xref: /rk3399_ARM-atf/docs/design/cpu-specific-build-macros.rst (revision 0e88b2c7aad7d1af5351079e19d0b4efca508d1e)
1Arm CPU Specific Build Macros
2=============================
3
4This document describes the various build options present in the CPU specific
5operations framework to enable errata workarounds and to enable optimizations
6for a specific CPU on a platform.
7
8Security Vulnerability Workarounds
9----------------------------------
10
11TF-A exports a series of build flags which control which security
12vulnerability workarounds should be applied at runtime.
13
14-  ``WORKAROUND_CVE_2017_5715``: Enables the security workaround for
15   `CVE-2017-5715`_. This flag can be set to 0 by the platform if none
16   of the PEs in the system need the workaround. Setting this flag to 0 provides
17   no performance benefit for non-affected platforms, it just helps to comply
18   with the recommendation in the spec regarding workaround discovery.
19   Defaults to 1.
20
21-  ``WORKAROUND_CVE_2018_3639``: Enables the security workaround for
22   `CVE-2018-3639`_. Defaults to 1. The TF-A project recommends to keep
23   the default value of 1 even on platforms that are unaffected by
24   CVE-2018-3639, in order to comply with the recommendation in the spec
25   regarding workaround discovery.
26
27-  ``DYNAMIC_WORKAROUND_CVE_2018_3639``: Enables dynamic mitigation for
28   `CVE-2018-3639`_. This build option should be set to 1 if the target
29   platform contains at least 1 CPU that requires dynamic mitigation.
30   Defaults to 0.
31
32-  ``WORKAROUND_CVE_2022_23960``: Enables mitigation for `CVE-2022-23960`_.
33   This build option should be set to 1 if the target platform contains at
34   least 1 CPU that requires this mitigation. Defaults to 1.
35
36-  ``WORKAROUND_CVE_2024_5660``: Enables mitigation for `CVE-2024-5660`.
37   The fix is to disable hardware page aggregation by setting CPUECTLR_EL1[46]
38   in EL3 FW. This build option should be set to 1 if the target platform contains
39   at least 1 CPU that requires this mitigation. Defaults to 1.
40
41-  ``WORKAROUND_CVE_2024_7881``: Enables mitigation for `CVE-2024-7881`.
42   This build option should be set to 1 if the target platform contains at
43   least 1 CPU that requires this mitigation. Defaults to 1.
44
45.. _arm_cpu_macros_errata_workarounds:
46
47CPU Errata Workarounds
48----------------------
49
50TF-A exports a series of build flags which control the errata workarounds that
51are applied to each CPU by the reset handler. The errata details can be found
52in the CPU specific errata documents published by Arm:
53For example: `Cortex-A72 MPCore Software Developers Errata Notice`_
54
55The errata workarounds are implemented for a particular revision or a set of
56processor revisions. This is checked by the reset handler at runtime. Each
57errata workaround is identified by its ``ID`` as specified in the processor's
58errata notice document. The format of the define used to enable/disable the
59errata workaround is ``ERRATA_<Processor name>_<ID>``, where the ``Processor name``
60is for example ``A57`` for the ``Cortex_A57`` CPU.
61
62Refer to :ref:`firmware_design_cpu_errata_implementation` for information on how to
63write errata workaround functions.
64
65All workarounds are disabled by default. The platform is responsible for
66enabling these workarounds according to its requirement by defining the
67errata workaround build flags in the platform specific makefile. In case
68these workarounds are enabled for the wrong CPU revision then the errata
69workaround is not applied. In the DEBUG build, this is indicated by
70printing a warning to the crash console.
71
72In the current implementation, a platform which has more than 1 variant
73with different revisions of a processor has no runtime mechanism available
74for it to specify which errata workarounds should be enabled or not.
75
76The value of the build flags is 0 by default, that is, disabled. A value of 1
77will enable it.
78
79For Cortex-A9, the following errata build flags are defined :
80
81-  ``ERRATA_A9_794073``: This applies errata 794073 workaround to Cortex-A9
82   CPU. This needs to be enabled for all revisions of the CPU.
83
84For Cortex-A15, the following errata build flags are defined :
85
86-  ``ERRATA_A15_816470``: This applies errata 816470 workaround to Cortex-A15
87   CPU. This needs to be enabled only for revision >= r3p0 of the CPU.
88
89-  ``ERRATA_A15_827671``: This applies errata 827671 workaround to Cortex-A15
90   CPU. This needs to be enabled only for revision >= r3p0 of the CPU.
91
92For Cortex-A17, the following errata build flags are defined :
93
94-  ``ERRATA_A17_852421``: This applies errata 852421 workaround to Cortex-A17
95   CPU. This needs to be enabled only for revision <= r1p2 of the CPU.
96
97-  ``ERRATA_A17_852423``: This applies errata 852423 workaround to Cortex-A17
98   CPU. This needs to be enabled only for revision <= r1p2 of the CPU.
99
100For Cortex-A35, the following errata build flags are defined :
101
102-  ``ERRATA_A35_855472``: This applies errata 855472 workaround to Cortex-A35
103   CPUs. This needs to be enabled only for revision r0p0 of Cortex-A35.
104
105For Cortex-A53, the following errata build flags are defined :
106
107-  ``ERRATA_A53_819472``: This applies errata 819472 workaround to all
108   CPUs. This needs to be enabled only for revision <= r0p1 of Cortex-A53.
109
110-  ``ERRATA_A53_824069``: This applies errata 824069 workaround to all
111   CPUs. This needs to be enabled only for revision <= r0p2 of Cortex-A53.
112
113-  ``ERRATA_A53_826319``: This applies errata 826319 workaround to Cortex-A53
114   CPU. This needs to be enabled only for revision <= r0p2 of the CPU.
115
116-  ``ERRATA_A53_827319``: This applies errata 827319 workaround to all
117   CPUs. This needs to be enabled only for revision <= r0p2 of Cortex-A53.
118
119-  ``ERRATA_A53_835769``: This applies erratum 835769 workaround at compile and
120   link time to Cortex-A53 CPU. This needs to be enabled for some variants of
121   revision <= r0p4. This workaround can lead the linker to create ``*.stub``
122   sections.
123
124-  ``ERRATA_A53_836870``: This applies errata 836870 workaround to Cortex-A53
125   CPU. This needs to be enabled only for revision <= r0p3 of the CPU. From
126   r0p4 and onwards, this errata is enabled by default in hardware. Identical to
127   ``A53_DISABLE_NON_TEMPORAL_HINT``.
128
129-  ``ERRATA_A53_843419``: This applies erratum 843419 workaround at link time
130   to Cortex-A53 CPU.  This needs to be enabled for some variants of revision
131   <= r0p4. This workaround can lead the linker to emit ``*.stub`` sections
132   which are 4kB aligned.
133
134-  ``ERRATA_A53_855873``: This applies errata 855873 workaround to Cortex-A53
135   CPUs. Though the erratum is present in every revision of the CPU,
136   this workaround is only applied to CPUs from r0p3 onwards, which feature
137   a chicken bit in CPUACTLR_EL1 to enable a hardware workaround.
138   Earlier revisions of the CPU have other errata which require the same
139   workaround in software, so they should be covered anyway.
140
141-  ``ERRATA_A53_1530924``: This applies errata 1530924 workaround to all
142   revisions of Cortex-A53 CPU.
143
144For Cortex-A55, the following errata build flags are defined :
145
146-  ``ERRATA_A55_768277``: This applies errata 768277 workaround to Cortex-A55
147   CPU. This needs to be enabled only for revision r0p0 of the CPU.
148
149-  ``ERRATA_A55_778703``: This applies errata 778703 workaround to Cortex-A55
150   CPU. This needs to be enabled only for revision r0p0 of the CPU.
151
152-  ``ERRATA_A55_798797``: This applies errata 798797 workaround to Cortex-A55
153   CPU. This needs to be enabled only for revision r0p0 of the CPU.
154
155-  ``ERRATA_A55_846532``: This applies errata 846532 workaround to Cortex-A55
156   CPU. This needs to be enabled only for revision <= r0p1 of the CPU.
157
158-  ``ERRATA_A55_903758``: This applies errata 903758 workaround to Cortex-A55
159   CPU. This needs to be enabled only for revision <= r0p1 of the CPU.
160
161-  ``ERRATA_A55_1221012``: This applies errata 1221012 workaround to Cortex-A55
162   CPU. This needs to be enabled only for revision <= r1p0 of the CPU.
163
164-  ``ERRATA_A55_1530923``: This applies errata 1530923 workaround to all
165   revisions of Cortex-A55 CPU.
166
167For Cortex-A57, the following errata build flags are defined :
168
169-  ``ERRATA_A57_806969``: This applies errata 806969 workaround to Cortex-A57
170   CPU. This needs to be enabled only for revision r0p0 of the CPU.
171
172-  ``ERRATA_A57_813419``: This applies errata 813419 workaround to Cortex-A57
173   CPU. This needs to be enabled only for revision r0p0 of the CPU.
174
175-  ``ERRATA_A57_813420``: This applies errata 813420 workaround to Cortex-A57
176   CPU. This needs to be enabled only for revision r0p0 of the CPU.
177
178-  ``ERRATA_A57_814670``: This applies errata 814670 workaround to Cortex-A57
179   CPU. This needs to be enabled only for revision r0p0 of the CPU.
180
181-  ``ERRATA_A57_817169``: This applies errata 817169 workaround to Cortex-A57
182   CPU. This needs to be enabled only for revision <= r0p1 of the CPU.
183
184-  ``ERRATA_A57_826974``: This applies errata 826974 workaround to Cortex-A57
185   CPU. This needs to be enabled only for revision <= r1p1 of the CPU.
186
187-  ``ERRATA_A57_826977``: This applies errata 826977 workaround to Cortex-A57
188   CPU. This needs to be enabled only for revision <= r1p1 of the CPU.
189
190-  ``ERRATA_A57_828024``: This applies errata 828024 workaround to Cortex-A57
191   CPU. This needs to be enabled only for revision <= r1p1 of the CPU.
192
193-  ``ERRATA_A57_829520``: This applies errata 829520 workaround to Cortex-A57
194   CPU. This needs to be enabled only for revision <= r1p2 of the CPU.
195
196-  ``ERRATA_A57_833471``: This applies errata 833471 workaround to Cortex-A57
197   CPU. This needs to be enabled only for revision <= r1p2 of the CPU.
198
199-  ``ERRATA_A57_859972``: This applies errata 859972 workaround to Cortex-A57
200   CPU. This needs to be enabled only for revision <= r1p3 of the CPU.
201
202-  ``ERRATA_A57_1319537``: This applies errata 1319537 workaround to all
203   revisions of Cortex-A57 CPU.
