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_implementation` 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. Identical to
121   ``A53_DISABLE_NON_TEMPORAL_HINT``.
122
123-  ``ERRATA_A53_843419``: This applies erratum 843419 workaround at link time
124   to Cortex-A53 CPU.  This needs to be enabled for some variants of revision
125   <= r0p4. This workaround can lead the linker to emit ``*.stub`` sections
126   which are 4kB aligned.
127
128-  ``ERRATA_A53_855873``: This applies errata 855873 workaround to Cortex-A53
129   CPUs. Though the erratum is present in every revision of the CPU,
130   this workaround is only applied to CPUs from r0p3 onwards, which feature
131   a chicken bit in CPUACTLR_EL1 to enable a hardware workaround.
132   Earlier revisions of the CPU have other errata which require the same
133   workaround in software, so they should be covered anyway.
134
135-  ``ERRATA_A53_1530924``: This applies errata 1530924 workaround to all
136   revisions of Cortex-A53 CPU.
137
138For Cortex-A55, the following errata build flags are defined :
139
140-  ``ERRATA_A55_768277``: This applies errata 768277 workaround to Cortex-A55
141   CPU. This needs to be enabled only for revision r0p0 of the CPU.
142
143-  ``ERRATA_A55_778703``: This applies errata 778703 workaround to Cortex-A55
144   CPU. This needs to be enabled only for revision r0p0 of the CPU.
145
146-  ``ERRATA_A55_798797``: This applies errata 798797 workaround to Cortex-A55
147   CPU. This needs to be enabled only for revision r0p0 of the CPU.
148
149-  ``ERRATA_A55_846532``: This applies errata 846532 workaround to Cortex-A55
150   CPU. This needs to be enabled only for revision <= r0p1 of the CPU.
151
152-  ``ERRATA_A55_903758``: This applies errata 903758 workaround to Cortex-A55
153   CPU. This needs to be enabled only for revision <= r0p1 of the CPU.
154
155-  ``ERRATA_A55_1221012``: This applies errata 1221012 workaround to Cortex-A55
156   CPU. This needs to be enabled only for revision <= r1p0 of the CPU.
157
158-  ``ERRATA_A55_1530923``: This applies errata 1530923 workaround to all
159   revisions of Cortex-A55 CPU.
160
161For Cortex-A57, the following errata build flags are defined :
162
163-  ``ERRATA_A57_806969``: This applies errata 806969 workaround to Cortex-A57
164   CPU. This needs to be enabled only for revision r0p0 of the CPU.
165
166-  ``ERRATA_A57_813419``: This applies errata 813419 workaround to Cortex-A57
167   CPU. This needs to be enabled only for revision r0p0 of the CPU.
168
169-  ``ERRATA_A57_813420``: This applies errata 813420 workaround to Cortex-A57
170   CPU. This needs to be enabled only for revision r0p0 of the CPU.
171
172-  ``ERRATA_A57_814670``: This applies errata 814670 workaround to Cortex-A57
173   CPU. This needs to be enabled only for revision r0p0 of the CPU.
174
175-  ``ERRATA_A57_817169``: This applies errata 817169 workaround to Cortex-A57
176   CPU. This needs to be enabled only for revision <= r0p1 of the CPU.
177
178-  ``ERRATA_A57_826974``: This applies errata 826974 workaround to Cortex-A57
179   CPU. This needs to be enabled only for revision <= r1p1 of the CPU.
180
181-  ``ERRATA_A57_826977``: This applies errata 826977 workaround to Cortex-A57
182   CPU. This needs to be enabled only for revision <= r1p1 of the CPU.
183
184-  ``ERRATA_A57_828024``: This applies errata 828024 workaround to Cortex-A57
185   CPU. This needs to be enabled only for revision <= r1p1 of the CPU.
186
187-  ``ERRATA_A57_829520``: This applies errata 829520 workaround to Cortex-A57
188   CPU. This needs to be enabled only for revision <= r1p2 of the CPU.
189
190-  ``ERRATA_A57_833471``: This applies errata 833471 workaround to Cortex-A57
191   CPU. This needs to be enabled only for revision <= r1p2 of the CPU.
192
193-  ``ERRATA_A57_859972``: This applies errata 859972 workaround to Cortex-A57
194   CPU. This needs to be enabled only for revision <= r1p3 of the CPU.
195
196-  ``ERRATA_A57_1319537``: This applies errata 1319537 workaround to all
197   revisions of Cortex-A57 CPU.
198
199For Cortex-A72, the following errata build flags are defined :
200
201-  ``ERRATA_A72_859971``: This applies errata 859971 workaround to Cortex-A72
202   CPU. This needs to be enabled only for revision <= r0p3 of the CPU.
203
204-  ``ERRATA_A72_1319367``: This applies errata 1319367 workaround to all
205   revisions of Cortex-A72 CPU.
206
207For Cortex-A73, the following errata build flags are defined :
208
209-  ``ERRATA_A73_852427``: This applies errata 852427 workaround to Cortex-A73
210   CPU. This needs to be enabled only for revision r0p0 of the CPU.
211
212-  ``ERRATA_A73_855423``: This applies errata 855423 workaround to Cortex-A73
213   CPU. This needs to be enabled only for revision <= r0p1 of the CPU.
214
215For Cortex-A75, the following errata build flags are defined :
216
217-  ``ERRATA_A75_764081``: This applies errata 764081 workaround to Cortex-A75
218   CPU. This needs to be enabled only for revision r0p0 of the CPU.
219
220-  ``ERRATA_A75_790748``: This applies errata 790748 workaround to Cortex-A75
221    CPU. This needs to be enabled only for revision r0p0 of the CPU.
222
223For Cortex-A76, the following errata build flags are defined :
224
225-  ``ERRATA_A76_1073348``: This applies errata 1073348 workaround to Cortex-A76
226   CPU. This needs to be enabled only for revision <= r1p0 of the CPU.
227
228-  ``ERRATA_A76_1130799``: This applies errata 1130799 workaround to Cortex-A76
229   CPU. This needs to be enabled only for revision <= r2p0 of the CPU.
230
231-  ``ERRATA_A76_1220197``: This applies errata 1220197 workaround to Cortex-A76
