xref: /rk3399_ARM-atf/docs/design/cpu-specific-build-macros.rst (revision 281548c3c43ed8bd7d6b319699c16fbf3895dd1c)
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
301For Cortex-A77, the following errata build flags are defined :
302
303-  ``ERRATA_A77_1508412``: This applies errata 1508412 workaround to Cortex-A77
304   CPU. This needs to be enabled only for revision <= r1p0 of the CPU.
305
306-  ``ERRATA_A77_1925769``: This applies errata 1925769 workaround to Cortex-A77
307   CPU. This needs to be enabled only for revision <= r1p1 of the CPU.
308
309-  ``ERRATA_A77_1946167``: This applies errata 1946167 workaround to Cortex-A77
310   CPU. This needs to be enabled only for revision <= r1p1 of the CPU.
311
312-  ``ERRATA_A77_1791578``: This applies errata 1791578 workaround to Cortex-A77
313   CPU. This needs to be enabled for r0p0, r1p0, and r1p1, it is still open.
314
315-  ``ERRATA_A77_2356587``: This applies errata 2356587 workaround to Cortex-A77
316   CPU. This needs to be enabled for r0p0, r1p0, and r1p1, it is still open.
317
318 -  ``ERRATA_A77_1800714``: This applies errata 1800714 workaround to Cortex-A77
319    CPU. This needs to be enabled for revisions <= r1p1 of the CPU.
320
321 -  ``ERRATA_A77_2743100``: This applies errata 2743100 workaround to Cortex-A77
322    CPU. This needs to be enabled for r0p0, r1p0, and r1p1, it is still open.
323
324For Cortex-A78, the following errata build flags are defined :
325
326-  ``ERRATA_A78_1688305``: This applies errata 1688305 workaround to Cortex-A78
327   CPU. This needs to be enabled only for revision r0p0 - r1p0 of the CPU.
328
329-  ``ERRATA_A78_1941498``: This applies errata 1941498 workaround to Cortex-A78
330   CPU. This needs to be enabled for revisions r0p0, r1p0, and r1p1 of the CPU.
331
332-  ``ERRATA_A78_1951500``: This applies errata 1951500 workaround to Cortex-A78
333   CPU. This needs to be enabled for revisions r1p0 and r1p1, r0p0 has the same
334   issue but there is no workaround for that revision.
335
336-  ``ERRATA_A78_1821534``: This applies errata 1821534 workaround to Cortex-A78
337   CPU. This needs to be enabled for revisions r0p0 and r1p0.
338
339-  ``ERRATA_A78_1952683``: This applies errata 1952683 workaround to Cortex-A78
340   CPU. This needs to be enabled for revision r0p0, it is fixed in r1p0.
341
342-  ``ERRATA_A78_2242635``: This applies errata 2242635 workaround to Cortex-A78
343   CPU. This needs to be enabled for revisions r1p0, r1p1, and r1p2. The issue
344   is present in r0p0 but there is no workaround. It is still open.
345
346-  ``ERRATA_A78_2376745``: This applies errata 2376745 workaround to Cortex-A78
347   CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1, and r1p2, and
348   it is still open.
349
350-  ``ERRATA_A78_2395406``: This applies errata 2395406 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_2712571``: This applies erratum 2712571 workaround to Cortex-A78
355   CPU, this erratum affects system configurations that do not use an ARM
356   interconnect IP. This needs to be enabled for revisions r0p0, r1p0, r1p1
357   and r1p2 and it is still open.
358
359-  ``ERRATA_A78_2742426``: This applies erratum 2742426 workaround to Cortex-A78
360   CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1 and r1p2 and
361   it is still open.
362
363-  ``ERRATA_A78_2772019``: This applies errata 2772019 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_2779479``: This applies erratum 2779479 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
371For Cortex-A78AE, the following errata build flags are defined :
372
373- ``ERRATA_A78_AE_1941500`` : This applies errata 1941500 workaround to
374   Cortex-A78AE CPU. This needs to be enabled for revisions r0p0 and r0p1.
375   This erratum is still open.
376
377- ``ERRATA_A78_AE_1951502`` : This applies errata 1951502 workaround to
378  Cortex-A78AE CPU. This needs to be enabled for revisions r0p0 and r0p1. This
379  erratum is still open.
380
381- ``ERRATA_A78_AE_2376748`` : This applies errata 2376748 workaround to
382  Cortex-A78AE CPU. This needs to be enabled for revisions r0p0, r0p1 and r0p2.
383  This erratum is still open.
384
385- ``ERRATA_A78_AE_2395408`` : This applies errata 2395408 workaround to
386  Cortex-A78AE CPU. This needs to be enabled for revisions r0p0 and r0p1. This
387  erratum is still open.
388
389- ``ERRATA_A78_AE_2712574`` : This applies erratum 2712574 workaround to
390  Cortex-A78AE CPU. This erratum affects system configurations that do not use
391  an ARM interconnect IP. This needs to be enabled for revisions r0p0, r0p1 and
392  r0p2. This erratum is still open.
393
394For Cortex-A78C, the following errata build flags are defined :
395
396- ``ERRATA_A78C_1827430`` : This applies errata 1827430 workaround to
397  Cortex-A78C CPU. This needs to be enabled for revision r0p0. The erratum is
398  fixed in r0p1.
399
400- ``ERRATA_A78C_1827440`` : This applies errata 1827440 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_2242638`` : This applies errata 2242638 workaround to
405  Cortex-A78C CPU. This needs to be enabled for revisions r0p1, r0p2 and
406  it is still open.
407
408- ``ERRATA_A78C_2376749`` : This applies errata 2376749 workaround to
409  Cortex-A78C CPU. This needs to be enabled for revisions r0p1 and r0p2. This
410  erratum is still open.
411
412- ``ERRATA_A78C_2395411`` : This applies errata 2395411 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_2683027`` : This applies errata 2683027 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_2712575`` : This applies erratum 2712575 workaround to
421  Cortex-A78C CPU, this erratum affects system configurations that do not use
422  an ARM interconnect IP. This needs to be enabled for revisions r0p1 and r0p2
423  and is still open.
424
425- ``ERRATA_A78C_2743232`` : This applies erratum 2743232 workaround to
426  Cortex-A78C CPU. This needs to be enabled for revisions r0p1 and r0p2.
427  This erratum is still open.
428
429- ``ERRATA_A78C_2772121`` : This applies errata 2772121 workaround to
430  Cortex-A78C CPU. This needs to be enabled for revisions r0p0, r0p1 and r0p2.
431  This erratum is still open.
432
433- ``ERRATA_A78C_2779484`` : This applies errata 2779484 workaround to
434  Cortex-A78C CPU. This needs to be enabled for revisions r0p1 and r0p2.
435  This erratum is still open.
436
437For Cortex-X1 CPU, the following errata build flags are defined:
438
439- ``ERRATA_X1_1821534`` : This applies errata 1821534 workaround to Cortex-X1
440   CPU. This needs to be enabled only for revision <= r1p0 of the CPU.
441
442- ``ERRATA_X1_1688305`` : This applies errata 1688305 workaround to Cortex-X1
443   CPU. This needs to be enabled only for revision <= r1p0 of the CPU.
444
445- ``ERRATA_X1_1827429`` : This applies errata 1827429 workaround to Cortex-X1
446   CPU. This needs to be enabled only for revision <= r1p0 of the CPU.
447
448For Neoverse N1, the following errata build flags are defined :
449
450-  ``ERRATA_N1_1073348``: This applies errata 1073348 workaround to Neoverse-N1
451   CPU. This needs to be enabled only for revision r0p0 and r1p0 of the CPU.
452
453-  ``ERRATA_N1_1130799``: This applies errata 1130799 workaround to Neoverse-N1
454   CPU. This needs to be enabled only for revision <= r2p0 of the CPU.
455
456-  ``ERRATA_N1_1165347``: This applies errata 1165347 workaround to Neoverse-N1
457   CPU. This needs to be enabled only for revision <= r2p0 of the CPU.
458
459-  ``ERRATA_N1_1207823``: This applies errata 1207823 workaround to Neoverse-N1
460   CPU. This needs to be enabled only for revision <= r2p0 of the CPU.
461
462-  ``ERRATA_N1_1220197``: This applies errata 1220197 workaround to Neoverse-N1
463   CPU. This needs to be enabled only for revision <= r2p0 of the CPU.
464
465-  ``ERRATA_N1_1257314``: This applies errata 1257314 workaround to Neoverse-N1
466   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
467
468-  ``ERRATA_N1_1262606``: This applies errata 1262606 workaround to Neoverse-N1
469   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
470
471-  ``ERRATA_N1_1262888``: This applies errata 1262888 workaround to Neoverse-N1
472   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
473
474-  ``ERRATA_N1_1275112``: This applies errata 1275112 workaround to Neoverse-N1
475   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
476
477-  ``ERRATA_N1_1315703``: This applies errata 1315703 workaround to Neoverse-N1
478   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
479
480-  ``ERRATA_N1_1542419``: This applies errata 1542419 workaround to Neoverse-N1
481   CPU. This needs to be enabled only for revisions r3p0 - r4p0 of the CPU.
482
483-  ``ERRATA_N1_1868343``: This applies errata 1868343 workaround to Neoverse-N1
484   CPU. This needs to be enabled only for revision <= r4p0 of the CPU.
485
486-  ``ERRATA_N1_1946160``: This applies errata 1946160 workaround to Neoverse-N1
487   CPU. This needs to be enabled for revisions r3p0, r3p1, r4p0, and r4p1, for
488   revisions r0p0, r1p0, and r2p0 there is no workaround.
489
490-  ``ERRATA_N1_2743102``: This applies errata 2743102 workaround to Neoverse-N1
491   CPU. This needs to be enabled for all revisions <= r4p1 of the CPU and is
492   still open.
493
494For Neoverse V1, the following errata build flags are defined :
495
496-  ``ERRATA_V1_1618635``: This applies errata 1618635 workaround to Neoverse-V1
497   CPU. This needs to be enabled for revision r0p0 of the CPU, it is fixed in
498   r1p0.
499
500-  ``ERRATA_V1_1774420``: This applies errata 1774420 workaround to Neoverse-V1
501   CPU. This needs to be enabled only for revisions r0p0 and r1p0, it is fixed
502   in r1p1.
503
504-  ``ERRATA_V1_1791573``: This applies errata 1791573 workaround to Neoverse-V1
505   CPU. This needs to be enabled only for revisions r0p0 and r1p0, it is fixed
506   in r1p1.
507
508-  ``ERRATA_V1_1852267``: This applies errata 1852267 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_1925756``: This applies errata 1925756 workaround to Neoverse-V1
513   CPU. This needs to be enabled for r0p0, r1p0, and r1p1, it is still open.
514
515-  ``ERRATA_V1_1940577``: This applies errata 1940577 workaround to Neoverse-V1
516   CPU. This needs to be enabled only for revision r1p0 and r1p1 of the
517   CPU.
518
519-  ``ERRATA_V1_1966096``: This applies errata 1966096 workaround to Neoverse-V1
520   CPU. This needs to be enabled for revisions r1p0 and r1p1 of the CPU, the
521   issue is present in r0p0 as well but there is no workaround for that
522   revision.  It is still open.
523
524-  ``ERRATA_V1_2139242``: This applies errata 2139242 workaround to Neoverse-V1
525   CPU. This needs to be enabled for revisions r0p0, r1p0, and r1p1 of the
526   CPU.  It is still open.
527
528-  ``ERRATA_V1_2216392``: This applies errata 2216392 workaround to Neoverse-V1
529   CPU. This needs to be enabled for revisions r1p0 and r1p1 of the CPU, the
530   issue is present in r0p0 as well but there is no workaround for that
531   revision.  It is still open.
532
533-  ``ERRATA_V1_2294912``: This applies errata 2294912 workaround to Neoverse-V1
534   CPU. This needs to be enabled for revisions r0p0, r1p0, and r1p1 and r1p2 of
535   the CPU.
536
537-  ``ERRATA_V1_2348377``: This applies errata 2348377 workaroud to Neoverse-V1
538   CPU. This needs to be enabled for revisions r0p0, r1p0 and r1p1 of the CPU.
539   It has been fixed in r1p2.
540
541-  ``ERRATA_V1_2372203``: This applies errata 2372203 workaround to Neoverse-V1
542   CPU. This needs to be enabled for revisions r0p0, r1p0 and r1p1 of the CPU.
543   It is still open.
544
545- ``ERRATA_V1_2701953``: This applies erratum 2701953 workaround to Neoverse-V1
546   CPU, this erratum affects system configurations that do not use an ARM
547   interconnect IP. This needs to be enabled for revisions r0p0, r1p0 and r1p1.
548   It has been fixed in r1p2.
549
550-  ``ERRATA_V1_2743093``: This applies errata 2743093 workaround to Neoverse-V1
551   CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1 and r1p2 of the
552   CPU. It is still open.
553
554-  ``ERRATA_V1_2743233``: This applies erratum 2743233 workaround to Neoverse-V1
555   CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1, and r1p2 of the
556   CPU. It is still open.
557
558-  ``ERRATA_V1_2779461``: This applies erratum 2779461 workaround to Neoverse-V1
559   CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1, r1p2 of the
560   CPU. It is still open.
561
562For Neoverse V2, the following errata build flags are defined :
563
564-  ``ERRATA_V2_2618597``: This applies errata 2618597 workaround to Neoverse-V2
565   CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed in
566   r0p2.
567
568-  ``ERRATA_V2_2662553``: This applies errata 2662553 workaround to Neoverse-V2
569   CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed in
570   r0p2.
571
572-  ``ERRATA_V2_2719103``: This applies errata 2719103 workaround to Neoverse-V2
573   CPU, this affects system configurations that do not use and ARM interconnect
574   IP. This needs to be enabled for revisions r0p0 and r0p1. It has been fixed
575   in r0p2.
576
577-  ``ERRATA_V2_2719105``: This applies errata 2719105 workaround to Neoverse-V2
578   CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed in
579   r0p2.
580
581-  ``ERRATA_V2_2743011``: This applies errata 2743011 workaround to Neoverse-V2
582   CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed in
583   r0p2.
584
585-  ``ERRATA_V2_2779510``: This applies errata 2779510 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_2801372``: This applies errata 2801372 workaround to Neoverse-V2
590   CPU, this affects all configurations. This needs to be enabled for revisions
591   r0p0 and r0p1. It has been fixed in r0p2.