204
205For Cortex-A65, the following errata build flags are defined :
206
207-  ``ERRATA_A65_1179935``: This applies errata 1179935 workaround to Cortex-A65
208   CPU. This needs to be enabled only for revision r0p0 of the CPU, and is fixed
209   in r1p0.
210
211-  ``ERRATA_A65_1227419``: This applies errata 1227419 workaround to Cortex-A65
212   CPU. This needs to be enabled only for revision r0p0 and r1p0 of the CPU and
213   is fixed in r1p1.
214
215-  ``ERRATA_A65_1541130``: This applies errata 1541130 workaround to r0p0, r1p0,
216   r1p1, r1p2 revisions of the CPU and is still open.
217
218For Cortex-A72, the following errata build flags are defined :
219
220-  ``ERRATA_A72_859971``: This applies errata 859971 workaround to Cortex-A72
221   CPU. This needs to be enabled only for revision <= r0p3 of the CPU.
222
223-  ``ERRATA_A72_1319367``: This applies errata 1319367 workaround to all
224   revisions of Cortex-A72 CPU.
225
226For Cortex-A73, the following errata build flags are defined :
227
228-  ``ERRATA_A73_852427``: This applies errata 852427 workaround to Cortex-A73
229   CPU. This needs to be enabled only for revision r0p0 of the CPU.
230
231-  ``ERRATA_A73_855423``: This applies errata 855423 workaround to Cortex-A73
232   CPU. This needs to be enabled only for revision <= r0p1 of the CPU.
233
234For Cortex-A75, the following errata build flags are defined :
235
236-  ``ERRATA_A75_764081``: This applies errata 764081 workaround to Cortex-A75
237   CPU. This needs to be enabled only for revision r0p0 of the CPU.
238
239-  ``ERRATA_A75_790748``: This applies errata 790748 workaround to Cortex-A75
240    CPU. This needs to be enabled only for revision r0p0 of the CPU.
241
242For Cortex-A76, the following errata build flags are defined :
243
244-  ``ERRATA_A76_1073348``: This applies errata 1073348 workaround to Cortex-A76
245   CPU. This needs to be enabled only for revision <= r1p0 of the CPU.
246
247-  ``ERRATA_A76_1130799``: This applies errata 1130799 workaround to Cortex-A76
248   CPU. This needs to be enabled only for revision <= r2p0 of the CPU.
249
250-  ``ERRATA_A76_1220197``: This applies errata 1220197 workaround to Cortex-A76
251   CPU. This needs to be enabled only for revision <= r2p0 of the CPU.
252
253-  ``ERRATA_A76_1257314``: This applies errata 1257314 workaround to Cortex-A76
254   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
255
256-  ``ERRATA_A76_1262606``: This applies errata 1262606 workaround to Cortex-A76
257   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
258
259-  ``ERRATA_A76_1262888``: This applies errata 1262888 workaround to Cortex-A76
260   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
261
262-  ``ERRATA_A76_1275112``: This applies errata 1275112 workaround to Cortex-A76
263   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
264
265-  ``ERRATA_A76_1791580``: This applies errata 1791580 workaround to Cortex-A76
266   CPU. This needs to be enabled only for revision <= r4p0 of the CPU.
267
268-  ``ERRATA_A76_1165522``: This applies errata 1165522 workaround to all
269   revisions of Cortex-A76 CPU. This errata is fixed in r3p0 but due to
270   limitation of errata framework this errata is applied to all revisions
271   of Cortex-A76 CPU.
272
273-  ``ERRATA_A76_1868343``: This applies errata 1868343 workaround to Cortex-A76
274   CPU. This needs to be enabled only for revision <= r4p0 of the CPU.
275
276-  ``ERRATA_A76_1946160``: This applies errata 1946160 workaround to Cortex-A76
277   CPU. This needs to be enabled only for revisions r3p0 - r4p1 of the CPU.
278
279-  ``ERRATA_A76_2743102``: This applies errata 2743102 workaround to Cortex-A76
280   CPU. This needs to be enabled for all revisions <= r4p1 of the CPU and is
281   still open.
282
283For Cortex-A76AE, the following errata build flags are defined :
284
285-  ``ERRATA_A76AE_1931427``: This applies errata 1931427 workaround to Cortex-A76AE
286   CPU. This needs to be enabled for revision r0p0 and r1p0 of the CPU and it is
287   fixed in r1p1.
288
289-  ``ERRATA_A76AE_1931435``: This applies errata 1931435 workaround to Cortex-A76AE
290   CPU. This needs to be enabled for revision r0p0 and r1p0 of the CPU and it is
291   fixed in r1p1.
292
293-  ``ERRATA_A76AE_1969401``: This applies errata 1969401 workaround to Cortex-A76AE
294   CPU. This needs to be enabled for revision r0p0 and r1p0 of the CPU and it is
295   fixed in r1p1.
296
297-  ``ERRATA_A76AE_2371140``: This applies errata 2371140 workaround to Cortex-A76AE
298   CPU. This needs to be enabled for all revisions <= r1p1 of the CPU and is
299   still open.
300
301-  ``ERRATA_A76AE_2753838``: This applies errata 2753838 workaround to Cortex-A76AE
302   CPU. This needs to be enabled for all revisions <= r1p1 of the CPU and is
303   still open.
304
305For Cortex-A77, the following errata build flags are defined :
306
307-  ``ERRATA_A77_1508412``: This applies errata 1508412 workaround to Cortex-A77
308   CPU. This needs to be enabled only for revision <= r1p0 of the CPU.
309
310-  ``ERRATA_A77_1925769``: This applies errata 1925769 workaround to Cortex-A77
311   CPU. This needs to be enabled only for revision <= r1p1 of the CPU.
312
313-  ``ERRATA_A77_1946167``: This applies errata 1946167 workaround to Cortex-A77
314   CPU. This needs to be enabled only for revision <= r1p1 of the CPU.
315
316-  ``ERRATA_A77_1791578``: This applies errata 1791578 workaround to Cortex-A77
317   CPU. This needs to be enabled for r0p0, r1p0, and r1p1, it is still open.
318
319-  ``ERRATA_A77_2356587``: This applies errata 2356587 workaround to Cortex-A77
320   CPU. This needs to be enabled for r0p0, r1p0, and r1p1, it is still open.
321
322 -  ``ERRATA_A77_1800714``: This applies errata 1800714 workaround to Cortex-A77
323    CPU. This needs to be enabled for revisions <= r1p1 of the CPU.
324
325 -  ``ERRATA_A77_2743100``: This applies errata 2743100 workaround to Cortex-A77
326    CPU. This needs to be enabled for r0p0, r1p0, and r1p1, it is still open.
327
328For Cortex-A78, the following errata build flags are defined :
329
330-  ``ERRATA_A78_1688305``: This applies errata 1688305 workaround to Cortex-A78
331   CPU. This needs to be enabled only for revision r0p0 - r1p0 of the CPU.
332
333-  ``ERRATA_A78_1941498``: This applies errata 1941498 workaround to Cortex-A78
334   CPU. This needs to be enabled for revisions r0p0, r1p0, and r1p1 of the CPU.
335
336-  ``ERRATA_A78_1951500``: This applies errata 1951500 workaround to Cortex-A78
337   CPU. This needs to be enabled for revisions r1p0 and r1p1, r0p0 has the same
338   issue but there is no workaround for that revision.
339
340-  ``ERRATA_A78_1821534``: This applies errata 1821534 workaround to Cortex-A78
341   CPU. This needs to be enabled for revisions r0p0 and r1p0.
342
343-  ``ERRATA_A78_1952683``: This applies errata 1952683 workaround to Cortex-A78
344   CPU. This needs to be enabled for revision r0p0, it is fixed in r1p0.
345
346-  ``ERRATA_A78_2242635``: This applies errata 2242635 workaround to Cortex-A78
347   CPU. This needs to be enabled for revisions r1p0, r1p1, and r1p2. The issue
348   is present in r0p0 but there is no workaround. It is still open.
349
350-  ``ERRATA_A78_2376745``: This applies errata 2376745 workaround to Cortex-A78
351   CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1, and r1p2, and
352   it is still open.
353
354-  ``ERRATA_A78_2395406``: This applies errata 2395406 workaround to Cortex-A78
355   CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1, and r1p2, and
356   it is still open.
357
358- ``ERRATA_A78_2712571``: This applies erratum 2712571 workaround to Cortex-A78
359   CPU, this erratum affects system configurations that do not use an ARM
360   interconnect IP. This needs to be enabled for revisions r0p0, r1p0, r1p1
361   and r1p2 and it is still open.
362
363-  ``ERRATA_A78_2742426``: This applies erratum 2742426 workaround to Cortex-A78
364   CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1 and r1p2 and
365   it is still open.
