xref: /rk3399_ARM-atf/docs/design/cpu-specific-build-macros.rst (revision f2bd35282066f512c26d859aa086cff13955d76b)
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:
53
54-  `Cortex-A53 MPCore Software Developers Errata Notice`_
55-  `Cortex-A57 MPCore Software Developers Errata Notice`_
56-  `Cortex-A72 MPCore Software Developers Errata Notice`_
57
58The errata workarounds are implemented for a particular revision or a set of
59processor revisions. This is checked by the reset handler at runtime. Each
60errata workaround is identified by its ``ID`` as specified in the processor's
61errata notice document. The format of the define used to enable/disable the
62errata workaround is ``ERRATA_<Processor name>_<ID>``, where the ``Processor name``
63is for example ``A57`` for the ``Cortex_A57`` CPU.
64
65Refer to :ref:`firmware_design_cpu_errata_implementation` for information on how to
66write errata workaround functions.
67
68All workarounds are disabled by default. The platform is responsible for
69enabling these workarounds according to its requirement by defining the
70errata workaround build flags in the platform specific makefile. In case
71these workarounds are enabled for the wrong CPU revision then the errata
72workaround is not applied. In the DEBUG build, this is indicated by
73printing a warning to the crash console.
74
75In the current implementation, a platform which has more than 1 variant
76with different revisions of a processor has no runtime mechanism available
77for it to specify which errata workarounds should be enabled or not.
78
79The value of the build flags is 0 by default, that is, disabled. A value of 1
80will enable it.
81
82For Cortex-A9, the following errata build flags are defined :
83
84-  ``ERRATA_A9_794073``: This applies errata 794073 workaround to Cortex-A9
85   CPU. This needs to be enabled for all revisions of the CPU.
86
87For Cortex-A15, the following errata build flags are defined :
88
89-  ``ERRATA_A15_816470``: This applies errata 816470 workaround to Cortex-A15
90   CPU. This needs to be enabled only for revision >= r3p0 of the CPU.
91
92-  ``ERRATA_A15_827671``: This applies errata 827671 workaround to Cortex-A15
93   CPU. This needs to be enabled only for revision >= r3p0 of the CPU.
94
95For Cortex-A17, the following errata build flags are defined :
96
97-  ``ERRATA_A17_852421``: This applies errata 852421 workaround to Cortex-A17
98   CPU. This needs to be enabled only for revision <= r1p2 of the CPU.
99
100-  ``ERRATA_A17_852423``: This applies errata 852423 workaround to Cortex-A17
101   CPU. This needs to be enabled only for revision <= r1p2 of the CPU.
102
103For Cortex-A35, the following errata build flags are defined :
104
105-  ``ERRATA_A35_855472``: This applies errata 855472 workaround to Cortex-A35
106   CPUs. This needs to be enabled only for revision r0p0 of Cortex-A35.
107
108For Cortex-A53, the following errata build flags are defined :
109
110-  ``ERRATA_A53_819472``: This applies errata 819472 workaround to all
111   CPUs. This needs to be enabled only for revision <= r0p1 of Cortex-A53.
112
113-  ``ERRATA_A53_824069``: This applies errata 824069 workaround to all
114   CPUs. This needs to be enabled only for revision <= r0p2 of Cortex-A53.
115
116-  ``ERRATA_A53_826319``: This applies errata 826319 workaround to Cortex-A53
117   CPU. This needs to be enabled only for revision <= r0p2 of the CPU.
118
119-  ``ERRATA_A53_827319``: This applies errata 827319 workaround to all
120   CPUs. This needs to be enabled only for revision <= r0p2 of Cortex-A53.
121
122-  ``ERRATA_A53_835769``: This applies erratum 835769 workaround at compile and
123   link time to Cortex-A53 CPU. This needs to be enabled for some variants of
124   revision <= r0p4. This workaround can lead the linker to create ``*.stub``
125   sections.
126
127-  ``ERRATA_A53_836870``: This applies errata 836870 workaround to Cortex-A53
128   CPU. This needs to be enabled only for revision <= r0p3 of the CPU. From
129   r0p4 and onwards, this errata is enabled by default in hardware. Identical to
130   ``A53_DISABLE_NON_TEMPORAL_HINT``.
131
132-  ``ERRATA_A53_843419``: This applies erratum 843419 workaround at link time
133   to Cortex-A53 CPU.  This needs to be enabled for some variants of revision
134   <= r0p4. This workaround can lead the linker to emit ``*.stub`` sections
135   which are 4kB aligned.
136
137-  ``ERRATA_A53_855873``: This applies errata 855873 workaround to Cortex-A53
138   CPUs. Though the erratum is present in every revision of the CPU,
139   this workaround is only applied to CPUs from r0p3 onwards, which feature
140   a chicken bit in CPUACTLR_EL1 to enable a hardware workaround.
141   Earlier revisions of the CPU have other errata which require the same
142   workaround in software, so they should be covered anyway.
143
144-  ``ERRATA_A53_1530924``: This applies errata 1530924 workaround to all
145   revisions of Cortex-A53 CPU.
146
147For Cortex-A55, the following errata build flags are defined :
148
149-  ``ERRATA_A55_768277``: This applies errata 768277 workaround to Cortex-A55
150   CPU. This needs to be enabled only for revision r0p0 of the CPU.
151
152-  ``ERRATA_A55_778703``: This applies errata 778703 workaround to Cortex-A55
153   CPU. This needs to be enabled only for revision r0p0 of the CPU.
154
155-  ``ERRATA_A55_798797``: This applies errata 798797 workaround to Cortex-A55
156   CPU. This needs to be enabled only for revision r0p0 of the CPU.
157
158-  ``ERRATA_A55_846532``: This applies errata 846532 workaround to Cortex-A55
159   CPU. This needs to be enabled only for revision <= r0p1 of the CPU.
160
161-  ``ERRATA_A55_903758``: This applies errata 903758 workaround to Cortex-A55
162   CPU. This needs to be enabled only for revision <= r0p1 of the CPU.
163
164-  ``ERRATA_A55_1221012``: This applies errata 1221012 workaround to Cortex-A55
165   CPU. This needs to be enabled only for revision <= r1p0 of the CPU.
166
167-  ``ERRATA_A55_1530923``: This applies errata 1530923 workaround to all
168   revisions of Cortex-A55 CPU.
