xref: /rk3399_ARM-atf/docs/design/cpu-specific-build-macros.rst (revision d428b422d3365c48e1c9eac0ae45ca1b9ffe5207)
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-A72, the following errata build flags are defined :
206
207-  ``ERRATA_A72_859971``: This applies errata 859971 workaround to Cortex-A72
208   CPU. This needs to be enabled only for revision <= r0p3 of the CPU.
209
210-  ``ERRATA_A72_1319367``: This applies errata 1319367 workaround to all
211   revisions of Cortex-A72 CPU.
212
213For Cortex-A73, the following errata build flags are defined :
214
215-  ``ERRATA_A73_852427``: This applies errata 852427 workaround to Cortex-A73
216   CPU. This needs to be enabled only for revision r0p0 of the CPU.
217
218-  ``ERRATA_A73_855423``: This applies errata 855423 workaround to Cortex-A73
219   CPU. This needs to be enabled only for revision <= r0p1 of the CPU.
220
221For Cortex-A75, the following errata build flags are defined :
222
223-  ``ERRATA_A75_764081``: This applies errata 764081 workaround to Cortex-A75
224   CPU. This needs to be enabled only for revision r0p0 of the CPU.
225
226-  ``ERRATA_A75_790748``: This applies errata 790748 workaround to Cortex-A75
227    CPU. This needs to be enabled only for revision r0p0 of the CPU.
228
229For Cortex-A76, the following errata build flags are defined :
230
231-  ``ERRATA_A76_1073348``: This applies errata 1073348 workaround to Cortex-A76
232   CPU. This needs to be enabled only for revision <= r1p0 of the CPU.
233
234-  ``ERRATA_A76_1130799``: This applies errata 1130799 workaround to Cortex-A76
235   CPU. This needs to be enabled only for revision <= r2p0 of the CPU.
236
237-  ``ERRATA_A76_1220197``: This applies errata 1220197 workaround to Cortex-A76
238   CPU. This needs to be enabled only for revision <= r2p0 of the CPU.
239
240-  ``ERRATA_A76_1257314``: This applies errata 1257314 workaround to Cortex-A76
241   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
242
243-  ``ERRATA_A76_1262606``: This applies errata 1262606 workaround to Cortex-A76
244   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
245
246-  ``ERRATA_A76_1262888``: This applies errata 1262888 workaround to Cortex-A76
247   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
248
249-  ``ERRATA_A76_1275112``: This applies errata 1275112 workaround to Cortex-A76
250   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
251
252-  ``ERRATA_A76_1791580``: This applies errata 1791580 workaround to Cortex-A76
253   CPU. This needs to be enabled only for revision <= r4p0 of the CPU.
254
255-  ``ERRATA_A76_1165522``: This applies errata 1165522 workaround to all
256   revisions of Cortex-A76 CPU. This errata is fixed in r3p0 but due to
257   limitation of errata framework this errata is applied to all revisions
258   of Cortex-A76 CPU.
259
260-  ``ERRATA_A76_1868343``: This applies errata 1868343 workaround to Cortex-A76
261   CPU. This needs to be enabled only for revision <= r4p0 of the CPU.
262
263-  ``ERRATA_A76_1946160``: This applies errata 1946160 workaround to Cortex-A76
264   CPU. This needs to be enabled only for revisions r3p0 - r4p1 of the CPU.
265
266-  ``ERRATA_A76_2743102``: This applies errata 2743102 workaround to Cortex-A76
267   CPU. This needs to be enabled for all revisions <= r4p1 of the CPU and is
268   still open.
269
270For Cortex-A76AE, the following errata build flags are defined :
271
272-  ``ERRATA_A76AE_1931427``: This applies errata 1931427 workaround to Cortex-A76AE
273   CPU. This needs to be enabled for revision r0p0 and r1p0 of the CPU and it is
274   fixed in r1p1.
275
276-  ``ERRATA_A76AE_1931435``: This applies errata 1931435 workaround to Cortex-A76AE
277   CPU. This needs to be enabled for revision r0p0 and r1p0 of the CPU and it is
278   fixed in r1p1.
279
280-  ``ERRATA_A76AE_1969401``: This applies errata 1969401 workaround to Cortex-A76AE
281   CPU. This needs to be enabled for revision r0p0 and r1p0 of the CPU and it is
282   fixed in r1p1.
283
284For Cortex-A77, the following errata build flags are defined :
285
286-  ``ERRATA_A77_1508412``: This applies errata 1508412 workaround to Cortex-A77
287   CPU. This needs to be enabled only for revision <= r1p0 of the CPU.
288
289-  ``ERRATA_A77_1925769``: This applies errata 1925769 workaround to Cortex-A77
290   CPU. This needs to be enabled only for revision <= r1p1 of the CPU.
291
292-  ``ERRATA_A77_1946167``: This applies errata 1946167 workaround to Cortex-A77
293   CPU. This needs to be enabled only for revision <= r1p1 of the CPU.
294
295-  ``ERRATA_A77_1791578``: This applies errata 1791578 workaround to Cortex-A77
296   CPU. This needs to be enabled for r0p0, r1p0, and r1p1, it is still open.
297
298-  ``ERRATA_A77_2356587``: This applies errata 2356587 workaround to Cortex-A77
299   CPU. This needs to be enabled for r0p0, r1p0, and r1p1, it is still open.
300
301 -  ``ERRATA_A77_1800714``: This applies errata 1800714 workaround to Cortex-A77
302    CPU. This needs to be enabled for revisions <= r1p1 of the CPU.
303
304 -  ``ERRATA_A77_2743100``: This applies errata 2743100 workaround to Cortex-A77
305    CPU. This needs to be enabled for r0p0, r1p0, and r1p1, it is still open.
306
307For Cortex-A78, the following errata build flags are defined :
308
309-  ``ERRATA_A78_1688305``: This applies errata 1688305 workaround to Cortex-A78
310   CPU. This needs to be enabled only for revision r0p0 - r1p0 of the CPU.
311
312-  ``ERRATA_A78_1941498``: This applies errata 1941498 workaround to Cortex-A78
313   CPU. This needs to be enabled for revisions r0p0, r1p0, and r1p1 of the CPU.
314
315-  ``ERRATA_A78_1951500``: This applies errata 1951500 workaround to Cortex-A78
316   CPU. This needs to be enabled for revisions r1p0 and r1p1, r0p0 has the same
317   issue but there is no workaround for that revision.
