xref: /rk3399_ARM-atf/docs/design/cpu-specific-build-macros.rst (revision 3d6edc325c52082ab63ffd003c55a4ed875a52c5)
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.. _arm_cpu_macros_errata_workarounds:
37
38CPU Errata Workarounds
39----------------------
40
41TF-A exports a series of build flags which control the errata workarounds that
42are applied to each CPU by the reset handler. The errata details can be found
43in the CPU specific errata documents published by Arm:
44
45-  `Cortex-A53 MPCore Software Developers Errata Notice`_
46-  `Cortex-A57 MPCore Software Developers Errata Notice`_
47-  `Cortex-A72 MPCore Software Developers Errata Notice`_
48
49The errata workarounds are implemented for a particular revision or a set of
50processor revisions. This is checked by the reset handler at runtime. Each
51errata workaround is identified by its ``ID`` as specified in the processor's
52errata notice document. The format of the define used to enable/disable the
53errata workaround is ``ERRATA_<Processor name>_<ID>``, where the ``Processor name``
54is for example ``A57`` for the ``Cortex_A57`` CPU.
55
56Refer to :ref:`firmware_design_cpu_errata_implementation` for information on how to
57write errata workaround functions.
58
59All workarounds are disabled by default. The platform is responsible for
60enabling these workarounds according to its requirement by defining the
61errata workaround build flags in the platform specific makefile. In case
62these workarounds are enabled for the wrong CPU revision then the errata
63workaround is not applied. In the DEBUG build, this is indicated by
64printing a warning to the crash console.
65
66In the current implementation, a platform which has more than 1 variant
67with different revisions of a processor has no runtime mechanism available
68for it to specify which errata workarounds should be enabled or not.
69
70The value of the build flags is 0 by default, that is, disabled. A value of 1
71will enable it.
72
73For Cortex-A9, the following errata build flags are defined :
74
75-  ``ERRATA_A9_794073``: This applies errata 794073 workaround to Cortex-A9
76   CPU. This needs to be enabled for all revisions of the CPU.
77
78For Cortex-A15, the following errata build flags are defined :
79
80-  ``ERRATA_A15_816470``: This applies errata 816470 workaround to Cortex-A15
81   CPU. This needs to be enabled only for revision >= r3p0 of the CPU.
82
83-  ``ERRATA_A15_827671``: This applies errata 827671 workaround to Cortex-A15
84   CPU. This needs to be enabled only for revision >= r3p0 of the CPU.
85
86For Cortex-A17, the following errata build flags are defined :
87
88-  ``ERRATA_A17_852421``: This applies errata 852421 workaround to Cortex-A17
89   CPU. This needs to be enabled only for revision <= r1p2 of the CPU.
90
91-  ``ERRATA_A17_852423``: This applies errata 852423 workaround to Cortex-A17
92   CPU. This needs to be enabled only for revision <= r1p2 of the CPU.
93
94For Cortex-A35, the following errata build flags are defined :
95
96-  ``ERRATA_A35_855472``: This applies errata 855472 workaround to Cortex-A35
97   CPUs. This needs to be enabled only for revision r0p0 of Cortex-A35.
98
99For Cortex-A53, the following errata build flags are defined :
100
101-  ``ERRATA_A53_819472``: This applies errata 819472 workaround to all
102   CPUs. This needs to be enabled only for revision <= r0p1 of Cortex-A53.
103
104-  ``ERRATA_A53_824069``: This applies errata 824069 workaround to all
105   CPUs. This needs to be enabled only for revision <= r0p2 of Cortex-A53.
106
107-  ``ERRATA_A53_826319``: This applies errata 826319 workaround to Cortex-A53
108   CPU. This needs to be enabled only for revision <= r0p2 of the CPU.
109
110-  ``ERRATA_A53_827319``: This applies errata 827319 workaround to all
111   CPUs. This needs to be enabled only for revision <= r0p2 of Cortex-A53.
112
113-  ``ERRATA_A53_835769``: This applies erratum 835769 workaround at compile and
114   link time to Cortex-A53 CPU. This needs to be enabled for some variants of
115   revision <= r0p4. This workaround can lead the linker to create ``*.stub``
116   sections.