592
593-  ``ERRATA_V2_3701771``: This applies errata 3701771 workaround to Neoverse-V2
594   CPU. This needs to be enabled for revisions r0p0, r0p1 and r0p2 and is
595   still open.
596
597-  ``ERRATA_V2_3841324``: This applies errata 3841324 workaround to Neoverse-V2
598   CPU. This needs to be enabled only for revisions r0p0 and r0p1 of
599   the CPU. It is fixed in r0p2.
600
601For Neoverse V3, the following errata build flags are defined :
602
603- ``ERRATA_V3_2970647``: This applies errata 2970647 workaround to Neoverse-V3
604  CPU. This needs to be enabled for revision r0p0. It is fixed in r0p1.
605
606- ``ERRATA_V3_3696307``: This applies errata 3696307 workaround to Neoverse-V3
607  CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed in
608  r0p2.
609
610- ``ERRATA_V3_3701767``: This applies errata 3701767 workaround to Neoverse-V3
611  CPU. This needs to be enabled for revisions r0p0, r0p1, r0p2 of the CPU and
612  is still open.
613
614- ``ERRATA_V3_3734562``: This applies errata 3734562 workaround to Neoverse-V3
615  CPU. This needs to be enabled for revisions r0p0 and r0p1 of the CPU and
616  is fixed in r0p2.
617
618- ``ERRATA_V3_3782181``: This applies errata 3782181 workaround to Neoverse-V3
619  CPU. This needs to be enabled for revision r0p1 of the CPU and is fixed in
620  r0p2.
621
622- ``ERRATA_V3_3864536``: This applies errata 3864536 workaround to Neoverse-V3
623  CPU. This needs to be enabled for revisions r0p0, r0p1 and r0p2 of the CPU and
624  is still open.
625
626- ``ERRATA_V3_3878291``: This applies errata 3878291 workaround to Neoverse-V3
627  CPU. This needs to be enabled for revisions r0p0, r0p1 and r0p2 of the CPU and
628  is still open.
629
630For Cortex-A710, the following errata build flags are defined :
631
632-  ``ERRATA_A710_1901946``: This applies errata 1901946 workaround to
633   Cortex-A710 CPU. This needs to be enabled only for revision r1p0. It has
634   been fixed in r2p0.
635
636-  ``ERRATA_A710_1916945``: This applies errata 1916945 workaround to
637   Cortex-A710 CPU. This needs to be enabled only for revisions r0p0 and r1p0.
638   It has been fixed in r2p0.
639
640-  ``ERRATA_A710_1917258``: This applies errata 1917258 workaround to
641   Cortex-A710 CPU. This needs to be enabled only for revisions r0p0 and r1p0.
642   It has been fixed in r2p0.
643
644-  ``ERRATA_A710_1927200``: This applies errata 1927200 workaround to
645   Cortex-A710 CPU. This needs to be enabled only for revisions r0p0 and r1p0.
646   It has been fixed in r2p0.
647
648-  ``ERRATA_A710_1987031``: This applies errata 1987031 workaround to
649   Cortex-A710 CPU. This needs to be enabled only for revisions r0p0, r1p0 and
650   r2p0 of the CPU. It is still open.
651
652-  ``ERRATA_A710_2081180``: This applies errata 2081180 workaround to
653   Cortex-A710 CPU. This needs to be enabled only for revisions r0p0, r1p0 and
654   r2p0 of the CPU. It is still open.
655
656-  ``ERRATA_A710_2055002``: This applies errata 2055002 workaround to
657   Cortex-A710 CPU. This needs to be enabled for revisions r1p0, r2p0 of the CPU
658   and is still open.
659
660-  ``ERRATA_A710_2017096``: This applies errata 2017096 workaround to
661   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
662   of the CPU and is still open.
663
664-  ``ERRATA_A710_2083908``: This applies errata 2083908 workaround to
665   Cortex-A710 CPU. This needs to be enabled for revision r2p0 of the CPU and
666   is still open.
667
668-  ``ERRATA_A710_2267065``: This applies errata 2267065 workaround to
669   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
670   of the CPU and is fixed in r2p1.
671
672-  ``ERRATA_A710_2136059``: This applies errata 2136059 workaround to
673   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
674   of the CPU and is fixed in r2p1.
675
676-  ``ERRATA_A710_2147715``: This applies errata 2147715 workaround to
677   Cortex-A710 CPU. This needs to be enabled for revision r2p0 of the CPU
678   and is fixed in r2p1.
679
680-  ``ERRATA_A710_2216384``: This applies errata 2216384 workaround to
681   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
682   of the CPU and is fixed in r2p1.
683
684-  ``ERRATA_A710_2282622``: This applies errata 2282622 workaround to
685   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and
686   r2p1 of the CPU and is still open.
687
688- ``ERRATA_A710_2291219``: This applies errata 2291219 workaround to
689   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
690   of the CPU and is fixed in r2p1.
691
692-  ``ERRATA_A710_2008768``: This applies errata 2008768 workaround to
693   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
694   of the CPU and is fixed in r2p1.
695
696-  ``ERRATA_A710_2371105``: This applies errata 2371105 workaround to
697   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
698   of the CPU and is fixed in r2p1.
699
700-  ``ERRATA_A710_2701952``: This applies erratum 2701952 workaround to Cortex-A710
701   CPU, and applies to system configurations that do not use and ARM
702   interconnect IP. This needs to be enabled for r0p0, r1p0, r2p0 and r2p1 and
703   is still open.
704
705-  ``ERRATA_A710_2742423``: This applies errata 2742423 workaround to
706   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and
707   r2p1 of the CPU and is still open.
708
709-  ``ERRATA_A710_2768515``: This applies errata 2768515 workaround to
710   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and
711   r2p1 of the CPU and is still open.
712
713-  ``ERRATA_A710_2778471``: This applies errata 2778471 workaround to Cortex-A710
714   CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and r2p1 of the
715   CPU and is still open.
716
717-  ``ERRATA_A710_3324338``: This applies errata 3324338 workaround to
718   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and
719   r2p1 of the CPU and is still open.
720
721- ``ERRATA_A710_3701772``: This applies errata 3701772 workaround to Cortex-A710
722  CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0, r2p1 of the
723  CPU and is still open.
724
725For Neoverse N2, the following errata build flags are defined :
726
727-  ``ERRATA_N2_2002655``: This applies errata 2002655 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_2009478``: This applies errata 2009478 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_2067956``: This applies errata 2067956 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_2025414``: This applies errata 2025414 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_2189731``: This applies errata 2189731 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_2138956``: This applies errata 2138956 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_2242415``: This applies errata 2242415 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_2138958``: This applies errata 2138958 workaround to Neoverse-N2
749   CPU. This needs to be enabled for revision r0p0 of the CPU and is fixed in r0p1.
750
751-  ``ERRATA_N2_2242400``: This applies errata 2242400 workaround to Neoverse-N2
752   CPU. This needs to be enabled for revision r0p0 of the CPU and is fixed in r0p1.
753
754-  ``ERRATA_N2_2280757``: This applies errata 2280757 workaround to Neoverse-N2
755   CPU. This needs to be enabled for revision r0p0 of the CPU and is fixed in r0p1.
756
757-  ``ERRATA_N2_2326639``: This applies errata 2326639 workaround to Neoverse-N2
758   CPU. This needs to be enabled for revision r0p0 of the CPU, it is fixed in
759   r0p1.