232   CPU. This needs to be enabled only for revision <= r2p0 of the CPU.
233
234-  ``ERRATA_A76_1257314``: This applies errata 1257314 workaround to Cortex-A76
235   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
236
237-  ``ERRATA_A76_1262606``: This applies errata 1262606 workaround to Cortex-A76
238   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
239
240-  ``ERRATA_A76_1262888``: This applies errata 1262888 workaround to Cortex-A76
241   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
242
243-  ``ERRATA_A76_1275112``: This applies errata 1275112 workaround to Cortex-A76
244   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
245
246-  ``ERRATA_A76_1791580``: This applies errata 1791580 workaround to Cortex-A76
247   CPU. This needs to be enabled only for revision <= r4p0 of the CPU.
248
249-  ``ERRATA_A76_1165522``: This applies errata 1165522 workaround to all
250   revisions of Cortex-A76 CPU. This errata is fixed in r3p0 but due to
251   limitation of errata framework this errata is applied to all revisions
252   of Cortex-A76 CPU.
253
254-  ``ERRATA_A76_1868343``: This applies errata 1868343 workaround to Cortex-A76
255   CPU. This needs to be enabled only for revision <= r4p0 of the CPU.
256
257-  ``ERRATA_A76_1946160``: This applies errata 1946160 workaround to Cortex-A76
258   CPU. This needs to be enabled only for revisions r3p0 - r4p1 of the CPU.
259
260-  ``ERRATA_A76_2743102``: This applies errata 2743102 workaround to Cortex-A76
261   CPU. This needs to be enabled for all revisions <= r4p1 of the CPU and is
262   still open.
263
264For Cortex-A77, the following errata build flags are defined :
265
266-  ``ERRATA_A77_1508412``: This applies errata 1508412 workaround to Cortex-A77
267   CPU. This needs to be enabled only for revision <= r1p0 of the CPU.
268
269-  ``ERRATA_A77_1925769``: This applies errata 1925769 workaround to Cortex-A77
270   CPU. This needs to be enabled only for revision <= r1p1 of the CPU.
271
272-  ``ERRATA_A77_1946167``: This applies errata 1946167 workaround to Cortex-A77
273   CPU. This needs to be enabled only for revision <= r1p1 of the CPU.
274
275-  ``ERRATA_A77_1791578``: This applies errata 1791578 workaround to Cortex-A77
276   CPU. This needs to be enabled for r0p0, r1p0, and r1p1, it is still open.
277
278-  ``ERRATA_A77_2356587``: This applies errata 2356587 workaround to Cortex-A77
279   CPU. This needs to be enabled for r0p0, r1p0, and r1p1, it is still open.
280
281 -  ``ERRATA_A77_1800714``: This applies errata 1800714 workaround to Cortex-A77
282    CPU. This needs to be enabled for revisions <= r1p1 of the CPU.
283
284 -  ``ERRATA_A77_2743100``: This applies errata 2743100 workaround to Cortex-A77
285    CPU. This needs to be enabled for r0p0, r1p0, and r1p1, it is still open.
286
287For Cortex-A78, the following errata build flags are defined :
288
289-  ``ERRATA_A78_1688305``: This applies errata 1688305 workaround to Cortex-A78
290   CPU. This needs to be enabled only for revision r0p0 - r1p0 of the CPU.
291
292-  ``ERRATA_A78_1941498``: This applies errata 1941498 workaround to Cortex-A78
293   CPU. This needs to be enabled for revisions r0p0, r1p0, and r1p1 of the CPU.
294
295-  ``ERRATA_A78_1951500``: This applies errata 1951500 workaround to Cortex-A78
296   CPU. This needs to be enabled for revisions r1p0 and r1p1, r0p0 has the same
297   issue but there is no workaround for that revision.
298
299-  ``ERRATA_A78_1821534``: This applies errata 1821534 workaround to Cortex-A78
300   CPU. This needs to be enabled for revisions r0p0 and r1p0.
301
302-  ``ERRATA_A78_1952683``: This applies errata 1952683 workaround to Cortex-A78
303   CPU. This needs to be enabled for revision r0p0, it is fixed in r1p0.
304
305-  ``ERRATA_A78_2132060``: This applies errata 2132060 workaround to Cortex-A78
306   CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1, and r1p2. It
307   is still open.
308
309-  ``ERRATA_A78_2242635``: This applies errata 2242635 workaround to Cortex-A78
310   CPU. This needs to be enabled for revisions r1p0, r1p1, and r1p2. The issue
311   is present in r0p0 but there is no workaround. It is still open.
312
313-  ``ERRATA_A78_2376745``: This applies errata 2376745 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
317-  ``ERRATA_A78_2395406``: This applies errata 2395406 workaround to Cortex-A78
318   CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1, and r1p2, and
319   it is still open.
320
321- ``ERRATA_A78_2712571``: This applies erratum 2712571 workaround to Cortex-A78
322   CPU, this erratum affects system configurations that do not use an ARM
323   interconnect IP. This needs to be enabled for revisions r0p0, r1p0, r1p1
324   and r1p2 and it is still open.
325
326-  ``ERRATA_A78_2742426``: This applies erratum 2742426 workaround to Cortex-A78
327   CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1 and r1p2 and
328   it is still open.
329
330-  ``ERRATA_A78_2772019``: This applies errata 2772019 workaround to Cortex-A78
331   CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1, and r1p2, and
332   it is still open.
333
334-  ``ERRATA_A78_2779479``: This applies erratum 2779479 workaround to Cortex-A78
335   CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1 and r1p2 and
336   it is still open.
337
338For Cortex-A78AE, the following errata build flags are defined :
339
340- ``ERRATA_A78_AE_1941500`` : This applies errata 1941500 workaround to
341   Cortex-A78AE CPU. This needs to be enabled for revisions r0p0 and r0p1.
342   This erratum is still open.
343
344- ``ERRATA_A78_AE_1951502`` : This applies errata 1951502 workaround to
345  Cortex-A78AE CPU. This needs to be enabled for revisions r0p0 and r0p1. This
346  erratum is still open.