169
170For Cortex-A57, the following errata build flags are defined :
171
172-  ``ERRATA_A57_806969``: This applies errata 806969 workaround to Cortex-A57
173   CPU. This needs to be enabled only for revision r0p0 of the CPU.
174
175-  ``ERRATA_A57_813419``: This applies errata 813419 workaround to Cortex-A57
176   CPU. This needs to be enabled only for revision r0p0 of the CPU.
177
178-  ``ERRATA_A57_813420``: This applies errata 813420 workaround to Cortex-A57
179   CPU. This needs to be enabled only for revision r0p0 of the CPU.
180
181-  ``ERRATA_A57_814670``: This applies errata 814670 workaround to Cortex-A57
182   CPU. This needs to be enabled only for revision r0p0 of the CPU.
183
184-  ``ERRATA_A57_817169``: This applies errata 817169 workaround to Cortex-A57
185   CPU. This needs to be enabled only for revision <= r0p1 of the CPU.
186
187-  ``ERRATA_A57_826974``: This applies errata 826974 workaround to Cortex-A57
188   CPU. This needs to be enabled only for revision <= r1p1 of the CPU.
189
190-  ``ERRATA_A57_826977``: This applies errata 826977 workaround to Cortex-A57
191   CPU. This needs to be enabled only for revision <= r1p1 of the CPU.
192
193-  ``ERRATA_A57_828024``: This applies errata 828024 workaround to Cortex-A57
194   CPU. This needs to be enabled only for revision <= r1p1 of the CPU.
195
196-  ``ERRATA_A57_829520``: This applies errata 829520 workaround to Cortex-A57
197   CPU. This needs to be enabled only for revision <= r1p2 of the CPU.
198
199-  ``ERRATA_A57_833471``: This applies errata 833471 workaround to Cortex-A57
200   CPU. This needs to be enabled only for revision <= r1p2 of the CPU.
201
202-  ``ERRATA_A57_859972``: This applies errata 859972 workaround to Cortex-A57
203   CPU. This needs to be enabled only for revision <= r1p3 of the CPU.
204
205-  ``ERRATA_A57_1319537``: This applies errata 1319537 workaround to all
206   revisions of Cortex-A57 CPU.
207
208For Cortex-A72, the following errata build flags are defined :
209
210-  ``ERRATA_A72_859971``: This applies errata 859971 workaround to Cortex-A72
211   CPU. This needs to be enabled only for revision <= r0p3 of the CPU.
212
213-  ``ERRATA_A72_1319367``: This applies errata 1319367 workaround to all
214   revisions of Cortex-A72 CPU.
215
216For Cortex-A73, the following errata build flags are defined :
217
218-  ``ERRATA_A73_852427``: This applies errata 852427 workaround to Cortex-A73
219   CPU. This needs to be enabled only for revision r0p0 of the CPU.
220
221-  ``ERRATA_A73_855423``: This applies errata 855423 workaround to Cortex-A73
222   CPU. This needs to be enabled only for revision <= r0p1 of the CPU.
223
224For Cortex-A75, the following errata build flags are defined :
225
226-  ``ERRATA_A75_764081``: This applies errata 764081 workaround to Cortex-A75
227   CPU. This needs to be enabled only for revision r0p0 of the CPU.
228
229-  ``ERRATA_A75_790748``: This applies errata 790748 workaround to Cortex-A75
230    CPU. This needs to be enabled only for revision r0p0 of the CPU.
231
232For Cortex-A76, the following errata build flags are defined :
233
234-  ``ERRATA_A76_1073348``: This applies errata 1073348 workaround to Cortex-A76
235   CPU. This needs to be enabled only for revision <= r1p0 of the CPU.
236
237-  ``ERRATA_A76_1130799``: This applies errata 1130799 workaround to Cortex-A76
238   CPU. This needs to be enabled only for revision <= r2p0 of the CPU.
239
240-  ``ERRATA_A76_1220197``: This applies errata 1220197 workaround to Cortex-A76
241   CPU. This needs to be enabled only for revision <= r2p0 of the CPU.
242
243-  ``ERRATA_A76_1257314``: This applies errata 1257314 workaround to Cortex-A76
244   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
245
246-  ``ERRATA_A76_1262606``: This applies errata 1262606 workaround to Cortex-A76
247   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
248
249-  ``ERRATA_A76_1262888``: This applies errata 1262888 workaround to Cortex-A76
250   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
251
252-  ``ERRATA_A76_1275112``: This applies errata 1275112 workaround to Cortex-A76
253   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
254
255-  ``ERRATA_A76_1791580``: This applies errata 1791580 workaround to Cortex-A76
256   CPU. This needs to be enabled only for revision <= r4p0 of the CPU.
257
258-  ``ERRATA_A76_1165522``: This applies errata 1165522 workaround to all
259   revisions of Cortex-A76 CPU. This errata is fixed in r3p0 but due to
260   limitation of errata framework this errata is applied to all revisions
261   of Cortex-A76 CPU.
262
263-  ``ERRATA_A76_1868343``: This applies errata 1868343 workaround to Cortex-A76
264   CPU. This needs to be enabled only for revision <= r4p0 of the CPU.
265
266-  ``ERRATA_A76_1946160``: This applies errata 1946160 workaround to Cortex-A76
267   CPU. This needs to be enabled only for revisions r3p0 - r4p1 of the CPU.
268
269-  ``ERRATA_A76_2743102``: This applies errata 2743102 workaround to Cortex-A76
270   CPU. This needs to be enabled for all revisions <= r4p1 of the CPU and is
271   still open.
272
273For Cortex-A77, the following errata build flags are defined :
274
275-  ``ERRATA_A77_1508412``: This applies errata 1508412 workaround to Cortex-A77
276   CPU. This needs to be enabled only for revision <= r1p0 of the CPU.
277
278-  ``ERRATA_A77_1925769``: This applies errata 1925769 workaround to Cortex-A77
279   CPU. This needs to be enabled only for revision <= r1p1 of the CPU.
280
281-  ``ERRATA_A77_1946167``: This applies errata 1946167 workaround to Cortex-A77
282   CPU. This needs to be enabled only for revision <= r1p1 of the CPU.
283
284-  ``ERRATA_A77_1791578``: This applies errata 1791578 workaround to Cortex-A77
285   CPU. This needs to be enabled for r0p0, r1p0, and r1p1, it is still open.
286
287-  ``ERRATA_A77_2356587``: This applies errata 2356587 workaround to Cortex-A77
288   CPU. This needs to be enabled for r0p0, r1p0, and r1p1, it is still open.
289
290 -  ``ERRATA_A77_1800714``: This applies errata 1800714 workaround to Cortex-A77
291    CPU. This needs to be enabled for revisions <= r1p1 of the CPU.
292
293 -  ``ERRATA_A77_2743100``: This applies errata 2743100 workaround to Cortex-A77
294    CPU. This needs to be enabled for r0p0, r1p0, and r1p1, it is still open.
295
296For Cortex-A78, the following errata build flags are defined :
297
298-  ``ERRATA_A78_1688305``: This applies errata 1688305 workaround to Cortex-A78
299   CPU. This needs to be enabled only for revision r0p0 - r1p0 of the CPU.
300
301-  ``ERRATA_A78_1941498``: This applies errata 1941498 workaround to Cortex-A78
302   CPU. This needs to be enabled for revisions r0p0, r1p0, and r1p1 of the CPU.
303
304-  ``ERRATA_A78_1951500``: This applies errata 1951500 workaround to Cortex-A78
305   CPU. This needs to be enabled for revisions r1p0 and r1p1, r0p0 has the same
306   issue but there is no workaround for that revision.
307
308-  ``ERRATA_A78_1821534``: This applies errata 1821534 workaround to Cortex-A78
309   CPU. This needs to be enabled for revisions r0p0 and r1p0.
310
311-  ``ERRATA_A78_1952683``: This applies errata 1952683 workaround to Cortex-A78
312   CPU. This needs to be enabled for revision r0p0, it is fixed in r1p0.
313
314-  ``ERRATA_A78_2132060``: This applies errata 2132060 workaround to Cortex-A78
315   CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1, and r1p2. It
316   is still open.