117
118-  ``ERRATA_A53_836870``: This applies errata 836870 workaround to Cortex-A53
119   CPU. This needs to be enabled only for revision <= r0p3 of the CPU. From
120   r0p4 and onwards, this errata is enabled by default in hardware. Identical to
121   ``A53_DISABLE_NON_TEMPORAL_HINT``.
122
123-  ``ERRATA_A53_843419``: This applies erratum 843419 workaround at link time
124   to Cortex-A53 CPU.  This needs to be enabled for some variants of revision
125   <= r0p4. This workaround can lead the linker to emit ``*.stub`` sections
126   which are 4kB aligned.
127
128-  ``ERRATA_A53_855873``: This applies errata 855873 workaround to Cortex-A53
129   CPUs. Though the erratum is present in every revision of the CPU,
130   this workaround is only applied to CPUs from r0p3 onwards, which feature
131   a chicken bit in CPUACTLR_EL1 to enable a hardware workaround.
132   Earlier revisions of the CPU have other errata which require the same
133   workaround in software, so they should be covered anyway.
134
135-  ``ERRATA_A53_1530924``: This applies errata 1530924 workaround to all
136   revisions of Cortex-A53 CPU.
137
138For Cortex-A55, the following errata build flags are defined :
139
140-  ``ERRATA_A55_768277``: This applies errata 768277 workaround to Cortex-A55
141   CPU. This needs to be enabled only for revision r0p0 of the CPU.
142
143-  ``ERRATA_A55_778703``: This applies errata 778703 workaround to Cortex-A55
144   CPU. This needs to be enabled only for revision r0p0 of the CPU.
145
146-  ``ERRATA_A55_798797``: This applies errata 798797 workaround to Cortex-A55
147   CPU. This needs to be enabled only for revision r0p0 of the CPU.
148
149-  ``ERRATA_A55_846532``: This applies errata 846532 workaround to Cortex-A55
150   CPU. This needs to be enabled only for revision <= r0p1 of the CPU.
151
152-  ``ERRATA_A55_903758``: This applies errata 903758 workaround to Cortex-A55
153   CPU. This needs to be enabled only for revision <= r0p1 of the CPU.
154
155-  ``ERRATA_A55_1221012``: This applies errata 1221012 workaround to Cortex-A55
156   CPU. This needs to be enabled only for revision <= r1p0 of the CPU.
157
158-  ``ERRATA_A55_1530923``: This applies errata 1530923 workaround to all
159   revisions of Cortex-A55 CPU.
160
161For Cortex-A57, the following errata build flags are defined :
