xref: /rk3399_ARM-atf/docs/design/cpu-specific-build-macros.rst (revision 015e1cd5572dab8546ecf025ed4bcc0af4484f86)
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-  ``WORKAROUND_CVE_2024_5660``: Enables mitigation for `CVE-2024-5660`.
37   The fix is to disable hardware page aggregation by setting CPUECTLR_EL1[46]
38   in EL3 FW. This build option should be set to 1 if the target platform contains
39   at least 1 CPU that requires this mitigation. Defaults to 1.
40
41-  ``WORKAROUND_CVE_2024_7881``: Enables mitigation for `CVE-2024-7881`.
42   This build option should be set to 1 if the target platform contains at
43   least 1 CPU that requires this mitigation. Defaults to 1.
44
45.. _arm_cpu_macros_errata_workarounds:
46
47CPU Errata Workarounds
48----------------------
49
50TF-A exports a series of build flags which control the errata workarounds that
51are applied to each CPU by the reset handler. The errata details can be found
52in the CPU specific errata documents published by Arm:
53For example: `Cortex-A72 MPCore Software Developers Errata Notice`_
54
55The errata workarounds are implemented for a particular revision or a set of
56processor revisions. This is checked by the reset handler at runtime. Each
57errata workaround is identified by its ``ID`` as specified in the processor's
58errata notice document. The format of the define used to enable/disable the
59errata workaround is ``ERRATA_<Processor name>_<ID>``, where the ``Processor name``
60is for example ``A57`` for the ``Cortex_A57`` CPU.
61
62Refer to :ref:`firmware_design_cpu_errata_implementation` for information on how to
63write errata workaround functions.
64
65All workarounds are disabled by default. The platform is responsible for
66enabling these workarounds according to its requirement by defining the
67errata workaround build flags in the platform specific makefile. In case
68these workarounds are enabled for the wrong CPU revision then the errata
69workaround is not applied. In the DEBUG build, this is indicated by
70printing a warning to the crash console.
71
72In the current implementation, a platform which has more than 1 variant
73with different revisions of a processor has no runtime mechanism available
74for it to specify which errata workarounds should be enabled or not.
75
76The value of the build flags is 0 by default, that is, disabled. A value of 1
77will enable it.
78
79For Cortex-A9, the following errata build flags are defined :
80
81-  ``ERRATA_A9_794073``: This applies errata 794073 workaround to Cortex-A9
82   CPU. This needs to be enabled for all revisions of the CPU.
83
84For Cortex-A15, the following errata build flags are defined :
85
86-  ``ERRATA_A15_816470``: This applies errata 816470 workaround to Cortex-A15
87   CPU. This needs to be enabled only for revision >= r3p0 of the CPU.
88
89-  ``ERRATA_A15_827671``: This applies errata 827671 workaround to Cortex-A15
90   CPU. This needs to be enabled only for revision >= r3p0 of the CPU.
91
92For Cortex-A17, the following errata build flags are defined :
93
94-  ``ERRATA_A17_852421``: This applies errata 852421 workaround to Cortex-A17
95   CPU. This needs to be enabled only for revision <= r1p2 of the CPU.
96
97-  ``ERRATA_A17_852423``: This applies errata 852423 workaround to Cortex-A17
98   CPU. This needs to be enabled only for revision <= r1p2 of the CPU.
99
100For Cortex-A35, the following errata build flags are defined :
101
102-  ``ERRATA_A35_855472``: This applies errata 855472 workaround to Cortex-A35
103   CPUs. This needs to be enabled only for revision r0p0 of Cortex-A35.
104
105For Cortex-A53, the following errata build flags are defined :
106
107-  ``ERRATA_A53_819472``: This applies errata 819472 workaround to all
108   CPUs. This needs to be enabled only for revision <= r0p1 of Cortex-A53.
109
110-  ``ERRATA_A53_824069``: This applies errata 824069 workaround to all
111   CPUs. This needs to be enabled only for revision <= r0p2 of Cortex-A53.
112
113-  ``ERRATA_A53_826319``: This applies errata 826319 workaround to Cortex-A53
114   CPU. This needs to be enabled only for revision <= r0p2 of the CPU.
115
116-  ``ERRATA_A53_827319``: This applies errata 827319 workaround to all
117   CPUs. This needs to be enabled only for revision <= r0p2 of Cortex-A53.
118
119-  ``ERRATA_A53_835769``: This applies erratum 835769 workaround at compile and
120   link time to Cortex-A53 CPU. This needs to be enabled for some variants of
121   revision <= r0p4. This workaround can lead the linker to create ``*.stub``
122   sections.
123
124-  ``ERRATA_A53_836870``: This applies errata 836870 workaround to Cortex-A53
125   CPU. This needs to be enabled only for revision <= r0p3 of the CPU. From
126   r0p4 and onwards, this errata is enabled by default in hardware. Identical to
127   ``A53_DISABLE_NON_TEMPORAL_HINT``.
128
129-  ``ERRATA_A53_843419``: This applies erratum 843419 workaround at link time
130   to Cortex-A53 CPU.  This needs to be enabled for some variants of revision
131   <= r0p4. This workaround can lead the linker to emit ``*.stub`` sections
132   which are 4kB aligned.
133
134-  ``ERRATA_A53_855873``: This applies errata 855873 workaround to Cortex-A53
135   CPUs. Though the erratum is present in every revision of the CPU,
136   this workaround is only applied to CPUs from r0p3 onwards, which feature
137   a chicken bit in CPUACTLR_EL1 to enable a hardware workaround.
138   Earlier revisions of the CPU have other errata which require the same
139   workaround in software, so they should be covered anyway.
140
141-  ``ERRATA_A53_1530924``: This applies errata 1530924 workaround to all
142   revisions of Cortex-A53 CPU.
143
144For Cortex-A55, the following errata build flags are defined :
145
146-  ``ERRATA_A55_768277``: This applies errata 768277 workaround to Cortex-A55
147   CPU. This needs to be enabled only for revision r0p0 of the CPU.
148
149-  ``ERRATA_A55_778703``: This applies errata 778703 workaround to Cortex-A55
150   CPU. This needs to be enabled only for revision r0p0 of the CPU.
151
152-  ``ERRATA_A55_798797``: This applies errata 798797 workaround to Cortex-A55
153   CPU. This needs to be enabled only for revision r0p0 of the CPU.
154
155-  ``ERRATA_A55_846532``: This applies errata 846532 workaround to Cortex-A55
156   CPU. This needs to be enabled only for revision <= r0p1 of the CPU.
157
158-  ``ERRATA_A55_903758``: This applies errata 903758 workaround to Cortex-A55
159   CPU. This needs to be enabled only for revision <= r0p1 of the CPU.
160
161-  ``ERRATA_A55_1221012``: This applies errata 1221012 workaround to Cortex-A55
162   CPU. This needs to be enabled only for revision <= r1p0 of the CPU.
163
164-  ``ERRATA_A55_1530923``: This applies errata 1530923 workaround to all
165   revisions of Cortex-A55 CPU.