347
348- ``ERRATA_A78_AE_2376748`` : This applies errata 2376748 workaround to
349  Cortex-A78AE CPU. This needs to be enabled for revisions r0p0, r0p1 and r0p2.
350  This erratum is still open.
351
352- ``ERRATA_A78_AE_2395408`` : This applies errata 2395408 workaround to
353  Cortex-A78AE CPU. This needs to be enabled for revisions r0p0 and r0p1. This
354  erratum is still open.
355
356- ``ERRATA_A78_AE_2712574`` : This applies erratum 2712574 workaround to
357  Cortex-A78AE CPU. This erratum affects system configurations that do not use
358  an ARM interconnect IP. This needs to be enabled for revisions r0p0, r0p1 and
359  r0p2. This erratum is still open.
360
361For Cortex-A78C, the following errata build flags are defined :
362
363- ``ERRATA_A78C_1827430`` : This applies errata 1827430 workaround to
364  Cortex-A78C CPU. This needs to be enabled for revision r0p0. The erratum is
365  fixed in r0p1.
366
367- ``ERRATA_A78C_1827440`` : This applies errata 1827440 workaround to
368  Cortex-A78C CPU. This needs to be enabled for revision r0p0. The erratum is
369  fixed in r0p1.
370
371- ``ERRATA_A78C_2132064`` : This applies errata 2132064 workaround to
372  Cortex-A78C CPU. This needs to be enabled for revisions r0p1, r0p2 and
373  it is still open.
374
375- ``ERRATA_A78C_2242638`` : This applies errata 2242638 workaround to
376  Cortex-A78C CPU. This needs to be enabled for revisions r0p1, r0p2 and
377  it is still open.
378
379- ``ERRATA_A78C_2376749`` : This applies errata 2376749 workaround to
380  Cortex-A78C CPU. This needs to be enabled for revisions r0p1 and r0p2. This
381  erratum is still open.
382
383- ``ERRATA_A78C_2395411`` : This applies errata 2395411 workaround to
384  Cortex-A78C CPU. This needs to be enabled for revisions r0p1 and r0p2. This
385  erratum is still open.
386
387- ``ERRATA_A78C_2683027`` : This applies errata 2683027 workaround to
388  Cortex-A78C CPU. This needs to be enabled for revisions r0p1 and r0p2. This
389  erratum is still open.
390
391- ``ERRATA_A78C_2712575`` : This applies erratum 2712575 workaround to
392  Cortex-A78C CPU, this erratum affects system configurations that do not use
393  an ARM interconnect IP. This needs to be enabled for revisions r0p1 and r0p2
394  and is still open.
395
396- ``ERRATA_A78C_2743232`` : This applies erratum 2743232 workaround to
397  Cortex-A78C CPU. This needs to be enabled for revisions r0p1 and r0p2.
398  This erratum is still open.
399
400- ``ERRATA_A78C_2772121`` : This applies errata 2772121 workaround to
401  Cortex-A78C CPU. This needs to be enabled for revisions r0p0, r0p1 and r0p2.
402  This erratum is still open.
403
404- ``ERRATA_A78C_2779484`` : This applies errata 2779484 workaround to
405  Cortex-A78C CPU. This needs to be enabled for revisions r0p1 and r0p2.
406  This erratum is still open.
407
408For Cortex-X1 CPU, the following errata build flags are defined:
409
410- ``ERRATA_X1_1821534`` : This applies errata 1821534 workaround to Cortex-X1
411   CPU. This needs to be enabled only for revision <= r1p0 of the CPU.
412
413- ``ERRATA_X1_1688305`` : This applies errata 1688305 workaround to Cortex-X1
414   CPU. This needs to be enabled only for revision <= r1p0 of the CPU.
415
416- ``ERRATA_X1_1827429`` : This applies errata 1827429 workaround to Cortex-X1
417   CPU. This needs to be enabled only for revision <= r1p0 of the CPU.
418
419For Neoverse N1, the following errata build flags are defined :
420
421-  ``ERRATA_N1_1073348``: This applies errata 1073348 workaround to Neoverse-N1
422   CPU. This needs to be enabled only for revision r0p0 and r1p0 of the CPU.
423
424-  ``ERRATA_N1_1130799``: This applies errata 1130799 workaround to Neoverse-N1
425   CPU. This needs to be enabled only for revision <= r2p0 of the CPU.
426
427-  ``ERRATA_N1_1165347``: This applies errata 1165347 workaround to Neoverse-N1
428   CPU. This needs to be enabled only for revision <= r2p0 of the CPU.
429
430-  ``ERRATA_N1_1207823``: This applies errata 1207823 workaround to Neoverse-N1
431   CPU. This needs to be enabled only for revision <= r2p0 of the CPU.
432
433-  ``ERRATA_N1_1220197``: This applies errata 1220197 workaround to Neoverse-N1
434   CPU. This needs to be enabled only for revision <= r2p0 of the CPU.
435
436-  ``ERRATA_N1_1257314``: This applies errata 1257314 workaround to Neoverse-N1
437   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
438
439-  ``ERRATA_N1_1262606``: This applies errata 1262606 workaround to Neoverse-N1
440   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
441
442-  ``ERRATA_N1_1262888``: This applies errata 1262888 workaround to Neoverse-N1
443   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
444
445-  ``ERRATA_N1_1275112``: This applies errata 1275112 workaround to Neoverse-N1
446   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
447
448-  ``ERRATA_N1_1315703``: This applies errata 1315703 workaround to Neoverse-N1
449   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
450
451-  ``ERRATA_N1_1542419``: This applies errata 1542419 workaround to Neoverse-N1
452   CPU. This needs to be enabled only for revisions r3p0 - r4p0 of the CPU.
453
454-  ``ERRATA_N1_1868343``: This applies errata 1868343 workaround to Neoverse-N1
455   CPU. This needs to be enabled only for revision <= r4p0 of the CPU.
456
457-  ``ERRATA_N1_1946160``: This applies errata 1946160 workaround to Neoverse-N1
458   CPU. This needs to be enabled for revisions r3p0, r3p1, r4p0, and r4p1, for
459   revisions r0p0, r1p0, and r2p0 there is no workaround.
460
461-  ``ERRATA_N1_2743102``: This applies errata 2743102 workaround to Neoverse-N1
462   CPU. This needs to be enabled for all revisions <= r4p1 of the CPU and is
463   still open.