318
319-  ``ERRATA_A78_1821534``: This applies errata 1821534 workaround to Cortex-A78
320   CPU. This needs to be enabled for revisions r0p0 and r1p0.
321
322-  ``ERRATA_A78_1952683``: This applies errata 1952683 workaround to Cortex-A78
323   CPU. This needs to be enabled for revision r0p0, it is fixed in r1p0.
324
325-  ``ERRATA_A78_2242635``: This applies errata 2242635 workaround to Cortex-A78
326   CPU. This needs to be enabled for revisions r1p0, r1p1, and r1p2. The issue
327   is present in r0p0 but there is no workaround. It is still open.
328
329-  ``ERRATA_A78_2376745``: This applies errata 2376745 workaround to Cortex-A78
330   CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1, and r1p2, and
331   it is still open.
332
333-  ``ERRATA_A78_2395406``: This applies errata 2395406 workaround to Cortex-A78
334   CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1, and r1p2, and
335   it is still open.
336
337- ``ERRATA_A78_2712571``: This applies erratum 2712571 workaround to Cortex-A78
338   CPU, this erratum affects system configurations that do not use an ARM
339   interconnect IP. This needs to be enabled for revisions r0p0, r1p0, r1p1
340   and r1p2 and it is still open.
341
342-  ``ERRATA_A78_2742426``: This applies erratum 2742426 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
346-  ``ERRATA_A78_2772019``: This applies errata 2772019 workaround to Cortex-A78
347   CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1, and r1p2, and
348   it is still open.
349
350-  ``ERRATA_A78_2779479``: This applies erratum 2779479 workaround to Cortex-A78
351   CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1 and r1p2 and
352   it is still open.
353
354For Cortex-A78AE, the following errata build flags are defined :
355
356- ``ERRATA_A78_AE_1941500`` : This applies errata 1941500 workaround to
357   Cortex-A78AE CPU. This needs to be enabled for revisions r0p0 and r0p1.
358   This erratum is still open.
359
360- ``ERRATA_A78_AE_1951502`` : This applies errata 1951502 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_2376748`` : This applies errata 2376748 workaround to
365  Cortex-A78AE CPU. This needs to be enabled for revisions r0p0, r0p1 and r0p2.
366  This erratum is still open.
367
368- ``ERRATA_A78_AE_2395408`` : This applies errata 2395408 workaround to
369  Cortex-A78AE CPU. This needs to be enabled for revisions r0p0 and r0p1. This
370  erratum is still open.
371
372- ``ERRATA_A78_AE_2712574`` : This applies erratum 2712574 workaround to
373  Cortex-A78AE CPU. This erratum affects system configurations that do not use
374  an ARM interconnect IP. This needs to be enabled for revisions r0p0, r0p1 and
375  r0p2. This erratum is still open.
376
377For Cortex-A78C, the following errata build flags are defined :
378
379- ``ERRATA_A78C_1827430`` : This applies errata 1827430 workaround to
380  Cortex-A78C CPU. This needs to be enabled for revision r0p0. The erratum is
381  fixed in r0p1.
382
383- ``ERRATA_A78C_1827440`` : This applies errata 1827440 workaround to
384  Cortex-A78C CPU. This needs to be enabled for revision r0p0. The erratum is
385  fixed in r0p1.
386
387- ``ERRATA_A78C_2242638`` : This applies errata 2242638 workaround to
388  Cortex-A78C CPU. This needs to be enabled for revisions r0p1, r0p2 and
389  it is still open.
390
391- ``ERRATA_A78C_2376749`` : This applies errata 2376749 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_2395411`` : This applies errata 2395411 workaround to
396  Cortex-A78C CPU. This needs to be enabled for revisions r0p1 and r0p2. This
397  erratum is still open.
398
399- ``ERRATA_A78C_2683027`` : This applies errata 2683027 workaround to
400  Cortex-A78C CPU. This needs to be enabled for revisions r0p1 and r0p2. This
401  erratum is still open.
402
403- ``ERRATA_A78C_2712575`` : This applies erratum 2712575 workaround to
404  Cortex-A78C CPU, this erratum affects system configurations that do not use
405  an ARM interconnect IP. This needs to be enabled for revisions r0p1 and r0p2
406  and is still open.
407
408- ``ERRATA_A78C_2743232`` : This applies erratum 2743232 workaround to
409  Cortex-A78C CPU. This needs to be enabled for revisions r0p1 and r0p2.
410  This erratum is still open.
411
412- ``ERRATA_A78C_2772121`` : This applies errata 2772121 workaround to
413  Cortex-A78C CPU. This needs to be enabled for revisions r0p0, r0p1 and r0p2.
414  This erratum is still open.
415
416- ``ERRATA_A78C_2779484`` : This applies errata 2779484 workaround to
417  Cortex-A78C CPU. This needs to be enabled for revisions r0p1 and r0p2.
418  This erratum is still open.
419
420For Cortex-X1 CPU, the following errata build flags are defined:
421
422- ``ERRATA_X1_1821534`` : This applies errata 1821534 workaround to Cortex-X1
423   CPU. This needs to be enabled only for revision <= r1p0 of the CPU.
424
425- ``ERRATA_X1_1688305`` : This applies errata 1688305 workaround to Cortex-X1
426   CPU. This needs to be enabled only for revision <= r1p0 of the CPU.
427
428- ``ERRATA_X1_1827429`` : This applies errata 1827429 workaround to Cortex-X1
429   CPU. This needs to be enabled only for revision <= r1p0 of the CPU.
430
431For Neoverse N1, the following errata build flags are defined :
432
433-  ``ERRATA_N1_1073348``: This applies errata 1073348 workaround to Neoverse-N1
434   CPU. This needs to be enabled only for revision r0p0 and r1p0 of the CPU.
435
436-  ``ERRATA_N1_1130799``: This applies errata 1130799 workaround to Neoverse-N1
437   CPU. This needs to be enabled only for revision <= r2p0 of the CPU.
438
439-  ``ERRATA_N1_1165347``: This applies errata 1165347 workaround to Neoverse-N1
440   CPU. This needs to be enabled only for revision <= r2p0 of the CPU.
441
442-  ``ERRATA_N1_1207823``: This applies errata 1207823 workaround to Neoverse-N1
443   CPU. This needs to be enabled only for revision <= r2p0 of the CPU.
444
445-  ``ERRATA_N1_1220197``: This applies errata 1220197 workaround to Neoverse-N1
446   CPU. This needs to be enabled only for revision <= r2p0 of the CPU.
447
448-  ``ERRATA_N1_1257314``: This applies errata 1257314 workaround to Neoverse-N1
449   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
450
451-  ``ERRATA_N1_1262606``: This applies errata 1262606 workaround to Neoverse-N1
452   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
453
454-  ``ERRATA_N1_1262888``: This applies errata 1262888 workaround to Neoverse-N1
455   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
456
457-  ``ERRATA_N1_1275112``: This applies errata 1275112 workaround to Neoverse-N1
458   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
459
460-  ``ERRATA_N1_1315703``: This applies errata 1315703 workaround to Neoverse-N1
461   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
462
463-  ``ERRATA_N1_1542419``: This applies errata 1542419 workaround to Neoverse-N1
464   CPU. This needs to be enabled only for revisions r3p0 - r4p0 of the CPU.
465
466-  ``ERRATA_N1_1868343``: This applies errata 1868343 workaround to Neoverse-N1
467   CPU. This needs to be enabled only for revision <= r4p0 of the CPU.
468
469-  ``ERRATA_N1_1946160``: This applies errata 1946160 workaround to Neoverse-N1
470   CPU. This needs to be enabled for revisions r3p0, r3p1, r4p0, and r4p1, for
471   revisions r0p0, r1p0, and r2p0 there is no workaround.