162
163-  ``ERRATA_A57_806969``: This applies errata 806969 workaround to Cortex-A57
164   CPU. This needs to be enabled only for revision r0p0 of the CPU.
165
166-  ``ERRATA_A57_813419``: This applies errata 813419 workaround to Cortex-A57
167   CPU. This needs to be enabled only for revision r0p0 of the CPU.
168
169-  ``ERRATA_A57_813420``: This applies errata 813420 workaround to Cortex-A57
170   CPU. This needs to be enabled only for revision r0p0 of the CPU.
171
172-  ``ERRATA_A57_814670``: This applies errata 814670 workaround to Cortex-A57
173   CPU. This needs to be enabled only for revision r0p0 of the CPU.
174
175-  ``ERRATA_A57_817169``: This applies errata 817169 workaround to Cortex-A57
176   CPU. This needs to be enabled only for revision <= r0p1 of the CPU.
177
178-  ``ERRATA_A57_826974``: This applies errata 826974 workaround to Cortex-A57
179   CPU. This needs to be enabled only for revision <= r1p1 of the CPU.
180
181-  ``ERRATA_A57_826977``: This applies errata 826977 workaround to Cortex-A57
182   CPU. This needs to be enabled only for revision <= r1p1 of the CPU.
183
184-  ``ERRATA_A57_828024``: This applies errata 828024 workaround to Cortex-A57
185   CPU. This needs to be enabled only for revision <= r1p1 of the CPU.
186
187-  ``ERRATA_A57_829520``: This applies errata 829520 workaround to Cortex-A57
188   CPU. This needs to be enabled only for revision <= r1p2 of the CPU.
189
190-  ``ERRATA_A57_833471``: This applies errata 833471 workaround to Cortex-A57
191   CPU. This needs to be enabled only for revision <= r1p2 of the CPU.
192
193-  ``ERRATA_A57_859972``: This applies errata 859972 workaround to Cortex-A57
194   CPU. This needs to be enabled only for revision <= r1p3 of the CPU.
195
196-  ``ERRATA_A57_1319537``: This applies errata 1319537 workaround to all
197   revisions of Cortex-A57 CPU.
198
199For Cortex-A72, the following errata build flags are defined :
200
201-  ``ERRATA_A72_859971``: This applies errata 859971 workaround to Cortex-A72
202   CPU. This needs to be enabled only for revision <= r0p3 of the CPU.
203
204-  ``ERRATA_A72_1319367``: This applies errata 1319367 workaround to all
205   revisions of Cortex-A72 CPU.
206
207For Cortex-A73, the following errata build flags are defined :
208
209-  ``ERRATA_A73_852427``: This applies errata 852427 workaround to Cortex-A73
210   CPU. This needs to be enabled only for revision r0p0 of the CPU.
211
212-  ``ERRATA_A73_855423``: This applies errata 855423 workaround to Cortex-A73
213   CPU. This needs to be enabled only for revision <= r0p1 of the CPU.
214
215For Cortex-A75, the following errata build flags are defined :
216
217-  ``ERRATA_A75_764081``: This applies errata 764081 workaround to Cortex-A75
218   CPU. This needs to be enabled only for revision r0p0 of the CPU.
219
220-  ``ERRATA_A75_790748``: This applies errata 790748 workaround to Cortex-A75
221    CPU. This needs to be enabled only for revision r0p0 of the CPU.
222
223For Cortex-A76, the following errata build flags are defined :
224
225-  ``ERRATA_A76_1073348``: This applies errata 1073348 workaround to Cortex-A76
226   CPU. This needs to be enabled only for revision <= r1p0 of the CPU.
227
228-  ``ERRATA_A76_1130799``: This applies errata 1130799 workaround to Cortex-A76
229   CPU. This needs to be enabled only for revision <= r2p0 of the CPU.
230
231-  ``ERRATA_A76_1220197``: This applies errata 1220197 workaround to Cortex-A76
232   CPU. This needs to be enabled only for revision <= r2p0 of the CPU.
233
234-  ``ERRATA_A76_1257314``: This applies errata 1257314 workaround to Cortex-A76
235   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
236
237-  ``ERRATA_A76_1262606``: This applies errata 1262606 workaround to Cortex-A76
238   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
239
240-  ``ERRATA_A76_1262888``: This applies errata 1262888 workaround to Cortex-A76
241   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
242
243-  ``ERRATA_A76_1275112``: This applies errata 1275112 workaround to Cortex-A76
244   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
245
246-  ``ERRATA_A76_1791580``: This applies errata 1791580 workaround to Cortex-A76
247   CPU. This needs to be enabled only for revision <= r4p0 of the CPU.
248
249-  ``ERRATA_A76_1165522``: This applies errata 1165522 workaround to all
250   revisions of Cortex-A76 CPU. This errata is fixed in r3p0 but due to
251   limitation of errata framework this errata is applied to all revisions
252   of Cortex-A76 CPU.