464
465For Neoverse V1, the following errata build flags are defined :
466
467-  ``ERRATA_V1_1618635``: This applies errata 1618635 workaround to Neoverse-V1
468   CPU. This needs to be enabled for revision r0p0 of the CPU, it is fixed in
469   r1p0.
470
471-  ``ERRATA_V1_1774420``: This applies errata 1774420 workaround to Neoverse-V1
472   CPU. This needs to be enabled only for revisions r0p0 and r1p0, it is fixed
473   in r1p1.
474
475-  ``ERRATA_V1_1791573``: This applies errata 1791573 workaround to Neoverse-V1
476   CPU. This needs to be enabled only for revisions r0p0 and r1p0, it is fixed
477   in r1p1.
478
479-  ``ERRATA_V1_1852267``: This applies errata 1852267 workaround to Neoverse-V1
480   CPU. This needs to be enabled only for revisions r0p0 and r1p0, it is fixed
481   in r1p1.
482
483-  ``ERRATA_V1_1925756``: This applies errata 1925756 workaround to Neoverse-V1
484   CPU. This needs to be enabled for r0p0, r1p0, and r1p1, it is still open.
485
486-  ``ERRATA_V1_1940577``: This applies errata 1940577 workaround to Neoverse-V1
487   CPU. This needs to be enabled only for revision r1p0 and r1p1 of the
488   CPU.
489
490-  ``ERRATA_V1_1966096``: This applies errata 1966096 workaround to Neoverse-V1
491   CPU. This needs to be enabled for revisions r1p0 and r1p1 of the CPU, the
492   issue is present in r0p0 as well but there is no workaround for that
493   revision.  It is still open.
494
495-  ``ERRATA_V1_2139242``: This applies errata 2139242 workaround to Neoverse-V1
496   CPU. This needs to be enabled for revisions r0p0, r1p0, and r1p1 of the
497   CPU.  It is still open.
498
499-  ``ERRATA_V1_2108267``: This applies errata 2108267 workaround to Neoverse-V1
500   CPU. This needs to be enabled for revisions r0p0, r1p0, and r1p1 of the CPU.
501   It is still open.
502
503-  ``ERRATA_V1_2216392``: This applies errata 2216392 workaround to Neoverse-V1
504   CPU. This needs to be enabled for revisions r1p0 and r1p1 of the CPU, the
505   issue is present in r0p0 as well but there is no workaround for that
506   revision.  It is still open.
507
508-  ``ERRATA_V1_2294912``: This applies errata 2294912 workaround to Neoverse-V1
509   CPU. This needs to be enabled for revisions r0p0, r1p0, and r1p1 and r1p2 of
510   the CPU.
511
512-  ``ERRATA_V1_2348377``: This applies errata 2348377 workaroud to Neoverse-V1
513   CPU. This needs to be enabled for revisions r0p0, r1p0 and r1p1 of the CPU.
514   It has been fixed in r1p2.
515
516-  ``ERRATA_V1_2372203``: This applies errata 2372203 workaround to Neoverse-V1
517   CPU. This needs to be enabled for revisions r0p0, r1p0 and r1p1 of the CPU.
518   It is still open.
519
520- ``ERRATA_V1_2701953``: This applies erratum 2701953 workaround to Neoverse-V1
521   CPU, this erratum affects system configurations that do not use an ARM
522   interconnect IP. This needs to be enabled for revisions r0p0, r1p0 and r1p1.
523   It has been fixed in r1p2.
524
525-  ``ERRATA_V1_2743093``: This applies errata 2743093 workaround to Neoverse-V1
526   CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1 and r1p2 of the
527   CPU. It is still open.
528
529-  ``ERRATA_V1_2743233``: This applies erratum 2743233 workaround to Neoverse-V1
530   CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1, and r1p2 of the
531   CPU. It is still open.
532
533-  ``ERRATA_V1_2779461``: This applies erratum 2779461 workaround to Neoverse-V1
534   CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1, r1p2 of the
535   CPU. It is still open.
536
537For Neoverse V2, the following errata build flags are defined :
538
539-  ``ERRATA_V2_2331132``: This applies errata 2331132 workaround to Neoverse-V2
540   CPU. This needs to be enabled for revisions r0p0, r0p1 and r0p2. It is still
541   open.
542
543-  ``ERRATA_V2_2618597``: This applies errata 2618597 workaround to Neoverse-V2
544   CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed in
545   r0p2.
546
547-  ``ERRATA_V2_2662553``: This applies errata 2662553 workaround to Neoverse-V2
548   CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed in
549   r0p2.
550
551-  ``ERRATA_V2_2719103``: This applies errata 2719103 workaround to Neoverse-V2
552   CPU, this affects system configurations that do not use and ARM interconnect
553   IP. This needs to be enabled for revisions r0p0 and r0p1. It has been fixed
554   in r0p2.
555
556-  ``ERRATA_V2_2719105``: This applies errata 2719105 workaround to Neoverse-V2
557   CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed in
558   r0p2.
559
560-  ``ERRATA_V2_2743011``: This applies errata 2743011 workaround to Neoverse-V2
561   CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed in
562   r0p2.
563
564-  ``ERRATA_V2_2779510``: This applies errata 2779510 workaround to Neoverse-V2
565   CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed in
566   r0p2.
567
568-  ``ERRATA_V2_2801372``: This applies errata 2801372 workaround to Neoverse-V2
569   CPU, this affects all configurations. This needs to be enabled for revisions
570   r0p0 and r0p1. It has been fixed in r0p2.
571
572For Cortex-A710, the following errata build flags are defined :
573
574-  ``ERRATA_A710_1987031``: This applies errata 1987031 workaround to
575   Cortex-A710 CPU. This needs to be enabled only for revisions r0p0, r1p0 and
576   r2p0 of the CPU. It is still open.
577
578-  ``ERRATA_A710_2081180``: This applies errata 2081180 workaround to
579   Cortex-A710 CPU. This needs to be enabled only for revisions r0p0, r1p0 and
580   r2p0 of the CPU. It is still open.
581
582-  ``ERRATA_A710_2055002``: This applies errata 2055002 workaround to
583   Cortex-A710 CPU. This needs to be enabled for revisions r1p0, r2p0 of the CPU
584   and is still open.