366
367-  ``ERRATA_A78_2772019``: This applies errata 2772019 workaround to Cortex-A78
368   CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1, and r1p2, and
369   it is still open.
370
371-  ``ERRATA_A78_2779479``: This applies erratum 2779479 workaround to Cortex-A78
372   CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1 and r1p2 and
373   it is still open.
374
375For Cortex-A78AE, the following errata build flags are defined :
376
377- ``ERRATA_A78_AE_1941500`` : This applies errata 1941500 workaround to
378   Cortex-A78AE CPU. This needs to be enabled for revisions r0p0 and r0p1.
379   This erratum is still open.
380
381- ``ERRATA_A78_AE_1951502`` : This applies errata 1951502 workaround to
382  Cortex-A78AE CPU. This needs to be enabled for revisions r0p0 and r0p1. This
383  erratum is still open.
384
385- ``ERRATA_A78_AE_2376748`` : This applies errata 2376748 workaround to
386  Cortex-A78AE CPU. This needs to be enabled for revisions r0p0, r0p1 and r0p2.
387  This erratum is still open.
388
389- ``ERRATA_A78_AE_2395408`` : This applies errata 2395408 workaround to
390  Cortex-A78AE CPU. This needs to be enabled for revisions r0p0 and r0p1. This
391  erratum is still open.
392
393- ``ERRATA_A78_AE_2712574`` : This applies erratum 2712574 workaround to
394  Cortex-A78AE CPU. This erratum affects system configurations that do not use
395  an ARM interconnect IP. This needs to be enabled for revisions r0p0, r0p1 and
396  r0p2. This erratum is still open.
397
398For Cortex-A78C, the following errata build flags are defined :
399
400- ``ERRATA_A78C_1827430`` : This applies errata 1827430 workaround to
401  Cortex-A78C CPU. This needs to be enabled for revision r0p0. The erratum is
402  fixed in r0p1.
403
404- ``ERRATA_A78C_1827440`` : This applies errata 1827440 workaround to
405  Cortex-A78C CPU. This needs to be enabled for revision r0p0. The erratum is
406  fixed in r0p1.
407
408- ``ERRATA_A78C_2242638`` : This applies errata 2242638 workaround to
409  Cortex-A78C CPU. This needs to be enabled for revisions r0p1, r0p2 and
410  it is still open.
411
412- ``ERRATA_A78C_2376749`` : This applies errata 2376749 workaround to
413  Cortex-A78C CPU. This needs to be enabled for revisions r0p1 and r0p2. This
414  erratum is still open.
415
416- ``ERRATA_A78C_2395411`` : This applies errata 2395411 workaround to
417  Cortex-A78C CPU. This needs to be enabled for revisions r0p1 and r0p2. This
418  erratum is still open.
419
420- ``ERRATA_A78C_2683027`` : This applies errata 2683027 workaround to
421  Cortex-A78C CPU. This needs to be enabled for revisions r0p1 and r0p2. This
422  erratum is still open.
423
424- ``ERRATA_A78C_2712575`` : This applies erratum 2712575 workaround to
425  Cortex-A78C CPU, this erratum affects system configurations that do not use
426  an ARM interconnect IP. This needs to be enabled for revisions r0p1 and r0p2
427  and is still open.
428
429- ``ERRATA_A78C_2743232`` : This applies erratum 2743232 workaround to
430  Cortex-A78C CPU. This needs to be enabled for revisions r0p1 and r0p2.
431  This erratum is still open.
432
433- ``ERRATA_A78C_2772121`` : This applies errata 2772121 workaround to
434  Cortex-A78C CPU. This needs to be enabled for revisions r0p0, r0p1 and r0p2.
435  This erratum is still open.
436
437- ``ERRATA_A78C_2779484`` : This applies errata 2779484 workaround to
438  Cortex-A78C CPU. This needs to be enabled for revisions r0p1 and r0p2.
439  This erratum is still open.
440
441For Cortex-X1 CPU, the following errata build flags are defined:
442
443- ``ERRATA_X1_1821534`` : This applies errata 1821534 workaround to Cortex-X1
444   CPU. This needs to be enabled only for revision <= r1p0 of the CPU.
445
446- ``ERRATA_X1_1688305`` : This applies errata 1688305 workaround to Cortex-X1
447   CPU. This needs to be enabled only for revision <= r1p0 of the CPU.
448
449- ``ERRATA_X1_1827429`` : This applies errata 1827429 workaround to Cortex-X1
450   CPU. This needs to be enabled only for revision <= r1p0 of the CPU.
451
452For Neoverse N1, the following errata build flags are defined :
453
454-  ``ERRATA_N1_1073348``: This applies errata 1073348 workaround to Neoverse-N1
455   CPU. This needs to be enabled only for revision r0p0 and r1p0 of the CPU.
456
457-  ``ERRATA_N1_1130799``: This applies errata 1130799 workaround to Neoverse-N1
458   CPU. This needs to be enabled only for revision <= r2p0 of the CPU.
459
460-  ``ERRATA_N1_1165347``: This applies errata 1165347 workaround to Neoverse-N1
461   CPU. This needs to be enabled only for revision <= r2p0 of the CPU.
462
463-  ``ERRATA_N1_1207823``: This applies errata 1207823 workaround to Neoverse-N1
464   CPU. This needs to be enabled only for revision <= r2p0 of the CPU.
465
466-  ``ERRATA_N1_1220197``: This applies errata 1220197 workaround to Neoverse-N1
467   CPU. This needs to be enabled only for revision <= r2p0 of the CPU.
468
469-  ``ERRATA_N1_1257314``: This applies errata 1257314 workaround to Neoverse-N1
470   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
471
472-  ``ERRATA_N1_1262606``: This applies errata 1262606 workaround to Neoverse-N1
473   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
474
475-  ``ERRATA_N1_1262888``: This applies errata 1262888 workaround to Neoverse-N1
476   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
477
478-  ``ERRATA_N1_1275112``: This applies errata 1275112 workaround to Neoverse-N1
479   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
480
481-  ``ERRATA_N1_1315703``: This applies errata 1315703 workaround to Neoverse-N1
482   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
483
484-  ``ERRATA_N1_1542419``: This applies errata 1542419 workaround to Neoverse-N1
485   CPU. This needs to be enabled only for revisions r3p0 - r4p0 of the CPU.
486
487-  ``ERRATA_N1_1868343``: This applies errata 1868343 workaround to Neoverse-N1
488   CPU. This needs to be enabled only for revision <= r4p0 of the CPU.
489
490-  ``ERRATA_N1_1946160``: This applies errata 1946160 workaround to Neoverse-N1
491   CPU. This needs to be enabled for revisions r3p0, r3p1, r4p0, and r4p1, for
492   revisions r0p0, r1p0, and r2p0 there is no workaround.
493
494-  ``ERRATA_N1_2743102``: This applies errata 2743102 workaround to Neoverse-N1
495   CPU. This needs to be enabled for all revisions <= r4p1 of the CPU and is
496   still open.
497
498-  ``ERRATA_N1_3324349``: This applies errata 3324349 workaround to Neoverse-N1
499   CPU. This needs to be enabled for all revisions <= r4p1 of the CPU and is
500   still open.
501
502For Neoverse V1, the following errata build flags are defined :
503
504-  ``ERRATA_V1_1618635``: This applies errata 1618635 workaround to Neoverse-V1
505   CPU. This needs to be enabled for revision r0p0 of the CPU, it is fixed in
506   r1p0.
507
508-  ``ERRATA_V1_1774420``: This applies errata 1774420 workaround to Neoverse-V1
509   CPU. This needs to be enabled only for revisions r0p0 and r1p0, it is fixed
510   in r1p1.
511
512-  ``ERRATA_V1_1791573``: This applies errata 1791573 workaround to Neoverse-V1
513   CPU. This needs to be enabled only for revisions r0p0 and r1p0, it is fixed
514   in r1p1.
515
516-  ``ERRATA_V1_1852267``: This applies errata 1852267 workaround to Neoverse-V1
517   CPU. This needs to be enabled only for revisions r0p0 and r1p0, it is fixed
518   in r1p1.
519
520-  ``ERRATA_V1_1925756``: This applies errata 1925756 workaround to Neoverse-V1
521   CPU. This needs to be enabled for r0p0, r1p0, and r1p1, it is still open.
522
523-  ``ERRATA_V1_1940577``: This applies errata 1940577 workaround to Neoverse-V1
524   CPU. This needs to be enabled only for revision r1p0 and r1p1 of the
525   CPU.
526
527-  ``ERRATA_V1_1966096``: This applies errata 1966096 workaround to Neoverse-V1
528   CPU. This needs to be enabled for revisions r1p0 and r1p1 of the CPU, the
529   issue is present in r0p0 as well but there is no workaround for that
530   revision.  It is still open.
531
532-  ``ERRATA_V1_2139242``: This applies errata 2139242 workaround to Neoverse-V1
533   CPU. This needs to be enabled for revisions r0p0, r1p0, and r1p1 of the
534   CPU.  It is still open.
535
536-  ``ERRATA_V1_2216392``: This applies errata 2216392 workaround to Neoverse-V1
537   CPU. This needs to be enabled for revisions r1p0 and r1p1 of the CPU, the
538   issue is present in r0p0 as well but there is no workaround for that
539   revision.  It is still open.
540
541-  ``ERRATA_V1_2294912``: This applies errata 2294912 workaround to Neoverse-V1
542   CPU. This needs to be enabled for revisions r0p0, r1p0, and r1p1 and r1p2 of
543   the CPU.