472
473-  ``ERRATA_N1_2743102``: This applies errata 2743102 workaround to Neoverse-N1
474   CPU. This needs to be enabled for all revisions <= r4p1 of the CPU and is
475   still open.
476
477For Neoverse V1, the following errata build flags are defined :
478
479-  ``ERRATA_V1_1618635``: This applies errata 1618635 workaround to Neoverse-V1
480   CPU. This needs to be enabled for revision r0p0 of the CPU, it is fixed in
481   r1p0.
482
483-  ``ERRATA_V1_1774420``: This applies errata 1774420 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_1791573``: This applies errata 1791573 workaround to Neoverse-V1
488   CPU. This needs to be enabled only for revisions r0p0 and r1p0, it is fixed
489   in r1p1.
490
491-  ``ERRATA_V1_1852267``: This applies errata 1852267 workaround to Neoverse-V1
492   CPU. This needs to be enabled only for revisions r0p0 and r1p0, it is fixed
493   in r1p1.
494
495-  ``ERRATA_V1_1925756``: This applies errata 1925756 workaround to Neoverse-V1
496   CPU. This needs to be enabled for r0p0, r1p0, and r1p1, it is still open.
497
498-  ``ERRATA_V1_1940577``: This applies errata 1940577 workaround to Neoverse-V1
499   CPU. This needs to be enabled only for revision r1p0 and r1p1 of the
500   CPU.
501
502-  ``ERRATA_V1_1966096``: This applies errata 1966096 workaround to Neoverse-V1
503   CPU. This needs to be enabled for revisions r1p0 and r1p1 of the CPU, the
504   issue is present in r0p0 as well but there is no workaround for that
505   revision.  It is still open.
506
507-  ``ERRATA_V1_2139242``: This applies errata 2139242 workaround to Neoverse-V1
508   CPU. This needs to be enabled for revisions r0p0, r1p0, and r1p1 of the
509   CPU.  It is still open.
510
511-  ``ERRATA_V1_2216392``: This applies errata 2216392 workaround to Neoverse-V1
512   CPU. This needs to be enabled for revisions r1p0 and r1p1 of the CPU, the
513   issue is present in r0p0 as well but there is no workaround for that
514   revision.  It is still open.
515
516-  ``ERRATA_V1_2294912``: This applies errata 2294912 workaround to Neoverse-V1
517   CPU. This needs to be enabled for revisions r0p0, r1p0, and r1p1 and r1p2 of
518   the CPU.
519
520-  ``ERRATA_V1_2348377``: This applies errata 2348377 workaroud to Neoverse-V1
521   CPU. This needs to be enabled for revisions r0p0, r1p0 and r1p1 of the CPU.
522   It has been fixed in r1p2.
523
524-  ``ERRATA_V1_2372203``: This applies errata 2372203 workaround to Neoverse-V1
525   CPU. This needs to be enabled for revisions r0p0, r1p0 and r1p1 of the CPU.
526   It is still open.
527
528- ``ERRATA_V1_2701953``: This applies erratum 2701953 workaround to Neoverse-V1
529   CPU, this erratum affects system configurations that do not use an ARM
530   interconnect IP. This needs to be enabled for revisions r0p0, r1p0 and r1p1.
531   It has been fixed in r1p2.
532
533-  ``ERRATA_V1_2743093``: This applies errata 2743093 workaround to Neoverse-V1
534   CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1 and r1p2 of the
535   CPU. It is still open.
536
537-  ``ERRATA_V1_2743233``: This applies erratum 2743233 workaround to Neoverse-V1
538   CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1, and r1p2 of the
539   CPU. It is still open.
540
541-  ``ERRATA_V1_2779461``: This applies erratum 2779461 workaround to Neoverse-V1
542   CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1, r1p2 of the
543   CPU. It is still open.
544
545For Neoverse V2, the following errata build flags are defined :
546
547-  ``ERRATA_V2_2618597``: This applies errata 2618597 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_2662553``: This applies errata 2662553 workaround to Neoverse-V2
552   CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed in
553   r0p2.
554
555-  ``ERRATA_V2_2719103``: This applies errata 2719103 workaround to Neoverse-V2
556   CPU, this affects system configurations that do not use and ARM interconnect
557   IP. This needs to be enabled for revisions r0p0 and r0p1. It has been fixed
558   in r0p2.
559
560-  ``ERRATA_V2_2719105``: This applies errata 2719105 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_2743011``: This applies errata 2743011 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_2779510``: This applies errata 2779510 workaround to Neoverse-V2
569   CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed in
570   r0p2.
571
572-  ``ERRATA_V2_2801372``: This applies errata 2801372 workaround to Neoverse-V2
573   CPU, this affects all configurations. This needs to be enabled for revisions
574   r0p0 and r0p1. It has been fixed in r0p2.
575
576-  ``ERRATA_V2_3701771``: This applies errata 3701771 workaround to Neoverse-V2
577   CPU. This needs to be enabled for revisions r0p0, r0p1 and r0p2 and is
578   still open.
579
580-  ``ERRATA_V2_3841324``: This applies errata 3841324 workaround to Neoverse-V2
581   CPU. This needs to be enabled only for revisions r0p0 and r0p1 of
582   the CPU. It is fixed in r0p2.
583
584For Neoverse V3, the following errata build flags are defined :
585
586- ``ERRATA_V3_2970647``: This applies errata 2970647 workaround to Neoverse-V3
587  CPU. This needs to be enabled for revision r0p0. It is fixed in r0p1.
588
589- ``ERRATA_V3_3701767``: This applies errata 3701767 workaround to Neoverse-V3
590  CPU. This needs to be enabled for revisions r0p0, r0p1, r0p2 of the CPU and
591  is still open.
592
593For Cortex-A710, the following errata build flags are defined :
594
595-  ``ERRATA_A710_1901946``: This applies errata 1901946 workaround to
596   Cortex-A710 CPU. This needs to be enabled only for revision r1p0. It has
597   been fixed in r2p0.