585
586-  ``ERRATA_A710_2017096``: This applies errata 2017096 workaround to
587   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
588   of the CPU and is still open.
589
590-  ``ERRATA_A710_2083908``: This applies errata 2083908 workaround to
591   Cortex-A710 CPU. This needs to be enabled for revision r2p0 of the CPU and
592   is still open.
593
594-  ``ERRATA_A710_2058056``: This applies errata 2058056 workaround to
595   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
596   and r2p1 of the CPU and is still open.
597
598-  ``ERRATA_A710_2267065``: This applies errata 2267065 workaround to
599   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
600   of the CPU and is fixed in r2p1.
601
602-  ``ERRATA_A710_2136059``: This applies errata 2136059 workaround to
603   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
604   of the CPU and is fixed in r2p1.
605
606-  ``ERRATA_A710_2147715``: This applies errata 2147715 workaround to
607   Cortex-A710 CPU. This needs to be enabled for revision r2p0 of the CPU
608   and is fixed in r2p1.
609
610-  ``ERRATA_A710_2216384``: This applies errata 2216384 workaround to
611   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
612   of the CPU and is fixed in r2p1.
613
614-  ``ERRATA_A710_2282622``: This applies errata 2282622 workaround to
615   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and
616   r2p1 of the CPU and is still open.
617
618- ``ERRATA_A710_2291219``: This applies errata 2291219 workaround to
619   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
620   of the CPU and is fixed in r2p1.
621
622-  ``ERRATA_A710_2008768``: This applies errata 2008768 workaround to
623   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
624   of the CPU and is fixed in r2p1.
625
626-  ``ERRATA_A710_2371105``: This applies errata 2371105 workaround to
627   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
628   of the CPU and is fixed in r2p1.
629
630-  ``ERRATA_A710_2701952``: This applies erratum 2701952 workaround to Cortex-A710
631   CPU, and applies to system configurations that do not use and ARM
632   interconnect IP. This needs to be enabled for r0p0, r1p0, r2p0 and r2p1 and
633   is still open.
634
635-  ``ERRATA_A710_2742423``: This applies errata 2742423 workaround to
636   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and
637   r2p1 of the CPU and is still open.
638
639-  ``ERRATA_A710_2768515``: This applies errata 2768515 workaround to
640   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and
641   r2p1 of the CPU and is still open.
642
643-  ``ERRATA_A710_2778471``: This applies errata 2778471 workaround to Cortex-A710
644   CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and r2p1 of the
645   CPU and is still open.
646
647For Neoverse N2, the following errata build flags are defined :
648
649-  ``ERRATA_N2_2002655``: This applies errata 2002655 workaround to Neoverse-N2
650   CPU. This needs to be enabled for revision r0p0 of the CPU and is fixed in r0p1.
651
652-  ``ERRATA_N2_2009478``: This applies errata 2009478 workaround to Neoverse-N2
653   CPU. This needs to be enabled for revision r0p0 of the CPU and is fixed in r0p1.
654
655-  ``ERRATA_N2_2067956``: This applies errata 2067956 workaround to Neoverse-N2
656   CPU. This needs to be enabled for revision r0p0 of the CPU and is fixed in r0p1.
657
658-  ``ERRATA_N2_2025414``: This applies errata 2025414 workaround to Neoverse-N2
659   CPU. This needs to be enabled for revision r0p0 of the CPU and is fixed in r0p1.
660
661-  ``ERRATA_N2_2189731``: This applies errata 2189731 workaround to Neoverse-N2
662   CPU. This needs to be enabled for revision r0p0 of the CPU and is fixed in r0p1.
663
664-  ``ERRATA_N2_2138956``: This applies errata 2138956 workaround to Neoverse-N2
665   CPU. This needs to be enabled for revision r0p0 of the CPU and is fixed in r0p1.
666
667-  ``ERRATA_N2_2138953``: This applies errata 2138953 workaround to Neoverse-N2
668   CPU. This needs to be enabled for revisions r0p0, r0p1, r0p2, r0p3 and is still open.
669
670-  ``ERRATA_N2_2242415``: This applies errata 2242415 workaround to Neoverse-N2
671   CPU. This needs to be enabled for revision r0p0 of the CPU and is fixed in r0p1.
672
673-  ``ERRATA_N2_2138958``: This applies errata 2138958 workaround to Neoverse-N2
674   CPU. This needs to be enabled for revision r0p0 of the CPU and is fixed in r0p1.
675
676-  ``ERRATA_N2_2242400``: This applies errata 2242400 workaround to Neoverse-N2
677   CPU. This needs to be enabled for revision r0p0 of the CPU and is fixed in r0p1.
678
679-  ``ERRATA_N2_2280757``: This applies errata 2280757 workaround to Neoverse-N2
680   CPU. This needs to be enabled for revision r0p0 of the CPU and is fixed in r0p1.
681
682-  ``ERRATA_N2_2326639``: This applies errata 2326639 workaround to Neoverse-N2
683   CPU. This needs to be enabled for revision r0p0 of the CPU, it is fixed in
684   r0p1.
685
686-  ``ERRATA_N2_2340933``: This applies errata 2340933 workaround to Neoverse-N2
687   CPU. This needs to be enabled for revision r0p0 of the CPU, it is fixed in
688   r0p1.
689
690-  ``ERRATA_N2_2346952``: This applies errata 2346952 workaround to Neoverse-N2
691   CPU. This needs to be enabled for revisions r0p0, r0p1 and r0p2 of the CPU,
692   it is fixed in r0p3.
693
694-  ``ERRATA_N2_2376738``: This applies errata 2376738 workaround to Neoverse-N2
695   CPU. This needs to be enabled for revision r0p0, r0p1, r0p2, r0p3 and is still open.
696
697-  ``ERRATA_N2_2388450``: This applies errata 2388450 workaround to Neoverse-N2
698   CPU. This needs to be enabled for revision r0p0 of the CPU, it is fixed in
699   r0p1.
700
701-  ``ERRATA_N2_2743014``: This applies errata 2743014 workaround to Neoverse-N2
702   CPU. This needs to be enabled for revisions r0p0, r0p1 and r0p2. It is fixed
703   in r0p3.