760
761-  ``ERRATA_N2_2340933``: This applies errata 2340933 workaround to Neoverse-N2
762   CPU. This needs to be enabled for revision r0p0 of the CPU, it is fixed in
763   r0p1.
764
765-  ``ERRATA_N2_2346952``: This applies errata 2346952 workaround to Neoverse-N2
766   CPU. This needs to be enabled for revisions r0p0, r0p1 and r0p2 of the CPU,
767   it is fixed in r0p3.
768
769-  ``ERRATA_N2_2376738``: This applies errata 2376738 workaround to Neoverse-N2
770   CPU. This needs to be enabled for revision r0p0, r0p1, r0p2, r0p3 and is still open.
771
772-  ``ERRATA_N2_2388450``: This applies errata 2388450 workaround to Neoverse-N2
773   CPU. This needs to be enabled for revision r0p0 of the CPU, it is fixed in
774   r0p1.
775
776-  ``ERRATA_N2_2743014``: This applies errata 2743014 workaround to Neoverse-N2
777   CPU. This needs to be enabled for revisions r0p0, r0p1 and r0p2. It is fixed
778   in r0p3.
779
780-  ``ERRATA_N2_2743089``: This applies errata 2743089 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_2728475``: This applies erratum 2728475 workaround to Neoverse-N2
785   CPU, this erratum affects system configurations that do not use and ARM
786   interconnect IP. This needs to be enabled for revisions r0p0, r0p1 and r0p2.
787   It is fixed in r0p3.
788
789-  ``ERRATA_N2_2779511``: This applies errata 2779511 workaround to Neoverse-N2
790   CPU. This needs to be enabled for revisions r0p0, r0p1 and r0p2. It is fixed
791   in r0p3.
792
793-  ``ERRATA_N2_3701773``: This applies errata 3701773 workaround to Neoverse-N2
794   CPU. This needs to be enabled for revisions r0p0, r0p1, r0p2, r0p3 and is
795   still open.
796
797For Neoverse N3, the following errata build flags are defined :
798
799-  ``ERRATA_N3_3699563``: This applies errata 3699563 workaround to Neoverse-N3
800   CPU. This needs to be enabled for revisions r0p0 and is still open.
801
802For Cortex-X2, the following errata build flags are defined :
803
804-  ``ERRATA_X2_1901946``: This applies errata 1901946 workaround to Cortex-X2
805   CPU. This needs to be enabled only for r1p0, it is fixed in r2p0.
806
807-  ``ERRATA_X2_1916945``: This applies errata 1916945 workaround to Cortex-X2
808   CPU. This needs to be enabled only for revisions r0p0 and r1p0 of the CPU, it
809   is fixed in r2p0.
810
811-  ``ERRATA_X2_1917258``: This applies errata 1917258 workaround to Cortex-X2
812   CPU. This needs to be enabled only for revisions r0p0 and r1p0 of the CPU, it
813   is fixed in r2p0.
814
815-  ``ERRATA_X2_1927200``: This applies errata 1927200 workaround to Cortex-X2
816   CPU. This needs to be enabled only for revisions r0p0 and r1p0 of the CPU, it
817   is fixed in r2p0.
818
819-  ``ERRATA_X2_1934260``: This applies errata 1934260 workaround to Cortex-X2
820   CPU. This needs to be enabled only for revision r1p0 of the CPU, it is fixed
821   in r2p0.
822
823-  ``ERRATA_X2_2002765``: This applies errata 2002765 workaround to Cortex-X2
824   CPU. This needs to be enabled only for revisions r0p0, r1p0 and r2p0 of the
825   CPU, it is fixed in r2p1.
826
827-  ``ERRATA_X2_2017096``: This applies errata 2017096 workaround to Cortex-X2
828   CPU. This needs to be enabled only for revisions r0p0, r1p0 and r2p0 of the
829   CPU, it is fixed in r2p1.
830
831-  ``ERRATA_X2_2081180``: This applies errata 2081180 workaround to Cortex-X2
832   CPU. This needs to be enabled only for revisions r0p0, r1p0 and r2p0 of the
833   CPU, it is fixed in r2p1.
834
835-  ``ERRATA_X2_2083908``: This applies errata 2083908 workaround to Cortex-X2
836   CPU. This needs to be enabled only for revision r2p0 of the CPU, it is fixed
837   in r2p1.
838
839-  ``ERRATA_X2_2136059``: This applies errata 2136059 workaround to Cortex-X2
840   CPU. This needs to be enabled only for revisions r0p0, r1p0 and r2p0 of the
841   CPU, it is fixed in r2p1.
842
843-  ``ERRATA_X2_2147715``: This applies errata 2147715 workaround to Cortex-X2
844   CPU. This needs to be enabled only for revision r2p0 of the CPU, it is fixed
845   in r2p1.
846
847-  ``ERRATA_X2_2216384``: This applies errata 2216384 workaround to Cortex-X2
848   CPU. This needs to be enabled only for revisions r0p0, r1p0 and r2p0 of the
849   CPU, it is fixed in r2p1.
850
851-  ``ERRATA_X2_2267065``: This applies errata 2267065 workaround to Cortex-X2
852   CPU. This needs to be enabled only for revisions r0p0, r1p0 and r2p0 of the
853   CPU, it is fixed in r2p1.
854
855-  ``ERRATA_X2_2282622``: This applies errata 2282622 workaround to Cortex-X2
856   CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and r2p1 of the
857   CPU and is still open.
858
859-  ``ERRATA_X2_2291219``: This applies errata 2291219 workaround to Cortex-X2
860   CPU. This needs to be enabled only for revisions r0p0, r1p0 and r2p0 of the
861   CPU, it is fixed in r2p1.
862
863-  ``ERRATA_X2_2371105``: This applies errata 2371105 workaround to Cortex-X2
864   CPU. This needs to be enabled only for revisions r0p0, r1p0 and r2p0 of the
865   CPU, it is fixed in r2p1.
866
867- ``ERRATA_X2_2701952``: This applies errata 2701952 workaround to Cortex-X2
868   CPU and affects system configurations that do not use an Arm interconnect IP.
869   This needs to be enabled for revisions r0p0, r1p0, r2p0 and r2p1 and is
870   still open.
871
872-  ``ERRATA_X2_2742423``: This applies errata 2742423 workaround to Cortex-X2
873   CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and r2p1 of the
874   CPU and is still open.
875
876-  ``ERRATA_X2_2768515``: This applies errata 2768515 workaround to Cortex-X2
877   CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and r2p1 of the
878   CPU and is still open.
879
880-  ``ERRATA_X2_2778471``: This applies errata 2778471 workaround to Cortex-X2
881   CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and r2p1 of the
882   CPU and is still open.
883
884-  ``ERRATA_X2_3324338``: This applies errata 3324338 workaround to Cortex-X2
885   CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and r2p1 of the
886   CPU and is still open.
887
888-  ``ERRATA_X2_3701772``: This applies errata 3701772 workaround to Cortex-X2
889   CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and r2p1 of the
890   CPU and is still open.
891
892For Cortex-X3, the following errata build flags are defined :
893
894- ``ERRATA_X3_2266875``: This applies errata 2266875 workaround to the Cortex-X3
895  CPU. This needs to be enabled only for revisions r0p0 and r1p0 of the CPU, it
896  is fixed in r1p1.