598
599-  ``ERRATA_A710_1916945``: This applies errata 1916945 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_1917258``: This applies errata 1917258 workaround to
604   Cortex-A710 CPU. This needs to be enabled only for revisions r0p0 and r1p0.
605   It has been fixed in r2p0.
606
607-  ``ERRATA_A710_1927200``: This applies errata 1927200 workaround to
608   Cortex-A710 CPU. This needs to be enabled only for revisions r0p0 and r1p0.
609   It has been fixed in r2p0.
610
611-  ``ERRATA_A710_1987031``: This applies errata 1987031 workaround to
612   Cortex-A710 CPU. This needs to be enabled only for revisions r0p0, r1p0 and
613   r2p0 of the CPU. It is still open.
614
615-  ``ERRATA_A710_2081180``: This applies errata 2081180 workaround to
616   Cortex-A710 CPU. This needs to be enabled only for revisions r0p0, r1p0 and
617   r2p0 of the CPU. It is still open.
618
619-  ``ERRATA_A710_2055002``: This applies errata 2055002 workaround to
620   Cortex-A710 CPU. This needs to be enabled for revisions r1p0, r2p0 of the CPU
621   and is still open.
622
623-  ``ERRATA_A710_2017096``: This applies errata 2017096 workaround to
624   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
625   of the CPU and is still open.
626
627-  ``ERRATA_A710_2083908``: This applies errata 2083908 workaround to
628   Cortex-A710 CPU. This needs to be enabled for revision r2p0 of the CPU and
629   is still open.
630
631-  ``ERRATA_A710_2267065``: This applies errata 2267065 workaround to
632   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
633   of the CPU and is fixed in r2p1.
634
635-  ``ERRATA_A710_2136059``: This applies errata 2136059 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_2147715``: This applies errata 2147715 workaround to
640   Cortex-A710 CPU. This needs to be enabled for revision r2p0 of the CPU
641   and is fixed in r2p1.
642
643-  ``ERRATA_A710_2216384``: This applies errata 2216384 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_2282622``: This applies errata 2282622 workaround to
648   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and
649   r2p1 of the CPU and is still open.
650
651- ``ERRATA_A710_2291219``: This applies errata 2291219 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_2008768``: This applies errata 2008768 workaround to
656   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
657   of the CPU and is fixed in r2p1.
658
659-  ``ERRATA_A710_2371105``: This applies errata 2371105 workaround to
660   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
661   of the CPU and is fixed in r2p1.
662
663-  ``ERRATA_A710_2701952``: This applies erratum 2701952 workaround to Cortex-A710
664   CPU, and applies to system configurations that do not use and ARM
665   interconnect IP. This needs to be enabled for r0p0, r1p0, r2p0 and r2p1 and
666   is still open.
667
668-  ``ERRATA_A710_2742423``: This applies errata 2742423 workaround to
669   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and
670   r2p1 of the CPU and is still open.
671
672-  ``ERRATA_A710_2768515``: This applies errata 2768515 workaround to
673   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and
674   r2p1 of the CPU and is still open.
675
676-  ``ERRATA_A710_2778471``: This applies errata 2778471 workaround to Cortex-A710
677   CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and r2p1 of the
678   CPU and is still open.
679
680- ``ERRATA_A710_3701772``: This applies errata 3701772 workaround to Cortex-A710
681  CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0, r2p1 of the
682  CPU and is still open.
683
684For Neoverse N2, the following errata build flags are defined :
685
686-  ``ERRATA_N2_2002655``: This applies errata 2002655 workaround to Neoverse-N2
687   CPU. This needs to be enabled for revision r0p0 of the CPU and is fixed in r0p1.
688
689-  ``ERRATA_N2_2009478``: This applies errata 2009478 workaround to Neoverse-N2
690   CPU. This needs to be enabled for revision r0p0 of the CPU and is fixed in r0p1.
691
692-  ``ERRATA_N2_2067956``: This applies errata 2067956 workaround to Neoverse-N2
693   CPU. This needs to be enabled for revision r0p0 of the CPU and is fixed in r0p1.
694
695-  ``ERRATA_N2_2025414``: This applies errata 2025414 workaround to Neoverse-N2
696   CPU. This needs to be enabled for revision r0p0 of the CPU and is fixed in r0p1.
697
698-  ``ERRATA_N2_2189731``: This applies errata 2189731 workaround to Neoverse-N2
699   CPU. This needs to be enabled for revision r0p0 of the CPU and is fixed in r0p1.
700
701-  ``ERRATA_N2_2138956``: This applies errata 2138956 workaround to Neoverse-N2
702   CPU. This needs to be enabled for revision r0p0 of the CPU and is fixed in r0p1.
703
704-  ``ERRATA_N2_2242415``: This applies errata 2242415 workaround to Neoverse-N2
705   CPU. This needs to be enabled for revision r0p0 of the CPU and is fixed in r0p1.
706
707-  ``ERRATA_N2_2138958``: This applies errata 2138958 workaround to Neoverse-N2
708   CPU. This needs to be enabled for revision r0p0 of the CPU and is fixed in r0p1.
709
710-  ``ERRATA_N2_2242400``: This applies errata 2242400 workaround to Neoverse-N2
711   CPU. This needs to be enabled for revision r0p0 of the CPU and is fixed in r0p1.
712
713-  ``ERRATA_N2_2280757``: This applies errata 2280757 workaround to Neoverse-N2
714   CPU. This needs to be enabled for revision r0p0 of the CPU and is fixed in r0p1.
715
716-  ``ERRATA_N2_2326639``: This applies errata 2326639 workaround to Neoverse-N2
717   CPU. This needs to be enabled for revision r0p0 of the CPU, it is fixed in
718   r0p1.
719
720-  ``ERRATA_N2_2340933``: This applies errata 2340933 workaround to Neoverse-N2
721   CPU. This needs to be enabled for revision r0p0 of the CPU, it is fixed in
722   r0p1.
723
724-  ``ERRATA_N2_2346952``: This applies errata 2346952 workaround to Neoverse-N2
725   CPU. This needs to be enabled for revisions r0p0, r0p1 and r0p2 of the CPU,
726   it is fixed in r0p3.
727
728-  ``ERRATA_N2_2376738``: This applies errata 2376738 workaround to Neoverse-N2
729   CPU. This needs to be enabled for revision r0p0, r0p1, r0p2, r0p3 and is still open.
730
731-  ``ERRATA_N2_2388450``: This applies errata 2388450 workaround to Neoverse-N2
732   CPU. This needs to be enabled for revision r0p0 of the CPU, it is fixed in
733   r0p1.