253
254-  ``ERRATA_A76_1868343``: This applies errata 1868343 workaround to Cortex-A76
255   CPU. This needs to be enabled only for revision <= r4p0 of the CPU.
256
257-  ``ERRATA_A76_1946160``: This applies errata 1946160 workaround to Cortex-A76
258   CPU. This needs to be enabled only for revisions r3p0 - r4p1 of the CPU.
259
260-  ``ERRATA_A76_2743102``: This applies errata 2743102 workaround to Cortex-A76
261   CPU. This needs to be enabled for all revisions <= r4p1 of the CPU and is
262   still open.
263
264For Cortex-A77, the following errata build flags are defined :
265
266-  ``ERRATA_A77_1508412``: This applies errata 1508412 workaround to Cortex-A77
267   CPU. This needs to be enabled only for revision <= r1p0 of the CPU.
268
269-  ``ERRATA_A77_1925769``: This applies errata 1925769 workaround to Cortex-A77
270   CPU. This needs to be enabled only for revision <= r1p1 of the CPU.
271
272-  ``ERRATA_A77_1946167``: This applies errata 1946167 workaround to Cortex-A77
273   CPU. This needs to be enabled only for revision <= r1p1 of the CPU.
274
275-  ``ERRATA_A77_1791578``: This applies errata 1791578 workaround to Cortex-A77
276   CPU. This needs to be enabled for r0p0, r1p0, and r1p1, it is still open.
277
278-  ``ERRATA_A77_2356587``: This applies errata 2356587 workaround to Cortex-A77
279   CPU. This needs to be enabled for r0p0, r1p0, and r1p1, it is still open.
280
281 -  ``ERRATA_A77_1800714``: This applies errata 1800714 workaround to Cortex-A77
282    CPU. This needs to be enabled for revisions <= r1p1 of the CPU.
283
284 -  ``ERRATA_A77_2743100``: This applies errata 2743100 workaround to Cortex-A77
285    CPU. This needs to be enabled for r0p0, r1p0, and r1p1, it is still open.
286
287For Cortex-A78, the following errata build flags are defined :
288
289-  ``ERRATA_A78_1688305``: This applies errata 1688305 workaround to Cortex-A78
290   CPU. This needs to be enabled only for revision r0p0 - r1p0 of the CPU.
291
292-  ``ERRATA_A78_1941498``: This applies errata 1941498 workaround to Cortex-A78
293   CPU. This needs to be enabled for revisions r0p0, r1p0, and r1p1 of the CPU.
294
295-  ``ERRATA_A78_1951500``: This applies errata 1951500 workaround to Cortex-A78
296   CPU. This needs to be enabled for revisions r1p0 and r1p1, r0p0 has the same
297   issue but there is no workaround for that revision.
298
299-  ``ERRATA_A78_1821534``: This applies errata 1821534 workaround to Cortex-A78
300   CPU. This needs to be enabled for revisions r0p0 and r1p0.
301
302-  ``ERRATA_A78_1952683``: This applies errata 1952683 workaround to Cortex-A78
303   CPU. This needs to be enabled for revision r0p0, it is fixed in r1p0.
304
305-  ``ERRATA_A78_2132060``: This applies errata 2132060 workaround to Cortex-A78
306   CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1, and r1p2. It
307   is still open.
308
309-  ``ERRATA_A78_2242635``: This applies errata 2242635 workaround to Cortex-A78
310   CPU. This needs to be enabled for revisions r1p0, r1p1, and r1p2. The issue
311   is present in r0p0 but there is no workaround. It is still open.
312
313-  ``ERRATA_A78_2376745``: This applies errata 2376745 workaround to Cortex-A78
314   CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1, and r1p2, and
315   it is still open.
316
317-  ``ERRATA_A78_2395406``: This applies errata 2395406 workaround to Cortex-A78
318   CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1, and r1p2, and
319   it is still open.
320
321- ``ERRATA_A78_2712571``: This applies erratum 2712571 workaround to Cortex-A78
322   CPU, this erratum affects system configurations that do not use an ARM
323   interconnect IP. This needs to be enabled for revisions r0p0, r1p0, r1p1
324   and r1p2 and it is still open.