897
898- ``ERRATA_X3_2302506``: This applies errata 2302506 workaround to the Cortex-X3
899  CPU. This needs to be enabled only for revisions r0p0, r1p0 and r1p1, it is
900  fixed in r1p2.
901
902- ``ERRATA_X3_2313909``: This applies errata 2313909 workaround to
903  Cortex-X3 CPU. This needs to be enabled only for revisions r0p0 and r1p0
904  of the CPU, it is fixed in r1p1.
905
906- ``ERRATA_X3_2372204``: This applies errata 2372204 workaround to
907  Cortex-X3 CPU. This needs to be enabled only for revisions r0p0 and r1p0
908  of the CPU, it is fixed in r1p1.
909
910- ``ERRATA_X3_2615812``: This applies errata 2615812 workaround to Cortex-X3
911  CPU. This needs to be enabled only for revisions r0p0, r1p0 and r1p1 of the
912  CPU, it is fixed in r1p2.
913
914- ``ERRATA_X3_2641945``: This applies errata 2641945 workaround to Cortex-X3
915  CPU. This needs to be enabled only for revisions r0p0 and r1p0 of the CPU.
916  It is fixed in r1p1.
917
918- ``ERRATA_X3_2701951``: This applies erratum 2701951 workaround to Cortex-X3
919  CPU and affects system configurations that do not use an ARM interconnect
920  IP. This needs to be applied to revisions r0p0, r1p0 and r1p1. It is fixed
921  in r1p2.
922
923- ``ERRATA_X3_2742421``: This applies errata 2742421 workaround to
924  Cortex-X3 CPU. This needs to be enabled only for revisions r0p0, r1p0 and
925  r1p1. It is fixed in r1p2.
926
927- ``ERRATA_X3_2743088``: This applies errata 2743088 workaround to Cortex-X3
928  CPU. This needs to be enabled only for revisions r0p0, r1p0 and r1p1. It is
929  fixed in r1p2.
930
931- ``ERRATA_X3_2779509``: This applies errata 2779509 workaround to Cortex-X3
932  CPU. This needs to be enabled only for revisions r0p0, r1p0 and r1p1 of the
933  CPU. It is fixed in r1p2.
934
935- ``ERRATA_X3_3213672``: This applies errata 3213672 workaround to Cortex-X3
936  CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1 and r1p2
937  of the CPU. It is still open.
938
939- ``ERRATA_X3_3692984``: This applies errata 3692984 workaround to Cortex-X3
940  CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1 and r1p2
941  of the CPU. It is still open.
942
943- ``ERRATA_X3_3701769``: This applies errata 3701769 workaround to Cortex-X3
944  CPU. This needs to be enabled only for revisions r0p0, r1p0, r1p1 and r1p2
945  of the CPU and it is still open.
946
947- ``ERRATA_X3_3827463``: This applies errata 3827463 workaround to Cortex-X3
948  CPU. This needs to be enabled only for revisions r0p0, r1p0 and r1p1 of
949  the CPU. It is fixed in r1p2.
950
951For Cortex-X4, the following errata build flags are defined :
952
953- ``ERRATA_X4_2701112``: This applies erratum 2701112 workaround to Cortex-X4
954  CPU and affects system configurations that do not use an Arm interconnect IP.
955  This needs to be enabled for revisions r0p0 and is fixed in r0p1.
956  The workaround for this erratum is not implemented in EL3, but the flag can
957  be enabled/disabled at the platform level. The flag is used when the errata ABI
958  feature is enabled and can assist the Kernel in the process of
959  mitigation of the erratum.
960
961- ``ERRATA_X4_2726228``: This applies erratum 2726228 workaround to Cortex-X4
962  CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed in
963  r0p2.
964
965-  ``ERRATA_X4_2740089``: This applies errata 2740089 workaround to Cortex-X4
966   CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed
967   in r0p2.
968
969- ``ERRATA_X4_2763018``: This applies errata 2763018 workaround to Cortex-X4
970  CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed in r0p2.
971
972- ``ERRATA_X4_2816013``: This applies errata 2816013 workaround to Cortex-X4
973  CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed in r0p2.
974
975- ``ERRATA_X4_2897503``: This applies errata 2897503 workaround to Cortex-X4
976  CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed in r0p2.
977
978- ``ERRATA_X4_2923985``: This applies errata 2923985 workaround to Cortex-X4
979  CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed in r0p2.
980
981- ``ERRATA_X4_2957258``: This applies errata 2957258 workaround to Cortex-X4
982  CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed in r0p2.
983
984- ``ERRATA_X4_3076789``: This applies errata 3076789 workaround to Cortex-X4
985  CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed in r0p2.
986
987- ``ERRATA_X4_3133195``: This applies errata 3133195 workaround to Cortex-X4
988  CPU. This needs to be enabled for revision r0p2. It is fixed in r0p3.
989
990- ``ERRATA_X4_3701758``: This applies errata 3701758 workaround to Cortex-X4
991  CPU. This needs to be enabled for revisions r0p0, r0p1, r0p2 and r0p3.
992  It is still open.
993
994- ``ERRATA_X4_3887999``: This applies errata 3887999 workaround to Cortex-X4
995  CPU. This needs to be enabled for revision r0p0, r0p1, r0p2 and r0p3.
996  It is still open.
997
998For Cortex-X925, the following errata build flags are defined :
999
1000- ``ERRATA_X925_2963999``: This applies errata 2963999 workaround to Cortex-X925
1001  CPU. This needs to be enabled for revision r0p0. It is fixed in r0p1.
1002
1003- ``ERRATA_X925_3701747``: This applies errata 3701747 workaround to Cortex-X925
1004  CPU. This needs to be enabled for revisions r0p0 and r0p1. It is still open.
1005
1006For Cortex-A510, the following errata build flags are defined :
1007
1008-  ``ERRATA_A510_2008766``: This applies errata 2008766 workaround to
1009   Cortex-A510 CPU. This needs to be enabled for revisions r0p0, r0p1, r0p2,
1010   r0p3, r1p0, r1p1, r1p2 and r1p3. It is still open.
1011
1012-  ``ERRATA_A510_2288014``: This applies errata 2288014 workaround to
1013   Cortex-A510 CPU. This needs to be enabled only for revisions r0p0, r0p1,
1014   r0p2, r0p3 and r1p0, it is fixed in r1p1.
1015
1016-  ``ERRATA_A510_2042739``: This applies errata 2042739 workaround to
1017   Cortex-A510 CPU. This needs to be enabled only for revisions r0p0, r0p1 and
1018   r0p2, it is fixed in r0p3.
1019
1020-  ``ERRATA_A510_2041909``: This applies errata 2041909 workaround to
1021   Cortex-A510 CPU. This needs to be enabled only for revision r0p2 and is fixed
1022   in r0p3. The issue is also present in r0p0 and r0p1 but there is no
1023   workaround for those revisions.