734
735-  ``ERRATA_N2_2743014``: This applies errata 2743014 workaround to Neoverse-N2
736   CPU. This needs to be enabled for revisions r0p0, r0p1 and r0p2. It is fixed
737   in r0p3.
738
739-  ``ERRATA_N2_2743089``: This applies errata 2743089 workaround to Neoverse-N2
740   CPU. This needs to be enabled for revisions r0p0, r0p1 and r0p2. It is fixed
741   in r0p3.
742
743- ``ERRATA_N2_2728475``: This applies erratum 2728475 workaround to Neoverse-N2
744   CPU, this erratum affects system configurations that do not use and ARM
745   interconnect IP. This needs to be enabled for revisions r0p0, r0p1 and r0p2.
746   It is fixed in r0p3.
747
748-  ``ERRATA_N2_2779511``: This applies errata 2779511 workaround to Neoverse-N2
749   CPU. This needs to be enabled for revisions r0p0, r0p1 and r0p2. It is fixed
750   in r0p3.
751
752-  ``ERRATA_N2_3701773``: This applies errata 3701773 workaround to Neoverse-N2
753   CPU. This needs to be enabled for revisions r0p0, r0p1, r0p2, r0p3 and is
754   still open.
755
756For Neoverse N3, the following errata build flags are defined :
757
758-  ``ERRATA_N3_3699563``: This applies errata 3699563 workaround to Neoverse-N3
759   CPU. This needs to be enabled for revisions r0p0 and is still open.
760
761For Cortex-X2, the following errata build flags are defined :
762
763-  ``ERRATA_X2_1901946``: This applies errata 1901946 workaround to Cortex-X2
764   CPU. This needs to be enabled only for r1p0, it is fixed in r2p0.
765
766-  ``ERRATA_X2_1916945``: This applies errata 1916945 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_1917258``: This applies errata 1917258 workaround to Cortex-X2
771   CPU. This needs to be enabled only for revisions r0p0 and r1p0 of the CPU, it
772   is fixed in r2p0.
773
774-  ``ERRATA_X2_1927200``: This applies errata 1927200 workaround to Cortex-X2
775   CPU. This needs to be enabled only for revisions r0p0 and r1p0 of the CPU, it
776   is fixed in r2p0.
777
778-  ``ERRATA_X2_1934260``: This applies errata 1934260 workaround to Cortex-X2
779   CPU. This needs to be enabled only for revision r1p0 of the CPU, it is fixed
780   in r2p0.
781
782-  ``ERRATA_X2_2002765``: This applies errata 2002765 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_2017096``: This applies errata 2017096 workaround to Cortex-X2
787   CPU. This needs to be enabled only for revisions r0p0, r1p0 and r2p0 of the
788   CPU, it is fixed in r2p1.
789
790-  ``ERRATA_X2_2081180``: This applies errata 2081180 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_2083908``: This applies errata 2083908 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_2136059``: This applies errata 2136059 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_2147715``: This applies errata 2147715 workaround to Cortex-X2
803   CPU. This needs to be enabled only for revision r2p0 of the CPU, it is fixed
804   in r2p1.
805
806-  ``ERRATA_X2_2216384``: This applies errata 2216384 workaround to Cortex-X2
807   CPU. This needs to be enabled only for revisions r0p0, r1p0 and r2p0 of the
808   CPU, it is fixed in r2p1.
809
810-  ``ERRATA_X2_2267065``: This applies errata 2267065 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_2282622``: This applies errata 2282622 workaround to Cortex-X2
815   CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and r2p1 of the
816   CPU and is still open.
817
818-  ``ERRATA_X2_2291219``: This applies errata 2291219 workaround to Cortex-X2
819   CPU. This needs to be enabled only for revisions r0p0, r1p0 and r2p0 of the
820   CPU, it is fixed in r2p1.
821
822-  ``ERRATA_X2_2371105``: This applies errata 2371105 workaround to Cortex-X2
823   CPU. This needs to be enabled only for revisions r0p0, r1p0 and r2p0 of the
824   CPU, it is fixed in r2p1.
825
826- ``ERRATA_X2_2701952``: This applies errata 2701952 workaround to Cortex-X2
827   CPU and affects system configurations that do not use an Arm interconnect IP.
828   This needs to be enabled for revisions r0p0, r1p0, r2p0 and r2p1 and is
829   still open.
830
831-  ``ERRATA_X2_2742423``: This applies errata 2742423 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_2768515``: This applies errata 2768515 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
839-  ``ERRATA_X2_2778471``: This applies errata 2778471 workaround to Cortex-X2
840   CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and r2p1 of the
841   CPU and is still open.
842
843-  ``ERRATA_X2_3701772``: This applies errata 3701772 workaround to Cortex-X2
844   CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and r2p1 of the
845   CPU and is still open.
846
847For Cortex-X3, the following errata build flags are defined :
848
849- ``ERRATA_X3_2266875``: This applies errata 2266875 workaround to the Cortex-X3
850  CPU. This needs to be enabled only for revisions r0p0 and r1p0 of the CPU, it
851  is fixed in r1p1.
852
853- ``ERRATA_X3_2302506``: This applies errata 2302506 workaround to the Cortex-X3
854  CPU. This needs to be enabled only for revisions r0p0, r1p0 and r1p1, it is
855  fixed in r1p2.
856
857- ``ERRATA_X3_2313909``: This applies errata 2313909 workaround to
858  Cortex-X3 CPU. This needs to be enabled only for revisions r0p0 and r1p0
859  of the CPU, it is fixed in r1p1.
860
861- ``ERRATA_X3_2372204``: This applies errata 2372204 workaround to
862  Cortex-X3 CPU. This needs to be enabled only for revisions r0p0 and r1p0
863  of the CPU, it is fixed in r1p1.
864
865- ``ERRATA_X3_2615812``: This applies errata 2615812 workaround to Cortex-X3
866  CPU. This needs to be enabled only for revisions r0p0, r1p0 and r1p1 of the
867  CPU, it is fixed in r1p2.
868
869- ``ERRATA_X3_2641945``: This applies errata 2641945 workaround to Cortex-X3
870  CPU. This needs to be enabled only for revisions r0p0 and r1p0 of the CPU.
871  It is fixed in r1p1.
872
873- ``ERRATA_X3_2701951``: This applies erratum 2701951 workaround to Cortex-X3
874  CPU and affects system configurations that do not use an ARM interconnect
875  IP. This needs to be applied to revisions r0p0, r1p0 and r1p1. It is fixed
876  in r1p2.
877
878- ``ERRATA_X3_2742421``: This applies errata 2742421 workaround to
879  Cortex-X3 CPU. This needs to be enabled only for revisions r0p0, r1p0 and
880  r1p1. It is fixed in r1p2.