325
326-  ``ERRATA_A78_2742426``: This applies erratum 2742426 workaround to Cortex-A78
327   CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1 and r1p2 and
328   it is still open.
329
330-  ``ERRATA_A78_2772019``: This applies errata 2772019 workaround to Cortex-A78
331   CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1, and r1p2, and
332   it is still open.
333
334-  ``ERRATA_A78_2779479``: This applies erratum 2779479 workaround to Cortex-A78
335   CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1 and r1p2 and
336   it is still open.
337
338For Cortex-A78AE, the following errata build flags are defined :
339
340- ``ERRATA_A78_AE_1941500`` : This applies errata 1941500 workaround to
341   Cortex-A78AE CPU. This needs to be enabled for revisions r0p0 and r0p1.
342   This erratum is still open.
343
344- ``ERRATA_A78_AE_1951502`` : This applies errata 1951502 workaround to
345  Cortex-A78AE CPU. This needs to be enabled for revisions r0p0 and r0p1. This
346  erratum is still open.
347
348- ``ERRATA_A78_AE_2376748`` : This applies errata 2376748 workaround to
349  Cortex-A78AE CPU. This needs to be enabled for revisions r0p0, r0p1 and r0p2.
350  This erratum is still open.
351
352- ``ERRATA_A78_AE_2395408`` : This applies errata 2395408 workaround to
353  Cortex-A78AE CPU. This needs to be enabled for revisions r0p0 and r0p1. This
354  erratum is still open.
355
356- ``ERRATA_A78_AE_2712574`` : This applies erratum 2712574 workaround to
357  Cortex-A78AE CPU. This erratum affects system configurations that do not use
358  an ARM interconnect IP. This needs to be enabled for revisions r0p0, r0p1 and
359  r0p2. This erratum is still open.
360
361For Cortex-A78C, the following errata build flags are defined :
362
363- ``ERRATA_A78C_1827430`` : This applies errata 1827430 workaround to
364  Cortex-A78C CPU. This needs to be enabled for revision r0p0. The erratum is
365  fixed in r0p1.
366
367- ``ERRATA_A78C_1827440`` : This applies errata 1827440 workaround to
368  Cortex-A78C CPU. This needs to be enabled for revision r0p0. The erratum is
369  fixed in r0p1.
370
371- ``ERRATA_A78C_2132064`` : This applies errata 2132064 workaround to
372  Cortex-A78C CPU. This needs to be enabled for revisions r0p1, r0p2 and
373  it is still open.
374
375- ``ERRATA_A78C_2242638`` : This applies errata 2242638 workaround to
376  Cortex-A78C CPU. This needs to be enabled for revisions r0p1, r0p2 and
377  it is still open.
378
379- ``ERRATA_A78C_2376749`` : This applies errata 2376749 workaround to
380  Cortex-A78C CPU. This needs to be enabled for revisions r0p1 and r0p2. This
381  erratum is still open.
382
383- ``ERRATA_A78C_2395411`` : This applies errata 2395411 workaround to
384  Cortex-A78C CPU. This needs to be enabled for revisions r0p1 and r0p2. This
385  erratum is still open.
386
387- ``ERRATA_A78C_2712575`` : This applies erratum 2712575 workaround to
388  Cortex-A78C CPU, this erratum affects system configurations that do not use
389  an ARM interconnect IP. This needs to be enabled for revisions r0p1 and r0p2
390  and is still open.
