xref: /rk3399_ARM-atf/docs/design/cpu-specific-build-macros.rst (revision 6d415de83fe084c08558895837d0eb90210420a9)
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.. _arm_cpu_macros_errata_workarounds:
42
43CPU Errata Workarounds
44----------------------
45
46TF-A exports a series of build flags which control the errata workarounds that
47are applied to each CPU by the reset handler. The errata details can be found
48in the CPU specific errata documents published by Arm:
49
50-  `Cortex-A53 MPCore Software Developers Errata Notice`_
51-  `Cortex-A57 MPCore Software Developers Errata Notice`_
52-  `Cortex-A72 MPCore Software Developers Errata Notice`_
53
54The errata workarounds are implemented for a particular revision or a set of
55processor revisions. This is checked by the reset handler at runtime. Each
56errata workaround is identified by its ``ID`` as specified in the processor's
57errata notice document. The format of the define used to enable/disable the
58errata workaround is ``ERRATA_<Processor name>_<ID>``, where the ``Processor name``
59is for example ``A57`` for the ``Cortex_A57`` CPU.
60
61Refer to :ref:`firmware_design_cpu_errata_implementation` for information on how to
62write errata workaround functions.
63
64All workarounds are disabled by default. The platform is responsible for
65enabling these workarounds according to its requirement by defining the
66errata workaround build flags in the platform specific makefile. In case
67these workarounds are enabled for the wrong CPU revision then the errata
68workaround is not applied. In the DEBUG build, this is indicated by
69printing a warning to the crash console.
70
71In the current implementation, a platform which has more than 1 variant
72with different revisions of a processor has no runtime mechanism available
73for it to specify which errata workarounds should be enabled or not.
74
75The value of the build flags is 0 by default, that is, disabled. A value of 1
76will enable it.
77
78For Cortex-A9, the following errata build flags are defined :
79
80-  ``ERRATA_A9_794073``: This applies errata 794073 workaround to Cortex-A9
81   CPU. This needs to be enabled for all revisions of the CPU.
82
83For Cortex-A15, the following errata build flags are defined :
84
85-  ``ERRATA_A15_816470``: This applies errata 816470 workaround to Cortex-A15
86   CPU. This needs to be enabled only for revision >= r3p0 of the CPU.
87
88-  ``ERRATA_A15_827671``: This applies errata 827671 workaround to Cortex-A15
89   CPU. This needs to be enabled only for revision >= r3p0 of the CPU.
90
91For Cortex-A17, the following errata build flags are defined :
92
93-  ``ERRATA_A17_852421``: This applies errata 852421 workaround to Cortex-A17
94   CPU. This needs to be enabled only for revision <= r1p2 of the CPU.
95
96-  ``ERRATA_A17_852423``: This applies errata 852423 workaround to Cortex-A17
97   CPU. This needs to be enabled only for revision <= r1p2 of the CPU.
98
99For Cortex-A35, the following errata build flags are defined :
100
101-  ``ERRATA_A35_855472``: This applies errata 855472 workaround to Cortex-A35
102   CPUs. This needs to be enabled only for revision r0p0 of Cortex-A35.
103
104For Cortex-A53, the following errata build flags are defined :
105
106-  ``ERRATA_A53_819472``: This applies errata 819472 workaround to all
107   CPUs. This needs to be enabled only for revision <= r0p1 of Cortex-A53.
108
109-  ``ERRATA_A53_824069``: This applies errata 824069 workaround to all
110   CPUs. This needs to be enabled only for revision <= r0p2 of Cortex-A53.
111
112-  ``ERRATA_A53_826319``: This applies errata 826319 workaround to Cortex-A53
113   CPU. This needs to be enabled only for revision <= r0p2 of the CPU.
114
115-  ``ERRATA_A53_827319``: This applies errata 827319 workaround to all
116   CPUs. This needs to be enabled only for revision <= r0p2 of Cortex-A53.
117
118-  ``ERRATA_A53_835769``: This applies erratum 835769 workaround at compile and
119   link time to Cortex-A53 CPU. This needs to be enabled for some variants of
120   revision <= r0p4. This workaround can lead the linker to create ``*.stub``
121   sections.
122
123-  ``ERRATA_A53_836870``: This applies errata 836870 workaround to Cortex-A53
124   CPU. This needs to be enabled only for revision <= r0p3 of the CPU. From
125   r0p4 and onwards, this errata is enabled by default in hardware. Identical to
126   ``A53_DISABLE_NON_TEMPORAL_HINT``.
127
128-  ``ERRATA_A53_843419``: This applies erratum 843419 workaround at link time
129   to Cortex-A53 CPU.  This needs to be enabled for some variants of revision
130   <= r0p4. This workaround can lead the linker to emit ``*.stub`` sections
131   which are 4kB aligned.
132
133-  ``ERRATA_A53_855873``: This applies errata 855873 workaround to Cortex-A53
134   CPUs. Though the erratum is present in every revision of the CPU,
135   this workaround is only applied to CPUs from r0p3 onwards, which feature
136   a chicken bit in CPUACTLR_EL1 to enable a hardware workaround.
137   Earlier revisions of the CPU have other errata which require the same
138   workaround in software, so they should be covered anyway.
139
140-  ``ERRATA_A53_1530924``: This applies errata 1530924 workaround to all
141   revisions of Cortex-A53 CPU.
142
143For Cortex-A55, the following errata build flags are defined :
144
145-  ``ERRATA_A55_768277``: This applies errata 768277 workaround to Cortex-A55
146   CPU. This needs to be enabled only for revision r0p0 of the CPU.
147
148-  ``ERRATA_A55_778703``: This applies errata 778703 workaround to Cortex-A55
149   CPU. This needs to be enabled only for revision r0p0 of the CPU.
150
151-  ``ERRATA_A55_798797``: This applies errata 798797 workaround to Cortex-A55
152   CPU. This needs to be enabled only for revision r0p0 of the CPU.
153
154-  ``ERRATA_A55_846532``: This applies errata 846532 workaround to Cortex-A55
155   CPU. This needs to be enabled only for revision <= r0p1 of the CPU.
156
157-  ``ERRATA_A55_903758``: This applies errata 903758 workaround to Cortex-A55
158   CPU. This needs to be enabled only for revision <= r0p1 of the CPU.
159
160-  ``ERRATA_A55_1221012``: This applies errata 1221012 workaround to Cortex-A55
161   CPU. This needs to be enabled only for revision <= r1p0 of the CPU.
162
163-  ``ERRATA_A55_1530923``: This applies errata 1530923 workaround to all
164   revisions of Cortex-A55 CPU.