317
318-  ``ERRATA_A78_2242635``: This applies errata 2242635 workaround to Cortex-A78
319   CPU. This needs to be enabled for revisions r1p0, r1p1, and r1p2. The issue
320   is present in r0p0 but there is no workaround. It is still open.
321
322-  ``ERRATA_A78_2376745``: This applies errata 2376745 workaround to Cortex-A78
323   CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1, and r1p2, and
324   it is still open.
325
326-  ``ERRATA_A78_2395406``: This applies errata 2395406 workaround to Cortex-A78
327   CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1, and r1p2, and
328   it is still open.
329
330- ``ERRATA_A78_2712571``: This applies erratum 2712571 workaround to Cortex-A78
331   CPU, this erratum affects system configurations that do not use an ARM
332   interconnect IP. This needs to be enabled for revisions r0p0, r1p0, r1p1
333   and r1p2 and it is still open.
334
335-  ``ERRATA_A78_2742426``: This applies erratum 2742426 workaround to Cortex-A78
336   CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1 and r1p2 and
337   it is still open.
338
339-  ``ERRATA_A78_2772019``: This applies errata 2772019 workaround to Cortex-A78
340   CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1, and r1p2, and
341   it is still open.
342
343-  ``ERRATA_A78_2779479``: This applies erratum 2779479 workaround to Cortex-A78
344   CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1 and r1p2 and
345   it is still open.
346
347For Cortex-A78AE, the following errata build flags are defined :
348
349- ``ERRATA_A78_AE_1941500`` : This applies errata 1941500 workaround to
350   Cortex-A78AE CPU. This needs to be enabled for revisions r0p0 and r0p1.
351   This erratum is still open.
352
353- ``ERRATA_A78_AE_1951502`` : This applies errata 1951502 workaround to
354  Cortex-A78AE CPU. This needs to be enabled for revisions r0p0 and r0p1. This
355  erratum is still open.
356
357- ``ERRATA_A78_AE_2376748`` : This applies errata 2376748 workaround to
358  Cortex-A78AE CPU. This needs to be enabled for revisions r0p0, r0p1 and r0p2.
359  This erratum is still open.
360
361- ``ERRATA_A78_AE_2395408`` : This applies errata 2395408 workaround to
362  Cortex-A78AE CPU. This needs to be enabled for revisions r0p0 and r0p1. This
363  erratum is still open.
364
365- ``ERRATA_A78_AE_2712574`` : This applies erratum 2712574 workaround to
366  Cortex-A78AE CPU. This erratum affects system configurations that do not use
367  an ARM interconnect IP. This needs to be enabled for revisions r0p0, r0p1 and
368  r0p2. This erratum is still open.
369
370For Cortex-A78C, the following errata build flags are defined :
371
372- ``ERRATA_A78C_1827430`` : This applies errata 1827430 workaround to
373  Cortex-A78C CPU. This needs to be enabled for revision r0p0. The erratum is
374  fixed in r0p1.
375
376- ``ERRATA_A78C_1827440`` : This applies errata 1827440 workaround to
377  Cortex-A78C CPU. This needs to be enabled for revision r0p0. The erratum is
378  fixed in r0p1.
379
380- ``ERRATA_A78C_2132064`` : This applies errata 2132064 workaround to
381  Cortex-A78C CPU. This needs to be enabled for revisions r0p1, r0p2 and
382  it is still open.
383
384- ``ERRATA_A78C_2242638`` : This applies errata 2242638 workaround to
385  Cortex-A78C CPU. This needs to be enabled for revisions r0p1, r0p2 and
386  it is still open.
387
388- ``ERRATA_A78C_2376749`` : This applies errata 2376749 workaround to
389  Cortex-A78C CPU. This needs to be enabled for revisions r0p1 and r0p2. This
390  erratum is still open.
391
392- ``ERRATA_A78C_2395411`` : This applies errata 2395411 workaround to
393  Cortex-A78C CPU. This needs to be enabled for revisions r0p1 and r0p2. This
394  erratum is still open.
395
396- ``ERRATA_A78C_2683027`` : This applies errata 2683027 workaround to
397  Cortex-A78C CPU. This needs to be enabled for revisions r0p1 and r0p2. This
398  erratum is still open.
399
400- ``ERRATA_A78C_2712575`` : This applies erratum 2712575 workaround to
401  Cortex-A78C CPU, this erratum affects system configurations that do not use
402  an ARM interconnect IP. This needs to be enabled for revisions r0p1 and r0p2
403  and is still open.
404
405- ``ERRATA_A78C_2743232`` : This applies erratum 2743232 workaround to
406  Cortex-A78C CPU. This needs to be enabled for revisions r0p1 and r0p2.
407  This erratum is still open.
408
409- ``ERRATA_A78C_2772121`` : This applies errata 2772121 workaround to
410  Cortex-A78C CPU. This needs to be enabled for revisions r0p0, r0p1 and r0p2.
411  This erratum is still open.
412
413- ``ERRATA_A78C_2779484`` : This applies errata 2779484 workaround to
414  Cortex-A78C CPU. This needs to be enabled for revisions r0p1 and r0p2.
415  This erratum is still open.
416
417For Cortex-X1 CPU, the following errata build flags are defined:
418
419- ``ERRATA_X1_1821534`` : This applies errata 1821534 workaround to Cortex-X1
420   CPU. This needs to be enabled only for revision <= r1p0 of the CPU.
421
422- ``ERRATA_X1_1688305`` : This applies errata 1688305 workaround to Cortex-X1
423   CPU. This needs to be enabled only for revision <= r1p0 of the CPU.
424
425- ``ERRATA_X1_1827429`` : This applies errata 1827429 workaround to Cortex-X1
426   CPU. This needs to be enabled only for revision <= r1p0 of the CPU.
427
428For Neoverse N1, the following errata build flags are defined :
429
430-  ``ERRATA_N1_1073348``: This applies errata 1073348 workaround to Neoverse-N1
431   CPU. This needs to be enabled only for revision r0p0 and r1p0 of the CPU.
432
433-  ``ERRATA_N1_1130799``: This applies errata 1130799 workaround to Neoverse-N1
434   CPU. This needs to be enabled only for revision <= r2p0 of the CPU.
435
436-  ``ERRATA_N1_1165347``: This applies errata 1165347 workaround to Neoverse-N1
437   CPU. This needs to be enabled only for revision <= r2p0 of the CPU.
438
439-  ``ERRATA_N1_1207823``: This applies errata 1207823 workaround to Neoverse-N1
440   CPU. This needs to be enabled only for revision <= r2p0 of the CPU.
441
442-  ``ERRATA_N1_1220197``: This applies errata 1220197 workaround to Neoverse-N1
443   CPU. This needs to be enabled only for revision <= r2p0 of the CPU.
444
445-  ``ERRATA_N1_1257314``: This applies errata 1257314 workaround to Neoverse-N1
446   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
447
448-  ``ERRATA_N1_1262606``: This applies errata 1262606 workaround to Neoverse-N1
449   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
450
451-  ``ERRATA_N1_1262888``: This applies errata 1262888 workaround to Neoverse-N1
452   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
453
454-  ``ERRATA_N1_1275112``: This applies errata 1275112 workaround to Neoverse-N1
455   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
456
457-  ``ERRATA_N1_1315703``: This applies errata 1315703 workaround to Neoverse-N1
458   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
459
460-  ``ERRATA_N1_1542419``: This applies errata 1542419 workaround to Neoverse-N1
461   CPU. This needs to be enabled only for revisions r3p0 - r4p0 of the CPU.
462
463-  ``ERRATA_N1_1868343``: This applies errata 1868343 workaround to Neoverse-N1
464   CPU. This needs to be enabled only for revision <= r4p0 of the CPU.
465
466-  ``ERRATA_N1_1946160``: This applies errata 1946160 workaround to Neoverse-N1
467   CPU. This needs to be enabled for revisions r3p0, r3p1, r4p0, and r4p1, for
468   revisions r0p0, r1p0, and r2p0 there is no workaround.