704
705-  ``ERRATA_N2_2743089``: This applies errata 2743089 workaround to Neoverse-N2
706   CPU. This needs to be enabled for revisions r0p0, r0p1 and r0p2. It is fixed
707   in r0p3.
708
709- ``ERRATA_N2_2728475``: This applies erratum 2728475 workaround to Neoverse-N2
710   CPU, this erratum affects system configurations that do not use and ARM
711   interconnect IP. This needs to be enabled for revisions r0p0, r0p1 and r0p2.
712   It is fixed in r0p3.
713
714-  ``ERRATA_N2_2779511``: This applies errata 2779511 workaround to Neoverse-N2
715   CPU. This needs to be enabled for revisions r0p0, r0p1 and r0p2. It is fixed
716   in r0p3.
717
718For Cortex-X2, the following errata build flags are defined :
719
720-  ``ERRATA_X2_2002765``: This applies errata 2002765 workaround to Cortex-X2
721   CPU. This needs to be enabled for revisions r0p0, r1p0, and r2p0 of the CPU,
722   it is still open.
723
724-  ``ERRATA_X2_2058056``: This applies errata 2058056 workaround to Cortex-X2
725   CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and r2p1 of the CPU,
726   it is still open.
727
728-  ``ERRATA_X2_2083908``: This applies errata 2083908 workaround to Cortex-X2
729   CPU. This needs to be enabled for revision r2p0 of the CPU, it is still open.
730
731-  ``ERRATA_X2_2017096``: This applies errata 2017096 workaround to Cortex-X2
732   CPU. This needs to be enabled only for revisions r0p0, r1p0 and r2p0 of the
733   CPU, it is fixed in r2p1.
734
735-  ``ERRATA_X2_2081180``: This applies errata 2081180 workaround to Cortex-X2
736   CPU. This needs to be enabled only for revisions r0p0, r1p0 and r2p0 of the
737   CPU, it is fixed in r2p1.
738
739-  ``ERRATA_X2_2216384``: This applies errata 2216384 workaround to Cortex-X2
740   CPU. This needs to be enabled only for revisions r0p0, r1p0 and r2p0 of the
741   CPU, it is fixed in r2p1.
742
743-  ``ERRATA_X2_2147715``: This applies errata 2147715 workaround to Cortex-X2
744   CPU. This needs to be enabled only for revision r2p0 of the CPU, it is fixed
745   in r2p1.
746
747-  ``ERRATA_X2_2282622``: This applies errata 2282622 workaround to Cortex-X2
748   CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and r2p1 of the
749   CPU and is still open.
750
751-  ``ERRATA_X2_2371105``: This applies errata 2371105 workaround to Cortex-X2
752   CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0 of the CPU
753   and is fixed in r2p1.
754
755- ``ERRATA_X2_2701952``: This applies erratum 2701952 workaround to Cortex-X2
756   CPU and affects system configurations that do not use an ARM interconnect IP.
757   This needs to be enabled for revisions r0p0, r1p0, r2p0 and r2p1 and is
758   still open.
759
760-  ``ERRATA_X2_2742423``: This applies errata 2742423 workaround to Cortex-X2
761   CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and r2p1 of the
762   CPU and is still open.
763
764-  ``ERRATA_X2_2768515``: This applies errata 2768515 workaround to Cortex-X2
765   CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and r2p1 of the
766   CPU and is still open.
767
768-  ``ERRATA_X2_2778471``: This applies errata 2778471 workaround to Cortex-X2
769   CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and r2p1 of the
770   CPU and it is still open.
771
772For Cortex-X3, the following errata build flags are defined :
773
774- ``ERRATA_X3_2070301``: This applies errata 2070301 workaround to the Cortex-X3
775  CPU. This needs to be enabled only for revisions r0p0, r1p0, r1p1 and r1p2 of
776  the CPU and is still open.
777
778- ``ERRATA_X3_2266875``: This applies errata 2266875 workaround to the Cortex-X3
779  CPU. This needs to be enabled only for revisions r0p0 and r1p0 of the CPU, it
780  is fixed in r1p1.
781
782- ``ERRATA_X3_2302506``: This applies errata 2302506 workaround to the Cortex-X3
783  CPU. This needs to be enabled only for revisions r0p0, r1p0 and r1p1, it is
784  fixed in r1p2.
785
786- ``ERRATA_X3_2313909``: This applies errata 2313909 workaround to
787  Cortex-X3 CPU. This needs to be enabled only for revisions r0p0 and r1p0
788  of the CPU, it is fixed in r1p1.
789
790- ``ERRATA_X3_2372204``: This applies errata 2372204 workaround to
791  Cortex-X3 CPU. This needs to be enabled only for revisions r0p0 and r1p0
792  of the CPU, it is fixed in r1p1.
793
794- ``ERRATA_X3_2615812``: This applies errata 2615812 workaround to Cortex-X3
795  CPU. This needs to be enabled only for revisions r0p0, r1p0 and r1p1 of the
796  CPU, it is fixed in r1p2.
797
798- ``ERRATA_X3_2641945``: This applies errata 2641945 workaround to Cortex-X3
799  CPU. This needs to be enabled only for revisions r0p0 and r1p0 of the CPU.
800  It is fixed in r1p1.
801
802- ``ERRATA_X3_2701951``: This applies erratum 2701951 workaround to Cortex-X3
803  CPU and affects system configurations that do not use an ARM interconnect
804  IP. This needs to be applied to revisions r0p0, r1p0 and r1p1. It is fixed
805  in r1p2.
806
807- ``ERRATA_X3_2742421``: This applies errata 2742421 workaround to
808  Cortex-X3 CPU. This needs to be enabled only for revisions r0p0, r1p0 and
809  r1p1. It is fixed in r1p2.
810
811- ``ERRATA_X3_2743088``: This applies errata 2743088 workaround to Cortex-X3
812  CPU. This needs to be enabled only for revisions r0p0, r1p0 and r1p1. It is
813  fixed in r1p2.