166
167For Cortex-A57, the following errata build flags are defined :
168
169-  ``ERRATA_A57_806969``: This applies errata 806969 workaround to Cortex-A57
170   CPU. This needs to be enabled only for revision r0p0 of the CPU.
171
172-  ``ERRATA_A57_813419``: This applies errata 813419 workaround to Cortex-A57
173   CPU. This needs to be enabled only for revision r0p0 of the CPU.
174
175-  ``ERRATA_A57_813420``: This applies errata 813420 workaround to Cortex-A57
176   CPU. This needs to be enabled only for revision r0p0 of the CPU.
177
178-  ``ERRATA_A57_814670``: This applies errata 814670 workaround to Cortex-A57
179   CPU. This needs to be enabled only for revision r0p0 of the CPU.
180
181-  ``ERRATA_A57_817169``: This applies errata 817169 workaround to Cortex-A57
182   CPU. This needs to be enabled only for revision <= r0p1 of the CPU.
183
184-  ``ERRATA_A57_826974``: This applies errata 826974 workaround to Cortex-A57
185   CPU. This needs to be enabled only for revision <= r1p1 of the CPU.
186
187-  ``ERRATA_A57_826977``: This applies errata 826977 workaround to Cortex-A57
188   CPU. This needs to be enabled only for revision <= r1p1 of the CPU.
189
190-  ``ERRATA_A57_828024``: This applies errata 828024 workaround to Cortex-A57
191   CPU. This needs to be enabled only for revision <= r1p1 of the CPU.
192
193-  ``ERRATA_A57_829520``: This applies errata 829520 workaround to Cortex-A57
194   CPU. This needs to be enabled only for revision <= r1p2 of the CPU.
195
196-  ``ERRATA_A57_833471``: This applies errata 833471 workaround to Cortex-A57
197   CPU. This needs to be enabled only for revision <= r1p2 of the CPU.
198
199-  ``ERRATA_A57_859972``: This applies errata 859972 workaround to Cortex-A57
200   CPU. This needs to be enabled only for revision <= r1p3 of the CPU.
201
202-  ``ERRATA_A57_1319537``: This applies errata 1319537 workaround to all
203   revisions of Cortex-A57 CPU.
204
205For Cortex-A65, the following errata build flags are defined :
206
207-  ``ERRATA_A65_1179935``: This applies errata 1179935 workaround to Cortex-A65
208   CPU. This needs to be enabled only for revision r0p0 of the CPU, and is fixed
209   in r1p0.
210
211For Cortex-A72, the following errata build flags are defined :
212
213-  ``ERRATA_A72_859971``: This applies errata 859971 workaround to Cortex-A72
214   CPU. This needs to be enabled only for revision <= r0p3 of the CPU.
215
216-  ``ERRATA_A72_1319367``: This applies errata 1319367 workaround to all
217   revisions of Cortex-A72 CPU.
218
219For Cortex-A73, the following errata build flags are defined :
220
221-  ``ERRATA_A73_852427``: This applies errata 852427 workaround to Cortex-A73
222   CPU. This needs to be enabled only for revision r0p0 of the CPU.
223
224-  ``ERRATA_A73_855423``: This applies errata 855423 workaround to Cortex-A73
225   CPU. This needs to be enabled only for revision <= r0p1 of the CPU.
226
227For Cortex-A75, the following errata build flags are defined :
228
229-  ``ERRATA_A75_764081``: This applies errata 764081 workaround to Cortex-A75
230   CPU. This needs to be enabled only for revision r0p0 of the CPU.
231
232-  ``ERRATA_A75_790748``: This applies errata 790748 workaround to Cortex-A75
233    CPU. This needs to be enabled only for revision r0p0 of the CPU.
234
235For Cortex-A76, the following errata build flags are defined :
236
237-  ``ERRATA_A76_1073348``: This applies errata 1073348 workaround to Cortex-A76
238   CPU. This needs to be enabled only for revision <= r1p0 of the CPU.
239
240-  ``ERRATA_A76_1130799``: This applies errata 1130799 workaround to Cortex-A76
241   CPU. This needs to be enabled only for revision <= r2p0 of the CPU.
242
243-  ``ERRATA_A76_1220197``: This applies errata 1220197 workaround to Cortex-A76
244   CPU. This needs to be enabled only for revision <= r2p0 of the CPU.
245
246-  ``ERRATA_A76_1257314``: This applies errata 1257314 workaround to Cortex-A76
247   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
248
249-  ``ERRATA_A76_1262606``: This applies errata 1262606 workaround to Cortex-A76
250   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
251
252-  ``ERRATA_A76_1262888``: This applies errata 1262888 workaround to Cortex-A76
253   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
254
255-  ``ERRATA_A76_1275112``: This applies errata 1275112 workaround to Cortex-A76
256   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
257
258-  ``ERRATA_A76_1791580``: This applies errata 1791580 workaround to Cortex-A76
259   CPU. This needs to be enabled only for revision <= r4p0 of the CPU.
260
261-  ``ERRATA_A76_1165522``: This applies errata 1165522 workaround to all
262   revisions of Cortex-A76 CPU. This errata is fixed in r3p0 but due to
263   limitation of errata framework this errata is applied to all revisions
264   of Cortex-A76 CPU.
265
266-  ``ERRATA_A76_1868343``: This applies errata 1868343 workaround to Cortex-A76
267   CPU. This needs to be enabled only for revision <= r4p0 of the CPU.
268
269-  ``ERRATA_A76_1946160``: This applies errata 1946160 workaround to Cortex-A76
270   CPU. This needs to be enabled only for revisions r3p0 - r4p1 of the CPU.
271
272-  ``ERRATA_A76_2743102``: This applies errata 2743102 workaround to Cortex-A76
273   CPU. This needs to be enabled for all revisions <= r4p1 of the CPU and is
274   still open.
275
276For Cortex-A77, the following errata build flags are defined :
277
278-  ``ERRATA_A77_1508412``: This applies errata 1508412 workaround to Cortex-A77
279   CPU. This needs to be enabled only for revision <= r1p0 of the CPU.
280
281-  ``ERRATA_A77_1925769``: This applies errata 1925769 workaround to Cortex-A77
282   CPU. This needs to be enabled only for revision <= r1p1 of the CPU.
283
284-  ``ERRATA_A77_1946167``: This applies errata 1946167 workaround to Cortex-A77
285   CPU. This needs to be enabled only for revision <= r1p1 of the CPU.
286
287-  ``ERRATA_A77_1791578``: This applies errata 1791578 workaround to Cortex-A77
288   CPU. This needs to be enabled for r0p0, r1p0, and r1p1, it is still open.
289
290-  ``ERRATA_A77_2356587``: This applies errata 2356587 workaround to Cortex-A77
291   CPU. This needs to be enabled for r0p0, r1p0, and r1p1, it is still open.
292
293 -  ``ERRATA_A77_1800714``: This applies errata 1800714 workaround to Cortex-A77
294    CPU. This needs to be enabled for revisions <= r1p1 of the CPU.
295
296 -  ``ERRATA_A77_2743100``: This applies errata 2743100 workaround to Cortex-A77
297    CPU. This needs to be enabled for r0p0, r1p0, and r1p1, it is still open.
298
299For Cortex-A78, the following errata build flags are defined :
300
301-  ``ERRATA_A78_1688305``: This applies errata 1688305 workaround to Cortex-A78
302   CPU. This needs to be enabled only for revision r0p0 - r1p0 of the CPU.
303
304-  ``ERRATA_A78_1941498``: This applies errata 1941498 workaround to Cortex-A78
305   CPU. This needs to be enabled for revisions r0p0, r1p0, and r1p1 of the CPU.
306
307-  ``ERRATA_A78_1951500``: This applies errata 1951500 workaround to Cortex-A78
308   CPU. This needs to be enabled for revisions r1p0 and r1p1, r0p0 has the same
309   issue but there is no workaround for that revision.
310
311-  ``ERRATA_A78_1821534``: This applies errata 1821534 workaround to Cortex-A78
312   CPU. This needs to be enabled for revisions r0p0 and r1p0.
313
314-  ``ERRATA_A78_1952683``: This applies errata 1952683 workaround to Cortex-A78
315   CPU. This needs to be enabled for revision r0p0, it is fixed in r1p0.
316
317-  ``ERRATA_A78_2242635``: This applies errata 2242635 workaround to Cortex-A78
318   CPU. This needs to be enabled for revisions r1p0, r1p1, and r1p2. The issue
319   is present in r0p0 but there is no workaround. It is still open.