469
470-  ``ERRATA_N1_2743102``: This applies errata 2743102 workaround to Neoverse-N1
471   CPU. This needs to be enabled for all revisions <= r4p1 of the CPU and is
472   still open.
473
474For Neoverse V1, the following errata build flags are defined :
475
476-  ``ERRATA_V1_1618635``: This applies errata 1618635 workaround to Neoverse-V1
477   CPU. This needs to be enabled for revision r0p0 of the CPU, it is fixed in
478   r1p0.
479
480-  ``ERRATA_V1_1774420``: This applies errata 1774420 workaround to Neoverse-V1
481   CPU. This needs to be enabled only for revisions r0p0 and r1p0, it is fixed
482   in r1p1.
483
484-  ``ERRATA_V1_1791573``: This applies errata 1791573 workaround to Neoverse-V1
485   CPU. This needs to be enabled only for revisions r0p0 and r1p0, it is fixed
486   in r1p1.
487
488-  ``ERRATA_V1_1852267``: This applies errata 1852267 workaround to Neoverse-V1
489   CPU. This needs to be enabled only for revisions r0p0 and r1p0, it is fixed
490   in r1p1.
491
492-  ``ERRATA_V1_1925756``: This applies errata 1925756 workaround to Neoverse-V1
493   CPU. This needs to be enabled for r0p0, r1p0, and r1p1, it is still open.
494
495-  ``ERRATA_V1_1940577``: This applies errata 1940577 workaround to Neoverse-V1
496   CPU. This needs to be enabled only for revision r1p0 and r1p1 of the
497   CPU.
498
499-  ``ERRATA_V1_1966096``: This applies errata 1966096 workaround to Neoverse-V1
500   CPU. This needs to be enabled for revisions r1p0 and r1p1 of the CPU, the
501   issue is present in r0p0 as well but there is no workaround for that
502   revision.  It is still open.
503
504-  ``ERRATA_V1_2139242``: This applies errata 2139242 workaround to Neoverse-V1
505   CPU. This needs to be enabled for revisions r0p0, r1p0, and r1p1 of the
506   CPU.  It is still open.
507
508-  ``ERRATA_V1_2108267``: This applies errata 2108267 workaround to Neoverse-V1
509   CPU. This needs to be enabled for revisions r0p0, r1p0, and r1p1 of the CPU.
510   It is still open.
511
512-  ``ERRATA_V1_2216392``: This applies errata 2216392 workaround to Neoverse-V1
513   CPU. This needs to be enabled for revisions r1p0 and r1p1 of the CPU, the
514   issue is present in r0p0 as well but there is no workaround for that
515   revision.  It is still open.
516
517-  ``ERRATA_V1_2294912``: This applies errata 2294912 workaround to Neoverse-V1
518   CPU. This needs to be enabled for revisions r0p0, r1p0, and r1p1 and r1p2 of
519   the CPU.
520
521-  ``ERRATA_V1_2348377``: This applies errata 2348377 workaroud to Neoverse-V1
522   CPU. This needs to be enabled for revisions r0p0, r1p0 and r1p1 of the CPU.
523   It has been fixed in r1p2.
524
525-  ``ERRATA_V1_2372203``: This applies errata 2372203 workaround to Neoverse-V1
526   CPU. This needs to be enabled for revisions r0p0, r1p0 and r1p1 of the CPU.
527   It is still open.
528
529- ``ERRATA_V1_2701953``: This applies erratum 2701953 workaround to Neoverse-V1
530   CPU, this erratum affects system configurations that do not use an ARM
531   interconnect IP. This needs to be enabled for revisions r0p0, r1p0 and r1p1.
532   It has been fixed in r1p2.
533
534-  ``ERRATA_V1_2743093``: This applies errata 2743093 workaround to Neoverse-V1
535   CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1 and r1p2 of the
536   CPU. It is still open.
537
538-  ``ERRATA_V1_2743233``: This applies erratum 2743233 workaround to Neoverse-V1
539   CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1, and r1p2 of the
540   CPU. It is still open.
541
542-  ``ERRATA_V1_2779461``: This applies erratum 2779461 workaround to Neoverse-V1
543   CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1, r1p2 of the
544   CPU. It is still open.
545
546For Neoverse V2, the following errata build flags are defined :
547
548-  ``ERRATA_V2_2331132``: This applies errata 2331132 workaround to Neoverse-V2
549   CPU. This needs to be enabled for revisions r0p0, r0p1 and r0p2. It is still
550   open.
551
552-  ``ERRATA_V2_2618597``: This applies errata 2618597 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_2662553``: This applies errata 2662553 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_2719103``: This applies errata 2719103 workaround to Neoverse-V2
561   CPU, this affects system configurations that do not use and ARM interconnect
562   IP. This needs to be enabled for revisions r0p0 and r0p1. It has been fixed
563   in r0p2.
564
565-  ``ERRATA_V2_2719105``: This applies errata 2719105 workaround to Neoverse-V2
566   CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed in
567   r0p2.
568
569-  ``ERRATA_V2_2743011``: This applies errata 2743011 workaround to Neoverse-V2
570   CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed in
571   r0p2.
572
573-  ``ERRATA_V2_2779510``: This applies errata 2779510 workaround to Neoverse-V2
574   CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed in
575   r0p2.
576
577-  ``ERRATA_V2_2801372``: This applies errata 2801372 workaround to Neoverse-V2
578   CPU, this affects all configurations. This needs to be enabled for revisions
579   r0p0 and r0p1. It has been fixed in r0p2.
580
581For Neoverse V3, the following errata build flags are defined :
582
583- ``ERRATA_V3_2970647``: This applies errata 2970647 workaround to Neoverse-V3
584  CPU. This needs to be enabled for revision r0p0. It is fixed in r0p1.
585
586- ``ERRATA_V3_3701767``: This applies errata 3701767 workaround to Neoverse-V3
587  CPU. This needs to be enabled for revisions r0p0, r0p1, r0p2 of the CPU and
588  is still open.
589
590For Cortex-A710, the following errata build flags are defined :
591
592-  ``ERRATA_A710_1987031``: This applies errata 1987031 workaround to
593   Cortex-A710 CPU. This needs to be enabled only for revisions r0p0, r1p0 and
594   r2p0 of the CPU. It is still open.