881
882- ``ERRATA_X3_2743088``: This applies errata 2743088 workaround to Cortex-X3
883  CPU. This needs to be enabled only for revisions r0p0, r1p0 and r1p1. It is
884  fixed in r1p2.
885
886- ``ERRATA_X3_2779509``: This applies errata 2779509 workaround to Cortex-X3
887  CPU. This needs to be enabled only for revisions r0p0, r1p0 and r1p1 of the
888  CPU. It is fixed in r1p2.
889
890- ``ERRATA_X3_3213672``: This applies errata 3213672 workaround to Cortex-X3
891  CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1 and r1p2
892  of the CPU. It is still open.
893
894- ``ERRATA_X3_3692984``: This applies errata 3692984 workaround to Cortex-X3
895  CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1 and r1p2
896  of the CPU. It is still open.
897
898- ``ERRATA_X3_3701769``: This applies errata 3701769 workaround to Cortex-X3
899  CPU. This needs to be enabled only for revisions r0p0, r1p0, r1p1 and r1p2
900  of the CPU and it is still open.
901
902- ``ERRATA_X3_3827463``: This applies errata 3827463 workaround to Cortex-X3
903  CPU. This needs to be enabled only for revisions r0p0, r1p0 and r1p1 of
904  the CPU. It is fixed in r1p2.
905
906For Cortex-X4, the following errata build flags are defined :
907
908- ``ERRATA_X4_2701112``: This applies erratum 2701112 workaround to Cortex-X4
909  CPU and affects system configurations that do not use an Arm interconnect IP.
910  This needs to be enabled for revisions r0p0 and is fixed in r0p1.
911  The workaround for this erratum is not implemented in EL3, but the flag can
912  be enabled/disabled at the platform level. The flag is used when the errata ABI
913  feature is enabled and can assist the Kernel in the process of
914  mitigation of the erratum.
915
916- ``ERRATA_X4_2726228``: This applies erratum 2726228 workaround to Cortex-X4
917  CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed in
918  r0p2.
919
920-  ``ERRATA_X4_2740089``: This applies errata 2740089 workaround to Cortex-X4
921   CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed
922   in r0p2.
923
924- ``ERRATA_X4_2763018``: This applies errata 2763018 workaround to Cortex-X4
925  CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed in r0p2.
926
927- ``ERRATA_X4_2816013``: This applies errata 2816013 workaround to Cortex-X4
928  CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed in r0p2.
929
930- ``ERRATA_X4_2897503``: This applies errata 2897503 workaround to Cortex-X4
931  CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed in r0p2.
932
933- ``ERRATA_X4_2923985``: This applies errata 2923985 workaround to Cortex-X4
934  CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed in r0p2.
935
936- ``ERRATA_X4_2957258``: This applies errata 2957258 workaround to Cortex-X4
937  CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed in r0p2.
938
939- ``ERRATA_X4_3076789``: This applies errata 3076789 workaround to Cortex-X4
940  CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed in r0p2.
941
942- ``ERRATA_X4_3133195``: This applies errata 3133195 workaround to Cortex-X4
943  CPU. This needs to be enabled for revision r0p2. It is fixed in r0p3.
944
945- ``ERRATA_X4_3701758``: This applies errata 3701758 workaround to Cortex-X4
946  CPU. This needs to be enabled for revisions r0p0, r0p1, r0p2 and r0p3.
947  It is still open.
948
949- ``ERRATA_X4_3887999``: This applies errata 3887999 workaround to Cortex-X4
950  CPU. This needs to be enabled for revision r0p0, r0p1, r0p2 and r0p3.
951  It is still open.
952
953For Cortex-X925, the following errata build flags are defined :
954
955- ``ERRATA_X925_2963999``: This applies errata 2963999 workaround to Cortex-X925
956  CPU. This needs to be enabled for revision r0p0. It is fixed in r0p1.
957
958- ``ERRATA_X925_3701747``: This applies errata 3701747 workaround to Cortex-X925
959  CPU. This needs to be enabled for revisions r0p0 and r0p1. It is still open.
960
961For Cortex-A510, the following errata build flags are defined :
962
963-  ``ERRATA_A510_2008766``: This applies errata 2008766 workaround to
964   Cortex-A510 CPU. This needs to be enabled for revisions r0p0, r0p1, r0p2,
965   r0p3, r1p0, r1p1, r1p2 and r1p3. It is still open.
966
967-  ``ERRATA_A510_2288014``: This applies errata 2288014 workaround to
968   Cortex-A510 CPU. This needs to be enabled only for revisions r0p0, r0p1,
969   r0p2, r0p3 and r1p0, it is fixed in r1p1.
970
971-  ``ERRATA_A510_2042739``: This applies errata 2042739 workaround to
972   Cortex-A510 CPU. This needs to be enabled only for revisions r0p0, r0p1 and
973   r0p2, it is fixed in r0p3.
974
975-  ``ERRATA_A510_2041909``: This applies errata 2041909 workaround to
976   Cortex-A510 CPU. This needs to be enabled only for revision r0p2 and is fixed
977   in r0p3. The issue is also present in r0p0 and r0p1 but there is no
978   workaround for those revisions.
979
980-  ``ERRATA_A510_2080326``: This applies errata 2080326 workaround to
981   Cortex-A510 CPU. This needs to be enabled only for revision r0p2 and is
982   fixed in r0p3. This issue is also present in r0p0 and r0p1 but there is no
983   workaround for those revisions.
984
985-  ``ERRATA_A510_2169012``: This applies errata 2169012 workaround to
986   Cortex-A510 CPU. This needs to be enabled only for revisions r0p0, r0p1,
987   r0p2, r0p3 and r1p0, it is fixed in r1p1.
988
989-  ``ERRATA_A510_2218134``: This applies errata 2218134 workaround to
990   Cortex-A510 CPU. This needs to be enabled only for revision r1p0 and is fixed
991   in r1p1.
992
993-  ``ERRATA_A510_2250311``: This applies errata 2250311 workaround to
994   Cortex-A510 CPU. This needs to be enabled for revisions r0p0, r0p1, r0p2,
995   r0p3 and r1p0, it is fixed in r1p1. This workaround disables MPMM even if
996   ENABLE_MPMM=1.
997
998-  ``ERRATA_A510_2218950``: This applies errata 2218950 workaround to
999   Cortex-A510 CPU. This needs to be enabled for revisions r0p0, r0p1, r0p2,
1000   r0p3 and r1p0, it is fixed in r1p1.
1001
1002-  ``ERRATA_A510_2172148``: This applies errata 2172148 workaround to
1003   Cortex-A510 CPU. This needs to be enabled for revisions r0p0, r0p1, r0p2,
1004   r0p3 and r1p0, it is fixed in r1p1.