320
321-  ``ERRATA_A78_2376745``: This applies errata 2376745 workaround to Cortex-A78
322   CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1, and r1p2, and
323   it is still open.
324
325-  ``ERRATA_A78_2395406``: This applies errata 2395406 workaround to Cortex-A78
326   CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1, and r1p2, and
327   it is still open.
328
329- ``ERRATA_A78_2712571``: This applies erratum 2712571 workaround to Cortex-A78
330   CPU, this erratum affects system configurations that do not use an ARM
331   interconnect IP. This needs to be enabled for revisions r0p0, r1p0, r1p1
332   and r1p2 and it is still open.
333
334-  ``ERRATA_A78_2742426``: This applies erratum 2742426 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
338-  ``ERRATA_A78_2772019``: This applies errata 2772019 workaround to Cortex-A78
339   CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1, and r1p2, and
340   it is still open.
341
342-  ``ERRATA_A78_2779479``: This applies erratum 2779479 workaround to Cortex-A78
343   CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1 and r1p2 and
344   it is still open.
345
346For Cortex-A78AE, the following errata build flags are defined :
347
348- ``ERRATA_A78_AE_1941500`` : This applies errata 1941500 workaround to
349   Cortex-A78AE CPU. This needs to be enabled for revisions r0p0 and r0p1.
350   This erratum is still open.
351
352- ``ERRATA_A78_AE_1951502`` : This applies errata 1951502 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_2376748`` : This applies errata 2376748 workaround to
357  Cortex-A78AE CPU. This needs to be enabled for revisions r0p0, r0p1 and r0p2.
358  This erratum is still open.
359
360- ``ERRATA_A78_AE_2395408`` : This applies errata 2395408 workaround to
361  Cortex-A78AE CPU. This needs to be enabled for revisions r0p0 and r0p1. This
362  erratum is still open.
363
364- ``ERRATA_A78_AE_2712574`` : This applies erratum 2712574 workaround to
365  Cortex-A78AE CPU. This erratum affects system configurations that do not use
366  an ARM interconnect IP. This needs to be enabled for revisions r0p0, r0p1 and
367  r0p2. This erratum is still open.
368
369For Cortex-A78C, the following errata build flags are defined :
370
371- ``ERRATA_A78C_1827430`` : This applies errata 1827430 workaround to
372  Cortex-A78C CPU. This needs to be enabled for revision r0p0. The erratum is
373  fixed in r0p1.
374
375- ``ERRATA_A78C_1827440`` : This applies errata 1827440 workaround to
376  Cortex-A78C CPU. This needs to be enabled for revision r0p0. The erratum is
377  fixed in r0p1.
378
379- ``ERRATA_A78C_2242638`` : This applies errata 2242638 workaround to
380  Cortex-A78C CPU. This needs to be enabled for revisions r0p1, r0p2 and
381  it is still open.
382
383- ``ERRATA_A78C_2376749`` : This applies errata 2376749 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_2395411`` : This applies errata 2395411 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_2683027`` : This applies errata 2683027 workaround to
392  Cortex-A78C CPU. This needs to be enabled for revisions r0p1 and r0p2. This
393  erratum is still open.
394
395- ``ERRATA_A78C_2712575`` : This applies erratum 2712575 workaround to
396  Cortex-A78C CPU, this erratum affects system configurations that do not use
397  an ARM interconnect IP. This needs to be enabled for revisions r0p1 and r0p2
398  and is still open.
399
400- ``ERRATA_A78C_2743232`` : This applies erratum 2743232 workaround to
401  Cortex-A78C CPU. This needs to be enabled for revisions r0p1 and r0p2.
402  This erratum is still open.
403
404- ``ERRATA_A78C_2772121`` : This applies errata 2772121 workaround to
405  Cortex-A78C CPU. This needs to be enabled for revisions r0p0, r0p1 and r0p2.
406  This erratum is still open.
407
408- ``ERRATA_A78C_2779484`` : This applies errata 2779484 workaround to
409  Cortex-A78C CPU. This needs to be enabled for revisions r0p1 and r0p2.
410  This erratum is still open.
411
412For Cortex-X1 CPU, the following errata build flags are defined:
413
414- ``ERRATA_X1_1821534`` : This applies errata 1821534 workaround to Cortex-X1
415   CPU. This needs to be enabled only for revision <= r1p0 of the CPU.
416
417- ``ERRATA_X1_1688305`` : This applies errata 1688305 workaround to Cortex-X1
418   CPU. This needs to be enabled only for revision <= r1p0 of the CPU.
419
420- ``ERRATA_X1_1827429`` : This applies errata 1827429 workaround to Cortex-X1
421   CPU. This needs to be enabled only for revision <= r1p0 of the CPU.
422
423For Neoverse N1, the following errata build flags are defined :
424
425-  ``ERRATA_N1_1073348``: This applies errata 1073348 workaround to Neoverse-N1
426   CPU. This needs to be enabled only for revision r0p0 and r1p0 of the CPU.
427
428-  ``ERRATA_N1_1130799``: This applies errata 1130799 workaround to Neoverse-N1
429   CPU. This needs to be enabled only for revision <= r2p0 of the CPU.
430
431-  ``ERRATA_N1_1165347``: This applies errata 1165347 workaround to Neoverse-N1
432   CPU. This needs to be enabled only for revision <= r2p0 of the CPU.
433
434-  ``ERRATA_N1_1207823``: This applies errata 1207823 workaround to Neoverse-N1
435   CPU. This needs to be enabled only for revision <= r2p0 of the CPU.
436
437-  ``ERRATA_N1_1220197``: This applies errata 1220197 workaround to Neoverse-N1
438   CPU. This needs to be enabled only for revision <= r2p0 of the CPU.
439
440-  ``ERRATA_N1_1257314``: This applies errata 1257314 workaround to Neoverse-N1
441   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
442
443-  ``ERRATA_N1_1262606``: This applies errata 1262606 workaround to Neoverse-N1
444   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
445
446-  ``ERRATA_N1_1262888``: This applies errata 1262888 workaround to Neoverse-N1
447   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
448
449-  ``ERRATA_N1_1275112``: This applies errata 1275112 workaround to Neoverse-N1
450   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
451
452-  ``ERRATA_N1_1315703``: This applies errata 1315703 workaround to Neoverse-N1
453   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
454
455-  ``ERRATA_N1_1542419``: This applies errata 1542419 workaround to Neoverse-N1
456   CPU. This needs to be enabled only for revisions r3p0 - r4p0 of the CPU.
457
458-  ``ERRATA_N1_1868343``: This applies errata 1868343 workaround to Neoverse-N1
459   CPU. This needs to be enabled only for revision <= r4p0 of the CPU.
460
461-  ``ERRATA_N1_1946160``: This applies errata 1946160 workaround to Neoverse-N1
462   CPU. This needs to be enabled for revisions r3p0, r3p1, r4p0, and r4p1, for
463   revisions r0p0, r1p0, and r2p0 there is no workaround.
464
465-  ``ERRATA_N1_2743102``: This applies errata 2743102 workaround to Neoverse-N1
466   CPU. This needs to be enabled for all revisions <= r4p1 of the CPU and is
467   still open.
468
469For Neoverse V1, the following errata build flags are defined :
470
471-  ``ERRATA_V1_1618635``: This applies errata 1618635 workaround to Neoverse-V1
472   CPU. This needs to be enabled for revision r0p0 of the CPU, it is fixed in
473   r1p0.
474
475-  ``ERRATA_V1_1774420``: This applies errata 1774420 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_1791573``: This applies errata 1791573 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_1852267``: This applies errata 1852267 workaround to Neoverse-V1
484   CPU. This needs to be enabled only for revisions r0p0 and r1p0, it is fixed
485   in r1p1.