595
596-  ``ERRATA_A710_2081180``: This applies errata 2081180 workaround to
597   Cortex-A710 CPU. This needs to be enabled only for revisions r0p0, r1p0 and
598   r2p0 of the CPU. It is still open.
599
600-  ``ERRATA_A710_2055002``: This applies errata 2055002 workaround to
601   Cortex-A710 CPU. This needs to be enabled for revisions r1p0, r2p0 of the CPU
602   and is still open.
603
604-  ``ERRATA_A710_2017096``: This applies errata 2017096 workaround to
605   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
606   of the CPU and is still open.
607
608-  ``ERRATA_A710_2083908``: This applies errata 2083908 workaround to
609   Cortex-A710 CPU. This needs to be enabled for revision r2p0 of the CPU and
610   is still open.
611
612-  ``ERRATA_A710_2058056``: This applies errata 2058056 workaround to
613   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
614   and r2p1 of the CPU and is still open.
615
616-  ``ERRATA_A710_2267065``: This applies errata 2267065 workaround to
617   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
618   of the CPU and is fixed in r2p1.
619
620-  ``ERRATA_A710_2136059``: This applies errata 2136059 workaround to
621   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
622   of the CPU and is fixed in r2p1.
623
624-  ``ERRATA_A710_2147715``: This applies errata 2147715 workaround to
625   Cortex-A710 CPU. This needs to be enabled for revision r2p0 of the CPU
626   and is fixed in r2p1.
627
628-  ``ERRATA_A710_2216384``: This applies errata 2216384 workaround to
629   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
630   of the CPU and is fixed in r2p1.
631
632-  ``ERRATA_A710_2282622``: This applies errata 2282622 workaround to
633   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and
634   r2p1 of the CPU and is still open.
635
636- ``ERRATA_A710_2291219``: This applies errata 2291219 workaround to
637   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
638   of the CPU and is fixed in r2p1.
639
640-  ``ERRATA_A710_2008768``: This applies errata 2008768 workaround to
641   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
642   of the CPU and is fixed in r2p1.
643
644-  ``ERRATA_A710_2371105``: This applies errata 2371105 workaround to
645   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
646   of the CPU and is fixed in r2p1.
647
648-  ``ERRATA_A710_2701952``: This applies erratum 2701952 workaround to Cortex-A710
649   CPU, and applies to system configurations that do not use and ARM
650   interconnect IP. This needs to be enabled for r0p0, r1p0, r2p0 and r2p1 and
651   is still open.
652
653-  ``ERRATA_A710_2742423``: This applies errata 2742423 workaround to
654   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and
655   r2p1 of the CPU and is still open.
656
657-  ``ERRATA_A710_2768515``: This applies errata 2768515 workaround to
658   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and
659   r2p1 of the CPU and is still open.
660
661-  ``ERRATA_A710_2778471``: This applies errata 2778471 workaround to Cortex-A710
662   CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and r2p1 of the
663   CPU and is still open.
664
665- ``ERRATA_A710_3701772``: This applies errata 3701772 workaround to Cortex-A710
666  CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0, r2p1 of the
667  CPU and is still open.
668
669For Neoverse N2, the following errata build flags are defined :
670
671-  ``ERRATA_N2_2002655``: This applies errata 2002655 workaround to Neoverse-N2
672   CPU. This needs to be enabled for revision r0p0 of the CPU and is fixed in r0p1.
673
674-  ``ERRATA_N2_2009478``: This applies errata 2009478 workaround to Neoverse-N2
675   CPU. This needs to be enabled for revision r0p0 of the CPU and is fixed in r0p1.
676
677-  ``ERRATA_N2_2067956``: This applies errata 2067956 workaround to Neoverse-N2
678   CPU. This needs to be enabled for revision r0p0 of the CPU and is fixed in r0p1.
679
680-  ``ERRATA_N2_2025414``: This applies errata 2025414 workaround to Neoverse-N2
681   CPU. This needs to be enabled for revision r0p0 of the CPU and is fixed in r0p1.
682
683-  ``ERRATA_N2_2189731``: This applies errata 2189731 workaround to Neoverse-N2
684   CPU. This needs to be enabled for revision r0p0 of the CPU and is fixed in r0p1.
685
686-  ``ERRATA_N2_2138956``: This applies errata 2138956 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_2138953``: This applies errata 2138953 workaround to Neoverse-N2
690   CPU. This needs to be enabled for revisions r0p0, r0p1, r0p2, r0p3 and is still open.
691
692-  ``ERRATA_N2_2242415``: This applies errata 2242415 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_2138958``: This applies errata 2138958 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_2242400``: This applies errata 2242400 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_2280757``: This applies errata 2280757 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_2326639``: This applies errata 2326639 workaround to Neoverse-N2
705   CPU. This needs to be enabled for revision r0p0 of the CPU, it is fixed in
706   r0p1.
707
708-  ``ERRATA_N2_2340933``: This applies errata 2340933 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_2346952``: This applies errata 2346952 workaround to Neoverse-N2
713   CPU. This needs to be enabled for revisions r0p0, r0p1 and r0p2 of the CPU,
714   it is fixed in r0p3.
715
716-  ``ERRATA_N2_2376738``: This applies errata 2376738 workaround to Neoverse-N2
717   CPU. This needs to be enabled for revision r0p0, r0p1, r0p2, r0p3 and is still open.
718
719-  ``ERRATA_N2_2388450``: This applies errata 2388450 workaround to Neoverse-N2
720   CPU. This needs to be enabled for revision r0p0 of the CPU, it is fixed in
721   r0p1.
722
723-  ``ERRATA_N2_2743014``: This applies errata 2743014 workaround to Neoverse-N2
724   CPU. This needs to be enabled for revisions r0p0, r0p1 and r0p2. It is fixed
725   in r0p3.
726
727-  ``ERRATA_N2_2743089``: This applies errata 2743089 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_2728475``: This applies erratum 2728475 workaround to Neoverse-N2
732   CPU, this erratum affects system configurations that do not use and ARM
733   interconnect IP. This needs to be enabled for revisions r0p0, r0p1 and r0p2.
734   It is fixed in r0p3.
735
736-  ``ERRATA_N2_2779511``: This applies errata 2779511 workaround to Neoverse-N2
737   CPU. This needs to be enabled for revisions r0p0, r0p1 and r0p2. It is fixed
738   in r0p3.
739
740-  ``ERRATA_N2_3701773``: This applies errata 3701773 workaround to Neoverse-N2
741   CPU. This needs to be enabled for revisions r0p0, r0p1, r0p2, r0p3 and is
742   still open.
743
744For Neoverse N3, the following errata build flags are defined :
745
746-  ``ERRATA_N3_3699563``: This applies errata 3699563 workaround to Neoverse-N3
747   CPU. This needs to be enabled for revisions r0p0 and is still open.
748
749For Cortex-X2, the following errata build flags are defined :
750
751-  ``ERRATA_X2_2002765``: This applies errata 2002765 workaround to Cortex-X2
752   CPU. This needs to be enabled for revisions r0p0, r1p0, and r2p0 of the CPU,
753   it is still open.
754
755-  ``ERRATA_X2_2058056``: This applies errata 2058056 workaround to Cortex-X2
756   CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and r2p1 of the CPU,
757   it is still open.