165
166For Cortex-A57, the following errata build flags are defined :
167
168-  ``ERRATA_A57_806969``: This applies errata 806969 workaround to Cortex-A57
169   CPU. This needs to be enabled only for revision r0p0 of the CPU.
170
171-  ``ERRATA_A57_813419``: This applies errata 813419 workaround to Cortex-A57
172   CPU. This needs to be enabled only for revision r0p0 of the CPU.
173
174-  ``ERRATA_A57_813420``: This applies errata 813420 workaround to Cortex-A57
175   CPU. This needs to be enabled only for revision r0p0 of the CPU.
176
177-  ``ERRATA_A57_814670``: This applies errata 814670 workaround to Cortex-A57
178   CPU. This needs to be enabled only for revision r0p0 of the CPU.
179
180-  ``ERRATA_A57_817169``: This applies errata 817169 workaround to Cortex-A57
181   CPU. This needs to be enabled only for revision <= r0p1 of the CPU.
182
183-  ``ERRATA_A57_826974``: This applies errata 826974 workaround to Cortex-A57
184   CPU. This needs to be enabled only for revision <= r1p1 of the CPU.
185
186-  ``ERRATA_A57_826977``: This applies errata 826977 workaround to Cortex-A57
187   CPU. This needs to be enabled only for revision <= r1p1 of the CPU.
188
189-  ``ERRATA_A57_828024``: This applies errata 828024 workaround to Cortex-A57
190   CPU. This needs to be enabled only for revision <= r1p1 of the CPU.
191
192-  ``ERRATA_A57_829520``: This applies errata 829520 workaround to Cortex-A57
193   CPU. This needs to be enabled only for revision <= r1p2 of the CPU.
194
195-  ``ERRATA_A57_833471``: This applies errata 833471 workaround to Cortex-A57
196   CPU. This needs to be enabled only for revision <= r1p2 of the CPU.
197
198-  ``ERRATA_A57_859972``: This applies errata 859972 workaround to Cortex-A57
199   CPU. This needs to be enabled only for revision <= r1p3 of the CPU.
200
201-  ``ERRATA_A57_1319537``: This applies errata 1319537 workaround to all
202   revisions of Cortex-A57 CPU.
203
204For Cortex-A72, the following errata build flags are defined :
205
206-  ``ERRATA_A72_859971``: This applies errata 859971 workaround to Cortex-A72
207   CPU. This needs to be enabled only for revision <= r0p3 of the CPU.
208
209-  ``ERRATA_A72_1319367``: This applies errata 1319367 workaround to all
210   revisions of Cortex-A72 CPU.
211
212For Cortex-A73, the following errata build flags are defined :
213
214-  ``ERRATA_A73_852427``: This applies errata 852427 workaround to Cortex-A73
215   CPU. This needs to be enabled only for revision r0p0 of the CPU.
216
217-  ``ERRATA_A73_855423``: This applies errata 855423 workaround to Cortex-A73
218   CPU. This needs to be enabled only for revision <= r0p1 of the CPU.
219
220For Cortex-A75, the following errata build flags are defined :
221
222-  ``ERRATA_A75_764081``: This applies errata 764081 workaround to Cortex-A75
223   CPU. This needs to be enabled only for revision r0p0 of the CPU.
224
225-  ``ERRATA_A75_790748``: This applies errata 790748 workaround to Cortex-A75
226    CPU. This needs to be enabled only for revision r0p0 of the CPU.
227
228For Cortex-A76, the following errata build flags are defined :
229
230-  ``ERRATA_A76_1073348``: This applies errata 1073348 workaround to Cortex-A76
231   CPU. This needs to be enabled only for revision <= r1p0 of the CPU.
232
233-  ``ERRATA_A76_1130799``: This applies errata 1130799 workaround to Cortex-A76
234   CPU. This needs to be enabled only for revision <= r2p0 of the CPU.
235
236-  ``ERRATA_A76_1220197``: This applies errata 1220197 workaround to Cortex-A76
237   CPU. This needs to be enabled only for revision <= r2p0 of the CPU.
238
239-  ``ERRATA_A76_1257314``: This applies errata 1257314 workaround to Cortex-A76
240   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
241
242-  ``ERRATA_A76_1262606``: This applies errata 1262606 workaround to Cortex-A76
243   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
244
245-  ``ERRATA_A76_1262888``: This applies errata 1262888 workaround to Cortex-A76
246   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
247
248-  ``ERRATA_A76_1275112``: This applies errata 1275112 workaround to Cortex-A76
249   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
250
251-  ``ERRATA_A76_1791580``: This applies errata 1791580 workaround to Cortex-A76
252   CPU. This needs to be enabled only for revision <= r4p0 of the CPU.
253
254-  ``ERRATA_A76_1165522``: This applies errata 1165522 workaround to all
255   revisions of Cortex-A76 CPU. This errata is fixed in r3p0 but due to
256   limitation of errata framework this errata is applied to all revisions
257   of Cortex-A76 CPU.
258
259-  ``ERRATA_A76_1868343``: This applies errata 1868343 workaround to Cortex-A76
260   CPU. This needs to be enabled only for revision <= r4p0 of the CPU.
261
262-  ``ERRATA_A76_1946160``: This applies errata 1946160 workaround to Cortex-A76
263   CPU. This needs to be enabled only for revisions r3p0 - r4p1 of the CPU.
264
265-  ``ERRATA_A76_2743102``: This applies errata 2743102 workaround to Cortex-A76
266   CPU. This needs to be enabled for all revisions <= r4p1 of the CPU and is
267   still open.
268
269For Cortex-A77, the following errata build flags are defined :
270
271-  ``ERRATA_A77_1508412``: This applies errata 1508412 workaround to Cortex-A77
272   CPU. This needs to be enabled only for revision <= r1p0 of the CPU.
273
274-  ``ERRATA_A77_1925769``: This applies errata 1925769 workaround to Cortex-A77
275   CPU. This needs to be enabled only for revision <= r1p1 of the CPU.
276
277-  ``ERRATA_A77_1946167``: This applies errata 1946167 workaround to Cortex-A77
278   CPU. This needs to be enabled only for revision <= r1p1 of the CPU.
279
280-  ``ERRATA_A77_1791578``: This applies errata 1791578 workaround to Cortex-A77
281   CPU. This needs to be enabled for r0p0, r1p0, and r1p1, it is still open.
282
283-  ``ERRATA_A77_2356587``: This applies errata 2356587 workaround to Cortex-A77
284   CPU. This needs to be enabled for r0p0, r1p0, and r1p1, it is still open.
285
286 -  ``ERRATA_A77_1800714``: This applies errata 1800714 workaround to Cortex-A77
287    CPU. This needs to be enabled for revisions <= r1p1 of the CPU.
288
289 -  ``ERRATA_A77_2743100``: This applies errata 2743100 workaround to Cortex-A77
290    CPU. This needs to be enabled for r0p0, r1p0, and r1p1, it is still open.
291
292For Cortex-A78, the following errata build flags are defined :
293
294-  ``ERRATA_A78_1688305``: This applies errata 1688305 workaround to Cortex-A78
295   CPU. This needs to be enabled only for revision r0p0 - r1p0 of the CPU.
296
297-  ``ERRATA_A78_1941498``: This applies errata 1941498 workaround to Cortex-A78
298   CPU. This needs to be enabled for revisions r0p0, r1p0, and r1p1 of the CPU.
299
300-  ``ERRATA_A78_1951500``: This applies errata 1951500 workaround to Cortex-A78
301   CPU. This needs to be enabled for revisions r1p0 and r1p1, r0p0 has the same
302   issue but there is no workaround for that revision.