486
487-  ``ERRATA_V1_1925756``: This applies errata 1925756 workaround to Neoverse-V1
488   CPU. This needs to be enabled for r0p0, r1p0, and r1p1, it is still open.
489
490-  ``ERRATA_V1_1940577``: This applies errata 1940577 workaround to Neoverse-V1
491   CPU. This needs to be enabled only for revision r1p0 and r1p1 of the
492   CPU.
493
494-  ``ERRATA_V1_1966096``: This applies errata 1966096 workaround to Neoverse-V1
495   CPU. This needs to be enabled for revisions r1p0 and r1p1 of the CPU, the
496   issue is present in r0p0 as well but there is no workaround for that
497   revision.  It is still open.
498
499-  ``ERRATA_V1_2139242``: This applies errata 2139242 workaround to Neoverse-V1
500   CPU. This needs to be enabled for revisions r0p0, r1p0, and r1p1 of the
501   CPU.  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_2618597``: This applies errata 2618597 workaround to Neoverse-V2
540   CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed in
541   r0p2.
542
543-  ``ERRATA_V2_2662553``: This applies errata 2662553 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_2719103``: This applies errata 2719103 workaround to Neoverse-V2
548   CPU, this affects system configurations that do not use and ARM interconnect
549   IP. This needs to be enabled for revisions r0p0 and r0p1. It has been fixed
550   in r0p2.
551
552-  ``ERRATA_V2_2719105``: This applies errata 2719105 workaround to Neoverse-V2
553   CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed in
554   r0p2.
555
556-  ``ERRATA_V2_2743011``: This applies errata 2743011 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_2779510``: This applies errata 2779510 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_2801372``: This applies errata 2801372 workaround to Neoverse-V2
565   CPU, this affects all configurations. This needs to be enabled for revisions
566   r0p0 and r0p1. It has been fixed in r0p2.
567
568-  ``ERRATA_V2_3701771``: This applies errata 3701771 workaround to Neoverse-V2
569   CPU. This needs to be enabled for revisions r0p0, r0p1 and r0p2 and is
570   still open.
571
572-  ``ERRATA_V2_3841324``: This applies errata 3841324 workaround to Neoverse-V2
573   CPU. This needs to be enabled only for revisions r0p0 and r0p1 of
574   the CPU. It is fixed in r0p2.
575
576For Neoverse V3, the following errata build flags are defined :
577
578- ``ERRATA_V3_2970647``: This applies errata 2970647 workaround to Neoverse-V3
579  CPU. This needs to be enabled for revision r0p0. It is fixed in r0p1.
580
581- ``ERRATA_V3_3701767``: This applies errata 3701767 workaround to Neoverse-V3
582  CPU. This needs to be enabled for revisions r0p0, r0p1, r0p2 of the CPU and
583  is still open.
584
585For Cortex-A710, the following errata build flags are defined :
586
587-  ``ERRATA_A710_1901946``: This applies errata 1901946 workaround to
588   Cortex-A710 CPU. This needs to be enabled only for revision r1p0. It has
589   been fixed in r2p0.
590
591-  ``ERRATA_A710_1916945``: This applies errata 1916945 workaround to
592   Cortex-A710 CPU. This needs to be enabled only for revisions r0p0 and r1p0.
593   It has been fixed in r2p0.
594
595-  ``ERRATA_A710_1917258``: This applies errata 1917258 workaround to
596   Cortex-A710 CPU. This needs to be enabled only for revisions r0p0 and r1p0.
597   It has been fixed in r2p0.
598
599-  ``ERRATA_A710_1927200``: This applies errata 1927200 workaround to
600   Cortex-A710 CPU. This needs to be enabled only for revisions r0p0 and r1p0.
601   It has been fixed in r2p0.
602
603-  ``ERRATA_A710_1987031``: This applies errata 1987031 workaround to
604   Cortex-A710 CPU. This needs to be enabled only for revisions r0p0, r1p0 and
605   r2p0 of the CPU. It is still open.
606
607-  ``ERRATA_A710_2081180``: This applies errata 2081180 workaround to
608   Cortex-A710 CPU. This needs to be enabled only for revisions r0p0, r1p0 and
609   r2p0 of the CPU. It is still open.
610
611-  ``ERRATA_A710_2055002``: This applies errata 2055002 workaround to
612   Cortex-A710 CPU. This needs to be enabled for revisions r1p0, r2p0 of the CPU
613   and is still open.
614
615-  ``ERRATA_A710_2017096``: This applies errata 2017096 workaround to
616   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
617   of the CPU and is still open.
618
619-  ``ERRATA_A710_2083908``: This applies errata 2083908 workaround to
620   Cortex-A710 CPU. This needs to be enabled for revision r2p0 of the CPU and
621   is still open.
622
623-  ``ERRATA_A710_2267065``: This applies errata 2267065 workaround to
624   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
625   of the CPU and is fixed in r2p1.
626
627-  ``ERRATA_A710_2136059``: This applies errata 2136059 workaround to
628   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
629   of the CPU and is fixed in r2p1.
630
631-  ``ERRATA_A710_2147715``: This applies errata 2147715 workaround to
632   Cortex-A710 CPU. This needs to be enabled for revision r2p0 of the CPU
633   and is fixed in r2p1.
634
635-  ``ERRATA_A710_2216384``: This applies errata 2216384 workaround to
636   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
637   of the CPU and is fixed in r2p1.
638
639-  ``ERRATA_A710_2282622``: This applies errata 2282622 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_2291219``: This applies errata 2291219 workaround to
644   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
645   of the CPU and is fixed in r2p1.
646
647-  ``ERRATA_A710_2008768``: This applies errata 2008768 workaround to
648   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
649   of the CPU and is fixed in r2p1.
650
651-  ``ERRATA_A710_2371105``: This applies errata 2371105 workaround to
652   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
653   of the CPU and is fixed in r2p1.
654
655-  ``ERRATA_A710_2701952``: This applies erratum 2701952 workaround to Cortex-A710
656   CPU, and applies to system configurations that do not use and ARM
657   interconnect IP. This needs to be enabled for r0p0, r1p0, r2p0 and r2p1 and
658   is still open.
659
660-  ``ERRATA_A710_2742423``: This applies errata 2742423 workaround to
661   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and
662   r2p1 of the CPU and is still open.
663
664-  ``ERRATA_A710_2768515``: This applies errata 2768515 workaround to
665   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and
666   r2p1 of the CPU and is still open.
667
668-  ``ERRATA_A710_2778471``: This applies errata 2778471 workaround to Cortex-A710
669   CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and r2p1 of the
670   CPU and is still open.
671
672- ``ERRATA_A710_3701772``: This applies errata 3701772 workaround to Cortex-A710
673  CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0, r2p1 of the
674  CPU and is still open.
675
676For Neoverse N2, the following errata build flags are defined :
677
678-  ``ERRATA_N2_2002655``: This applies errata 2002655 workaround to Neoverse-N2
679   CPU. This needs to be enabled for revision r0p0 of the CPU and is fixed in r0p1.
680
681-  ``ERRATA_N2_2009478``: This applies errata 2009478 workaround to Neoverse-N2
682   CPU. This needs to be enabled for revision r0p0 of the CPU and is fixed in r0p1.
683
684-  ``ERRATA_N2_2067956``: This applies errata 2067956 workaround to Neoverse-N2
685   CPU. This needs to be enabled for revision r0p0 of the CPU and is fixed in r0p1.
686
687-  ``ERRATA_N2_2025414``: This applies errata 2025414 workaround to Neoverse-N2
688   CPU. This needs to be enabled for revision r0p0 of the CPU and is fixed in r0p1.
689
690-  ``ERRATA_N2_2189731``: This applies errata 2189731 workaround to Neoverse-N2