391
392- ``ERRATA_A78C_2772121`` : This applies errata 2772121 workaround to
393  Cortex-A78C CPU. This needs to be enabled for revisions r0p0, r0p1 and r0p2.
394  This erratum is still open.
395
396- ``ERRATA_A78C_2779484`` : This applies errata 2779484 workaround to
397  Cortex-A78C CPU. This needs to be enabled for revisions r0p1 and r0p2.
398  This erratum is still open.
399
400For Cortex-X1 CPU, the following errata build flags are defined:
401
402- ``ERRATA_X1_1821534`` : This applies errata 1821534 workaround to Cortex-X1
403   CPU. This needs to be enabled only for revision <= r1p0 of the CPU.
404
405- ``ERRATA_X1_1688305`` : This applies errata 1688305 workaround to Cortex-X1
406   CPU. This needs to be enabled only for revision <= r1p0 of the CPU.
407
408- ``ERRATA_X1_1827429`` : This applies errata 1827429 workaround to Cortex-X1
409   CPU. This needs to be enabled only for revision <= r1p0 of the CPU.
410
411For Neoverse N1, the following errata build flags are defined :
412
413-  ``ERRATA_N1_1073348``: This applies errata 1073348 workaround to Neoverse-N1
414   CPU. This needs to be enabled only for revision r0p0 and r1p0 of the CPU.
415
416-  ``ERRATA_N1_1130799``: This applies errata 1130799 workaround to Neoverse-N1
417   CPU. This needs to be enabled only for revision <= r2p0 of the CPU.
418
419-  ``ERRATA_N1_1165347``: This applies errata 1165347 workaround to Neoverse-N1
420   CPU. This needs to be enabled only for revision <= r2p0 of the CPU.
421
422-  ``ERRATA_N1_1207823``: This applies errata 1207823 workaround to Neoverse-N1
423   CPU. This needs to be enabled only for revision <= r2p0 of the CPU.
424
425-  ``ERRATA_N1_1220197``: This applies errata 1220197 workaround to Neoverse-N1
426   CPU. This needs to be enabled only for revision <= r2p0 of the CPU.
427
428-  ``ERRATA_N1_1257314``: This applies errata 1257314 workaround to Neoverse-N1
429   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
430
431-  ``ERRATA_N1_1262606``: This applies errata 1262606 workaround to Neoverse-N1
432   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
433
434-  ``ERRATA_N1_1262888``: This applies errata 1262888 workaround to Neoverse-N1
435   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
436
437-  ``ERRATA_N1_1275112``: This applies errata 1275112 workaround to Neoverse-N1
438   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
439
440-  ``ERRATA_N1_1315703``: This applies errata 1315703 workaround to Neoverse-N1
441   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
442
443-  ``ERRATA_N1_1542419``: This applies errata 1542419 workaround to Neoverse-N1
444   CPU. This needs to be enabled only for revisions r3p0 - r4p0 of the CPU.
445
446-  ``ERRATA_N1_1868343``: This applies errata 1868343 workaround to Neoverse-N1
447   CPU. This needs to be enabled only for revision <= r4p0 of the CPU.
448
449-  ``ERRATA_N1_1946160``: This applies errata 1946160 workaround to Neoverse-N1
450   CPU. This needs to be enabled for revisions r3p0, r3p1, r4p0, and r4p1, for
451   revisions r0p0, r1p0, and r2p0 there is no workaround.
452
453-  ``ERRATA_N1_2743102``: This applies errata 2743102 workaround to Neoverse-N1
454   CPU. This needs to be enabled for all revisions <= r4p1 of the CPU and is
455   still open.
456
457For Neoverse V1, the following errata build flags are defined :
458
459-  ``ERRATA_V1_1618635``: This applies errata 1618635 workaround to Neoverse-V1
460   CPU. This needs to be enabled for revision r0p0 of the CPU, it is fixed in
461   r1p0.
462
463-  ``ERRATA_V1_1774420``: This applies errata 1774420 workaround to Neoverse-V1
464   CPU. This needs to be enabled only for revisions r0p0 and r1p0, it is fixed
465   in r1p1.
466
467-  ``ERRATA_V1_1791573``: This applies errata 1791573 workaround to Neoverse-V1
468   CPU. This needs to be enabled only for revisions r0p0 and r1p0, it is fixed
469   in r1p1.