1024
1025-  ``ERRATA_A510_2080326``: This applies errata 2080326 workaround to
1026   Cortex-A510 CPU. This needs to be enabled only for revision r0p2 and is
1027   fixed in r0p3. This issue is also present in r0p0 and r0p1 but there is no
1028   workaround for those revisions.
1029
1030-  ``ERRATA_A510_2169012``: This applies errata 2169012 workaround to
1031   Cortex-A510 CPU. This needs to be enabled only for revisions r0p0, r0p1,
1032   r0p2, r0p3 and r1p0, it is fixed in r1p1.
1033
1034-  ``ERRATA_A510_2218134``: This applies errata 2218134 workaround to
1035   Cortex-A510 CPU. This needs to be enabled only for revision r1p0 and is fixed
1036   in r1p1.
1037
1038-  ``ERRATA_A510_2250311``: This applies errata 2250311 workaround to
1039   Cortex-A510 CPU. This needs to be enabled for revisions r0p0, r0p1, r0p2,
1040   r0p3 and r1p0, it is fixed in r1p1. This workaround disables MPMM even if
1041   ENABLE_MPMM=1.
1042
1043-  ``ERRATA_A510_2218950``: This applies errata 2218950 workaround to
1044   Cortex-A510 CPU. This needs to be enabled for revisions r0p0, r0p1, r0p2,
1045   r0p3 and r1p0, it is fixed in r1p1.
1046
1047-  ``ERRATA_A510_2172148``: This applies errata 2172148 workaround to
1048   Cortex-A510 CPU. This needs to be enabled for revisions r0p0, r0p1, r0p2,
1049   r0p3 and r1p0, it is fixed in r1p1.
1050
1051-  ``ERRATA_A510_2347730``: This applies errata 2347730 workaround to
1052   Cortex-A510 CPU. This needs to be enabled for revisions r0p0, r0p1, r0p2,
1053   r0p3, r1p0 and r1p1. It is fixed in r1p2.
1054
1055-  ``ERRATA_A510_2371937``: This applies errata 2371937 workaround to
1056   Cortex-A510 CPU. This needs to applied for revisions r0p0, r0p1, r0p2,
1057   r0p3, r1p0, r1p1, and is fixed in r1p2.
1058
1059-  ``ERRATA_A510_2420992``: This applies errata 2420992 workaround to
1060   Cortex-A510 CPU. This needs to applied for revisions r1p0 and r1p1, and is
1061   fixed in r1p2.
1062
1063-  ``ERRATA_A510_2666669``: This applies errata 2666669 workaround to
1064   Cortex-A510 CPU. This needs to applied for revisions r0p0, r0p1, r0p2,
1065   r0p3, r1p0, r1p1. It is fixed in r1p2.
1066
1067-  ``ERRATA_A510_2684597``: This applies erratum 2684597 workaround to
1068   Cortex-A510 CPU. This needs to be applied to revision r0p0, r0p1, r0p2,
1069   r0p3, r1p0, r1p1 and r1p2. It is fixed in r1p3.
1070
1071-  ``ERRATA_A510_2971420``: This applies erratum 2971420 workaround to
1072   Cortex-A510 CPU. This needs to be applied to revisions r0p1, r0p2, r0p3,
1073   r1p0, r1p1, r1p2 and r1p3 and is still open.
1074
1075-  ``ERRATA_A510_3672349``: This applies erratum 3672349 workaround to
1076   Cortex-A510 CPU. This needs to be applied to revisions r0p1, r0p2, r0p3,
1077   r1p0, r1p1, r1p2 and r1p3 and is still open.
1078
1079-  ``ERRATA_A510_3704847``: This applies erratum 3704847 workaround to
1080   Cortex-A510 CPU. This needs to be applied to revisions r0p1, r0p2, r0p3,
1081   r1p0, r1p1, r1p2 and r1p3 and is still open.
1082
1083For Cortex-A520, the following errata build flags are defined :
1084
1085-  ``ERRATA_A520_2630792``: This applies errata 2630792 workaround to
1086   Cortex-A520 CPU. This needs to applied for revisions r0p0, r0p1 of the
1087   CPU and is still open.
1088
1089-  ``ERRATA_A520_2858100``: This applies errata 2858100 workaround to
1090   Cortex-A520 CPU. This needs to be enabled for revisions r0p0 and r0p1.
1091   It is still open.
1092
1093-  ``ERRATA_A520_2938996``: This applies errata 2938996 workaround to
1094   Cortex-A520 CPU. This needs to be enabled for revisions r0p0 and r0p1.
1095   It is fixed in r0p2.
1096
1097For Cortex-A715, the following errata build flags are defined :
1098
1099-  ``ERRATA_A715_2331818``: This applies errata 2331818 workaround to
1100   Cortex-A715 CPU. This needs to be enabled for revisions r0p0 and r1p0.
1101   It is fixed in r1p1.
1102
1103- ``ERRATA_A715_2344187``: This applies errata 2344187 workaround to
1104   Cortex-A715 CPU. This needs to be enabled for revisions r0p0 and r1p0. It is
1105   fixed in r1p1.
1106
1107-  ``ERRATA_A715_2376701``: This applies errata 2376701 workaround to
1108   Cortex-A715 CPU. This needs to be enabled for revisions r0p0 and r1p0. It is
1109   fixed in r1p1.
1110
1111-  ``ERRATA_A715_2409570``: This applies errata 2409570 workaround to
1112   Cortex-A715 CPU. This needs to be enabled only for revision r1p0.
1113   It is fixed in r1p1. This errata also applies to r0p0 but that revision has a
1114   different workaround, and since r0p0 is not used in production hardware it is
1115   not implemented.
1116
1117-  ``ERRATA_A715_2413290``: This applies errata 2413290 workaround to
1118   Cortex-A715 CPU. This needs to be enabled only for revision r1p0 and
1119   when SPE(Statistical profiling extension)=True. The errata is fixed
1120   in r1p1.
1121
1122-  ``ERRATA_A715_2420947``: This applies errata 2420947 workaround to
1123   Cortex-A715 CPU. This needs to be enabled only for revision r1p0.
1124   It is fixed in r1p1.
1125
1126-  ``ERRATA_A715_2429384``: This applies errata 2429384 workaround to
1127   Cortex-A715 CPU. This needs to be enabled for revision r1p0. There is no
1128   workaround for revision r0p0. It is fixed in r1p1.
1129
1130-  ``ERRATA_A715_2561034``: This applies errata 2561034 workaround to
1131   Cortex-A715 CPU. This needs to be enabled only for revision r1p0.
1132   It is fixed in r1p1.
1133
1134-  ``ERRATA_A715_2728106``: This applies errata 2728106 workaround to
1135   Cortex-A715 CPU. This needs to be enabled for revisions r0p0, r1p0
1136   and r1p1. It is fixed in r1p2.
1137
1138-  ``ERRATA_A715_2804830``: This applies errata 2804830 workaround to
1139   Cortex-A715 CPU. This needs to be enabled for revisions r0p0, r1p0,
1140   r1p1 and r1p2. It is fixed in r1p3.
1141
1142-  ``ERRATA_A715_3456084``: This applies errata 3456084 workaround to
1143   Cortex-A715 CPU. This needs to be enabled for revisions r0p0, r1p0,
1144   r1p1, r1p2 and r1p3. It is still open.
