will most probably result in a
734   significant speed degradation to any code that employs them. The Armv8-A
735   architecture (see Arm DDI 0487A.h, section D3.4.3) allows cores to ignore
736   the non-temporal hint and treat LDNP/STNP as LDP/STP instead. Enabling this
737   flag enforces this behaviour. This needs to be enabled only for revisions
738   <= r0p3 of the CPU and is enabled by default.
739
740-  ``A57_DISABLE_NON_TEMPORAL_HINT``: This flag has the same behaviour as
741   ``A53_DISABLE_NON_TEMPORAL_HINT`` but for Cortex-A57. This needs to be
742   enabled only for revisions <= r1p2 of the CPU and is enabled by default,
743   as recommended in section "4.7 Non-Temporal Loads/Stores" of the
744   `Cortex-A57 Software Optimization Guide`_.
745
746- ''A57_ENABLE_NON_CACHEABLE_LOAD_FWD'': This flag enables non-cacheable
747   streaming enhancement feature for Cortex-A57 CPUs. Platforms can set
748   this bit only if their memory system meets the requirement that cache
749   line fill requests from the Cortex-A57 processor are atomic. Each
750   Cortex-A57 based platform must make its own decision on whether to use
751   the optimization. This flag is disabled by default.
752
753-  ``NEOVERSE_Nx_EXTERNAL_LLC``: This flag indicates that an external last
754   level cache(LLC) is present in the system, and that the DataSource field
755   on the master CHI interface indicates when data is returned from the LLC.
756   This is used to control how the LL_CACHE* PMU events count.
757   Default value is 0 (Disabled).
758
759GIC Errata Workarounds
760----------------------
761-  ``GIC600_ERRATA_WA_2384374``: This flag applies part 2 of errata 2384374
762   workaround for the affected GIC600 and GIC600-AE implementations. It applies
763   to implementations of GIC600 and GIC600-AE with revisions less than or equal
764   to r1p6 and r0p2 respectively. If the platform sets GICV3_SUPPORT_GIC600,
765   then this flag is enabled; otherwise, it is 0 (Disabled).
766
767--------------
768
769*Copyright (c) 2014-2023, Arm Limited and Contributors. All rights reserved.*
770
771.. _CVE-2017-5715: http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-5715
772.. _CVE-2018-3639: http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-3639
773.. _CVE-2022-23960: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-23960
774.. _Cortex-A53 MPCore Software Developers Errata Notice: http://infocenter.arm.com/help/topic/com.arm.doc.epm048406/index.html
775.. _Cortex-A57 MPCore Software Developers Errata Notice: http://infocenter.arm.com/help/topic/com.arm.doc.epm049219/index.html
776.. _Cortex-A72 MPCore Software Developers Errata Notice: http://infocenter.arm.com/help/topic/com.arm.doc.epm012079/index.html
777.. _Cortex-A57 Software Optimization Guide: http://infocenter.arm.com/help/topic/com.arm.doc.uan0015b/Cortex_A57_Software_Optimization_Guide_external.pdf
778.. _Arm DSU Software Developers Errata Notice: http://infocenter.arm.com/help/topic/com.arm.doc.epm138168/index.html
779