470
471-  ``ERRATA_V1_1852267``: This applies errata 1852267 workaround to Neoverse-V1
472   CPU. This needs to be enabled only for revisions r0p0 and r1p0, it is fixed
473   in r1p1.
474
475-  ``ERRATA_V1_1925756``: This applies errata 1925756 workaround to Neoverse-V1
476   CPU. This needs to be enabled for r0p0, r1p0, and r1p1, it is still open.
477
478-  ``ERRATA_V1_1940577``: This applies errata 1940577 workaround to Neoverse-V1
479   CPU. This needs to be enabled only for revision r1p0 and r1p1 of the
480   CPU.
481
482-  ``ERRATA_V1_1966096``: This applies errata 1966096 workaround to Neoverse-V1
483   CPU. This needs to be enabled for revisions r1p0 and r1p1 of the CPU, the
484   issue is present in r0p0 as well but there is no workaround for that
485   revision.  It is still open.
486
487-  ``ERRATA_V1_2139242``: This applies errata 2139242 workaround to Neoverse-V1
488   CPU. This needs to be enabled for revisions r0p0, r1p0, and r1p1 of the
489   CPU.  It is still open.
490
491-  ``ERRATA_V1_2108267``: This applies errata 2108267 workaround to Neoverse-V1
492   CPU. This needs to be enabled for revisions r0p0, r1p0, and r1p1 of the CPU.
493   It is still open.
494
495-  ``ERRATA_V1_2216392``: This applies errata 2216392 workaround to Neoverse-V1
496   CPU. This needs to be enabled for revisions r1p0 and r1p1 of the CPU, the
497   issue is present in r0p0 as well but there is no workaround for that
498   revision.  It is still open.
499
500-  ``ERRATA_V1_2294912``: This applies errata 2294912 workaround to Neoverse-V1
501   CPU. This needs to be enabled for revisions r0p0, r1p0, and r1p1 and r1p2 of
502   the CPU.
503
504-  ``ERRATA_V1_2372203``: This applies errata 2372203 workaround to Neoverse-V1
505   CPU. This needs to be enabled for revisions r0p0, r1p0 and r1p1 of the CPU.
506   It is still open.
507
508- ``ERRATA_V1_2701953``: This applies erratum 2701953 workaround to Neoverse-V1
509   CPU, this erratum affects system configurations that do not use an ARM
510   interconnect IP. This needs to be enabled for revisions r0p0, r1p0 and r1p1.
511   It has been fixed in r1p2.
512
513-  ``ERRATA_V1_2743093``: This applies errata 2743093 workaround to Neoverse-V1
514   CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1 and r1p2 of the
515   CPU. It is still open.
516
517-  ``ERRATA_V1_2743233``: This applies erratum 2743233 workaround to Neoverse-V1
518   CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1, and r1p2 of the
519   CPU. It is still open.
520
521-  ``ERRATA_V1_2779461``: This applies erratum 2779461 workaround to Neoverse-V1
522   CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1, r1p2 of the
523   CPU. It is still open.
524
525For Neoverse V2, the following errata build flags are defined :
526
527-  ``ERRATA_V2_2331132``: This applies errata 2331132 workaround to Neoverse-V2
528   CPU. This needs to be enabled for revisions r0p0, r0p1 and r0p2. It is still
529   open.
530
531-  ``ERRATA_V2_2719103``: This applies errata 2719103 workaround to Neoverse-V2
532   CPU, this affects system configurations that do not use and ARM interconnect
533   IP. This needs to be enabled for revisions r0p0 and r0p1. It has been fixed
534   in r0p2.
535
536-  ``ERRATA_V2_2719105``: This applies errata 2719105 workaround to Neoverse-V2
537   CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed in
538   r0p2.
539
540-  ``ERRATA_V2_2743011``: This applies errata 2743011 workaround to Neoverse-V2
541   CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed in
542   r0p2.
543
544-  ``ERRATA_V2_2779510``: This applies errata 2779510 workaround to Neoverse-V2
545   CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed in
546   r0p2.