303
304-  ``ERRATA_A78_1821534``: This applies errata 1821534 workaround to Cortex-A78
305   CPU. This needs to be enabled for revisions r0p0 and r1p0.
306
307-  ``ERRATA_A78_1952683``: This applies errata 1952683 workaround to Cortex-A78
308   CPU. This needs to be enabled for revision r0p0, it is fixed in r1p0.
309
310-  ``ERRATA_A78_2132060``: This applies errata 2132060 workaround to Cortex-A78
311   CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1, and r1p2. It
312   is still open.
313
314-  ``ERRATA_A78_2242635``: This applies errata 2242635 workaround to Cortex-A78
315   CPU. This needs to be enabled for revisions r1p0, r1p1, and r1p2. The issue
316   is present in r0p0 but there is no workaround. It is still open.
317
318-  ``ERRATA_A78_2376745``: This applies errata 2376745 workaround to Cortex-A78
319   CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1, and r1p2, and
320   it is still open.
321
322-  ``ERRATA_A78_2395406``: This applies errata 2395406 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_2712571``: This applies erratum 2712571 workaround to Cortex-A78
327   CPU, this erratum affects system configurations that do not use an ARM
328   interconnect IP. This needs to be enabled for revisions r0p0, r1p0, r1p1
329   and r1p2 and it is still open.
330
331-  ``ERRATA_A78_2742426``: This applies erratum 2742426 workaround to Cortex-A78
332   CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1 and r1p2 and
333   it is still open.
334
335-  ``ERRATA_A78_2772019``: This applies errata 2772019 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_2779479``: This applies erratum 2779479 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
343For Cortex-A78AE, the following errata build flags are defined :
344
345- ``ERRATA_A78_AE_1941500`` : This applies errata 1941500 workaround to
346   Cortex-A78AE CPU. This needs to be enabled for revisions r0p0 and r0p1.
347   This erratum is still open.
348
349- ``ERRATA_A78_AE_1951502`` : This applies errata 1951502 workaround to
350  Cortex-A78AE CPU. This needs to be enabled for revisions r0p0 and r0p1. This
351  erratum is still open.
352
353- ``ERRATA_A78_AE_2376748`` : This applies errata 2376748 workaround to
354  Cortex-A78AE CPU. This needs to be enabled for revisions r0p0, r0p1 and r0p2.
355  This erratum is still open.
356
357- ``ERRATA_A78_AE_2395408`` : This applies errata 2395408 workaround to
358  Cortex-A78AE CPU. This needs to be enabled for revisions r0p0 and r0p1. This
359  erratum is still open.
360
361- ``ERRATA_A78_AE_2712574`` : This applies erratum 2712574 workaround to
362  Cortex-A78AE CPU. This erratum affects system configurations that do not use
363  an ARM interconnect IP. This needs to be enabled for revisions r0p0, r0p1 and
364  r0p2. This erratum is still open.
365
366For Cortex-A78C, the following errata build flags are defined :
367
368- ``ERRATA_A78C_1827430`` : This applies errata 1827430 workaround to
369  Cortex-A78C CPU. This needs to be enabled for revision r0p0. The erratum is
370  fixed in r0p1.
371
372- ``ERRATA_A78C_1827440`` : This applies errata 1827440 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_2132064`` : This applies errata 2132064 workaround to
377  Cortex-A78C CPU. This needs to be enabled for revisions r0p1, r0p2 and
378  it is still open.
379
380- ``ERRATA_A78C_2242638`` : This applies errata 2242638 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_2376749`` : This applies errata 2376749 workaround to
385  Cortex-A78C CPU. This needs to be enabled for revisions r0p1 and r0p2. This
386  erratum is still open.
387
388- ``ERRATA_A78C_2395411`` : This applies errata 2395411 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_2683027`` : This applies errata 2683027 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_2712575`` : This applies erratum 2712575 workaround to
397  Cortex-A78C CPU, this erratum affects system configurations that do not use
398  an ARM interconnect IP. This needs to be enabled for revisions r0p1 and r0p2
399  and is still open.
400
401- ``ERRATA_A78C_2743232`` : This applies erratum 2743232 workaround to
402  Cortex-A78C CPU. This needs to be enabled for revisions r0p1 and r0p2.
403  This erratum is still open.
404
405- ``ERRATA_A78C_2772121`` : This applies errata 2772121 workaround to
406  Cortex-A78C CPU. This needs to be enabled for revisions r0p0, r0p1 and r0p2.
407  This erratum is still open.
408
409- ``ERRATA_A78C_2779484`` : This applies errata 2779484 workaround to
410  Cortex-A78C CPU. This needs to be enabled for revisions r0p1 and r0p2.
411  This erratum is still open.
412
413For Cortex-X1 CPU, the following errata build flags are defined:
414
415- ``ERRATA_X1_1821534`` : This applies errata 1821534 workaround to Cortex-X1
416   CPU. This needs to be enabled only for revision <= r1p0 of the CPU.
417
418- ``ERRATA_X1_1688305`` : This applies errata 1688305 workaround to Cortex-X1
419   CPU. This needs to be enabled only for revision <= r1p0 of the CPU.
420
421- ``ERRATA_X1_1827429`` : This applies errata 1827429 workaround to Cortex-X1
422   CPU. This needs to be enabled only for revision <= r1p0 of the CPU.
423
424For Neoverse N1, the following errata build flags are defined :
425
426-  ``ERRATA_N1_1073348``: This applies errata 1073348 workaround to Neoverse-N1
427   CPU. This needs to be enabled only for revision r0p0 and r1p0 of the CPU.
428
429-  ``ERRATA_N1_1130799``: This applies errata 1130799 workaround to Neoverse-N1