1145
1146-  ``ERRATA_A715_3699560``: This applies errata 3699560 workaround to
1147   Cortex-A715 CPU. This needs to be enabled for revisions r0p0, r1p0,
1148   r1p2 and r1p3. It is still open.
1149
1150-  ``ERRATA_A715_3711916``: This applies errata 3711916 workaround to
1151   Cortex-A715 CPU. This needs to be enabled for revisions r0p0, r1p0,
1152   r1p1, r1p2 and r1p3. It is still open.
1153
1154For Cortex-A720, the following errata build flags are defined :
1155
1156-  ``ERRATA_A720_2729604``: This applies errata 2729604 workaround to
1157   Cortex-A720 CPU. This needs to be enabled for revisions r0p0 and r0p1.
1158   It is fixed in r0p2.
1159
1160-  ``ERRATA_A720_2792132``: This applies errata 2792132 workaround to
1161   Cortex-A720 CPU. This needs to be enabled for revisions r0p0 and r0p1.
1162   It is fixed in r0p2.
1163
1164-  ``ERRATA_A720_2844092``: This applies errata 2844092 workaround to
1165   Cortex-A720 CPU. This needs to be enabled for revisions r0p0 and r0p1.
1166   It is fixed in r0p2.
1167
1168-  ``ERRATA_A720_2926083``: This applies errata 2926083 workaround to
1169   Cortex-A720 CPU. This needs to be enabled for revisions r0p0 and r0p1.
1170   It is fixed in r0p2.
1171
1172-  ``ERRATA_A720_2940794``: This applies errata 2940794 workaround to
1173   Cortex-A720 CPU. This needs to be enabled for revisions r0p0 and r0p1.
1174   It is fixed in r0p2.
1175
1176-  ``ERRATA_A720_3456091``: This applies errata 3456091 workaround to
1177   Cortex-A720 CPU. This needs to be enabled for revisions r0p0, r0p1
1178   and r0p2. It is still open.
1179
1180-  ``ERRATA_A720_3699561``: This applies errata 3699561 workaround to
1181   Cortex-A720 CPU. This needs to be enabled for revisions r0p0, r0p1
1182   and r0p2. It is still open.
1183
1184-  ``ERRATA_A720_3711910``: This applies errata 3711910 workaround to
1185   Cortex-A720 CPU. This needs to be enabled for revisions r0p0, r0p1
1186   and r0p2. It is still open.
1187
1188For Cortex-A720_AE, the following errata build flags are defined :
1189
1190-  ``ERRATA_A720_AE_3456103``: This applies errata 3456103 workaround to
1191   Cortex-A720_AE CPU. This needs to be enabled for revisions r0p0 and r0p1. It
1192   is still open.
1193
1194-  ``ERRATA_A720_AE_3699562``: This applies errata 3699562 workaround
1195   to Cortex-A720_AE CPU. This needs to be enabled for revisions r0p0.
1196   It is still open.
1197
1198For Cortex-A725, the following errata build flags are defined :
1199
1200-  ``ERRATA_A725_2874943``: This applies errata 2874943 workaround to
1201   Cortex-A725 CPU. This needs to be enabled for revisions r0p0 when
1202   FEAT_SPE is enabled. It is fixed in r0p1.
1203
1204-  ``ERRATA_A725_2936490``: This applies errata 2936490 workaround to
1205   Cortex-A725 CPU. This needs to be enabled for revisions r0p0.
1206   It is fixed in r0p1.
1207
1208-  ``ERRATA_A725_3456106``: This applies errata 3456106 workaround to
1209   Cortex-A725 CPU. This needs to be enabled for revisions r0p0, r0p1
1210   and r0p2. It is still open.
1211
1212-  ``ERRATA_A725_3699564``: This applies errata 3699564 workaround to
1213   Cortex-A725 CPU. This needs to be enabled for revisions r0p0 and r0p1.
1214   It is fixed in r0p2.
1215
1216-  ``ERRATA_A725_3711914``: This applies errata 3711914 workaround to
1217   Cortex-A725 CPU. This needs to be enabled for revisions r0p0 and r0p1.
1218   It is fixed in r0p2.
1219
1220For C1-Ultra, the following errata build flags are defined :
1221
1222-  ``ERRATA_C1ULTRA_3324333``: This applies erratum 3324333 workaround to
1223   C1-Ultra CPU. This needs to be enabled for revision r0p0 and is fixed
1224   in r1p0.
1225
1226-  ``ERRATA_C1ULTRA_3502731``: This applies erratum 3502731 workaround to
1227   C1-Ultra CPU. This needs to be enabled for revision r0p0 and is
1228   fixed in r1p0.
1229
1230-  ``ERRATA_C1ULTRA_3651221``: This applies erratum 3651221 workaround to
1231   C1-Ultra CPU. This needs to be enabled for revision r0p0 and is
1232   fixed in r1p0.
1233
1234-  ``ERRATA_C1ULTRA_3658374``: This applies erratum 3658374 workaround to
1235   C1-Ultra CPU. This needs to be enabled for revisions r0p0 and r1p0 and
1236   is still open.
1237
1238-  ``ERRATA_C1ULTRA_3684152``: This applies erratum 3684152 workaround to
1239   C1-Ultra CPU. This needs to be enabled for revision r0p0 and is
1240   fixed in r1p0.
1241
1242-  ``ERRATA_C1ULTRA_3705939``: This applies erratum 3705939 workaround to
1243   C1-Ultra CPU. This needs to be enabled for revisions r0p0 and r1p0 and
1244   is still open.
1245
1246-  ``ERRATA_C1ULTRA_3815514``: This applies erratum 3815514 workaround to
1247   C1-Ultra CPU. This needs to be enabled for revisions r0p0 and r1p0 and
1248   is still open.
1249
1250-  ``ERRATA_C1ULTRA_3865171``: This applies erratum 3865171 workaround to
1251   C1-Ultra CPU. This needs to be enabled for revisions r0p0 and r1p0 and
1252   is still open.
1253
1254-  ``ERRATA_C1ULTRA_3926381``: This applies erratum 3926381 workaround to
1255   C1-Ultra CPU. This needs to be enabled for revision r1p0 and is still
1256   open.
1257
1258-  ``ERRATA_C1ULTRA_4102704``: This applies erratum 4102704 workaround to
1259   C1-Ultra CPU. This needs to be enabled for revisions r0p0 and r1p0 and
1260   is still open.
1261
1262For C1-Premium, the following errata build flags are defined :
1263
1264-  ``ERRATA_C1PREMIUM_3324333``: This applies errata 3324333 workaround to
1265   C1-Premium CPU. This needs to be enabled for revision r0p0, and is
1266   fixed in r1p0.
1267
1268-  ``ERRATA_C1PREMIUM_3502731``: This applies errata 3502731 workaround to
1269   C1-Premium CPU. This needs to be enabled for revision r0p0, and is fixed
1270   in r1p0.
1271
1272-  ``ERRATA_C1PREMIUM_3651221``: This applies errata 3651221 workaround to
1273   C1-Premium CPU. This needs to be enabled for revision r0p0, and is fixed
1274   in r1p0.
1275
1276-  ``ERRATA_C1PREMIUM_3684152``: This applies errata 3684152 workaround to
1277   C1-Premium CPU. This needs to be enabled for revision r0p0, and is fixed
1278   in r1p0.