758
759-  ``ERRATA_X2_2083908``: This applies errata 2083908 workaround to Cortex-X2
760   CPU. This needs to be enabled for revision r2p0 of the CPU, it is still open.
761
762-  ``ERRATA_X2_2017096``: This applies errata 2017096 workaround to Cortex-X2
763   CPU. This needs to be enabled only for revisions r0p0, r1p0 and r2p0 of the
764   CPU, it is fixed in r2p1.
765
766-  ``ERRATA_X2_2081180``: This applies errata 2081180 workaround to Cortex-X2
767   CPU. This needs to be enabled only for revisions r0p0, r1p0 and r2p0 of the
768   CPU, it is fixed in r2p1.
769
770-  ``ERRATA_X2_2216384``: This applies errata 2216384 workaround to Cortex-X2
771   CPU. This needs to be enabled only for revisions r0p0, r1p0 and r2p0 of the
772   CPU, it is fixed in r2p1.
773
774-  ``ERRATA_X2_2147715``: This applies errata 2147715 workaround to Cortex-X2
775   CPU. This needs to be enabled only for revision r2p0 of the CPU, it is fixed
776   in r2p1.
777
778-  ``ERRATA_X2_2282622``: This applies errata 2282622 workaround to Cortex-X2
779   CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and r2p1 of the
780   CPU and is still open.
781
782-  ``ERRATA_X2_2371105``: This applies errata 2371105 workaround to Cortex-X2
783   CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0 of the CPU
784   and is fixed in r2p1.
785
786- ``ERRATA_X2_2701952``: This applies erratum 2701952 workaround to Cortex-X2
787   CPU and affects system configurations that do not use an ARM interconnect IP.
788   This needs to be enabled for revisions r0p0, r1p0, r2p0 and r2p1 and is
789   still open.
790
791-  ``ERRATA_X2_2742423``: This applies errata 2742423 workaround to Cortex-X2
792   CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and r2p1 of the
793   CPU and is still open.
794
795-  ``ERRATA_X2_2768515``: This applies errata 2768515 workaround to Cortex-X2
796   CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and r2p1 of the
797   CPU and is still open.
798
799-  ``ERRATA_X2_2778471``: This applies errata 2778471 workaround to Cortex-X2
800   CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and r2p1 of the
801   CPU and it is still open.
802
803-  ``ERRATA_X2_3701772``: This applies errata 3701772 workaround to Cortex-X2
804   CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and r2p1 of the
805   CPU and it is still open.
806
807For Cortex-X3, the following errata build flags are defined :
808
809- ``ERRATA_X3_2070301``: This applies errata 2070301 workaround to the Cortex-X3
810  CPU. This needs to be enabled only for revisions r0p0, r1p0, r1p1 and r1p2 of
811  the CPU and is still open.
812
813- ``ERRATA_X3_2266875``: This applies errata 2266875 workaround to the Cortex-X3
814  CPU. This needs to be enabled only for revisions r0p0 and r1p0 of the CPU, it
815  is fixed in r1p1.
816
817- ``ERRATA_X3_2302506``: This applies errata 2302506 workaround to the Cortex-X3
818  CPU. This needs to be enabled only for revisions r0p0, r1p0 and r1p1, it is
819  fixed in r1p2.
820
821- ``ERRATA_X3_2313909``: This applies errata 2313909 workaround to
822  Cortex-X3 CPU. This needs to be enabled only for revisions r0p0 and r1p0
823  of the CPU, it is fixed in r1p1.
824
825- ``ERRATA_X3_2372204``: This applies errata 2372204 workaround to
826  Cortex-X3 CPU. This needs to be enabled only for revisions r0p0 and r1p0
827  of the CPU, it is fixed in r1p1.
828
829- ``ERRATA_X3_2615812``: This applies errata 2615812 workaround to Cortex-X3
830  CPU. This needs to be enabled only for revisions r0p0, r1p0 and r1p1 of the
831  CPU, it is fixed in r1p2.
832
833- ``ERRATA_X3_2641945``: This applies errata 2641945 workaround to Cortex-X3
834  CPU. This needs to be enabled only for revisions r0p0 and r1p0 of the CPU.
835  It is fixed in r1p1.
836
837- ``ERRATA_X3_2701951``: This applies erratum 2701951 workaround to Cortex-X3
838  CPU and affects system configurations that do not use an ARM interconnect
839  IP. This needs to be applied to revisions r0p0, r1p0 and r1p1. It is fixed
840  in r1p2.
841
842- ``ERRATA_X3_2742421``: This applies errata 2742421 workaround to
843  Cortex-X3 CPU. This needs to be enabled only for revisions r0p0, r1p0 and
844  r1p1. It is fixed in r1p2.
845
846- ``ERRATA_X3_2743088``: This applies errata 2743088 workaround to Cortex-X3
847  CPU. This needs to be enabled only for revisions r0p0, r1p0 and r1p1. It is
848  fixed in r1p2.
849
850- ``ERRATA_X3_2779509``: This applies errata 2779509 workaround to Cortex-X3
851  CPU. This needs to be enabled only for revisions r0p0, r1p0 and r1p1 of the
852  CPU. It is fixed in r1p2.
853
854- ``ERRATA_X3_3701769``: This applies errata 3701769 workaround to Cortex-X3
855  CPU. This needs to be enabled only for revisions r0p0, r1p0, r1p1 and r1p2
856  of the CPU and it is still open.
857
858For Cortex-X4, the following errata build flags are defined :
859
860- ``ERRATA_X4_2701112``: This applies erratum 2701112 workaround to Cortex-X4
861  CPU and affects system configurations that do not use an Arm interconnect IP.
862  This needs to be enabled for revisions r0p0 and is fixed in r0p1.
863  The workaround for this erratum is not implemented in EL3, but the flag can
864  be enabled/disabled at the platform level. The flag is used when the errata ABI
865  feature is enabled and can assist the Kernel in the process of
866  mitigation of the erratum.
867
868- ``ERRATA_X4_2726228``: This applies erratum 2726228 workaround to Cortex-X4
869  CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed in
870  r0p2.
871
872-  ``ERRATA_X4_2740089``: This applies errata 2740089 workaround to Cortex-X4
873   CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed
874   in r0p2.
875
876- ``ERRATA_X4_2763018``: This applies errata 2763018 workaround to Cortex-X4
877  CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed in r0p2.
878
879- ``ERRATA_X4_2816013``: This applies errata 2816013 workaround to Cortex-X4
880  CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed in r0p2.
881
882- ``ERRATA_X4_2897503``: This applies errata 2897503 workaround to Cortex-X4
883  CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed in r0p2.
884
885- ``ERRATA_X4_2923985``: This applies errata 2923985 workaround to Cortex-X4
886  CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed in r0p2.
887
888- ``ERRATA_X4_2957258``: This applies errata 2957258 workaround to Cortex-X4
889  CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed in r0p2.
890
891- ``ERRATA_X4_3076789``: This applies errata 3076789 workaround to Cortex-X4
892  CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed in r0p2.
893
894- ``ERRATA_X4_3701758``: This applies errata 3701758 workaround to Cortex-X4
895  CPU. This needs to be enabled for revisions r0p0, r0p1, r0p2 and r0p3.
896  It is still open.
897
898For Cortex-X925, the following errata build flags are defined :
899
900- ``ERRATA_X925_2963999``: This applies errata 2963999 workaround to Cortex-X925
901  CPU. This needs to be enabled for revision r0p0. It is fixed in r0p1.
902
903- ``ERRATA_X925_3701747``: This applies errata 3701747 workaround to Cortex-X925
904  CPU. This needs to be enabled for revisions r0p0 and r0p1. It is still open.
905
906For Cortex-A510, the following errata build flags are defined :
907
908-  ``ERRATA_A510_1922240``: This applies errata 1922240 workaround to
909   Cortex-A510 CPU. This needs to be enabled only for revision r0p0, it is
910   fixed in r0p1.