814
815- ``ERRATA_X3_2779509``: This applies errata 2779509 workaround to Cortex-X3
816  CPU. This needs to be enabled only for revisions r0p0, r1p0 and r1p1 of the
817  CPU. It is fixed in r1p2.
818
819For Cortex-X4, the following errata build flags are defined :
820
821- ``ERRATA_X4_2701112``: This applies erratum 2701112 workaround to Cortex-X4
822  CPU and affects system configurations that do not use an Arm interconnect IP.
823  This needs to be enabled for revisions r0p0 and is fixed in r0p1.
824  The workaround for this erratum is not implemented in EL3, but the flag can
825  be enabled/disabled at the platform level. The flag is used when the errata ABI
826  feature is enabled and can assist the Kernel in the process of
827  mitigation of the erratum.
828
829-  ``ERRATA_X4_2740089``: This applies errata 2740089 workaround to Cortex-X4
830   CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed
831   in r0p2.
832
833- ``ERRATA_X4_2763018``: This applies errata 2763018 workaround to Cortex-X4
834  CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed in r0p2.
835
836For Cortex-A510, the following errata build flags are defined :
837
838-  ``ERRATA_A510_1922240``: This applies errata 1922240 workaround to
839   Cortex-A510 CPU. This needs to be enabled only for revision r0p0, it is
840   fixed in r0p1.
841
842-  ``ERRATA_A510_2288014``: This applies errata 2288014 workaround to
843   Cortex-A510 CPU. This needs to be enabled only for revisions r0p0, r0p1,
844   r0p2, r0p3 and r1p0, it is fixed in r1p1.
845
846-  ``ERRATA_A510_2042739``: This applies errata 2042739 workaround to
847   Cortex-A510 CPU. This needs to be enabled only for revisions r0p0, r0p1 and
848   r0p2, it is fixed in r0p3.
849
850-  ``ERRATA_A510_2041909``: This applies errata 2041909 workaround to
851   Cortex-A510 CPU. This needs to be enabled only for revision r0p2 and is fixed
852   in r0p3. The issue is also present in r0p0 and r0p1 but there is no
853   workaround for those revisions.
854
855-  ``ERRATA_A510_2080326``: This applies errata 2080326 workaround to
856   Cortex-A510 CPU. This needs to be enabled only for revision r0p2 and is
857   fixed in r0p3. This issue is also present in r0p0 and r0p1 but there is no
858   workaround for those revisions.
859
860-  ``ERRATA_A510_2250311``: This applies errata 2250311 workaround to
861   Cortex-A510 CPU. This needs to be enabled for revisions r0p0, r0p1, r0p2,
862   r0p3 and r1p0, it is fixed in r1p1. This workaround disables MPMM even if
863   ENABLE_MPMM=1.
864
865-  ``ERRATA_A510_2218950``: This applies errata 2218950 workaround to
866   Cortex-A510 CPU. This needs to be enabled for revisions r0p0, r0p1, r0p2,
867   r0p3 and r1p0, it is fixed in r1p1.
868
869-  ``ERRATA_A510_2172148``: This applies errata 2172148 workaround to
870   Cortex-A510 CPU. This needs to be enabled for revisions r0p0, r0p1, r0p2,
871   r0p3 and r1p0, it is fixed in r1p1.
872
873-  ``ERRATA_A510_2347730``: This applies errata 2347730 workaround to
874   Cortex-A510 CPU. This needs to be enabled for revisions r0p0, r0p1, r0p2,
875   r0p3, r1p0 and r1p1. It is fixed in r1p2.
876
877-  ``ERRATA_A510_2371937``: This applies errata 2371937 workaround to
878   Cortex-A510 CPU. This needs to applied for revisions r0p0, r0p1, r0p2,
879   r0p3, r1p0, r1p1, and is fixed in r1p2.
880
881-  ``ERRATA_A510_2666669``: This applies errata 2666669 workaround to
882   Cortex-A510 CPU. This needs to applied for revisions r0p0, r0p1, r0p2,
883   r0p3, r1p0, r1p1. It is fixed in r1p2.
884
885-  ``ERRATA_A510_2684597``: This applies erratum 2684597 workaround to
886   Cortex-A510 CPU. This needs to be applied to revision r0p0, r0p1, r0p2,
887   r0p3, r1p0, r1p1 and r1p2. It is fixed in r1p3.
888
889For Cortex-A520, the following errata build flags are defined :
890
891-  ``ERRATA_A520_2630792``: This applies errata 2630792 workaround to
892   Cortex-A520 CPU. This needs to applied for revisions r0p0, r0p1 of the
893   CPU and is still open.
894
895-  ``ERRATA_A520_2858100``: This applies errata 2858100 workaround to
896   Cortex-A520 CPU. This needs to be enabled for revisions r0p0 and r0p1.
897   It is still open.
898
899For Cortex-A715, the following errata build flags are defined :
900
901-  ``ERRATA_A715_2331818``: This applies errata 2331818 workaround to
902   Cortex-A715 CPU. This needs to be enabled for revisions r0p0 and r1p0.
903   It is fixed in r1p1.
904
905- ``ERRATA_A715_2344187``: This applies errata 2344187 workaround to
906   Cortex-A715 CPU. This needs to be enabled for revisions r0p0 and r1p0. It is
907   fixed in r1p1.
908
909-  ``ERRATA_A715_2413290``: This applies errata 2413290 workaround to
910   Cortex-A715 CPU. This needs to be enabled only for revision r1p0 and
911   when SPE(Statistical profiling extension)=True. The errata is fixed
912   in r1p1.
913
914-  ``ERRATA_A715_2420947``: This applies errata 2420947 workaround to
915   Cortex-A715 CPU. This needs to be enabled only for revision r1p0.
916   It is fixed in r1p1.
917
918-  ``ERRATA_A715_2429384``: This applies errata 2429384 workaround to
919   Cortex-A715 CPU. This needs to be enabled for revision r1p0. There is no
920   workaround for revision r0p0. It is fixed in r1p1.
921
922-  ``ERRATA_A715_2561034``: This applies errata 2561034 workaround to
923   Cortex-A715 CPU. This needs to be enabled only for revision r1p0.
924   It is fixed in r1p1.
925
926-  ``ERRATA_A715_2728106``: This applies errata 2728106 workaround to
927   Cortex-A715 CPU. This needs to be enabled for revisions r0p0, r1p0
928   and r1p1. It is fixed in r1p2.