1005
1006-  ``ERRATA_A510_2347730``: This applies errata 2347730 workaround to
1007   Cortex-A510 CPU. This needs to be enabled for revisions r0p0, r0p1, r0p2,
1008   r0p3, r1p0 and r1p1. It is fixed in r1p2.
1009
1010-  ``ERRATA_A510_2371937``: This applies errata 2371937 workaround to
1011   Cortex-A510 CPU. This needs to applied for revisions r0p0, r0p1, r0p2,
1012   r0p3, r1p0, r1p1, and is fixed in r1p2.
1013
1014-  ``ERRATA_A510_2420992``: This applies errata 2420992 workaround to
1015   Cortex-A510 CPU. This needs to applied for revisions r1p0 and r1p1, and is
1016   fixed in r1p2.
1017
1018-  ``ERRATA_A510_2666669``: This applies errata 2666669 workaround to
1019   Cortex-A510 CPU. This needs to applied for revisions r0p0, r0p1, r0p2,
1020   r0p3, r1p0, r1p1. It is fixed in r1p2.
1021
1022-  ``ERRATA_A510_2684597``: This applies erratum 2684597 workaround to
1023   Cortex-A510 CPU. This needs to be applied to revision r0p0, r0p1, r0p2,
1024   r0p3, r1p0, r1p1 and r1p2. It is fixed in r1p3.
1025
1026-  ``ERRATA_A510_2971420``: This applies erratum 2971420 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
1030-  ``ERRATA_A510_3672349``: This applies erratum 3672349 workaround to
1031   Cortex-A510 CPU. This needs to be applied to revisions r0p1, r0p2, r0p3,
1032   r1p0, r1p1, r1p2 and r1p3 and is still open.
1033
1034-  ``ERRATA_A510_3704847``: This applies erratum 3704847 workaround to
1035   Cortex-A510 CPU. This needs to be applied to revisions r0p1, r0p2, r0p3,
1036   r1p0, r1p1, r1p2 and r1p3 and is still open.
1037
1038For Cortex-A520, the following errata build flags are defined :
1039
1040-  ``ERRATA_A520_2630792``: This applies errata 2630792 workaround to
1041   Cortex-A520 CPU. This needs to applied for revisions r0p0, r0p1 of the
1042   CPU and is still open.
1043
1044-  ``ERRATA_A520_2858100``: This applies errata 2858100 workaround to
1045   Cortex-A520 CPU. This needs to be enabled for revisions r0p0 and r0p1.
1046   It is still open.
1047
1048-  ``ERRATA_A520_2938996``: This applies errata 2938996 workaround to
1049   Cortex-A520 CPU. This needs to be enabled for revisions r0p0 and r0p1.
1050   It is fixed in r0p2.
1051
1052For Cortex-A715, the following errata build flags are defined :
1053
1054-  ``ERRATA_A715_2331818``: This applies errata 2331818 workaround to
1055   Cortex-A715 CPU. This needs to be enabled for revisions r0p0 and r1p0.
1056   It is fixed in r1p1.
1057
1058- ``ERRATA_A715_2344187``: This applies errata 2344187 workaround to
1059   Cortex-A715 CPU. This needs to be enabled for revisions r0p0 and r1p0. It is
1060   fixed in r1p1.
1061
1062-  ``ERRATA_A715_2376701``: This applies errata 2376701 workaround to
1063   Cortex-A715 CPU. This needs to be enabled for revisions r0p0 and r1p0. It is
1064   fixed in r1p1.
1065
1066-  ``ERRATA_A715_2409570``: This applies errata 2409570 workaround to
1067   Cortex-A715 CPU. This needs to be enabled only for revision r1p0.
1068   It is fixed in r1p1. This errata also applies to r0p0 but that revision has a
1069   different workaround, and since r0p0 is not used in production hardware it is
1070   not implemented.
1071
1072-  ``ERRATA_A715_2413290``: This applies errata 2413290 workaround to
1073   Cortex-A715 CPU. This needs to be enabled only for revision r1p0 and
1074   when SPE(Statistical profiling extension)=True. The errata is fixed
1075   in r1p1.
1076
1077-  ``ERRATA_A715_2420947``: This applies errata 2420947 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_2429384``: This applies errata 2429384 workaround to
1082   Cortex-A715 CPU. This needs to be enabled for revision r1p0. There is no
1083   workaround for revision r0p0. It is fixed in r1p1.
1084
1085-  ``ERRATA_A715_2561034``: This applies errata 2561034 workaround to
1086   Cortex-A715 CPU. This needs to be enabled only for revision r1p0.
1087   It is fixed in r1p1.
1088
1089-  ``ERRATA_A715_2728106``: This applies errata 2728106 workaround to
1090   Cortex-A715 CPU. This needs to be enabled for revisions r0p0, r1p0
1091   and r1p1. It is fixed in r1p2.
1092
1093-  ``ERRATA_A715_2804830``: This applies errata 2804830 workaround to
1094   Cortex-A715 CPU. This needs to be enabled for revisions r0p0, r1p0,
1095   r1p1 and r1p2. It is fixed in r1p3.
1096
1097-  ``ERRATA_A715_3699560``: This applies errata 3699560 workaround to
1098   Cortex-A715 CPU. This needs to be enabled for revisions r0p0, r1p0,
1099   r1p2 and r1p3. It is still open.
1100
1101-  ``ERRATA_A715_3711916``: This applies errata 3711916 workaround to
1102   Cortex-A715 CPU. This needs to be enabled for revisions r0p0, r1p0,
1103   r1p1, r1p2 and r1p3. It is still open.
1104
1105For Cortex-A720, the following errata build flags are defined :
1106
1107-  ``ERRATA_A720_2729604``: This applies errata 2729604 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_2792132``: This applies errata 2792132 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_2844092``: This applies errata 2844092 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_2926083``: This applies errata 2926083 workaround to
1120   Cortex-A720 CPU. This needs to be enabled for revisions r0p0 and r0p1.
1121   It is fixed in r0p2.
1122
1123-  ``ERRATA_A720_2940794``: This applies errata 2940794 workaround to
1124   Cortex-A720 CPU. This needs to be enabled for revisions r0p0 and r0p1.
1125   It is fixed in r0p2.
1126
1127-  ``ERRATA_A720_3699561``: This applies errata 3699561 workaround to
1128   Cortex-A720 CPU. This needs to be enabled for revisions r0p0, r0p1
1129   and r0p2. It is still open.
1130
1131-  ``ERRATA_A720_3711910``: This applies errata 3711910 workaround to
1132   Cortex-A720 CPU. This needs to be enabled for revisions r0p0, r0p1
1133   and r0p2. It is still open.