430   CPU. This needs to be enabled only for revision <= r2p0 of the CPU.
431
432-  ``ERRATA_N1_1165347``: This applies errata 1165347 workaround to Neoverse-N1
433   CPU. This needs to be enabled only for revision <= r2p0 of the CPU.
434
435-  ``ERRATA_N1_1207823``: This applies errata 1207823 workaround to Neoverse-N1
436   CPU. This needs to be enabled only for revision <= r2p0 of the CPU.
437
438-  ``ERRATA_N1_1220197``: This applies errata 1220197 workaround to Neoverse-N1
439   CPU. This needs to be enabled only for revision <= r2p0 of the CPU.
440
441-  ``ERRATA_N1_1257314``: This applies errata 1257314 workaround to Neoverse-N1
442   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
443
444-  ``ERRATA_N1_1262606``: This applies errata 1262606 workaround to Neoverse-N1
445   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
446
447-  ``ERRATA_N1_1262888``: This applies errata 1262888 workaround to Neoverse-N1
448   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
449
450-  ``ERRATA_N1_1275112``: This applies errata 1275112 workaround to Neoverse-N1
451   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
452
453-  ``ERRATA_N1_1315703``: This applies errata 1315703 workaround to Neoverse-N1
454   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
455
456-  ``ERRATA_N1_1542419``: This applies errata 1542419 workaround to Neoverse-N1
457   CPU. This needs to be enabled only for revisions r3p0 - r4p0 of the CPU.
458
459-  ``ERRATA_N1_1868343``: This applies errata 1868343 workaround to Neoverse-N1
460   CPU. This needs to be enabled only for revision <= r4p0 of the CPU.
461
462-  ``ERRATA_N1_1946160``: This applies errata 1946160 workaround to Neoverse-N1
463   CPU. This needs to be enabled for revisions r3p0, r3p1, r4p0, and r4p1, for
464   revisions r0p0, r1p0, and r2p0 there is no workaround.
465
466-  ``ERRATA_N1_2743102``: This applies errata 2743102 workaround to Neoverse-N1
467   CPU. This needs to be enabled for all revisions <= r4p1 of the CPU and is
468   still open.
469
470For Neoverse V1, the following errata build flags are defined :
471
472-  ``ERRATA_V1_1618635``: This applies errata 1618635 workaround to Neoverse-V1
473   CPU. This needs to be enabled for revision r0p0 of the CPU, it is fixed in
474   r1p0.
475
476-  ``ERRATA_V1_1774420``: This applies errata 1774420 workaround to Neoverse-V1
477   CPU. This needs to be enabled only for revisions r0p0 and r1p0, it is fixed
478   in r1p1.
479
480-  ``ERRATA_V1_1791573``: This applies errata 1791573 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_1852267``: This applies errata 1852267 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_1925756``: This applies errata 1925756 workaround to Neoverse-V1
489   CPU. This needs to be enabled for r0p0, r1p0, and r1p1, it is still open.
490
491-  ``ERRATA_V1_1940577``: This applies errata 1940577 workaround to Neoverse-V1
492   CPU. This needs to be enabled only for revision r1p0 and r1p1 of the
493   CPU.
494
495-  ``ERRATA_V1_1966096``: This applies errata 1966096 workaround to Neoverse-V1
496   CPU. This needs to be enabled for revisions r1p0 and r1p1 of the CPU, the
497   issue is present in r0p0 as well but there is no workaround for that
498   revision.  It is still open.
499
500-  ``ERRATA_V1_2139242``: This applies errata 2139242 workaround to Neoverse-V1
501   CPU. This needs to be enabled for revisions r0p0, r1p0, and r1p1 of the
502   CPU.  It is still open.
503
504-  ``ERRATA_V1_2108267``: This applies errata 2108267 workaround to Neoverse-V1
505   CPU. This needs to be enabled for revisions r0p0, r1p0, and r1p1 of the CPU.
506   It is still open.
507
508-  ``ERRATA_V1_2216392``: This applies errata 2216392 workaround to Neoverse-V1
509   CPU. This needs to be enabled for revisions r1p0 and r1p1 of the CPU, the
510   issue is present in r0p0 as well but there is no workaround for that
511   revision.  It is still open.
512
513-  ``ERRATA_V1_2294912``: This applies errata 2294912 workaround to Neoverse-V1
514   CPU. This needs to be enabled for revisions r0p0, r1p0, and r1p1 and r1p2 of
515   the CPU.
516
517-  ``ERRATA_V1_2348377``: This applies errata 2348377 workaroud to Neoverse-V1
518   CPU. This needs to be enabled for revisions r0p0, r1p0 and r1p1 of the CPU.
519   It has been fixed in r1p2.
520
521-  ``ERRATA_V1_2372203``: This applies errata 2372203 workaround to Neoverse-V1
522   CPU. This needs to be enabled for revisions r0p0, r1p0 and r1p1 of the CPU.
523   It is still open.
524
525- ``ERRATA_V1_2701953``: This applies erratum 2701953 workaround to Neoverse-V1
526   CPU, this erratum affects system configurations that do not use an ARM
527   interconnect IP. This needs to be enabled for revisions r0p0, r1p0 and r1p1.
528   It has been fixed in r1p2.
529
530-  ``ERRATA_V1_2743093``: This applies errata 2743093 workaround to Neoverse-V1
531   CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1 and r1p2 of the
532   CPU. It is still open.
533
534-  ``ERRATA_V1_2743233``: This applies erratum 2743233 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_2779461``: This applies erratum 2779461 workaround to Neoverse-V1
539   CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1, r1p2 of the
540   CPU. It is still open.
541
542For Neoverse V2, the following errata build flags are defined :
543
544-  ``ERRATA_V2_2331132``: This applies errata 2331132 workaround to Neoverse-V2
545   CPU. This needs to be enabled for revisions r0p0, r0p1 and r0p2. It is still
546   open.
547
548-  ``ERRATA_V2_2618597``: This applies errata 2618597 workaround to Neoverse-V2
549   CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed in
550   r0p2.
551
552-  ``ERRATA_V2_2662553``: This applies errata 2662553 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_2719103``: This applies errata 2719103 workaround to Neoverse-V2
557   CPU, this affects system configurations that do not use and ARM interconnect
558   IP. This needs to be enabled for revisions r0p0 and r0p1. It has been fixed
559   in r0p2.
560
561-  ``ERRATA_V2_2719105``: This applies errata 2719105 workaround to Neoverse-V2
562   CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed in
563   r0p2.
564
565-  ``ERRATA_V2_2743011``: This applies errata 2743011 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_2779510``: This applies errata 2779510 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_2801372``: This applies errata 2801372 workaround to Neoverse-V2
574   CPU, this affects all configurations. This needs to be enabled for revisions
575   r0p0 and r0p1. It has been fixed in r0p2.