691   CPU. This needs to be enabled for revision r0p0 of the CPU and is fixed in r0p1.
692
693-  ``ERRATA_N2_2138956``: This applies errata 2138956 workaround to Neoverse-N2
694   CPU. This needs to be enabled for revision r0p0 of the CPU and is fixed in r0p1.
695
696-  ``ERRATA_N2_2242415``: This applies errata 2242415 workaround to Neoverse-N2
697   CPU. This needs to be enabled for revision r0p0 of the CPU and is fixed in r0p1.
698
699-  ``ERRATA_N2_2138958``: This applies errata 2138958 workaround to Neoverse-N2
700   CPU. This needs to be enabled for revision r0p0 of the CPU and is fixed in r0p1.
701
702-  ``ERRATA_N2_2242400``: This applies errata 2242400 workaround to Neoverse-N2
703   CPU. This needs to be enabled for revision r0p0 of the CPU and is fixed in r0p1.
704
705-  ``ERRATA_N2_2280757``: This applies errata 2280757 workaround to Neoverse-N2
706   CPU. This needs to be enabled for revision r0p0 of the CPU and is fixed in r0p1.
707
708-  ``ERRATA_N2_2326639``: This applies errata 2326639 workaround to Neoverse-N2
709   CPU. This needs to be enabled for revision r0p0 of the CPU, it is fixed in
710   r0p1.
711
712-  ``ERRATA_N2_2340933``: This applies errata 2340933 workaround to Neoverse-N2
713   CPU. This needs to be enabled for revision r0p0 of the CPU, it is fixed in
714   r0p1.
715
716-  ``ERRATA_N2_2346952``: This applies errata 2346952 workaround to Neoverse-N2
717   CPU. This needs to be enabled for revisions r0p0, r0p1 and r0p2 of the CPU,
718   it is fixed in r0p3.
719
720-  ``ERRATA_N2_2376738``: This applies errata 2376738 workaround to Neoverse-N2
721   CPU. This needs to be enabled for revision r0p0, r0p1, r0p2, r0p3 and is still open.
722
723-  ``ERRATA_N2_2388450``: This applies errata 2388450 workaround to Neoverse-N2
724   CPU. This needs to be enabled for revision r0p0 of the CPU, it is fixed in
725   r0p1.
726
727-  ``ERRATA_N2_2743014``: This applies errata 2743014 workaround to Neoverse-N2
728   CPU. This needs to be enabled for revisions r0p0, r0p1 and r0p2. It is fixed
729   in r0p3.
730
731-  ``ERRATA_N2_2743089``: This applies errata 2743089 workaround to Neoverse-N2
732   CPU. This needs to be enabled for revisions r0p0, r0p1 and r0p2. It is fixed
733   in r0p3.
734
735- ``ERRATA_N2_2728475``: This applies erratum 2728475 workaround to Neoverse-N2
736   CPU, this erratum affects system configurations that do not use and ARM
737   interconnect IP. This needs to be enabled for revisions r0p0, r0p1 and r0p2.
738   It is fixed in r0p3.
739
740-  ``ERRATA_N2_2779511``: This applies errata 2779511 workaround to Neoverse-N2
741   CPU. This needs to be enabled for revisions r0p0, r0p1 and r0p2. It is fixed
742   in r0p3.
743
744-  ``ERRATA_N2_3701773``: This applies errata 3701773 workaround to Neoverse-N2
745   CPU. This needs to be enabled for revisions r0p0, r0p1, r0p2, r0p3 and is
746   still open.
747
748For Neoverse N3, the following errata build flags are defined :
749
750-  ``ERRATA_N3_3699563``: This applies errata 3699563 workaround to Neoverse-N3
751   CPU. This needs to be enabled for revisions r0p0 and is still open.
752
753For Cortex-X2, the following errata build flags are defined :
754
755-  ``ERRATA_X2_1901946``: This applies errata 1901946 workaround to Cortex-X2
756   CPU. This needs to be enabled only for r1p0, it is fixed in r2p0.
757
758-  ``ERRATA_X2_1916945``: This applies errata 1916945 workaround to Cortex-X2
759   CPU. This needs to be enabled only for revisions r0p0 and r1p0 of the CPU, it
760   is fixed in r2p0.
761
762-  ``ERRATA_X2_1917258``: This applies errata 1917258 workaround to Cortex-X2
763   CPU. This needs to be enabled only for revisions r0p0 and r1p0 of the CPU, it
764   is fixed in r2p0.
765
766-  ``ERRATA_X2_1927200``: This applies errata 1927200 workaround to Cortex-X2
767   CPU. This needs to be enabled only for revisions r0p0 and r1p0 of the CPU, it
768   is fixed in r2p0.
769
770-  ``ERRATA_X2_1934260``: This applies errata 1934260 workaround to Cortex-X2
771   CPU. This needs to be enabled only for revision r1p0 of the CPU, it is fixed
772   in r2p0.
773
774-  ``ERRATA_X2_2002765``: This applies errata 2002765 workaround to Cortex-X2
775   CPU. This needs to be enabled only for revisions r0p0, r1p0 and r2p0 of the
776   CPU, it is fixed in r2p1.
777
778-  ``ERRATA_X2_2017096``: This applies errata 2017096 workaround to Cortex-X2
779   CPU. This needs to be enabled only for revisions r0p0, r1p0 and r2p0 of the
780   CPU, it is fixed in r2p1.
781
782-  ``ERRATA_X2_2081180``: This applies errata 2081180 workaround to Cortex-X2
783   CPU. This needs to be enabled only for revisions r0p0, r1p0 and r2p0 of the
784   CPU, it is fixed in r2p1.
785
786-  ``ERRATA_X2_2083908``: This applies errata 2083908 workaround to Cortex-X2
787   CPU. This needs to be enabled only for revision r2p0 of the CPU, it is fixed
788   in r2p1.
789
790-  ``ERRATA_X2_2136059``: This applies errata 2136059 workaround to Cortex-X2
791   CPU. This needs to be enabled only for revisions r0p0, r1p0 and r2p0 of the
792   CPU, it is fixed in r2p1.
793
794-  ``ERRATA_X2_2147715``: This applies errata 2147715 workaround to Cortex-X2
795   CPU. This needs to be enabled only for revision r2p0 of the CPU, it is fixed
796   in r2p1.
797
798-  ``ERRATA_X2_2216384``: This applies errata 2216384 workaround to Cortex-X2
799   CPU. This needs to be enabled only for revisions r0p0, r1p0 and r2p0 of the
800   CPU, it is fixed in r2p1.
801
802-  ``ERRATA_X2_2267065``: This applies errata 2267065 workaround to Cortex-X2
803   CPU. This needs to be enabled only for revisions r0p0, r1p0 and r2p0 of the
804   CPU, it is fixed in r2p1.
805
806-  ``ERRATA_X2_2282622``: This applies errata 2282622 workaround to Cortex-X2
807   CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and r2p1 of the
808   CPU and is still open.
809
810-  ``ERRATA_X2_2291219``: This applies errata 2291219 workaround to Cortex-X2
811   CPU. This needs to be enabled only for revisions r0p0, r1p0 and r2p0 of the
812   CPU, it is fixed in r2p1.
813
814-  ``ERRATA_X2_2371105``: This applies errata 2371105 workaround to Cortex-X2
815   CPU. This needs to be enabled only for revisions r0p0, r1p0 and r2p0 of the
816   CPU, it is fixed in r2p1.
817
818- ``ERRATA_X2_2701952``: This applies errata 2701952 workaround to Cortex-X2
819   CPU and affects system configurations that do not use an Arm interconnect IP.
820   This needs to be enabled for revisions r0p0, r1p0, r2p0 and r2p1 and is
821   still open.