929
930For Cortex-A720, the following errata build flags are defined :
931
932-  ``ERRATA_A720_2926083``: This applies errata 2926083 workaround to
933   Cortex-A720 CPU. This needs to be enabled for revisions r0p0 and r0p1.
934   It is fixed in r0p2.
935
936-  ``ERRATA_A720_2940794``: This applies errata 2940794 workaround to
937   Cortex-A720 CPU. This needs to be enabled for revisions r0p0 and r0p1.
938   It is fixed in r0p2.
939
940DSU Errata Workarounds
941----------------------
942
943Similar to CPU errata, TF-A also implements workarounds for DSU (DynamIQ
944Shared Unit) errata. The DSU errata details can be found in the respective Arm
945documentation:
946
947- `Arm DSU Software Developers Errata Notice`_.
948
949Each erratum is identified by an ``ID``, as defined in the DSU errata notice
950document. Thus, the build flags which enable/disable the errata workarounds
951have the format ``ERRATA_DSU_<ID>``. The implementation and application logic
952of DSU errata workarounds are similar to `CPU errata workarounds`_.
953
954For DSU errata, the following build flags are defined:
955
956-  ``ERRATA_DSU_798953``: This applies errata 798953 workaround for the
957   affected DSU configurations. This errata applies only for those DSUs that
958   revision is r0p0 (on r0p1 it is fixed). However, please note that this
959   workaround results in increased DSU power consumption on idle.
960
961-  ``ERRATA_DSU_936184``: This applies errata 936184 workaround for the
962   affected DSU configurations. This errata applies only for those DSUs that
963   contain the ACP interface **and** the DSU revision is older than r2p0 (on
964   r2p0 it is fixed). However, please note that this workaround results in
965   increased DSU power consumption on idle.
966
967-  ``ERRATA_DSU_2313941``: This applies errata 2313941 workaround for the
968   affected DSU configurations. This errata applies for those DSUs with
969   revisions r0p0, r1p0, r2p0, r2p1, r3p0, r3p1 and is still open. However,
970   please note that this workaround results in increased DSU power consumption
971   on idle.
972
973CPU Specific optimizations
974--------------------------
975
976This section describes some of the optimizations allowed by the CPU micro
977architecture that can be enabled by the platform as desired.
978
979-  ``SKIP_A57_L1_FLUSH_PWR_DWN``: This flag enables an optimization in the
980   Cortex-A57 cluster power down sequence by not flushing the Level 1 data
981   cache. The L1 data cache and the L2 unified cache are inclusive. A flush
982   of the L2 by set/way flushes any dirty lines from the L1 as well. This
983   is a known safe deviation from the Cortex-A57 TRM defined power down
984   sequence. Each Cortex-A57 based platform must make its own decision on
985   whether to use the optimization.
986
987-  ``A53_DISABLE_NON_TEMPORAL_HINT``: This flag disables the cache non-temporal
988   hint. The LDNP/STNP instructions as implemented on Cortex-A53 do not behave
989   in a way most programmers expect, and will most probably result in a
990   significant speed degradation to any code that employs them. The Armv8-A
991   architecture (see Arm DDI 0487A.h, section D3.4.3) allows cores to ignore
992   the non-temporal hint and treat LDNP/STNP as LDP/STP instead. Enabling this
993   flag enforces this behaviour. This needs to be enabled only for revisions
994   <= r0p3 of the CPU and is enabled by default.
995
996-  ``A57_DISABLE_NON_TEMPORAL_HINT``: This flag has the same behaviour as
997   ``A53_DISABLE_NON_TEMPORAL_HINT`` but for Cortex-A57. This needs to be
998   enabled only for revisions <= r1p2 of the CPU and is enabled by default,
999   as recommended in section "4.7 Non-Temporal Loads/Stores" of the
1000   `Cortex-A57 Software Optimization Guide`_.
1001
1002- ''A57_ENABLE_NON_CACHEABLE_LOAD_FWD'': This flag enables non-cacheable
1003   streaming enhancement feature for Cortex-A57 CPUs. Platforms can set
1004   this bit only if their memory system meets the requirement that cache
1005   line fill requests from the Cortex-A57 processor are atomic. Each
1006   Cortex-A57 based platform must make its own decision on whether to use
1007   the optimization. This flag is disabled by default.
1008
1009-  ``NEOVERSE_Nx_EXTERNAL_LLC``: This flag indicates that an external last
1010   level cache(LLC) is present in the system, and that the DataSource field
1011   on the master CHI interface indicates when data is returned from the LLC.
1012   This is used to control how the LL_CACHE* PMU events count.
1013   Default value is 0 (Disabled).
1014
1015GIC Errata Workarounds
1016----------------------
1017-  ``GIC600_ERRATA_WA_2384374``: This flag applies part 2 of errata 2384374
1018   workaround for the affected GIC600 and GIC600-AE implementations. It applies
1019   to implementations of GIC600 and GIC600-AE with revisions less than or equal
1020   to r1p6 and r0p2 respectively. If the platform sets GICV3_SUPPORT_GIC600,
1021   then this flag is enabled; otherwise, it is 0 (Disabled).
1022
1023--------------
1024
1025*Copyright (c) 2014-2024, Arm Limited and Contributors. All rights reserved.*
1026
1027.. _CVE-2017-5715: http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-5715
1028.. _CVE-2018-3639: http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-3639
1029.. _CVE-2022-23960: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-23960
1030.. _Cortex-A53 MPCore Software Developers Errata Notice: http://infocenter.arm.com/help/topic/com.arm.doc.epm048406/index.html
1031.. _Cortex-A57 MPCore Software Developers Errata Notice: http://infocenter.arm.com/help/topic/com.arm.doc.epm049219/index.html
1032.. _Cortex-A72 MPCore Software Developers Errata Notice: http://infocenter.arm.com/help/topic/com.arm.doc.epm012079/index.html
1033.. _Cortex-A57 Software Optimization Guide: http://infocenter.arm.com/help/topic/com.arm.doc.uan0015b/Cortex_A57_Software_Optimization_Guide_external.pdf
1034.. _Arm DSU Software Developers Errata Notice: http://infocenter.arm.com/help/topic/com.arm.doc.epm138168/index.html
1035