576
577For Cortex-A710, the following errata build flags are defined :
578
579-  ``ERRATA_A710_1987031``: This applies errata 1987031 workaround to
580   Cortex-A710 CPU. This needs to be enabled only for revisions r0p0, r1p0 and
581   r2p0 of the CPU. It is still open.
582
583-  ``ERRATA_A710_2081180``: This applies errata 2081180 workaround to
584   Cortex-A710 CPU. This needs to be enabled only for revisions r0p0, r1p0 and
585   r2p0 of the CPU. It is still open.
586
587-  ``ERRATA_A710_2055002``: This applies errata 2055002 workaround to
588   Cortex-A710 CPU. This needs to be enabled for revisions r1p0, r2p0 of the CPU
589   and is still open.
590
591-  ``ERRATA_A710_2017096``: This applies errata 2017096 workaround to
592   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
593   of the CPU and is still open.
594
595-  ``ERRATA_A710_2083908``: This applies errata 2083908 workaround to
596   Cortex-A710 CPU. This needs to be enabled for revision r2p0 of the CPU and
597   is still open.
598
599-  ``ERRATA_A710_2058056``: This applies errata 2058056 workaround to
600   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
601   and r2p1 of the CPU and is still open.
602
603-  ``ERRATA_A710_2267065``: This applies errata 2267065 workaround to
604   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
605   of the CPU and is fixed in r2p1.
606
607-  ``ERRATA_A710_2136059``: This applies errata 2136059 workaround to
608   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
609   of the CPU and is fixed in r2p1.
610
611-  ``ERRATA_A710_2147715``: This applies errata 2147715 workaround to
612   Cortex-A710 CPU. This needs to be enabled for revision r2p0 of the CPU
613   and is fixed in r2p1.
614
615-  ``ERRATA_A710_2216384``: This applies errata 2216384 workaround to
616   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
617   of the CPU and is fixed in r2p1.
618
619-  ``ERRATA_A710_2282622``: This applies errata 2282622 workaround to
620   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and
621   r2p1 of the CPU and is still open.
622
623- ``ERRATA_A710_2291219``: This applies errata 2291219 workaround to
624   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
625   of the CPU and is fixed in r2p1.
626
627-  ``ERRATA_A710_2008768``: This applies errata 2008768 workaround to
628   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
629   of the CPU and is fixed in r2p1.
630
631-  ``ERRATA_A710_2371105``: This applies errata 2371105 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_2701952``: This applies erratum 2701952 workaround to Cortex-A710
636   CPU, and applies to system configurations that do not use and ARM
637   interconnect IP. This needs to be enabled for r0p0, r1p0, r2p0 and r2p1 and
638   is still open.
639
640-  ``ERRATA_A710_2742423``: This applies errata 2742423 workaround to
641   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and
642   r2p1 of the CPU and is still open.
643
644-  ``ERRATA_A710_2768515``: This applies errata 2768515 workaround to
645   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and
646   r2p1 of the CPU and is still open.
647
648-  ``ERRATA_A710_2778471``: This applies errata 2778471 workaround to Cortex-A710
649   CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and r2p1 of the
650   CPU and is still open.
651
652For Neoverse N2, the following errata build flags are defined :
653
654-  ``ERRATA_N2_2002655``: This applies errata 2002655 workaround to Neoverse-N2
655   CPU. This needs to be enabled for revision r0p0 of the CPU and is fixed in r0p1.
656
657-  ``ERRATA_N2_2009478``: This applies errata 2009478 workaround to Neoverse-N2
658   CPU. This needs to be enabled for revision r0p0 of the CPU and is fixed in r0p1.
659
660-  ``ERRATA_N2_2067956``: This applies errata 2067956 workaround to Neoverse-N2
661   CPU. This needs to be enabled for revision r0p0 of the CPU and is fixed in r0p1.
662
663-  ``ERRATA_N2_2025414``: This applies errata 2025414 workaround to Neoverse-N2
664   CPU. This needs to be enabled for revision r0p0 of the CPU and is fixed in r0p1.
665
666-  ``ERRATA_N2_2189731``: This applies errata 2189731 workaround to Neoverse-N2
667   CPU. This needs to be enabled for revision r0p0 of the CPU and is fixed in r0p1.
668
669-  ``ERRATA_N2_2138956``: This applies errata 2138956 workaround to Neoverse-N2
670   CPU. This needs to be enabled for revision r0p0 of the CPU and is fixed in r0p1.
671
672-  ``ERRATA_N2_2138953``: This applies errata 2138953 workaround to Neoverse-N2
673   CPU. This needs to be enabled for revisions r0p0, r0p1, r0p2, r0p3 and is still open.
674
675-  ``ERRATA_N2_2242415``: This applies errata 2242415 workaround to Neoverse-N2
676   CPU. This needs to be enabled for revision r0p0 of the CPU and is fixed in r0p1.
677
678-  ``ERRATA_N2_2138958``: This applies errata 2138958 workaround to Neoverse-N2
679   CPU. This needs to be enabled for revision r0p0 of the CPU and is fixed in r0p1.
680
681-  ``ERRATA_N2_2242400``: This applies errata 2242400 workaround to Neoverse-N2
682   CPU. This needs to be enabled for revision r0p0 of the CPU and is fixed in r0p1.
683
684-  ``ERRATA_N2_2280757``: This applies errata 2280757 workaround to Neoverse-N2
685   CPU. This needs to be enabled for revision r0p0 of the CPU and is fixed in r0p1.
686
687-  ``ERRATA_N2_2326639``: This applies errata 2326639 workaround to Neoverse-N2
688   CPU. This needs to be enabled for revision r0p0 of the CPU, it is fixed in
689   r0p1.
690
691-  ``ERRATA_N2_2340933``: This applies errata 2340933 workaround to Neoverse-N2
692   CPU. This needs to be enabled for revision r0p0 of the CPU, it is fixed in
693   r0p1.
694
695-  ``ERRATA_N2_2346952``: This applies errata 2346952 workaround to Neoverse-N2
696   CPU. This needs to be enabled for revisions r0p0, r0p1 and r0p2 of the CPU,
697   it is fixed in r0p3.
698
699-  ``ERRATA_N2_2376738``: This applies errata 2376738 workaround to Neoverse-N2
700   CPU. This needs to be enabled for revision r0p0, r0p1, r0p2, r0p3 and is still open.
701
702-  ``ERRATA_N2_2388450``: This applies errata 2388450 workaround to Neoverse-N2
703   CPU. This needs to be enabled for revision r0p0 of the CPU, it is fixed in
704   r0p1.
705
706-  ``ERRATA_N2_2743014``: This applies errata 2743014 workaround to Neoverse-N2
707   CPU. This needs to be enabled for revisions r0p0, r0p1 and r0p2. It is fixed
708   in r0p3.