822
823-  ``ERRATA_X2_2742423``: This applies errata 2742423 workaround to Cortex-X2
824   CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and r2p1 of the
825   CPU and is still open.
826
827-  ``ERRATA_X2_2768515``: This applies errata 2768515 workaround to Cortex-X2
828   CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and r2p1 of the
829   CPU and is still open.
830
831-  ``ERRATA_X2_2778471``: This applies errata 2778471 workaround to Cortex-X2
832   CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and r2p1 of the
833   CPU and is still open.
834
835-  ``ERRATA_X2_3701772``: This applies errata 3701772 workaround to Cortex-X2
836   CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and r2p1 of the
837   CPU and is still open.
838
839For Cortex-X3, the following errata build flags are defined :
840
841- ``ERRATA_X3_2266875``: This applies errata 2266875 workaround to the Cortex-X3
842  CPU. This needs to be enabled only for revisions r0p0 and r1p0 of the CPU, it
843  is fixed in r1p1.
844
845- ``ERRATA_X3_2302506``: This applies errata 2302506 workaround to the Cortex-X3
846  CPU. This needs to be enabled only for revisions r0p0, r1p0 and r1p1, it is
847  fixed in r1p2.
848
849- ``ERRATA_X3_2313909``: This applies errata 2313909 workaround to
850  Cortex-X3 CPU. This needs to be enabled only for revisions r0p0 and r1p0
851  of the CPU, it is fixed in r1p1.
852
853- ``ERRATA_X3_2372204``: This applies errata 2372204 workaround to
854  Cortex-X3 CPU. This needs to be enabled only for revisions r0p0 and r1p0
855  of the CPU, it is fixed in r1p1.
856
857- ``ERRATA_X3_2615812``: This applies errata 2615812 workaround to Cortex-X3
858  CPU. This needs to be enabled only for revisions r0p0, r1p0 and r1p1 of the
859  CPU, it is fixed in r1p2.
860
861- ``ERRATA_X3_2641945``: This applies errata 2641945 workaround to Cortex-X3
862  CPU. This needs to be enabled only for revisions r0p0 and r1p0 of the CPU.
863  It is fixed in r1p1.
864
865- ``ERRATA_X3_2701951``: This applies erratum 2701951 workaround to Cortex-X3
866  CPU and affects system configurations that do not use an ARM interconnect
867  IP. This needs to be applied to revisions r0p0, r1p0 and r1p1. It is fixed
868  in r1p2.
869
870- ``ERRATA_X3_2742421``: This applies errata 2742421 workaround to
871  Cortex-X3 CPU. This needs to be enabled only for revisions r0p0, r1p0 and
872  r1p1. It is fixed in r1p2.
873
874- ``ERRATA_X3_2743088``: This applies errata 2743088 workaround to Cortex-X3
875  CPU. This needs to be enabled only for revisions r0p0, r1p0 and r1p1. It is
876  fixed in r1p2.
877
878- ``ERRATA_X3_2779509``: This applies errata 2779509 workaround to Cortex-X3
879  CPU. This needs to be enabled only for revisions r0p0, r1p0 and r1p1 of the
880  CPU. It is fixed in r1p2.
881
882- ``ERRATA_X3_3213672``: This applies errata 3213672 workaround to Cortex-X3
883  CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1 and r1p2
884  of the CPU. It is still open.
885
886- ``ERRATA_X3_3692984``: This applies errata 3692984 workaround to Cortex-X3
887  CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1 and r1p2
888  of the CPU. It is still open.
889
890- ``ERRATA_X3_3701769``: This applies errata 3701769 workaround to Cortex-X3
891  CPU. This needs to be enabled only for revisions r0p0, r1p0, r1p1 and r1p2
892  of the CPU and it is still open.
893
894- ``ERRATA_X3_3827463``: This applies errata 3827463 workaround to Cortex-X3
895  CPU. This needs to be enabled only for revisions r0p0, r1p0 and r1p1 of
896  the CPU. It is fixed in r1p2.
897
898For Cortex-X4, the following errata build flags are defined :
899
900- ``ERRATA_X4_2701112``: This applies erratum 2701112 workaround to Cortex-X4
901  CPU and affects system configurations that do not use an Arm interconnect IP.
902  This needs to be enabled for revisions r0p0 and is fixed in r0p1.
903  The workaround for this erratum is not implemented in EL3, but the flag can
904  be enabled/disabled at the platform level. The flag is used when the errata ABI
905  feature is enabled and can assist the Kernel in the process of
906  mitigation of the erratum.
907
908- ``ERRATA_X4_2726228``: This applies erratum 2726228 workaround to Cortex-X4
909  CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed in
910  r0p2.
911
912-  ``ERRATA_X4_2740089``: This applies errata 2740089 workaround to Cortex-X4
913   CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed
914   in r0p2.
915
916- ``ERRATA_X4_2763018``: This applies errata 2763018 workaround to Cortex-X4
917  CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed in r0p2.
918
919- ``ERRATA_X4_2816013``: This applies errata 2816013 workaround to Cortex-X4
920  CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed in r0p2.
921
922- ``ERRATA_X4_2897503``: This applies errata 2897503 workaround to Cortex-X4
923  CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed in r0p2.
924
925- ``ERRATA_X4_2923985``: This applies errata 2923985 workaround to Cortex-X4
926  CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed in r0p2.
927
928- ``ERRATA_X4_2957258``: This applies errata 2957258 workaround to Cortex-X4
929  CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed in r0p2.
930
931- ``ERRATA_X4_3076789``: This applies errata 3076789 workaround to Cortex-X4
932  CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed in r0p2.
933
934- ``ERRATA_X4_3133195``: This applies errata 3133195 workaround to Cortex-X4
935  CPU. This needs to be enabled for revision r0p2. It is fixed in r0p3.
936
937- ``ERRATA_X4_3701758``: This applies errata 3701758 workaround to Cortex-X4
938  CPU. This needs to be enabled for revisions r0p0, r0p1, r0p2 and r0p3.
939  It is still open.
940
941- ``ERRATA_X4_3887999``: This applies errata 3887999 workaround to Cortex-X4
942  CPU. This needs to be enabled for revision r0p0, r0p1, r0p2 and r0p3.
943  It is still open.
944
945For Cortex-X925, the following errata build flags are defined :
946
947- ``ERRATA_X925_2963999``: This applies errata 2963999 workaround to Cortex-X925
948  CPU. This needs to be enabled for revision r0p0. It is fixed in r0p1.
949
950- ``ERRATA_X925_3701747``: This applies errata 3701747 workaround to Cortex-X925
951  CPU. This needs to be enabled for revisions r0p0 and r0p1. It is still open.
952
953For Cortex-A510, the following errata build flags are defined :
954
955-  ``ERRATA_A510_2008766``: This applies errata 2008766 workaround to
956   Cortex-A510 CPU. This needs to be enabled for revisions r0p0, r0p1, r0p2,
957   r0p3, r1p0, r1p1, r1p2 and r1p3. It is still open.
958
959-  ``ERRATA_A510_2288014``: This applies errata 2288014 workaround to
960   Cortex-A510 CPU. This needs to be enabled only for revisions r0p0, r0p1,
961   r0p2, r0p3 and r1p0, it is fixed in r1p1.
962
963-  ``ERRATA_A510_2042739``: This applies errata 2042739 workaround to
964   Cortex-A510 CPU. This needs to be enabled only for revisions r0p0, r0p1 and
965   r0p2, it is fixed in r0p3.
966
967-  ``ERRATA_A510_2041909``: This applies errata 2041909 workaround to
968   Cortex-A510 CPU. This needs to be enabled only for revision r0p2 and is fixed
969   in r0p3. The issue is also present in r0p0 and r0p1 but there is no
970   workaround for those revisions.
971
972-  ``ERRATA_A510_2080326``: This applies errata 2080326 workaround to
973   Cortex-A510 CPU. This needs to be enabled only for revision r0p2 and is
974   fixed in r0p3. This issue is also present in r0p0 and r0p1 but there is no
975   workaround for those revisions.