544
545-  ``ERRATA_V1_2348377``: This applies errata 2348377 workaroud to Neoverse-V1
546   CPU. This needs to be enabled for revisions r0p0, r1p0 and r1p1 of the CPU.
547   It has been fixed in r1p2.
548
549-  ``ERRATA_V1_2372203``: This applies errata 2372203 workaround to Neoverse-V1
550   CPU. This needs to be enabled for revisions r0p0, r1p0 and r1p1 of the CPU.
551   It is still open.
552
553- ``ERRATA_V1_2701953``: This applies erratum 2701953 workaround to Neoverse-V1
554   CPU, this erratum affects system configurations that do not use an ARM
555   interconnect IP. This needs to be enabled for revisions r0p0, r1p0 and r1p1.
556   It has been fixed in r1p2.
557
558-  ``ERRATA_V1_2743093``: This applies errata 2743093 workaround to Neoverse-V1
559   CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1 and r1p2 of the
560   CPU. It is still open.
561
562-  ``ERRATA_V1_2743233``: This applies erratum 2743233 workaround to Neoverse-V1
563   CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1, and r1p2 of the
564   CPU. It is still open.
565
566-  ``ERRATA_V1_2779461``: This applies erratum 2779461 workaround to Neoverse-V1
567   CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1, r1p2 of the
568   CPU. It is still open.
569
570For Neoverse V2, the following errata build flags are defined :
571
572-  ``ERRATA_V2_2618597``: This applies errata 2618597 workaround to Neoverse-V2
573   CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed in
574   r0p2.
575
576-  ``ERRATA_V2_2662553``: This applies errata 2662553 workaround to Neoverse-V2
577   CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed in
578   r0p2.
579
580-  ``ERRATA_V2_2719103``: This applies errata 2719103 workaround to Neoverse-V2
581   CPU, this affects system configurations that do not use and ARM interconnect
582   IP. This needs to be enabled for revisions r0p0 and r0p1. It has been fixed
583   in r0p2.
584
585-  ``ERRATA_V2_2719105``: This applies errata 2719105 workaround to Neoverse-V2
586   CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed in
587   r0p2.
588
589-  ``ERRATA_V2_2743011``: This applies errata 2743011 workaround to Neoverse-V2
590   CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed in
591   r0p2.
592
593-  ``ERRATA_V2_2779510``: This applies errata 2779510 workaround to Neoverse-V2
594   CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed in
595   r0p2.
596
597-  ``ERRATA_V2_2801372``: This applies errata 2801372 workaround to Neoverse-V2
598   CPU, this affects all configurations. This needs to be enabled for revisions
599   r0p0 and r0p1. It has been fixed in r0p2.
600
601-  ``ERRATA_V2_3442699``: This applies errata 3442699 workaround to Neoverse-V2
602   CPU. This needs to be enabled for revision r0p0 - r0p2 and is still open.
603
604-  ``ERRATA_V2_3701771``: This applies errata 3701771 workaround to Neoverse-V2
605   CPU. This needs to be enabled for revisions r0p0, r0p1 and r0p2 and is
606   still open.
607
608-  ``ERRATA_V2_3841324``: This applies errata 3841324 workaround to Neoverse-V2
609   CPU. This needs to be enabled only for revisions r0p0 and r0p1 of
610   the CPU. It is fixed in r0p2.
611
612For Neoverse V3, the following errata build flags are defined :
613
614- ``ERRATA_V3_2970647``: This applies errata 2970647 workaround to Neoverse-V3
615  CPU. This needs to be enabled for revision r0p0. It is fixed in r0p1.
616
617- ``ERRATA_V3_3701767``: This applies errata 3701767 workaround to Neoverse-V3
618  CPU. This needs to be enabled for revisions r0p0, r0p1, r0p2 of the CPU and
619  is still open.
620
621For Cortex-A710, the following errata build flags are defined :
622
623-  ``ERRATA_A710_1901946``: This applies errata 1901946 workaround to
624   Cortex-A710 CPU. This needs to be enabled only for revision r1p0. It has
625   been fixed in r2p0.
626
627-  ``ERRATA_A710_1916945``: This applies errata 1916945 workaround to
628   Cortex-A710 CPU. This needs to be enabled only for revisions r0p0 and r1p0.
629   It has been fixed in r2p0.
630
631-  ``ERRATA_A710_1917258``: This applies errata 1917258 workaround to
632   Cortex-A710 CPU. This needs to be enabled only for revisions r0p0 and r1p0.
633   It has been fixed in r2p0.
634
635-  ``ERRATA_A710_1927200``: This applies errata 1927200 workaround to
636   Cortex-A710 CPU. This needs to be enabled only for revisions r0p0 and r1p0.
637   It has been fixed in r2p0.
638
639-  ``ERRATA_A710_1987031``: This applies errata 1987031 workaround to
640   Cortex-A710 CPU. This needs to be enabled only for revisions r0p0, r1p0 and
641   r2p0 of the CPU. It is still open.
642
643-  ``ERRATA_A710_2081180``: This applies errata 2081180 workaround to
644   Cortex-A710 CPU. This needs to be enabled only for revisions r0p0, r1p0 and
645   r2p0 of the CPU. It is still open.
646
647-  ``ERRATA_A710_2055002``: This applies errata 2055002 workaround to
648   Cortex-A710 CPU. This needs to be enabled for revisions r1p0, r2p0 of the CPU
649   and is still open.
650
651-  ``ERRATA_A710_2017096``: This applies errata 2017096 workaround to
652   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
653   of the CPU and is still open.
654
655-  ``ERRATA_A710_2083908``: This applies errata 2083908 workaround to
656   Cortex-A710 CPU. This needs to be enabled for revision r2p0 of the CPU and
657   is still open.
658
659-  ``ERRATA_A710_2267065``: This applies errata 2267065 workaround to
660   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
661   of the CPU and is fixed in r2p1.
662
663-  ``ERRATA_A710_2136059``: This applies errata 2136059 workaround to
664   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
665   of the CPU and is fixed in r2p1.
666
667-  ``ERRATA_A710_2147715``: This applies errata 2147715 workaround to
668   Cortex-A710 CPU. This needs to be enabled for revision r2p0 of the CPU
669   and is fixed in r2p1.
670
671-  ``ERRATA_A710_2216384``: This applies errata 2216384 workaround to
672   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
673   of the CPU and is fixed in r2p1.
674
675-  ``ERRATA_A710_2282622``: This applies errata 2282622 workaround to
676   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and
677   r2p1 of the CPU and is still open.
678
679- ``ERRATA_A710_2291219``: This applies errata 2291219 workaround to
680   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
681   of the CPU and is fixed in r2p1.
682
683-  ``ERRATA_A710_2008768``: This applies errata 2008768 workaround to
684   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
685   of the CPU and is fixed in r2p1.
686
687-  ``ERRATA_A710_2371105``: This applies errata 2371105 workaround to
688   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
689   of the CPU and is fixed in r2p1.
690
691-  ``ERRATA_A710_2701952``: This applies erratum 2701952 workaround to Cortex-A710
692   CPU, and applies to system configurations that do not use and ARM
693   interconnect IP. This needs to be enabled for r0p0, r1p0, r2p0 and r2p1 and
694   is still open.
695
696-  ``ERRATA_A710_2742423``: This applies errata 2742423 workaround to
697   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and
698   r2p1 of the CPU and is still open.
699
700-  ``ERRATA_A710_2768515``: This applies errata 2768515 workaround to
701   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and
702   r2p1 of the CPU and is still open.
703
704-  ``ERRATA_A710_2778471``: This applies errata 2778471 workaround to Cortex-A710
705   CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and r2p1 of the
706   CPU and is still open.
707
708-  ``ERRATA_A710_3324338``: This applies errata 3324338 workaround to
709   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and
710   r2p1 of the CPU and is still open.
711
712- ``ERRATA_A710_3701772``: This applies errata 3701772 workaround to Cortex-A710
713  CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0, r2p1 of the
714  CPU and is still open.
715
716For Neoverse N2, the following errata build flags are defined :
717
718-  ``ERRATA_N2_2002655``: This applies errata 2002655 workaround to Neoverse-N2
719   CPU. This needs to be enabled for revision r0p0 of the CPU and is fixed in r0p1.
720
721-  ``ERRATA_N2_2009478``: This applies errata 2009478 workaround to Neoverse-N2
722   CPU. This needs to be enabled for revision r0p0 of the CPU and is fixed in r0p1.
723
724-  ``ERRATA_N2_2067956``: This applies errata 2067956 workaround to Neoverse-N2
725   CPU. This needs to be enabled for revision r0p0 of the CPU and is fixed in r0p1.
726
727-  ``ERRATA_N2_2025414``: This applies errata 2025414 workaround to Neoverse-N2
728   CPU. This needs to be enabled for revision r0p0 of the CPU and is fixed in r0p1.
729
730-  ``ERRATA_N2_2189731``: This applies errata 2189731 workaround to Neoverse-N2
731   CPU. This needs to be enabled for revision r0p0 of the CPU and is fixed in r0p1.
732
733-  ``ERRATA_N2_2138956``: This applies errata 2138956 workaround to Neoverse-N2
734   CPU. This needs to be enabled for revision r0p0 of the CPU and is fixed in r0p1.
735
736-  ``ERRATA_N2_2242415``: This applies errata 2242415 workaround to Neoverse-N2
737   CPU. This needs to be enabled for revision r0p0 of the CPU and is fixed in r0p1.
738
739-  ``ERRATA_N2_2138958``: This applies errata 2138958 workaround to Neoverse-N2
740   CPU. This needs to be enabled for revision r0p0 of the CPU and is fixed in r0p1.
741
742-  ``ERRATA_N2_2242400``: This applies errata 2242400 workaround to Neoverse-N2
743   CPU. This needs to be enabled for revision r0p0 of the CPU and is fixed in r0p1.
744
745-  ``ERRATA_N2_2280757``: This applies errata 2280757 workaround to Neoverse-N2
746   CPU. This needs to be enabled for revision r0p0 of the CPU and is fixed in r0p1.
747
748-  ``ERRATA_N2_2326639``: This applies errata 2326639 workaround to Neoverse-N2
749   CPU. This needs to be enabled for revision r0p0 of the CPU, it is fixed in
750   r0p1.