709
710-  ``ERRATA_N2_2743089``: This applies errata 2743089 workaround to Neoverse-N2
711   CPU. This needs to be enabled for revisions r0p0, r0p1 and r0p2. It is fixed
712   in r0p3.
713
714- ``ERRATA_N2_2728475``: This applies erratum 2728475 workaround to Neoverse-N2
715   CPU, this erratum affects system configurations that do not use and ARM
716   interconnect IP. This needs to be enabled for revisions r0p0, r0p1 and r0p2.
717   It is fixed in r0p3.
718
719-  ``ERRATA_N2_2779511``: This applies errata 2779511 workaround to Neoverse-N2
720   CPU. This needs to be enabled for revisions r0p0, r0p1 and r0p2. It is fixed
721   in r0p3.
722
723For Cortex-X2, the following errata build flags are defined :
724
725-  ``ERRATA_X2_2002765``: This applies errata 2002765 workaround to Cortex-X2
726   CPU. This needs to be enabled for revisions r0p0, r1p0, and r2p0 of the CPU,
727   it is still open.
728
729-  ``ERRATA_X2_2058056``: This applies errata 2058056 workaround to Cortex-X2
730   CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and r2p1 of the CPU,
731   it is still open.
732
733-  ``ERRATA_X2_2083908``: This applies errata 2083908 workaround to Cortex-X2
734   CPU. This needs to be enabled for revision r2p0 of the CPU, it is still open.
735
736-  ``ERRATA_X2_2017096``: This applies errata 2017096 workaround to Cortex-X2
737   CPU. This needs to be enabled only for revisions r0p0, r1p0 and r2p0 of the
738   CPU, it is fixed in r2p1.
739
740-  ``ERRATA_X2_2081180``: This applies errata 2081180 workaround to Cortex-X2
741   CPU. This needs to be enabled only for revisions r0p0, r1p0 and r2p0 of the
742   CPU, it is fixed in r2p1.
743
744-  ``ERRATA_X2_2216384``: This applies errata 2216384 workaround to Cortex-X2
745   CPU. This needs to be enabled only for revisions r0p0, r1p0 and r2p0 of the
746   CPU, it is fixed in r2p1.
747
748-  ``ERRATA_X2_2147715``: This applies errata 2147715 workaround to Cortex-X2
749   CPU. This needs to be enabled only for revision r2p0 of the CPU, it is fixed
750   in r2p1.
751
752-  ``ERRATA_X2_2282622``: This applies errata 2282622 workaround to Cortex-X2
753   CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and r2p1 of the
754   CPU and is still open.
755
756-  ``ERRATA_X2_2371105``: This applies errata 2371105 workaround to Cortex-X2
757   CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0 of the CPU
758   and is fixed in r2p1.
759
760- ``ERRATA_X2_2701952``: This applies erratum 2701952 workaround to Cortex-X2
761   CPU and affects system configurations that do not use an ARM interconnect IP.
762   This needs to be enabled for revisions r0p0, r1p0, r2p0 and r2p1 and is
763   still open.
764
765-  ``ERRATA_X2_2742423``: This applies errata 2742423 workaround to Cortex-X2
766   CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and r2p1 of the
767   CPU and is still open.
768
769-  ``ERRATA_X2_2768515``: This applies errata 2768515 workaround to Cortex-X2
770   CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and r2p1 of the
771   CPU and is still open.
772
773-  ``ERRATA_X2_2778471``: This applies errata 2778471 workaround to Cortex-X2
774   CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and r2p1 of the
775   CPU and it is still open.
776
777For Cortex-X3, the following errata build flags are defined :
778
779- ``ERRATA_X3_2070301``: This applies errata 2070301 workaround to the Cortex-X3
780  CPU. This needs to be enabled only for revisions r0p0, r1p0, r1p1 and r1p2 of
781  the CPU and is still open.
782
783- ``ERRATA_X3_2266875``: This applies errata 2266875 workaround to the Cortex-X3
784  CPU. This needs to be enabled only for revisions r0p0 and r1p0 of the CPU, it
785  is fixed in r1p1.
786
787- ``ERRATA_X3_2302506``: This applies errata 2302506 workaround to the Cortex-X3
788  CPU. This needs to be enabled only for revisions r0p0, r1p0 and r1p1, it is
789  fixed in r1p2.
790
791- ``ERRATA_X3_2313909``: This applies errata 2313909 workaround to
792  Cortex-X3 CPU. This needs to be enabled only for revisions r0p0 and r1p0
793  of the CPU, it is fixed in r1p1.
794
795- ``ERRATA_X3_2372204``: This applies errata 2372204 workaround to
796  Cortex-X3 CPU. This needs to be enabled only for revisions r0p0 and r1p0
797  of the CPU, it is fixed in r1p1.
798
799- ``ERRATA_X3_2615812``: This applies errata 2615812 workaround to Cortex-X3
800  CPU. This needs to be enabled only for revisions r0p0, r1p0 and r1p1 of the
801  CPU, it is fixed in r1p2.
802
803- ``ERRATA_X3_2641945``: This applies errata 2641945 workaround to Cortex-X3
804  CPU. This needs to be enabled only for revisions r0p0 and r1p0 of the CPU.
805  It is fixed in r1p1.
806
807- ``ERRATA_X3_2701951``: This applies erratum 2701951 workaround to Cortex-X3
808  CPU and affects system configurations that do not use an ARM interconnect
809  IP. This needs to be applied to revisions r0p0, r1p0 and r1p1. It is fixed
810  in r1p2.
811
812- ``ERRATA_X3_2742421``: This applies errata 2742421 workaround to
813  Cortex-X3 CPU. This needs to be enabled only for revisions r0p0, r1p0 and
814  r1p1. It is fixed in r1p2.
815
816- ``ERRATA_X3_2743088``: This applies errata 2743088 workaround to Cortex-X3
817  CPU. This needs to be enabled only for revisions r0p0, r1p0 and r1p1. It is
818  fixed in r1p2.
819
820- ``ERRATA_X3_2779509``: This applies errata 2779509 workaround to Cortex-X3
821  CPU. This needs to be enabled only for revisions r0p0, r1p0 and r1p1 of the
822  CPU. It is fixed in r1p2.
823
824For Cortex-X4, the following errata build flags are defined :
825
826- ``ERRATA_X4_2701112``: This applies erratum 2701112 workaround to Cortex-X4
827  CPU and affects system configurations that do not use an Arm interconnect IP.
828  This needs to be enabled for revisions r0p0 and is fixed in r0p1.
829  The workaround for this erratum is not implemented in EL3, but the flag can
830  be enabled/disabled at the platform level. The flag is used when the errata ABI
831  feature is enabled and can assist the Kernel in the process of
832  mitigation of the erratum.