976
977-  ``ERRATA_A510_2169012``: This applies errata 2169012 workaround to
978   Cortex-A510 CPU. This needs to be enabled only for revisions r0p0, r0p1,
979   r0p2, r0p3 and r1p0, it is fixed in r1p1.
980
981-  ``ERRATA_A510_2218134``: This applies errata 2218134 workaround to
982   Cortex-A510 CPU. This needs to be enabled only for revision r1p0 and is fixed
983   in r1p1.
984
985-  ``ERRATA_A510_2250311``: This applies errata 2250311 workaround to
986   Cortex-A510 CPU. This needs to be enabled for revisions r0p0, r0p1, r0p2,
987   r0p3 and r1p0, it is fixed in r1p1. This workaround disables MPMM even if
988   ENABLE_MPMM=1.
989
990-  ``ERRATA_A510_2218950``: This applies errata 2218950 workaround to
991   Cortex-A510 CPU. This needs to be enabled for revisions r0p0, r0p1, r0p2,
992   r0p3 and r1p0, it is fixed in r1p1.
993
994-  ``ERRATA_A510_2172148``: This applies errata 2172148 workaround to
995   Cortex-A510 CPU. This needs to be enabled for revisions r0p0, r0p1, r0p2,
996   r0p3 and r1p0, it is fixed in r1p1.
997
998-  ``ERRATA_A510_2347730``: This applies errata 2347730 workaround to
999   Cortex-A510 CPU. This needs to be enabled for revisions r0p0, r0p1, r0p2,
1000   r0p3, r1p0 and r1p1. It is fixed in r1p2.
1001
1002-  ``ERRATA_A510_2371937``: This applies errata 2371937 workaround to
1003   Cortex-A510 CPU. This needs to applied for revisions r0p0, r0p1, r0p2,
1004   r0p3, r1p0, r1p1, and is fixed in r1p2.
1005
1006-  ``ERRATA_A510_2420992``: This applies errata 2420992 workaround to
1007   Cortex-A510 CPU. This needs to applied for revisions r1p0 and r1p1, and is
1008   fixed in r1p2.
1009
1010-  ``ERRATA_A510_2666669``: This applies errata 2666669 workaround to
1011   Cortex-A510 CPU. This needs to applied for revisions r0p0, r0p1, r0p2,
1012   r0p3, r1p0, r1p1. It is fixed in r1p2.
1013
1014-  ``ERRATA_A510_2684597``: This applies erratum 2684597 workaround to
1015   Cortex-A510 CPU. This needs to be applied to revision r0p0, r0p1, r0p2,
1016   r0p3, r1p0, r1p1 and r1p2. It is fixed in r1p3.
1017
1018-  ``ERRATA_A510_2971420``: This applies erratum 2971420 workaround to
1019   Cortex-A510 CPU. This needs to be applied to revisions r0p1, r0p2, r0p3,
1020   r1p0, r1p1, r1p2 and r1p3 and is still open.
1021
1022-  ``ERRATA_A510_3672349``: This applies erratum 3672349 workaround to
1023   Cortex-A510 CPU. This needs to be applied to revisions r0p1, r0p2, r0p3,
1024   r1p0, r1p1, r1p2 and r1p3 and is still open.
1025
1026-  ``ERRATA_A510_3704847``: This applies erratum 3704847 workaround to
1027   Cortex-A510 CPU. This needs to be applied to revisions r0p1, r0p2, r0p3,
1028   r1p0, r1p1, r1p2 and r1p3 and is still open.
1029
1030For Cortex-A520, the following errata build flags are defined :
1031
1032-  ``ERRATA_A520_2630792``: This applies errata 2630792 workaround to
1033   Cortex-A520 CPU. This needs to applied for revisions r0p0, r0p1 of the
1034   CPU and is still open.
1035
1036-  ``ERRATA_A520_2858100``: This applies errata 2858100 workaround to
1037   Cortex-A520 CPU. This needs to be enabled for revisions r0p0 and r0p1.
1038   It is still open.
1039
1040-  ``ERRATA_A520_2938996``: This applies errata 2938996 workaround to
1041   Cortex-A520 CPU. This needs to be enabled for revisions r0p0 and r0p1.
1042   It is fixed in r0p2.
1043
1044For Cortex-A715, the following errata build flags are defined :
1045
1046-  ``ERRATA_A715_2331818``: This applies errata 2331818 workaround to
1047   Cortex-A715 CPU. This needs to be enabled for revisions r0p0 and r1p0.
1048   It is fixed in r1p1.
1049
1050- ``ERRATA_A715_2344187``: This applies errata 2344187 workaround to
1051   Cortex-A715 CPU. This needs to be enabled for revisions r0p0 and r1p0. It is
1052   fixed in r1p1.
1053
1054-  ``ERRATA_A715_2376701``: This applies errata 2376701 workaround to
1055   Cortex-A715 CPU. This needs to be enabled for revisions r0p0 and r1p0. It is
1056   fixed in r1p1.
1057
1058-  ``ERRATA_A715_2409570``: This applies errata 2409570 workaround to
1059   Cortex-A715 CPU. This needs to be enabled only for revision r1p0.
1060   It is fixed in r1p1. This errata also applies to r0p0 but that revision has a
1061   different workaround, and since r0p0 is not used in production hardware it is
1062   not implemented.
1063
1064-  ``ERRATA_A715_2413290``: This applies errata 2413290 workaround to
1065   Cortex-A715 CPU. This needs to be enabled only for revision r1p0 and
1066   when SPE(Statistical profiling extension)=True. The errata is fixed
1067   in r1p1.
1068
1069-  ``ERRATA_A715_2420947``: This applies errata 2420947 workaround to
1070   Cortex-A715 CPU. This needs to be enabled only for revision r1p0.
1071   It is fixed in r1p1.
1072
1073-  ``ERRATA_A715_2429384``: This applies errata 2429384 workaround to
1074   Cortex-A715 CPU. This needs to be enabled for revision r1p0. There is no
1075   workaround for revision r0p0. It is fixed in r1p1.
1076
1077-  ``ERRATA_A715_2561034``: This applies errata 2561034 workaround to
1078   Cortex-A715 CPU. This needs to be enabled only for revision r1p0.
1079   It is fixed in r1p1.
1080
1081-  ``ERRATA_A715_2728106``: This applies errata 2728106 workaround to
1082   Cortex-A715 CPU. This needs to be enabled for revisions r0p0, r1p0
1083   and r1p1. It is fixed in r1p2.
1084
1085-  ``ERRATA_A715_2804830``: This applies errata 2804830 workaround to
1086   Cortex-A715 CPU. This needs to be enabled for revisions r0p0, r1p0,
1087   r1p1 and r1p2. It is fixed in r1p3.
1088
1089-  ``ERRATA_A715_3699560``: This applies errata 3699560 workaround to
1090   Cortex-A715 CPU. This needs to be enabled for revisions r0p0, r1p0,
1091   r1p2 and r1p3. It is still open.
1092
1093-  ``ERRATA_A715_3711916``: This applies errata 3711916 workaround to
1094   Cortex-A715 CPU. This needs to be enabled for revisions r0p0, r1p0,
1095   r1p1, r1p2 and r1p3. It is still open.