911
912-  ``ERRATA_A510_2288014``: This applies errata 2288014 workaround to
913   Cortex-A510 CPU. This needs to be enabled only for revisions r0p0, r0p1,
914   r0p2, r0p3 and r1p0, it is fixed in r1p1.
915
916-  ``ERRATA_A510_2042739``: This applies errata 2042739 workaround to
917   Cortex-A510 CPU. This needs to be enabled only for revisions r0p0, r0p1 and
918   r0p2, it is fixed in r0p3.
919
920-  ``ERRATA_A510_2041909``: This applies errata 2041909 workaround to
921   Cortex-A510 CPU. This needs to be enabled only for revision r0p2 and is fixed
922   in r0p3. The issue is also present in r0p0 and r0p1 but there is no
923   workaround for those revisions.
924
925-  ``ERRATA_A510_2080326``: This applies errata 2080326 workaround to
926   Cortex-A510 CPU. This needs to be enabled only for revision r0p2 and is
927   fixed in r0p3. This issue is also present in r0p0 and r0p1 but there is no
928   workaround for those revisions.
929
930-  ``ERRATA_A510_2250311``: This applies errata 2250311 workaround to
931   Cortex-A510 CPU. This needs to be enabled for revisions r0p0, r0p1, r0p2,
932   r0p3 and r1p0, it is fixed in r1p1. This workaround disables MPMM even if
933   ENABLE_MPMM=1.
934
935-  ``ERRATA_A510_2218950``: This applies errata 2218950 workaround to
936   Cortex-A510 CPU. This needs to be enabled for revisions r0p0, r0p1, r0p2,
937   r0p3 and r1p0, it is fixed in r1p1.
938
939-  ``ERRATA_A510_2172148``: This applies errata 2172148 workaround to
940   Cortex-A510 CPU. This needs to be enabled for revisions r0p0, r0p1, r0p2,
941   r0p3 and r1p0, it is fixed in r1p1.
942
943-  ``ERRATA_A510_2347730``: This applies errata 2347730 workaround to
944   Cortex-A510 CPU. This needs to be enabled for revisions r0p0, r0p1, r0p2,
945   r0p3, r1p0 and r1p1. It is fixed in r1p2.
946
947-  ``ERRATA_A510_2371937``: This applies errata 2371937 workaround to
948   Cortex-A510 CPU. This needs to applied for revisions r0p0, r0p1, r0p2,
949   r0p3, r1p0, r1p1, and is fixed in r1p2.
950
951-  ``ERRATA_A510_2666669``: This applies errata 2666669 workaround to
952   Cortex-A510 CPU. This needs to applied for revisions r0p0, r0p1, r0p2,
953   r0p3, r1p0, r1p1. It is fixed in r1p2.
954
955-  ``ERRATA_A510_2684597``: This applies erratum 2684597 workaround to
956   Cortex-A510 CPU. This needs to be applied to revision r0p0, r0p1, r0p2,
957   r0p3, r1p0, r1p1 and r1p2. It is fixed in r1p3.
958
959-  ``ERRATA_A510_2971420``: This applies erratum 2971420 workaround to
960   Cortex-A510 CPU. This needs to be applied to revisions r0p1, r0p2, r0p3,
961   r1p0, r1p1, r1p2 and r1p3 and is still open.
962
963For Cortex-A520, the following errata build flags are defined :
964
965-  ``ERRATA_A520_2630792``: This applies errata 2630792 workaround to
966   Cortex-A520 CPU. This needs to applied for revisions r0p0, r0p1 of the
967   CPU and is still open.
968
969-  ``ERRATA_A520_2858100``: This applies errata 2858100 workaround to
970   Cortex-A520 CPU. This needs to be enabled for revisions r0p0 and r0p1.
971   It is still open.
972
973-  ``ERRATA_A520_2938996``: This applies errata 2938996 workaround to
974   Cortex-A520 CPU. This needs to be enabled for revisions r0p0 and r0p1.
975   It is fixed in r0p2.
976
977For Cortex-A715, the following errata build flags are defined :
978
979-  ``ERRATA_A715_2331818``: This applies errata 2331818 workaround to
980   Cortex-A715 CPU. This needs to be enabled for revisions r0p0 and r1p0.
981   It is fixed in r1p1.
982
983- ``ERRATA_A715_2344187``: This applies errata 2344187 workaround to
984   Cortex-A715 CPU. This needs to be enabled for revisions r0p0 and r1p0. It is
985   fixed in r1p1.
986
987-  ``ERRATA_A715_2413290``: This applies errata 2413290 workaround to
988   Cortex-A715 CPU. This needs to be enabled only for revision r1p0 and
989   when SPE(Statistical profiling extension)=True. The errata is fixed
990   in r1p1.
991
992-  ``ERRATA_A715_2420947``: This applies errata 2420947 workaround to
993   Cortex-A715 CPU. This needs to be enabled only for revision r1p0.
994   It is fixed in r1p1.
995
996-  ``ERRATA_A715_2429384``: This applies errata 2429384 workaround to
997   Cortex-A715 CPU. This needs to be enabled for revision r1p0. There is no
998   workaround for revision r0p0. It is fixed in r1p1.
999
1000-  ``ERRATA_A715_2561034``: This applies errata 2561034 workaround to
1001   Cortex-A715 CPU. This needs to be enabled only for revision r1p0.
1002   It is fixed in r1p1.
1003
1004-  ``ERRATA_A715_2728106``: This applies errata 2728106 workaround to
1005   Cortex-A715 CPU. This needs to be enabled for revisions r0p0, r1p0
1006   and r1p1. It is fixed in r1p2.
1007
1008-  ``ERRATA_A715_2804830``: This applies errata 2804830 workaround to
1009   Cortex-A715 CPU. This needs to be enabled for revisions r0p0, r1p0,
1010   r1p1 and r1p2. It is fixed in r1p3.
1011
1012-  ``ERRATA_A715_3699560``: This applies errata 3699560 workaround to
1013   Cortex-A715 CPU. This needs to be enabled for revisions r0p0, r1p0,
1014   r1p2 and r1p3. It is still open.