1134
1135For Cortex-A720_AE, the following errata build flags are defined :
1136
1137-  ``ERRATA_A720_AE_3699562``: This applies errata 3699562 workaround
1138   to Cortex-A720_AE CPU. This needs to be enabled for revisions r0p0.
1139   It is still open.
1140
1141For Cortex-A725, the following errata build flags are defined :
1142
1143-  ``ERRATA_A725_3699564``: This applies errata 3699564 workaround to
1144   Cortex-A725 CPU. This needs to be enabled for revisions r0p0 and r0p1.
1145   It is fixed in r0p2.
1146
1147DSU Errata Workarounds
1148----------------------
1149
1150Similar to CPU errata, TF-A also implements workarounds for DSU (DynamIQ
1151Shared Unit) errata. The DSU errata details can be found in the respective Arm
1152documentation:
1153
1154- `Arm DSU Software Developers Errata Notice`_.
1155
1156Each erratum is identified by an ``ID``, as defined in the DSU errata notice
1157document. Thus, the build flags which enable/disable the errata workarounds
1158have the format ``ERRATA_DSU_<ID>``. The implementation and application logic
1159of DSU errata workarounds are similar to `CPU errata workarounds`_.
1160
1161For DSU errata, the following build flags are defined:
1162
1163-  ``ERRATA_DSU_798953``: This applies errata 798953 workaround for the
1164   affected DSU configurations. This errata applies only for those DSUs that
1165   revision is r0p0 (on r0p1 it is fixed). However, please note that this
1166   workaround results in increased DSU power consumption on idle.
1167
1168-  ``ERRATA_DSU_936184``: This applies errata 936184 workaround for the
1169   affected DSU configurations. This errata applies only for those DSUs that
1170   contain the ACP interface **and** the DSU revision is older than r2p0 (on
1171   r2p0 it is fixed). However, please note that this workaround results in
1172   increased DSU power consumption on idle.
1173
1174-  ``ERRATA_DSU_2313941``: This applies errata 2313941 workaround for the
1175   affected DSU configurations. This errata applies for those DSUs with
1176   revisions r0p0, r1p0, r2p0, r2p1, r3p0, r3p1 and is still open. However,
1177   please note that this workaround results in increased DSU power consumption
1178   on idle.
1179
1180-  ``ERRATA_DSU_2900952``: This applies errata 2900952 workaround for the
1181   affected DSU-120 configurations. This erratum applies to some r2p0
1182   implementations and is fixed in r2p1. The affected r2p0 implementations
1183   are determined by reading the IMP_CLUSTERREVIDR_EL1[1] register bit
1184   and making sure it's clear.
1185
1186CPU Specific optimizations
1187--------------------------
1188
1189This section describes some of the optimizations allowed by the CPU micro
1190architecture that can be enabled by the platform as desired.
1191
1192-  ``SKIP_A57_L1_FLUSH_PWR_DWN``: This flag enables an optimization in the
1193   Cortex-A57 cluster power down sequence by not flushing the Level 1 data
1194   cache. The L1 data cache and the L2 unified cache are inclusive. A flush
1195   of the L2 by set/way flushes any dirty lines from the L1 as well. This
1196   is a known safe deviation from the Cortex-A57 TRM defined power down
1197   sequence. Each Cortex-A57 based platform must make its own decision on
1198   whether to use the optimization.
1199
1200-  ``A53_DISABLE_NON_TEMPORAL_HINT``: This flag disables the cache non-temporal
1201   hint. The LDNP/STNP instructions as implemented on Cortex-A53 do not behave
1202   in a way most programmers expect, and will most probably result in a
1203   significant speed degradation to any code that employs them. The Armv8-A
1204   architecture (see Arm DDI 0487A.h, section D3.4.3) allows cores to ignore
1205   the non-temporal hint and treat LDNP/STNP as LDP/STP instead. Enabling this
1206   flag enforces this behaviour. This needs to be enabled only for revisions
1207   <= r0p3 of the CPU and is enabled by default.
1208
1209-  ``A57_DISABLE_NON_TEMPORAL_HINT``: This flag has the same behaviour as
1210   ``A53_DISABLE_NON_TEMPORAL_HINT`` but for Cortex-A57. This needs to be
1211   enabled only for revisions <= r1p2 of the CPU and is enabled by default,
1212   as recommended in section "4.7 Non-Temporal Loads/Stores" of the
1213   `Cortex-A57 Software Optimization Guide`_.
1214
1215- ''A57_ENABLE_NON_CACHEABLE_LOAD_FWD'': This flag enables non-cacheable
1216   streaming enhancement feature for Cortex-A57 CPUs. Platforms can set
1217   this bit only if their memory system meets the requirement that cache
1218   line fill requests from the Cortex-A57 processor are atomic. Each
1219   Cortex-A57 based platform must make its own decision on whether to use
1220   the optimization. This flag is disabled by default.
1221
1222-  ``NEOVERSE_Nx_EXTERNAL_LLC``: This flag indicates that an external last
1223   level cache(LLC) is present in the system, and that the DataSource field
1224   on the master CHI interface indicates when data is returned from the LLC.
1225   This is used to control how the LL_CACHE* PMU events count.
1226   Default value is 0 (Disabled).
1227
1228-  ``NEOVERSE_N2_PREFETCHER_DISABLE``: This flag disables the region prefetcher
1229   on the Neoverse N2 core. This is used during performance analysis to get clean
1230   and repeatable measurements of the cache by preventing speculative data fetches
1231   from interfering with benchmark results.
1232   Default value is 0 (Disabled).
1233
1234GIC Errata Workarounds
1235----------------------
1236-  ``GIC600_ERRATA_WA_2384374``: This flag applies part 2 of errata 2384374
1237   workaround for the affected GIC600 and GIC600-AE implementations. It applies
1238   to implementations of GIC600 and GIC600-AE with revisions less than or equal
1239   to r1p6 and r0p2 respectively. If the platform sets GICV3_SUPPORT_GIC600,
1240   then this flag is enabled; otherwise, it is 0 (Disabled).
1241
1242--------------
1243
1244*Copyright (c) 2014-2025, Arm Limited and Contributors. All rights reserved.*
1245
1246.. _CVE-2017-5715: http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-5715
1247.. _CVE-2018-3639: http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-3639
1248.. _CVE-2022-23960: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-23960
1249.. _Cortex-A72 MPCore Software Developers Errata Notice: https://developer.arm.com/documentation/epm012079/latest
1250.. _Cortex-A57 Software Optimization Guide: https://developer.arm.com/documentation/uan0015
1251.. _Arm DSU Software Developers Errata Notice: https://developer.arm.com/documentation/SDEN854652
1252