833
834- ``ERRATA_X4_2726228``: This applies erratum 2726228 workaround to Cortex-X4
835  CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed in
836  r0p2.
837
838-  ``ERRATA_X4_2740089``: This applies errata 2740089 workaround to Cortex-X4
839   CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed
840   in r0p2.
841
842- ``ERRATA_X4_2763018``: This applies errata 2763018 workaround to Cortex-X4
843  CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed in r0p2.
844
845- ``ERRATA_X4_2816013``: This applies errata 2816013 workaround to Cortex-X4
846  CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed in r0p2.
847
848- ``ERRATA_X4_2897503``: This applies errata 2897503 workaround to Cortex-X4
849  CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed in r0p2.
850
851- ``ERRATA_X4_2923985``: This applies errata 2923985 workaround to Cortex-X4
852  CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed in r0p2.
853
854- ``ERRATA_X4_3076789``: This applies errata 3076789 workaround to Cortex-X4
855  CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed in r0p2.
856
857For Cortex-A510, the following errata build flags are defined :
858
859-  ``ERRATA_A510_1922240``: This applies errata 1922240 workaround to
860   Cortex-A510 CPU. This needs to be enabled only for revision r0p0, it is
861   fixed in r0p1.
862
863-  ``ERRATA_A510_2288014``: This applies errata 2288014 workaround to
864   Cortex-A510 CPU. This needs to be enabled only for revisions r0p0, r0p1,
865   r0p2, r0p3 and r1p0, it is fixed in r1p1.
866
867-  ``ERRATA_A510_2042739``: This applies errata 2042739 workaround to
868   Cortex-A510 CPU. This needs to be enabled only for revisions r0p0, r0p1 and
869   r0p2, it is fixed in r0p3.
870
871-  ``ERRATA_A510_2041909``: This applies errata 2041909 workaround to
872   Cortex-A510 CPU. This needs to be enabled only for revision r0p2 and is fixed
873   in r0p3. The issue is also present in r0p0 and r0p1 but there is no
874   workaround for those revisions.
875
876-  ``ERRATA_A510_2080326``: This applies errata 2080326 workaround to
877   Cortex-A510 CPU. This needs to be enabled only for revision r0p2 and is
878   fixed in r0p3. This issue is also present in r0p0 and r0p1 but there is no
879   workaround for those revisions.
880
881-  ``ERRATA_A510_2250311``: This applies errata 2250311 workaround to
882   Cortex-A510 CPU. This needs to be enabled for revisions r0p0, r0p1, r0p2,
883   r0p3 and r1p0, it is fixed in r1p1. This workaround disables MPMM even if
884   ENABLE_MPMM=1.
885
886-  ``ERRATA_A510_2218950``: This applies errata 2218950 workaround to
887   Cortex-A510 CPU. This needs to be enabled for revisions r0p0, r0p1, r0p2,
888   r0p3 and r1p0, it is fixed in r1p1.
889
890-  ``ERRATA_A510_2172148``: This applies errata 2172148 workaround to
891   Cortex-A510 CPU. This needs to be enabled for revisions r0p0, r0p1, r0p2,
892   r0p3 and r1p0, it is fixed in r1p1.
893
894-  ``ERRATA_A510_2347730``: This applies errata 2347730 workaround to
895   Cortex-A510 CPU. This needs to be enabled for revisions r0p0, r0p1, r0p2,
896   r0p3, r1p0 and r1p1. It is fixed in r1p2.
897
898-  ``ERRATA_A510_2371937``: This applies errata 2371937 workaround to
899   Cortex-A510 CPU. This needs to applied for revisions r0p0, r0p1, r0p2,
900   r0p3, r1p0, r1p1, and is fixed in r1p2.
901
902-  ``ERRATA_A510_2666669``: This applies errata 2666669 workaround to
903   Cortex-A510 CPU. This needs to applied for revisions r0p0, r0p1, r0p2,
904   r0p3, r1p0, r1p1. It is fixed in r1p2.
905
906-  ``ERRATA_A510_2684597``: This applies erratum 2684597 workaround to
907   Cortex-A510 CPU. This needs to be applied to revision r0p0, r0p1, r0p2,
908   r0p3, r1p0, r1p1 and r1p2. It is fixed in r1p3.
909
910For Cortex-A520, the following errata build flags are defined :
911
912-  ``ERRATA_A520_2630792``: This applies errata 2630792 workaround to
913   Cortex-A520 CPU. This needs to applied for revisions r0p0, r0p1 of the
914   CPU and is still open.
915
916-  ``ERRATA_A520_2858100``: This applies errata 2858100 workaround to
917   Cortex-A520 CPU. This needs to be enabled for revisions r0p0 and r0p1.
918   It is still open.
919
920-  ``ERRATA_A520_2938996``: This applies errata 2938996 workaround to
921   Cortex-A520 CPU. This needs to be enabled for revisions r0p0 and r0p1.
922   It is fixed in r0p2.
923
924For Cortex-A715, the following errata build flags are defined :
925
926-  ``ERRATA_A715_2331818``: This applies errata 2331818 workaround to
927   Cortex-A715 CPU. This needs to be enabled for revisions r0p0 and r1p0.
928   It is fixed in r1p1.
929
930- ``ERRATA_A715_2344187``: This applies errata 2344187 workaround to
931   Cortex-A715 CPU. This needs to be enabled for revisions r0p0 and r1p0. It is
932   fixed in r1p1.
933
934-  ``ERRATA_A715_2413290``: This applies errata 2413290 workaround to
935   Cortex-A715 CPU. This needs to be enabled only for revision r1p0 and
936   when SPE(Statistical profiling extension)=True. The errata is fixed
937   in r1p1.
938
939-  ``ERRATA_A715_2420947``: This applies errata 2420947 workaround to
940   Cortex-A715 CPU. This needs to be enabled only for revision r1p0.
941   It is fixed in r1p1.
942
943-  ``ERRATA_A715_2429384``: This applies errata 2429384 workaround to
944   Cortex-A715 CPU. This needs to be enabled for revision r1p0. There is no
945   workaround for revision r0p0. It is fixed in r1p1.
946
947-  ``ERRATA_A715_2561034``: This applies errata 2561034 workaround to
948   Cortex-A715 CPU. This needs to be enabled only for revision r1p0.
949   It is fixed in r1p1.
950
951-  ``ERRATA_A715_2728106``: This applies errata 2728106 workaround to
952   Cortex-A715 CPU. This needs to be enabled for revisions r0p0, r1p0
953   and r1p1. It is fixed in r1p2.