1015
1016For Cortex-A720, the following errata build flags are defined :
1017
1018-  ``ERRATA_A720_2792132``: This applies errata 2792132 workaround to
1019   Cortex-A720 CPU. This needs to be enabled for revisions r0p0 and r0p1.
1020   It is fixed in r0p2.
1021
1022-  ``ERRATA_A720_2844092``: This applies errata 2844092 workaround to
1023   Cortex-A720 CPU. This needs to be enabled for revisions r0p0 and r0p1.
1024   It is fixed in r0p2.
1025
1026-  ``ERRATA_A720_2926083``: This applies errata 2926083 workaround to
1027   Cortex-A720 CPU. This needs to be enabled for revisions r0p0 and r0p1.
1028   It is fixed in r0p2.
1029
1030-  ``ERRATA_A720_2940794``: This applies errata 2940794 workaround to
1031   Cortex-A720 CPU. This needs to be enabled for revisions r0p0 and r0p1.
1032   It is fixed in r0p2.
1033
1034-  ``ERRATA_A720_3699561``: This applies errata 3699561 workaround to
1035   Cortex-A720 CPU. This needs to be enabled for revisions r0p0, r0p1
1036   and r0p2. It is still open.
1037
1038For Cortex-A720_AE, the following errata build flags are defined :
1039
1040-  ``ERRATA_A720_AE_3699562``: This applies errata 3699562 workaround
1041   to Cortex-A720_AE CPU. This needs to be enabled for revisions r0p0.
1042   It is still open.
1043
1044For Cortex-A725, the following errata build flags are defined :
1045
1046-  ``ERRATA_A725_3699564``: This applies errata 3699564 workaround to
1047   Cortex-A725 CPU. This needs to be enabled for revisions r0p0 and r0p1.
1048   It is fixed in r0p2.
1049
1050DSU Errata Workarounds
1051----------------------
1052
1053Similar to CPU errata, TF-A also implements workarounds for DSU (DynamIQ
1054Shared Unit) errata. The DSU errata details can be found in the respective Arm
1055documentation:
1056
1057- `Arm DSU Software Developers Errata Notice`_.
1058
1059Each erratum is identified by an ``ID``, as defined in the DSU errata notice
1060document. Thus, the build flags which enable/disable the errata workarounds
1061have the format ``ERRATA_DSU_<ID>``. The implementation and application logic
1062of DSU errata workarounds are similar to `CPU errata workarounds`_.
1063
1064For DSU errata, the following build flags are defined:
1065
1066-  ``ERRATA_DSU_798953``: This applies errata 798953 workaround for the
1067   affected DSU configurations. This errata applies only for those DSUs that
1068   revision is r0p0 (on r0p1 it is fixed). However, please note that this
1069   workaround results in increased DSU power consumption on idle.
1070
1071-  ``ERRATA_DSU_936184``: This applies errata 936184 workaround for the
1072   affected DSU configurations. This errata applies only for those DSUs that
1073   contain the ACP interface **and** the DSU revision is older than r2p0 (on
1074   r2p0 it is fixed). However, please note that this workaround results in
1075   increased DSU power consumption on idle.
1076
1077-  ``ERRATA_DSU_2313941``: This applies errata 2313941 workaround for the
1078   affected DSU configurations. This errata applies for those DSUs with
1079   revisions r0p0, r1p0, r2p0, r2p1, r3p0, r3p1 and is still open. However,
1080   please note that this workaround results in increased DSU power consumption
1081   on idle.
1082
1083CPU Specific optimizations
1084--------------------------
1085
1086This section describes some of the optimizations allowed by the CPU micro
1087architecture that can be enabled by the platform as desired.
1088
1089-  ``SKIP_A57_L1_FLUSH_PWR_DWN``: This flag enables an optimization in the
1090   Cortex-A57 cluster power down sequence by not flushing the Level 1 data
1091   cache. The L1 data cache and the L2 unified cache are inclusive. A flush
1092   of the L2 by set/way flushes any dirty lines from the L1 as well. This
1093   is a known safe deviation from the Cortex-A57 TRM defined power down
1094   sequence. Each Cortex-A57 based platform must make its own decision on
1095   whether to use the optimization.
1096
1097-  ``A53_DISABLE_NON_TEMPORAL_HINT``: This flag disables the cache non-temporal
1098   hint. The LDNP/STNP instructions as implemented on Cortex-A53 do not behave
1099   in a way most programmers expect, and will most probably result in a
1100   significant speed degradation to any code that employs them. The Armv8-A
1101   architecture (see Arm DDI 0487A.h, section D3.4.3) allows cores to ignore
1102   the non-temporal hint and treat LDNP/STNP as LDP/STP instead. Enabling this
1103   flag enforces this behaviour. This needs to be enabled only for revisions
1104   <= r0p3 of the CPU and is enabled by default.
1105
1106-  ``A57_DISABLE_NON_TEMPORAL_HINT``: This flag has the same behaviour as
1107   ``A53_DISABLE_NON_TEMPORAL_HINT`` but for Cortex-A57. This needs to be
1108   enabled only for revisions <= r1p2 of the CPU and is enabled by default,
1109   as recommended in section "4.7 Non-Temporal Loads/Stores" of the
1110   `Cortex-A57 Software Optimization Guide`_.
1111
1112- ''A57_ENABLE_NON_CACHEABLE_LOAD_FWD'': This flag enables non-cacheable
1113   streaming enhancement feature for Cortex-A57 CPUs. Platforms can set
1114   this bit only if their memory system meets the requirement that cache
1115   line fill requests from the Cortex-A57 processor are atomic. Each
1116   Cortex-A57 based platform must make its own decision on whether to use
1117   the optimization. This flag is disabled by default.
1118
1119-  ``NEOVERSE_Nx_EXTERNAL_LLC``: This flag indicates that an external last
1120   level cache(LLC) is present in the system, and that the DataSource field
1121   on the master CHI interface indicates when data is returned from the LLC.
1122   This is used to control how the LL_CACHE* PMU events count.
1123   Default value is 0 (Disabled).
1124
1125GIC Errata Workarounds
1126----------------------
1127-  ``GIC600_ERRATA_WA_2384374``: This flag applies part 2 of errata 2384374
1128   workaround for the affected GIC600 and GIC600-AE implementations. It applies
1129   to implementations of GIC600 and GIC600-AE with revisions less than or equal
1130   to r1p6 and r0p2 respectively. If the platform sets GICV3_SUPPORT_GIC600,
1131   then this flag is enabled; otherwise, it is 0 (Disabled).
1132
1133--------------
1134
1135*Copyright (c) 2014-2025, Arm Limited and Contributors. All rights reserved.*
1136
1137.. _CVE-2017-5715: http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-5715
1138.. _CVE-2018-3639: http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-3639
1139.. _CVE-2022-23960: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-23960
1140.. _Cortex-A53 MPCore Software Developers Errata Notice: http://infocenter.arm.com/help/topic/com.arm.doc.epm048406/index.html
1141.. _Cortex-A57 MPCore Software Developers Errata Notice: http://infocenter.arm.com/help/topic/com.arm.doc.epm049219/index.html
1142.. _Cortex-A72 MPCore Software Developers Errata Notice: http://infocenter.arm.com/help/topic/com.arm.doc.epm012079/index.html
1143.. _Cortex-A57 Software Optimization Guide: http://infocenter.arm.com/help/topic/com.arm.doc.uan0015b/Cortex_A57_Software_Optimization_Guide_external.pdf
1144.. _Arm DSU Software Developers Errata Notice: http://infocenter.arm.com/help/topic/com.arm.doc.epm138168/index.html
1145