1279
1280-  ``ERRATA_C1PREMIUM_3705939``: This applies errata 3705939 workaround to
1281   C1-Premium CPU. This needs to be enabled for revisions r0p0, r1p0 and
1282   is still open.
1283
1284-  ``ERRATA_C1PREMIUM_3815514``: This applies errata 3815514 workaround to
1285   C1-Premium CPU. This needs to be enabled for revisions r0p0, r1p0 and
1286   is still open.
1287
1288-  ``ERRATA_C1PREMIUM_3865171``: This applies errata 3865171 workaround to
1289   C1-Premium CPU. This needs to be enabled for revisions r0p0, r1p0 and
1290   is still open.
1291
1292-  ``ERRATA_C1PREMIUM_3926381``: This applies errata 3926381 workaround to
1293   C1-Premium CPU. This needs to be enabled for revision r1p0 and is
1294   still open.
1295
1296-  ``ERRATA_C1PREMIUM_4102704``: This applies errata 4102704 workaround to
1297   C1-Premium CPU. This needs to be enabled for revisions r0p0, r1p0 and
1298   is still open.
1299
1300DSU Errata Workarounds
1301----------------------
1302
1303Similar to CPU errata, TF-A also implements workarounds for DSU (DynamIQ
1304Shared Unit) errata. The DSU errata details can be found in the respective Arm
1305documentation:
1306
1307- `Arm DSU Software Developers Errata Notice`_.
1308
1309Each erratum is identified by an ``ID``, as defined in the DSU errata notice
1310document. Thus, the build flags which enable/disable the errata workarounds
1311have the format ``ERRATA_DSU_<ID>``. The implementation and application logic
1312of DSU errata workarounds are similar to `CPU errata workarounds`_.
1313
1314For DSU errata, the following build flags are defined:
1315
1316-  ``ERRATA_DSU_798953``: This applies errata 798953 workaround for the
1317   affected DSU configurations. This errata applies only for those DSUs that
1318   revision is r0p0 (on r0p1 it is fixed). However, please note that this
1319   workaround results in increased DSU power consumption on idle.
1320
1321-  ``ERRATA_DSU_936184``: This applies errata 936184 workaround for the
1322   affected DSU configurations. This errata applies only for those DSUs that
1323   contain the ACP interface **and** the DSU revision is older than r2p0 (on
1324   r2p0 it is fixed). However, please note that this workaround results in
1325   increased DSU power consumption on idle.
1326
1327-  ``ERRATA_DSU_2313941``: This applies errata 2313941 workaround for the
1328   affected DSU configurations. This errata applies for those DSUs with
1329   revisions r0p0, r1p0, r2p0, r2p1, r3p0, r3p1 and is still open. However,
1330   please note that this workaround results in increased DSU power consumption
1331   on idle.
1332
1333-  ``ERRATA_DSU_2900952``: This applies errata 2900952 workaround for the
1334   affected DSU-120 configurations. This erratum applies to some r2p0
1335   implementations and is fixed in r2p1. The affected r2p0 implementations
1336   are determined by reading the IMP_CLUSTERREVIDR_EL1[1] register bit
1337   and making sure it's clear.
1338
1339CPU Specific optimizations
1340--------------------------
1341
1342This section describes some of the optimizations allowed by the CPU micro
1343architecture that can be enabled by the platform as desired.
1344
1345-  ``SKIP_A57_L1_FLUSH_PWR_DWN``: This flag enables an optimization in the
1346   Cortex-A57 cluster power down sequence by not flushing the Level 1 data
1347   cache. The L1 data cache and the L2 unified cache are inclusive. A flush
1348   of the L2 by set/way flushes any dirty lines from the L1 as well. This
1349   is a known safe deviation from the Cortex-A57 TRM defined power down
1350   sequence. Each Cortex-A57 based platform must make its own decision on
1351   whether to use the optimization.
1352
1353-  ``A53_DISABLE_NON_TEMPORAL_HINT``: This flag disables the cache non-temporal
1354   hint. The LDNP/STNP instructions as implemented on Cortex-A53 do not behave
1355   in a way most programmers expect, and will most probably result in a
1356   significant speed degradation to any code that employs them. The Armv8-A
1357   architecture (see Arm DDI 0487A.h, section D3.4.3) allows cores to ignore
1358   the non-temporal hint and treat LDNP/STNP as LDP/STP instead. Enabling this
1359   flag enforces this behaviour. This needs to be enabled only for revisions
1360   <= r0p3 of the CPU and is enabled by default.
1361
1362-  ``A57_DISABLE_NON_TEMPORAL_HINT``: This flag has the same behaviour as
1363   ``A53_DISABLE_NON_TEMPORAL_HINT`` but for Cortex-A57. This needs to be
1364   enabled only for revisions <= r1p2 of the CPU and is enabled by default,
1365   as recommended in section "4.7 Non-Temporal Loads/Stores" of the
1366   `Cortex-A57 Software Optimization Guide`_.
1367
1368- ''A57_ENABLE_NON_CACHEABLE_LOAD_FWD'': This flag enables non-cacheable
1369   streaming enhancement feature for Cortex-A57 CPUs. Platforms can set
1370   this bit only if their memory system meets the requirement that cache
1371   line fill requests from the Cortex-A57 processor are atomic. Each
1372   Cortex-A57 based platform must make its own decision on whether to use
1373   the optimization. This flag is disabled by default.
1374
1375-  ``NEOVERSE_Nx_EXTERNAL_LLC``: This flag indicates that an external last
1376   level cache(LLC) is present in the system, and that the DataSource field
1377   on the master CHI interface indicates when data is returned from the LLC.
1378   This is used to control how the LL_CACHE* PMU events count.
1379   Default value is 0 (Disabled).
1380
1381-  ``NEOVERSE_N2_PREFETCHER_DISABLE``: This flag disables the region prefetcher
1382   on the Neoverse N2 core. This is used during performance analysis to get clean
1383   and repeatable measurements of the cache by preventing speculative data fetches
1384   from interfering with benchmark results.
1385   Default value is 0 (Disabled).
1386
1387GIC Errata Workarounds
1388----------------------
1389-  ``GIC600_ERRATA_WA_2384374``: This flag applies part 2 of errata 2384374
1390   workaround for the affected GIC600 and GIC600-AE implementations. It applies
1391   to implementations of GIC600 and GIC600-AE with revisions less than or equal
1392   to r1p6 and r0p2 respectively. If the platform sets GICV3_SUPPORT_GIC600,
1393   then this flag is enabled; otherwise, it is 0 (Disabled).
1394
1395--------------
1396
1397*Copyright (c) 2014-2025, Arm Limited and Contributors. All rights reserved.*
1398
1399.. _CVE-2017-5715: http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-5715
1400.. _CVE-2018-3639: http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-3639
1401.. _CVE-2022-23960: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-23960
1402.. _CVE-2024-5660: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2024-5660
1403.. _CVE-2024-7881: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2024-7881
1404.. _Cortex-A72 MPCore Software Developers Errata Notice: https://developer.arm.com/documentation/epm012079/latest
1405.. _Cortex-A57 Software Optimization Guide: https://developer.arm.com/documentation/uan0015
1406.. _Arm DSU Software Developers Errata Notice: https://developer.arm.com/documentation/SDEN854652
1407