751
752-  ``ERRATA_N2_2340933``: This applies errata 2340933 workaround to Neoverse-N2
753   CPU. This needs to be enabled for revision r0p0 of the CPU, it is fixed in
754   r0p1.
755
756-  ``ERRATA_N2_2346952``: This applies errata 2346952 workaround to Neoverse-N2
757   CPU. This needs to be enabled for revisions r0p0, r0p1 and r0p2 of the CPU,
758   it is fixed in r0p3.
759
760-  ``ERRATA_N2_2376738``: This applies errata 2376738 workaround to Neoverse-N2
761   CPU. This needs to be enabled for revision r0p0, r0p1, r0p2, r0p3 and is still open.
762
763-  ``ERRATA_N2_2388450``: This applies errata 2388450 workaround to Neoverse-N2
764   CPU. This needs to be enabled for revision r0p0 of the CPU, it is fixed in
765   r0p1.
766
767-  ``ERRATA_N2_2743014``: This applies errata 2743014 workaround to Neoverse-N2
768   CPU. This needs to be enabled for revisions r0p0, r0p1 and r0p2. It is fixed
769   in r0p3.
770
771-  ``ERRATA_N2_2743089``: This applies errata 2743089 workaround to Neoverse-N2
772   CPU. This needs to be enabled for revisions r0p0, r0p1 and r0p2. It is fixed
773   in r0p3.
774
775- ``ERRATA_N2_2728475``: This applies erratum 2728475 workaround to Neoverse-N2
776   CPU, this erratum affects system configurations that do not use and ARM
777   interconnect IP. This needs to be enabled for revisions r0p0, r0p1 and r0p2.
778   It is fixed in r0p3.
779
780-  ``ERRATA_N2_2779511``: This applies errata 2779511 workaround to Neoverse-N2
781   CPU. This needs to be enabled for revisions r0p0, r0p1 and r0p2. It is fixed
782   in r0p3.
783
784-  ``ERRATA_N2_3324339``: This applies errata 3324339 workaround to Neoverse-N2
785   CPU. This needs to be enabled for revisions r0p0, r0p1, r0p2, r0p3 and is
786   still open.
787
788-  ``ERRATA_N2_3701773``: This applies errata 3701773 workaround to Neoverse-N2
789   CPU. This needs to be enabled for revisions r0p0, r0p1, r0p2, r0p3 and is
790   still open.
791
792For Neoverse N3, the following errata build flags are defined :
793
794-  ``ERRATA_N3_3456111``: This applies errata 3456111 workaround to Neoverse-N3
795   CPU. This needs to be enabled for revisions r0p0 and r0p1 and is still open.
796
797-  ``ERRATA_N3_3699563``: This applies errata 3699563 workaround to Neoverse-N3
798   CPU. This needs to be enabled for revisions r0p0 and is still open.
799
800For Cortex-X2, the following errata build flags are defined :
801
802-  ``ERRATA_X2_1901946``: This applies errata 1901946 workaround to Cortex-X2
803   CPU. This needs to be enabled only for r1p0, it is fixed in r2p0.
804
805-  ``ERRATA_X2_1916945``: This applies errata 1916945 workaround to Cortex-X2
806   CPU. This needs to be enabled only for revisions r0p0 and r1p0 of the CPU, it
807   is fixed in r2p0.
808
809-  ``ERRATA_X2_1917258``: This applies errata 1917258 workaround to Cortex-X2
810   CPU. This needs to be enabled only for revisions r0p0 and r1p0 of the CPU, it
811   is fixed in r2p0.
812
813-  ``ERRATA_X2_1927200``: This applies errata 1927200 workaround to Cortex-X2
814   CPU. This needs to be enabled only for revisions r0p0 and r1p0 of the CPU, it
815   is fixed in r2p0.
816
817-  ``ERRATA_X2_1934260``: This applies errata 1934260 workaround to Cortex-X2
818   CPU. This needs to be enabled only for revision r1p0 of the CPU, it is fixed
819   in r2p0.
820
821-  ``ERRATA_X2_2002765``: This applies errata 2002765 workaround to Cortex-X2
822   CPU. This needs to be enabled only for revisions r0p0, r1p0 and r2p0 of the
823   CPU, it is fixed in r2p1.
824
825-  ``ERRATA_X2_2017096``: This applies errata 2017096 workaround to Cortex-X2
826   CPU. This needs to be enabled only for revisions r0p0, r1p0 and r2p0 of the
827   CPU, it is fixed in r2p1.
828
829-  ``ERRATA_X2_2081180``: This applies errata 2081180 workaround to Cortex-X2
830   CPU. This needs to be enabled only for revisions r0p0, r1p0 and r2p0 of the
831   CPU, it is fixed in r2p1.
832
833-  ``ERRATA_X2_2083908``: This applies errata 2083908 workaround to Cortex-X2
834   CPU. This needs to be enabled only for revision r2p0 of the CPU, it is fixed
835   in r2p1.
836
837-  ``ERRATA_X2_2136059``: This applies errata 2136059 workaround to Cortex-X2
838   CPU. This needs to be enabled only for revisions r0p0, r1p0 and r2p0 of the
839   CPU, it is fixed in r2p1.
840
841-  ``ERRATA_X2_2147715``: This applies errata 2147715 workaround to Cortex-X2
842   CPU. This needs to be enabled only for revision r2p0 of the CPU, it is fixed
843   in r2p1.
844
845-  ``ERRATA_X2_2216384``: This applies errata 2216384 workaround to Cortex-X2
846   CPU. This needs to be enabled only for revisions r0p0, r1p0 and r2p0 of the
847   CPU, it is fixed in r2p1.
848
849-  ``ERRATA_X2_2267065``: This applies errata 2267065 workaround to Cortex-X2
850   CPU. This needs to be enabled only for revisions r0p0, r1p0 and r2p0 of the
851   CPU, it is fixed in r2p1.
852
853-  ``ERRATA_X2_2282622``: This applies errata 2282622 workaround to Cortex-X2
854   CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and r2p1 of the
855   CPU and is still open.
856
857-  ``ERRATA_X2_2291219``: This applies errata 2291219 workaround to Cortex-X2
858   CPU. This needs to be enabled only for revisions r0p0, r1p0 and r2p0 of the
859   CPU, it is fixed in r2p1.
860
861-  ``ERRATA_X2_2371105``: This applies errata 2371105 workaround to Cortex-X2
862   CPU. This needs to be enabled only for revisions r0p0, r1p0 and r2p0 of the
863   CPU, it is fixed in r2p1.
864
865- ``ERRATA_X2_2701952``: This applies errata 2701952 workaround to Cortex-X2
866   CPU and affects system configurations that do not use an Arm interconnect IP.
867   This needs to be enabled for revisions r0p0, r1p0, r2p0 and r2p1 and is
868   still open.
869
870-  ``ERRATA_X2_2742423``: This applies errata 2742423 workaround to Cortex-X2
871   CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and r2p1 of the
872   CPU and is still open.
873
874-  ``ERRATA_X2_2768515``: This applies errata 2768515 workaround to Cortex-X2
875   CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and r2p1 of the
876   CPU and is still open.
877
878-  ``ERRATA_X2_2778471``: This applies errata 2778471 workaround to Cortex-X2
879   CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and r2p1 of the
880   CPU and is still open.
881
882-  ``ERRATA_X2_3324338``: This applies errata 3324338 workaround to Cortex-X2
883   CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and r2p1 of the
884   CPU and is still open.
885
886-  ``ERRATA_X2_3701772``: This applies errata 3701772 workaround to Cortex-X2
887   CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and r2p1 of the
888   CPU and is still open.
889
890For Cortex-X3, the following errata build flags are defined :
891
892- ``ERRATA_X3_2266875``: This applies errata 2266875 workaround to the Cortex-X3
893  CPU. This needs to be enabled only for revisions r0p0 and r1p0 of the CPU, it
894  is fixed in r1p1.
895
896- ``ERRATA_X3_2302506``: This applies errata 2302506 workaround to the Cortex-X3
897  CPU. This needs to be enabled only for revisions r0p0, r1p0 and r1p1, it is
898  fixed in r1p2.
899
900- ``ERRATA_X3_2313909``: This applies errata 2313909 workaround to
901  Cortex-X3 CPU. This needs to be enabled only for revisions r0p0 and r1p0
902  of the CPU, it is fixed in r1p1.
903
904- ``ERRATA_X3_2372204``: This applies errata 2372204 workaround to
905  Cortex-X3 CPU. This needs to be enabled only for revisions r0p0 and r1p0
906  of the CPU, it is fixed in r1p1.
907
908- ``ERRATA_X3_2615812``: This applies errata 2615812 workaround to Cortex-X3
909  CPU. This needs to be enabled only for revisions r0p0, r1p0 and r1p1 of the
910  CPU, it is fixed in r1p2.
911
912- ``ERRATA_X3_2641945``: This applies errata 2641945 workaround to Cortex-X3
913  CPU. This needs to be enabled only for revisions r0p0 and r1p0 of the CPU.
914  It is fixed in r1p1.
915
916- ``ERRATA_X3_2701951``: This applies erratum 2701951 workaround to Cortex-X3
917  CPU and affects system configurations that do not use an ARM interconnect
918  IP. This needs to be applied to revisions r0p0, r1p0 and r1p1. It is fixed
919  in r1p2.