954
955For Cortex-A720, the following errata build flags are defined :
956
957-  ``ERRATA_A720_2792132``: This applies errata 2792132 workaround to
958   Cortex-A720 CPU. This needs to be enabled for revisions r0p0 and r0p1.
959   It is fixed in r0p2.
960
961-  ``ERRATA_A720_2844092``: This applies errata 2844092 workaround to
962   Cortex-A720 CPU. This needs to be enabled for revisions r0p0 and r0p1.
963   It is fixed in r0p2.
964
965-  ``ERRATA_A720_2926083``: This applies errata 2926083 workaround to
966   Cortex-A720 CPU. This needs to be enabled for revisions r0p0 and r0p1.
967   It is fixed in r0p2.
968
969-  ``ERRATA_A720_2940794``: This applies errata 2940794 workaround to
970   Cortex-A720 CPU. This needs to be enabled for revisions r0p0 and r0p1.
971   It is fixed in r0p2.
972
973DSU Errata Workarounds
974----------------------
975
976Similar to CPU errata, TF-A also implements workarounds for DSU (DynamIQ
977Shared Unit) errata. The DSU errata details can be found in the respective Arm
978documentation:
979
980- `Arm DSU Software Developers Errata Notice`_.
981
982Each erratum is identified by an ``ID``, as defined in the DSU errata notice
983document. Thus, the build flags which enable/disable the errata workarounds
984have the format ``ERRATA_DSU_<ID>``. The implementation and application logic
985of DSU errata workarounds are similar to `CPU errata workarounds`_.
986
987For DSU errata, the following build flags are defined:
988
989-  ``ERRATA_DSU_798953``: This applies errata 798953 workaround for the
990   affected DSU configurations. This errata applies only for those DSUs that
991   revision is r0p0 (on r0p1 it is fixed). However, please note that this
992   workaround results in increased DSU power consumption on idle.
993
994-  ``ERRATA_DSU_936184``: This applies errata 936184 workaround for the
995   affected DSU configurations. This errata applies only for those DSUs that
996   contain the ACP interface **and** the DSU revision is older than r2p0 (on
997   r2p0 it is fixed). However, please note that this workaround results in
998   increased DSU power consumption on idle.
999
1000-  ``ERRATA_DSU_2313941``: This applies errata 2313941 workaround for the
1001   affected DSU configurations. This errata applies for those DSUs with
1002   revisions r0p0, r1p0, r2p0, r2p1, r3p0, r3p1 and is still open. However,
1003   please note that this workaround results in increased DSU power consumption
1004   on idle.
1005
1006CPU Specific optimizations
1007--------------------------
1008
1009This section describes some of the optimizations allowed by the CPU micro
1010architecture that can be enabled by the platform as desired.
1011
1012-  ``SKIP_A57_L1_FLUSH_PWR_DWN``: This flag enables an optimization in the
1013   Cortex-A57 cluster power down sequence by not flushing the Level 1 data
1014   cache. The L1 data cache and the L2 unified cache are inclusive. A flush
1015   of the L2 by set/way flushes any dirty lines from the L1 as well. This
1016   is a known safe deviation from the Cortex-A57 TRM defined power down
1017   sequence. Each Cortex-A57 based platform must make its own decision on
1018   whether to use the optimization.
1019
1020-  ``A53_DISABLE_NON_TEMPORAL_HINT``: This flag disables the cache non-temporal
1021   hint. The LDNP/STNP instructions as implemented on Cortex-A53 do not behave
1022   in a way most programmers expect, and will most probably result in a
1023   significant speed degradation to any code that employs them. The Armv8-A
1024   architecture (see Arm DDI 0487A.h, section D3.4.3) allows cores to ignore
1025   the non-temporal hint and treat LDNP/STNP as LDP/STP instead. Enabling this
1026   flag enforces this behaviour. This needs to be enabled only for revisions
1027   <= r0p3 of the CPU and is enabled by default.
1028
1029-  ``A57_DISABLE_NON_TEMPORAL_HINT``: This flag has the same behaviour as
1030   ``A53_DISABLE_NON_TEMPORAL_HINT`` but for Cortex-A57. This needs to be
1031   enabled only for revisions <= r1p2 of the CPU and is enabled by default,
1032   as recommended in section "4.7 Non-Temporal Loads/Stores" of the
1033   `Cortex-A57 Software Optimization Guide`_.
1034
1035- ''A57_ENABLE_NON_CACHEABLE_LOAD_FWD'': This flag enables non-cacheable
1036   streaming enhancement feature for Cortex-A57 CPUs. Platforms can set
1037   this bit only if their memory system meets the requirement that cache
1038   line fill requests from the Cortex-A57 processor are atomic. Each
1039   Cortex-A57 based platform must make its own decision on whether to use
1040   the optimization. This flag is disabled by default.
1041
1042-  ``NEOVERSE_Nx_EXTERNAL_LLC``: This flag indicates that an external last
1043   level cache(LLC) is present in the system, and that the DataSource field
1044   on the master CHI interface indicates when data is returned from the LLC.
1045   This is used to control how the LL_CACHE* PMU events count.
1046   Default value is 0 (Disabled).
1047
1048GIC Errata Workarounds
1049----------------------
1050-  ``GIC600_ERRATA_WA_2384374``: This flag applies part 2 of errata 2384374
1051   workaround for the affected GIC600 and GIC600-AE implementations. It applies
1052   to implementations of GIC600 and GIC600-AE with revisions less than or equal
1053   to r1p6 and r0p2 respectively. If the platform sets GICV3_SUPPORT_GIC600,
1054   then this flag is enabled; otherwise, it is 0 (Disabled).
1055
1056--------------
1057
1058*Copyright (c) 2014-2024, Arm Limited and Contributors. All rights reserved.*
1059
1060.. _CVE-2017-5715: http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-5715
1061.. _CVE-2018-3639: http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-3639
1062.. _CVE-2022-23960: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-23960
1063.. _Cortex-A53 MPCore Software Developers Errata Notice: http://infocenter.arm.com/help/topic/com.arm.doc.epm048406/index.html
1064.. _Cortex-A57 MPCore Software Developers Errata Notice: http://infocenter.arm.com/help/topic/com.arm.doc.epm049219/index.html
1065.. _Cortex-A72 MPCore Software Developers Errata Notice: http://infocenter.arm.com/help/topic/com.arm.doc.epm012079/index.html
1066.. _Cortex-A57 Software Optimization Guide: http://infocenter.arm.com/help/topic/com.arm.doc.uan0015b/Cortex_A57_Software_Optimization_Guide_external.pdf
1067.. _Arm DSU Software Developers Errata Notice: http://infocenter.arm.com/help/topic/com.arm.doc.epm138168/index.html
1068