1096
1097For Cortex-A720, the following errata build flags are defined :
1098
1099-  ``ERRATA_A720_2729604``: This applies errata 2729604 workaround to
1100   Cortex-A720 CPU. This needs to be enabled for revisions r0p0 and r0p1.
1101   It is fixed in r0p2.
1102
1103-  ``ERRATA_A720_2792132``: This applies errata 2792132 workaround to
1104   Cortex-A720 CPU. This needs to be enabled for revisions r0p0 and r0p1.
1105   It is fixed in r0p2.
1106
1107-  ``ERRATA_A720_2844092``: This applies errata 2844092 workaround to
1108   Cortex-A720 CPU. This needs to be enabled for revisions r0p0 and r0p1.
1109   It is fixed in r0p2.
1110
1111-  ``ERRATA_A720_2926083``: This applies errata 2926083 workaround to
1112   Cortex-A720 CPU. This needs to be enabled for revisions r0p0 and r0p1.
1113   It is fixed in r0p2.
1114
1115-  ``ERRATA_A720_2940794``: This applies errata 2940794 workaround to
1116   Cortex-A720 CPU. This needs to be enabled for revisions r0p0 and r0p1.
1117   It is fixed in r0p2.
1118
1119-  ``ERRATA_A720_3699561``: This applies errata 3699561 workaround to
1120   Cortex-A720 CPU. This needs to be enabled for revisions r0p0, r0p1
1121   and r0p2. It is still open.
1122
1123-  ``ERRATA_A720_3711910``: This applies errata 3711910 workaround to
1124   Cortex-A720 CPU. This needs to be enabled for revisions r0p0, r0p1
1125   and r0p2. It is still open.
1126
1127For Cortex-A720_AE, the following errata build flags are defined :
1128
1129-  ``ERRATA_A720_AE_3699562``: This applies errata 3699562 workaround
1130   to Cortex-A720_AE CPU. This needs to be enabled for revisions r0p0.
1131   It is still open.
1132
1133For Cortex-A725, the following errata build flags are defined :
1134
1135-  ``ERRATA_A725_3699564``: This applies errata 3699564 workaround to
1136   Cortex-A725 CPU. This needs to be enabled for revisions r0p0 and r0p1.
1137   It is fixed in r0p2.
1138
1139DSU Errata Workarounds
1140----------------------
1141
1142Similar to CPU errata, TF-A also implements workarounds for DSU (DynamIQ
1143Shared Unit) errata. The DSU errata details can be found in the respective Arm
1144documentation:
1145
1146- `Arm DSU Software Developers Errata Notice`_.
1147
1148Each erratum is identified by an ``ID``, as defined in the DSU errata notice
1149document. Thus, the build flags which enable/disable the errata workarounds
1150have the format ``ERRATA_DSU_<ID>``. The implementation and application logic
1151of DSU errata workarounds are similar to `CPU errata workarounds`_.
1152
1153For DSU errata, the following build flags are defined:
1154
1155-  ``ERRATA_DSU_798953``: This applies errata 798953 workaround for the
1156   affected DSU configurations. This errata applies only for those DSUs that
1157   revision is r0p0 (on r0p1 it is fixed). However, please note that this
1158   workaround results in increased DSU power consumption on idle.
1159
1160-  ``ERRATA_DSU_936184``: This applies errata 936184 workaround for the
1161   affected DSU configurations. This errata applies only for those DSUs that
1162   contain the ACP interface **and** the DSU revision is older than r2p0 (on
1163   r2p0 it is fixed). However, please note that this workaround results in
1164   increased DSU power consumption on idle.
1165
1166-  ``ERRATA_DSU_2313941``: This applies errata 2313941 workaround for the
1167   affected DSU configurations. This errata applies for those DSUs with
1168   revisions r0p0, r1p0, r2p0, r2p1, r3p0, r3p1 and is still open. However,
1169   please note that this workaround results in increased DSU power consumption
1170   on idle.
1171
1172-  ``ERRATA_DSU_2900952``: This applies errata 2900952 workaround for the
1173   affected DSU-120 configurations. This erratum applies to some r2p0
1174   implementations and is fixed in r2p1. The affected r2p0 implementations
1175   are determined by reading the IMP_CLUSTERREVIDR_EL1[1] register bit
1176   and making sure it's clear.
1177
1178CPU Specific optimizations
1179--------------------------
1180
1181This section describes some of the optimizations allowed by the CPU micro
1182architecture that can be enabled by the platform as desired.
1183
1184-  ``SKIP_A57_L1_FLUSH_PWR_DWN``: This flag enables an optimization in the
1185   Cortex-A57 cluster power down sequence by not flushing the Level 1 data
1186   cache. The L1 data cache and the L2 unified cache are inclusive. A flush
1187   of the L2 by set/way flushes any dirty lines from the L1 as well. This
1188   is a known safe deviation from the Cortex-A57 TRM defined power down
1189   sequence. Each Cortex-A57 based platform must make its own decision on
1190   whether to use the optimization.
1191
1192-  ``A53_DISABLE_NON_TEMPORAL_HINT``: This flag disables the cache non-temporal
1193   hint. The LDNP/STNP instructions as implemented on Cortex-A53 do not behave
1194   in a way most programmers expect, and will most probably result in a
1195   significant speed degradation to any code that employs them. The Armv8-A
1196   architecture (see Arm DDI 0487A.h, section D3.4.3) allows cores to ignore
1197   the non-temporal hint and treat LDNP/STNP as LDP/STP instead. Enabling this
1198   flag enforces this behaviour. This needs to be enabled only for revisions
1199   <= r0p3 of the CPU and is enabled by default.
1200
1201-  ``A57_DISABLE_NON_TEMPORAL_HINT``: This flag has the same behaviour as
1202   ``A53_DISABLE_NON_TEMPORAL_HINT`` but for Cortex-A57. This needs to be
1203   enabled only for revisions <= r1p2 of the CPU and is enabled by default,
1204   as recommended in section "4.7 Non-Temporal Loads/Stores" of the
1205   `Cortex-A57 Software Optimization Guide`_.
1206
1207- ''A57_ENABLE_NON_CACHEABLE_LOAD_FWD'': This flag enables non-cacheable
1208   streaming enhancement feature for Cortex-A57 CPUs. Platforms can set
1209   this bit only if their memory system meets the requirement that cache
1210   line fill requests from the Cortex-A57 processor are atomic. Each
1211   Cortex-A57 based platform must make its own decision on whether to use
1212   the optimization. This flag is disabled by default.
1213
1214-  ``NEOVERSE_Nx_EXTERNAL_LLC``: This flag indicates that an external last
1215   level cache(LLC) is present in the system, and that the DataSource field
1216   on the master CHI interface indicates when data is returned from the LLC.
1217   This is used to control how the LL_CACHE* PMU events count.
1218   Default value is 0 (Disabled).
1219
1220-  ``NEOVERSE_N2_PREFETCHER_DISABLE``: This flag disables the region prefetcher
1221   on the Neoverse N2 core. This is used during performance analysis to get clean
1222   and repeatable measurements of the cache by preventing speculative data fetches
1223   from interfering with benchmark results.
1224   Default value is 0 (Disabled).
1225
1226GIC Errata Workarounds
1227----------------------
1228-  ``GIC600_ERRATA_WA_2384374``: This flag applies part 2 of errata 2384374
1229   workaround for the affected GIC600 and GIC600-AE implementations. It applies
1230   to implementations of GIC600 and GIC600-AE with revisions less than or equal
1231   to r1p6 and r0p2 respectively. If the platform sets GICV3_SUPPORT_GIC600,
1232   then this flag is enabled; otherwise, it is 0 (Disabled).
1233
1234--------------
1235
1236*Copyright (c) 2014-2025, Arm Limited and Contributors. All rights reserved.*
1237
1238.. _CVE-2017-5715: http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-5715
1239.. _CVE-2018-3639: http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-3639
1240.. _CVE-2022-23960: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-23960
1241.. _Cortex-A72 MPCore Software Developers Errata Notice: https://developer.arm.com/documentation/epm012079/latest
1242.. _Cortex-A57 Software Optimization Guide: https://developer.arm.com/documentation/uan0015
1243.. _Arm DSU Software Developers Errata Notice: https://developer.arm.com/documentation/SDEN854652
1244