920
921- ``ERRATA_X3_2742421``: This applies errata 2742421 workaround to
922  Cortex-X3 CPU. This needs to be enabled only for revisions r0p0, r1p0 and
923  r1p1. It is fixed in r1p2.
924
925- ``ERRATA_X3_2743088``: This applies errata 2743088 workaround to Cortex-X3
926  CPU. This needs to be enabled only for revisions r0p0, r1p0 and r1p1. It is
927  fixed in r1p2.
928
929- ``ERRATA_X3_2779509``: This applies errata 2779509 workaround to Cortex-X3
930  CPU. This needs to be enabled only for revisions r0p0, r1p0 and r1p1 of the
931  CPU. It is fixed in r1p2.
932
933- ``ERRATA_X3_3213672``: This applies errata 3213672 workaround to Cortex-X3
934  CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1 and r1p2
935  of the CPU. It is still open.
936
937- ``ERRATA_X3_3692984``: This applies errata 3692984 workaround to Cortex-X3
938  CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1 and r1p2
939  of the CPU. It is still open.
940
941- ``ERRATA_X3_3701769``: This applies errata 3701769 workaround to Cortex-X3
942  CPU. This needs to be enabled only for revisions r0p0, r1p0, r1p1 and r1p2
943  of the CPU and it is still open.
944
945- ``ERRATA_X3_3827463``: This applies errata 3827463 workaround to Cortex-X3
946  CPU. This needs to be enabled only for revisions r0p0, r1p0 and r1p1 of
947  the CPU. It is fixed in r1p2.
948
949For Cortex-X4, the following errata build flags are defined :
950
951- ``ERRATA_X4_2701112``: This applies erratum 2701112 workaround to Cortex-X4
952  CPU and affects system configurations that do not use an Arm interconnect IP.
953  This needs to be enabled for revisions r0p0 and is fixed in r0p1.
954  The workaround for this erratum is not implemented in EL3, but the flag can
955  be enabled/disabled at the platform level. The flag is used when the errata ABI
956  feature is enabled and can assist the Kernel in the process of
957  mitigation of the erratum.
958
959- ``ERRATA_X4_2726228``: This applies erratum 2726228 workaround to Cortex-X4
960  CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed in
961  r0p2.
962
963-  ``ERRATA_X4_2740089``: This applies errata 2740089 workaround to Cortex-X4
964   CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed
965   in r0p2.
966
967- ``ERRATA_X4_2763018``: This applies errata 2763018 workaround to Cortex-X4
968  CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed in r0p2.
969
970- ``ERRATA_X4_2816013``: This applies errata 2816013 workaround to Cortex-X4
971  CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed in r0p2.
972
973- ``ERRATA_X4_2897503``: This applies errata 2897503 workaround to Cortex-X4
974  CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed in r0p2.
975
976- ``ERRATA_X4_2923985``: This applies errata 2923985 workaround to Cortex-X4
977  CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed in r0p2.
978
979- ``ERRATA_X4_2957258``: This applies errata 2957258 workaround to Cortex-X4
980  CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed in r0p2.
981
982- ``ERRATA_X4_3076789``: This applies errata 3076789 workaround to Cortex-X4
983  CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed in r0p2.
984
985- ``ERRATA_X4_3133195``: This applies errata 3133195 workaround to Cortex-X4
986  CPU. This needs to be enabled for revision r0p2. It is fixed in r0p3.
987
988- ``ERRATA_X4_3701758``: This applies errata 3701758 workaround to Cortex-X4
989  CPU. This needs to be enabled for revisions r0p0, r0p1, r0p2 and r0p3.
990  It is still open.
991
992- ``ERRATA_X4_3887999``: This applies errata 3887999 workaround to Cortex-X4
993  CPU. This needs to be enabled for revision r0p0, r0p1, r0p2 and r0p3.
994  It is still open.
995
996For Cortex-X925, the following errata build flags are defined :
997
998- ``ERRATA_X925_2963999``: This applies errata 2963999 workaround to Cortex-X925
999  CPU. This needs to be enabled for revision r0p0. It is fixed in r0p1.
1000
1001- ``ERRATA_X925_3701747``: This applies errata 3701747 workaround to Cortex-X925
1002  CPU. This needs to be enabled for revisions r0p0 and r0p1. It is still open.
1003
1004For Cortex-A510, the following errata build flags are defined :
1005
1006-  ``ERRATA_A510_2008766``: This applies errata 2008766 workaround to
1007   Cortex-A510 CPU. This needs to be enabled for revisions r0p0, r0p1, r0p2,
1008   r0p3, r1p0, r1p1, r1p2 and r1p3. It is still open.
1009
1010-  ``ERRATA_A510_2288014``: This applies errata 2288014 workaround to
1011   Cortex-A510 CPU. This needs to be enabled only for revisions r0p0, r0p1,
1012   r0p2, r0p3 and r1p0, it is fixed in r1p1.
1013
1014-  ``ERRATA_A510_2042739``: This applies errata 2042739 workaround to
1015   Cortex-A510 CPU. This needs to be enabled only for revisions r0p0, r0p1 and
1016   r0p2, it is fixed in r0p3.
1017
1018-  ``ERRATA_A510_2041909``: This applies errata 2041909 workaround to
1019   Cortex-A510 CPU. This needs to be enabled only for revision r0p2 and is fixed
1020   in r0p3. The issue is also present in r0p0 and r0p1 but there is no
1021   workaround for those revisions.
1022
1023-  ``ERRATA_A510_2080326``: This applies errata 2080326 workaround to
1024   Cortex-A510 CPU. This needs to be enabled only for revision r0p2 and is
1025   fixed in r0p3. This issue is also present in r0p0 and r0p1 but there is no
1026   workaround for those revisions.
1027
1028-  ``ERRATA_A510_2169012``: This applies errata 2169012 workaround to
1029   Cortex-A510 CPU. This needs to be enabled only for revisions r0p0, r0p1,
1030   r0p2, r0p3 and r1p0, it is fixed in r1p1.
1031
1032-  ``ERRATA_A510_2218134``: This applies errata 2218134 workaround to
1033   Cortex-A510 CPU. This needs to be enabled only for revision r1p0 and is fixed
1034   in r1p1.
1035
1036-  ``ERRATA_A510_2250311``: This applies errata 2250311 workaround to
1037   Cortex-A510 CPU. This needs to be enabled for revisions r0p0, r0p1, r0p2,
1038   r0p3 and r1p0, it is fixed in r1p1. This workaround disables MPMM even if
1039   ENABLE_MPMM=1.
1040
1041-  ``ERRATA_A510_2218950``: This applies errata 2218950 workaround to
1042   Cortex-A510 CPU. This needs to be enabled for revisions r0p0, r0p1, r0p2,
1043   r0p3 and r1p0, it is fixed in r1p1.
1044
1045-  ``ERRATA_A510_2172148``: This applies errata 2172148 workaround to
1046   Cortex-A510 CPU. This needs to be enabled for revisions r0p0, r0p1, r0p2,
1047   r0p3 and r1p0, it is fixed in r1p1.
1048
1049-  ``ERRATA_A510_2347730``: This applies errata 2347730 workaround to
1050   Cortex-A510 CPU. This needs to be enabled for revisions r0p0, r0p1, r0p2,
1051   r0p3, r1p0 and r1p1. It is fixed in r1p2.
1052
1053-  ``ERRATA_A510_2371937``: This applies errata 2371937 workaround to
1054   Cortex-A510 CPU. This needs to applied for revisions r0p0, r0p1, r0p2,
1055   r0p3, r1p0, r1p1, and is fixed in r1p2.
1056
1057-  ``ERRATA_A510_2420992``: This applies errata 2420992 workaround to
1058   Cortex-A510 CPU. This needs to applied for revisions r1p0 and r1p1, and is
1059   fixed in r1p2.
1060
1061-  ``ERRATA_A510_2666669``: This applies errata 2666669 workaround to
1062   Cortex-A510 CPU. This needs to applied for revisions r0p0, r0p1, r0p2,
1063   r0p3, r1p0, r1p1. It is fixed in r1p2.
1064
1065-  ``ERRATA_A510_2684597``: This applies erratum 2684597 workaround to
1066   Cortex-A510 CPU. This needs to be applied to revision r0p0, r0p1, r0p2,
1067   r0p3, r1p0, r1p1 and r1p2. It is fixed in r1p3.
1068
1069-  ``ERRATA_A510_2971420``: This applies erratum 2971420 workaround to
1070   Cortex-A510 CPU. This needs to be applied to revisions r0p1, r0p2, r0p3,
1071   r1p0, r1p1, r1p2 and r1p3 and is still open.
1072
1073-  ``ERRATA_A510_3672349``: This applies erratum 3672349 workaround to
1074   Cortex-A510 CPU. This needs to be applied to revisions r0p1, r0p2, r0p3,
1075   r1p0, r1p1, r1p2 and r1p3 and is still open.
1076
1077-  ``ERRATA_A510_3704847``: This applies erratum 3704847 workaround to
1078   Cortex-A510 CPU. This needs to be applied to revisions r0p1, r0p2, r0p3,
1079   r1p0, r1p1, r1p2 and r1p3 and is still open.
1080
1081For Cortex-A520, the following errata build flags are defined :
1082
1083-  ``ERRATA_A520_2630792``: This applies errata 2630792 workaround to
1084   Cortex-A520 CPU. This needs to applied for revisions r0p0, r0p1 of the
1085   CPU and is still open.
1086
1087-  ``ERRATA_A520_2858100``: This applies errata 2858100 workaround to
1088   Cortex-A520 CPU. This needs to be enabled for revisions r0p0 and r0p1.
1089   It is still open.
1090
1091-  ``ERRATA_A520_2938996``: This applies errata 2938996 workaround to
1092   Cortex-A520 CPU. This needs to be enabled for revisions r0p0 and r0p1.
1093   It is fixed in r0p2.
1094
1095For Cortex-A715, the following errata build flags are defined :
1096
1097-  ``ERRATA_A715_2331818``: This applies errata 2331818 workaround to
1098   Cortex-A715 CPU. This needs to be enabled for revisions r0p0 and r1p0.
1099   It is fixed in r1p1.
1100
1101- ``ERRATA_A715_2344187``: This applies errata 2344187 workaround to
1102   Cortex-A715 CPU. This needs to be enabled for revisions r0p0 and r1p0. It is
1103   fixed in r1p1.
1104
1105-  ``ERRATA_A715_2376701``: This applies errata 2376701 workaround to
1106   Cortex-A715 CPU. This needs to be enabled for revisions r0p0 and r1p0. It is
1107   fixed in r1p1.
1108
1109-  ``ERRATA_A715_2409570``: This applies errata 2409570 workaround to
1110   Cortex-A715 CPU. This needs to be enabled only for revision r1p0.
1111   It is fixed in r1p1. This errata also applies to r0p0 but that revision has a
1112   different workaround, and since r0p0 is not used in production hardware it is
1113   not implemented.
1114
1115-  ``ERRATA_A715_2413290``: This applies errata 2413290 workaround to
1116   Cortex-A715 CPU. This needs to be enabled only for revision r1p0 and
1117   when SPE(Statistical profiling extension)=True. The errata is fixed
1118   in r1p1.
1119
1120-  ``ERRATA_A715_2420947``: This applies errata 2420947 workaround to
1121   Cortex-A715 CPU. This needs to be enabled only for revision r1p0.
1122   It is fixed in r1p1.
1123
1124-  ``ERRATA_A715_2429384``: This applies errata 2429384 workaround to
1125   Cortex-A715 CPU. This needs to be enabled for revision r1p0. There is no
1126   workaround for revision r0p0. It is fixed in r1p1.
1127
1128-  ``ERRATA_A715_2561034``: This applies errata 2561034 workaround to
1129   Cortex-A715 CPU. This needs to be enabled only for revision r1p0.
1130   It is fixed in r1p1.
1131
1132-  ``ERRATA_A715_2728106``: This applies errata 2728106 workaround to
1133   Cortex-A715 CPU. This needs to be enabled for revisions r0p0, r1p0
1134   and r1p1. It is fixed in r1p2.
1135
1136-  ``ERRATA_A715_2804830``: This applies errata 2804830 workaround to
1137   Cortex-A715 CPU. This needs to be enabled for revisions r0p0, r1p0,
1138   r1p1 and r1p2. It is fixed in r1p3.
1139
1140-  ``ERRATA_A715_3456084``: This applies errata 3456084 workaround to
1141   Cortex-A715 CPU. This needs to be enabled for revisions r0p0, r1p0,
1142   r1p1, r1p2 and r1p3. It is still open.
1143
1144-  ``ERRATA_A715_3699560``: This applies errata 3699560 workaround to
1145   Cortex-A715 CPU. This needs to be enabled for revisions r0p0, r1p0,
1146   r1p2 and r1p3. It is still open.
1147
1148-  ``ERRATA_A715_3711916``: This applies errata 3711916 workaround to
1149   Cortex-A715 CPU. This needs to be enabled for revisions r0p0, r1p0,
1150   r1p1, r1p2 and r1p3. It is still open.
1151
1152For Cortex-A720, the following errata build flags are defined :
1153
1154-  ``ERRATA_A720_2729604``: This applies errata 2729604 workaround to
1155   Cortex-A720 CPU. This needs to be enabled for revisions r0p0 and r0p1.
1156   It is fixed in r0p2.
1157
1158-  ``ERRATA_A720_2792132``: This applies errata 2792132 workaround to
1159   Cortex-A720 CPU. This needs to be enabled for revisions r0p0 and r0p1.
1160   It is fixed in r0p2.
1161
1162-  ``ERRATA_A720_2844092``: This applies errata 2844092 workaround to
1163   Cortex-A720 CPU. This needs to be enabled for revisions r0p0 and r0p1.
1164   It is fixed in r0p2.
1165
1166-  ``ERRATA_A720_2926083``: This applies errata 2926083 workaround to
1167   Cortex-A720 CPU. This needs to be enabled for revisions r0p0 and r0p1.
1168   It is fixed in r0p2.
1169
1170-  ``ERRATA_A720_2940794``: This applies errata 2940794 workaround to
1171   Cortex-A720 CPU. This needs to be enabled for revisions r0p0 and r0p1.
1172   It is fixed in r0p2.
1173
1174-  ``ERRATA_A720_3456091``: This applies errata 3456091 workaround to
1175   Cortex-A720 CPU. This needs to be enabled for revisions r0p0, r0p1
1176   and r0p2. It is still open.
1177
1178-  ``ERRATA_A720_3699561``: This applies errata 3699561 workaround to
1179   Cortex-A720 CPU. This needs to be enabled for revisions r0p0, r0p1
1180   and r0p2. It is still open.
1181
1182-  ``ERRATA_A720_3711910``: This applies errata 3711910 workaround to
1183   Cortex-A720 CPU. This needs to be enabled for revisions r0p0, r0p1
1184   and r0p2. It is still open.
1185
1186For Cortex-A720_AE, the following errata build flags are defined :
1187
1188-  ``ERRATA_A720_AE_3456103``: This applies errata 3456103 workaround to
1189   Cortex-A720_AE CPU. This needs to be enabled for revisions r0p0 and r0p1. It
1190   is still open.
1191
1192-  ``ERRATA_A720_AE_3699562``: This applies errata 3699562 workaround
1193   to Cortex-A720_AE CPU. This needs to be enabled for revisions r0p0.
1194   It is still open.
1195
1196For Cortex-A725, the following errata build flags are defined :
1197
1198-  ``ERRATA_A725_2874943``: This applies errata 2874943 workaround to
1199   Cortex-A725 CPU. This needs to be enabled for revisions r0p0 when
1200   FEAT_SPE is enabled. It is fixed in r0p1.
1201
1202-  ``ERRATA_A725_2936490``: This applies errata 2936490 workaround to
1203   Cortex-A725 CPU. This needs to be enabled for revisions r0p0.
1204   It is fixed in r0p1.
1205
1206-  ``ERRATA_A725_3456106``: This applies errata 3456106 workaround to
1207   Cortex-A725 CPU. This needs to be enabled for revisions r0p0, r0p1
1208   and r0p2. It is still open.
1209
1210-  ``ERRATA_A725_3699564``: This applies errata 3699564 workaround to
1211   Cortex-A725 CPU. This needs to be enabled for revisions r0p0 and r0p1.
1212   It is fixed in r0p2.
1213
1214-  ``ERRATA_A725_3711914``: This applies errata 3711914 workaround to
1215   Cortex-A725 CPU. This needs to be enabled for revisions r0p0 and r0p1.
1216   It is fixed in r0p2.
1217
1218For C1-Ultra, the following errata build flags are defined :
1219
1220-  ``ERRATA_C1ULTRA_3324333``: This applies erratum 3324333 workaround to
1221   C1-Ultra CPU. This needs to be enabled for revision r0p0 and is fixed
1222   in r1p0.
1223
1224-  ``ERRATA_C1ULTRA_3502731``: This applies erratum 3502731 workaround to
1225   C1-Ultra CPU. This needs to be enabled for revision r0p0 and is
1226   fixed in r1p0.
1227
1228-  ``ERRATA_C1ULTRA_3651221``: This applies erratum 3651221 workaround to
1229   C1-Ultra CPU. This needs to be enabled for revision r0p0 and is
1230   fixed in r1p0.
1231
1232-  ``ERRATA_C1ULTRA_3658374``: This applies erratum 3658374 workaround to
1233   C1-Ultra CPU. This needs to be enabled for revisions r0p0 and r1p0 and
1234   is still open.
1235
1236-  ``ERRATA_C1ULTRA_3684152``: This applies erratum 3684152 workaround to
1237   C1-Ultra CPU. This needs to be enabled for revision r0p0 and is
1238   fixed in r1p0.
1239
1240-  ``ERRATA_C1ULTRA_3705939``: This applies erratum 3705939 workaround to
1241   C1-Ultra CPU. This needs to be enabled for revisions r0p0 and r1p0 and
1242   is still open.
1243
1244-  ``ERRATA_C1ULTRA_3815514``: This applies erratum 3815514 workaround to
1245   C1-Ultra CPU. This needs to be enabled for revisions r0p0 and r1p0 and
1246   is still open.
1247
1248-  ``ERRATA_C1ULTRA_3865171``: This applies erratum 3865171 workaround to
1249   C1-Ultra CPU. This needs to be enabled for revisions r0p0 and r1p0 and
1250   is still open.
1251
1252-  ``ERRATA_C1ULTRA_3926381``: This applies erratum 3926381 workaround to
1253   C1-Ultra CPU. This needs to be enabled for revision r1p0 and is still
1254   open.
1255
1256-  ``ERRATA_C1ULTRA_4102704``: This applies erratum 4102704 workaround to
1257   C1-Ultra CPU. This needs to be enabled for revisions r0p0 and r1p0 and
1258   is still open.
1259
1260For C1-Premium, the following errata build flags are defined :
1261
1262-  ``ERRATA_C1PREMIUM_3324333``: This applies errata 3324333 workaround to
1263   C1-Premium CPU. This needs to be enabled for revision r0p0, and is
1264   fixed in r1p0.
1265
1266-  ``ERRATA_C1PREMIUM_3502731``: This applies errata 3502731 workaround to
1267   C1-Premium CPU. This needs to be enabled for revision r0p0, and is fixed
1268   in r1p0.
1269
1270-  ``ERRATA_C1PREMIUM_3651221``: This applies errata 3651221 workaround to
1271   C1-Premium CPU. This needs to be enabled for revision r0p0, and is fixed
1272   in r1p0.
1273
1274-  ``ERRATA_C1PREMIUM_3684152``: This applies errata 3684152 workaround to
1275   C1-Premium CPU. This needs to be enabled for revision r0p0, and is fixed
1276   in r1p0.
1277
1278-  ``ERRATA_C1PREMIUM_3705939``: This applies errata 3705939 workaround to
1279   C1-Premium CPU. This needs to be enabled for revisions r0p0, r1p0 and
1280   is still open.
1281
1282-  ``ERRATA_C1PREMIUM_3815514``: This applies errata 3815514 workaround to
1283   C1-Premium CPU. This needs to be enabled for revisions r0p0, r1p0 and
1284   is still open.
1285
1286-  ``ERRATA_C1PREMIUM_3865171``: This applies errata 3865171 workaround to
1287   C1-Premium CPU. This needs to be enabled for revisions r0p0, r1p0 and
1288   is still open.
1289
1290-  ``ERRATA_C1PREMIUM_3926381``: This applies errata 3926381 workaround to
1291   C1-Premium CPU. This needs to be enabled for revision r1p0 and is
1292   still open.
1293
1294-  ``ERRATA_C1PREMIUM_4102704``: This applies errata 4102704 workaround to
1295   C1-Premium CPU. This needs to be enabled for revisions r0p0, r1p0 and
1296   is still open.
1297
1298For C1-Pro, the following errata build flags are defined :
1299
1300-  ``ERRATA_C1PRO_3619847``: This applies errata 3619847 workaround to C1-Pro
1301   CPU. This needs to be enabled only for revision r0p0 and is fixed in r1p0.
1302
1303-  ``ERRATA_C1PRO_3338470``: This applies errata 3338470 workaround to C1-Pro
1304   CPU. This needs to be enabled only for revision r0p0 and is fixed in r1p0.
1305
1306-  ``ERRATA_C1PRO_3362007``: This applies errata 3362007 workaround to C1-Pro
1307   CPU. This needs to be enabled only for revision r0p0 and is fixed in r1p0.
1308
1309-  ``ERRATA_C1PRO_3684268``: This applies errata 3684268 workaround to C1-Pro
1310   CPU. This needs to be enabled for revisions r0p0, r1p0 and is fixed in
1311   r1p1.
1312
1313-  ``ERRATA_C1PRO_3686597``: This applies errata 3686597 workaround to C1-Pro
1314   CPU. This needs to be enabled for revisions r0p0 and r1p0 of the CPU, it
1315   is fixed in r1p1.
1316
1317-  ``ERRATA_C1PRO_3694158``: This applies errata 3694158 workaround to C1-Pro
1318   CPU. This needs to be enabled for revisions r0p0, r1p0 and r1p1 and is
1319   fixed in r1p2.
1320
1321-  ``ERRATA_C1PRO_3706576``: This applies errata 3706576 workaround to C1-Pro
1322   CPU. This needs to be enabled for revisions r0p0 and r1p0 of the CPU, it
1323   is fixed in r1p1.
1324
1325-  ``ERRATA_C1PRO_3300099``: This applies errata 3300099 workaround to C1-Pro
1326   CPU. This needs to be enabled for revisions r0p0 and r1p0 of the CPU, it
1327   is fixed in r1p1.
1328
1329DSU Errata Workarounds
1330----------------------
1331
1332Similar to CPU errata, TF-A also implements workarounds for DSU (DynamIQ
1333Shared Unit) errata. The DSU errata details can be found in the respective Arm
1334documentation:
1335
1336- `Arm DSU Software Developers Errata Notice`_.
1337
1338Each erratum is identified by an ``ID``, as defined in the DSU errata notice
1339document. Thus, the build flags which enable/disable the errata workarounds
1340have the format ``ERRATA_DSU_<ID>``. The implementation and application logic
1341of DSU errata workarounds are similar to `CPU errata workarounds`_.
1342
1343For DSU errata, the following build flags are defined:
1344
1345-  ``ERRATA_DSU_798953``: This applies errata 798953 workaround for the
1346   affected DSU configurations. This errata applies only for those DSUs that
1347   revision is r0p0 (on r0p1 it is fixed). However, please note that this
1348   workaround results in increased DSU power consumption on idle.
1349
1350-  ``ERRATA_DSU_936184``: This applies errata 936184 workaround for the
1351   affected DSU configurations. This errata applies only for those DSUs that
1352   contain the ACP interface **and** the DSU revision is older than r2p0 (on
1353   r2p0 it is fixed). However, please note that this workaround results in
1354   increased DSU power consumption on idle.
1355
1356-  ``ERRATA_DSU_2313941``: This applies errata 2313941 workaround for the
1357   affected DSU configurations. This errata applies for those DSUs with
1358   revisions r0p0, r1p0, r2p0, r2p1, r3p0, r3p1 and is still open. However,
1359   please note that this workaround results in increased DSU power consumption
1360   on idle.
1361
1362-  ``ERRATA_DSU_2900952``: This applies errata 2900952 workaround for the
1363   affected DSU-120 configurations. This erratum applies to some r2p0
1364   implementations and is fixed in r2p1. The affected r2p0 implementations
1365   are determined by reading the IMP_CLUSTERREVIDR_EL1[1] register bit
1366   and making sure it's clear.
1367
1368CPU Specific optimizations
1369--------------------------
1370
1371This section describes some of the optimizations allowed by the CPU micro
1372architecture that can be enabled by the platform as desired.
1373
1374-  ``SKIP_A57_L1_FLUSH_PWR_DWN``: This flag enables an optimization in the
1375   Cortex-A57 cluster power down sequence by not flushing the Level 1 data
1376   cache. The L1 data cache and the L2 unified cache are inclusive. A flush
1377   of the L2 by set/way flushes any dirty lines from the L1 as well. This
1378   is a known safe deviation from the Cortex-A57 TRM defined power down
1379   sequence. Each Cortex-A57 based platform must make its own decision on
1380   whether to use the optimization.
1381
1382-  ``A53_DISABLE_NON_TEMPORAL_HINT``: This flag disables the cache non-temporal
1383   hint. The LDNP/STNP instructions as implemented on Cortex-A53 do not behave
1384   in a way most programmers expect, and will most probably result in a
1385   significant speed degradation to any code that employs them. The Armv8-A
1386   architecture (see Arm DDI 0487A.h, section D3.4.3) allows cores to ignore
1387   the non-temporal hint and treat LDNP/STNP as LDP/STP instead. Enabling this
1388   flag enforces this behaviour. This needs to be enabled only for revisions
1389   <= r0p3 of the CPU and is enabled by default.
1390
1391-  ``A57_DISABLE_NON_TEMPORAL_HINT``: This flag has the same behaviour as
1392   ``A53_DISABLE_NON_TEMPORAL_HINT`` but for Cortex-A57. This needs to be
1393   enabled only for revisions <= r1p2 of the CPU and is enabled by default,
1394   as recommended in section "4.7 Non-Temporal Loads/Stores" of the
1395   `Cortex-A57 Software Optimization Guide`_.
1396
1397- ''A57_ENABLE_NON_CACHEABLE_LOAD_FWD'': This flag enables non-cacheable
1398   streaming enhancement feature for Cortex-A57 CPUs. Platforms can set
1399   this bit only if their memory system meets the requirement that cache
1400   line fill requests from the Cortex-A57 processor are atomic. Each
1401   Cortex-A57 based platform must make its own decision on whether to use
1402   the optimization. This flag is disabled by default.
1403
1404-  ``NEOVERSE_Nx_EXTERNAL_LLC``: This flag indicates that an external last
1405   level cache(LLC) is present in the system, and that the DataSource field
1406   on the master CHI interface indicates when data is returned from the LLC.
1407   This is used to control how the LL_CACHE* PMU events count.
1408   Default value is 0 (Disabled).
1409
1410-  ``NEOVERSE_N2_PREFETCHER_DISABLE``: This flag disables the region prefetcher
1411   on the Neoverse N2 core. This is used during performance analysis to get clean
1412   and repeatable measurements of the cache by preventing speculative data fetches
1413   from interfering with benchmark results.
1414   Default value is 0 (Disabled).
1415
1416GIC Errata Workarounds
1417----------------------
1418-  ``GIC600_ERRATA_WA_2384374``: This flag applies part 2 of errata 2384374
1419   workaround for the affected GIC600 and GIC600-AE implementations. It applies
1420   to implementations of GIC600 and GIC600-AE with revisions less than or equal
1421   to r1p6 and r0p2 respectively. If the platform sets GICV3_SUPPORT_GIC600,
1422   then this flag is enabled; otherwise, it is 0 (Disabled).
1423
1424--------------
1425
1426*Copyright (c) 2014-2025, Arm Limited and Contributors. All rights reserved.*
1427
1428.. _CVE-2017-5715: http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-5715
1429.. _CVE-2018-3639: http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-3639
1430.. _CVE-2022-23960: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-23960
1431.. _CVE-2024-5660: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2024-5660
1432.. _CVE-2024-7881: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2024-7881
1433.. _Cortex-A72 MPCore Software Developers Errata Notice: https://developer.arm.com/documentation/epm012079/latest
1434.. _Cortex-A57 Software Optimization Guide: https://developer.arm.com/documentation/uan0015
1435.. _Arm DSU Software Developers Errata Notice: https://developer.arm.com/documentation/SDEN854652
1436