547
548-  ``ERRATA_V2_2801372``: This applies errata 2801372 workaround to Neoverse-V2
549   CPU, this affects all configurations. This needs to be enabled for revisions
550   r0p0 and r0p1. It has been fixed in r0p2.
551
552For Cortex-A710, the following errata build flags are defined :
553
554-  ``ERRATA_A710_1987031``: This applies errata 1987031 workaround to
555   Cortex-A710 CPU. This needs to be enabled only for revisions r0p0, r1p0 and
556   r2p0 of the CPU. It is still open.
557
558-  ``ERRATA_A710_2081180``: This applies errata 2081180 workaround to
559   Cortex-A710 CPU. This needs to be enabled only for revisions r0p0, r1p0 and
560   r2p0 of the CPU. It is still open.
561
562-  ``ERRATA_A710_2055002``: This applies errata 2055002 workaround to
563   Cortex-A710 CPU. This needs to be enabled for revisions r1p0, r2p0 of the CPU
564   and is still open.
565
566-  ``ERRATA_A710_2017096``: This applies errata 2017096 workaround to
567   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
568   of the CPU and is still open.
569
570-  ``ERRATA_A710_2083908``: This applies errata 2083908 workaround to
571   Cortex-A710 CPU. This needs to be enabled for revision r2p0 of the CPU and
572   is still open.
573
574-  ``ERRATA_A710_2058056``: This applies errata 2058056 workaround to
575   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
576   and r2p1 of the CPU and is still open.
577
578-  ``ERRATA_A710_2267065``: This applies errata 2267065 workaround to
579   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
580   of the CPU and is fixed in r2p1.
581
582-  ``ERRATA_A710_2136059``: This applies errata 2136059 workaround to
583   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
584   of the CPU and is fixed in r2p1.
585
586-  ``ERRATA_A710_2147715``: This applies errata 2147715 workaround to
587   Cortex-A710 CPU. This needs to be enabled for revision r2p0 of the CPU
588   and is fixed in r2p1.
589
590-  ``ERRATA_A710_2216384``: This applies errata 2216384 workaround to
591   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
592   of the CPU and is fixed in r2p1.
593
594-  ``ERRATA_A710_2282622``: This applies errata 2282622 workaround to
595   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and
596   r2p1 of the CPU and is still open.
597
598- ``ERRATA_A710_2291219``: This applies errata 2291219 workaround to
599   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
600   of the CPU and is fixed in r2p1.
601
602-  ``ERRATA_A710_2008768``: This applies errata 2008768 workaround to
603   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
604   of the CPU and is fixed in r2p1.
605
606-  ``ERRATA_A710_2371105``: This applies errata 2371105 workaround to
607   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
608   of the CPU and is fixed in r2p1.
609
610-  ``ERRATA_A710_2701952``: This applies erratum 2701952 workaround to Cortex-A710
611   CPU, and applies to system configurations that do not use and ARM
612   interconnect IP. This needs to be enabled for r0p0, r1p0, r2p0 and r2p1 and
613   is still open.
614
615-  ``ERRATA_A710_2742423``: This applies errata 2742423 workaround to
616   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and
617   r2p1 of the CPU and is still open.
618
619-  ``ERRATA_A710_2768515``: This applies errata 2768515 workaround to
620   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and
621   r2p1 of the CPU and is still open.
622
623For Neoverse N2, the following errata build flags are defined :
624
625-  ``ERRATA_N2_2002655``: This applies errata 2002655 workaround to Neoverse-N2
626   CPU. This needs to be enabled for revision r0p0 of the CPU and is fixed in r0p1.
627
628-  ``ERRATA_N2_2009478``: This applies errata 2009478 workaround to Neoverse-N2
629   CPU. This needs to be enabled for revision r0p0 of the CPU and is fixed in r0p1.
630
631-  ``ERRATA_N2_2067956``: This applies errata 2067956 workaround to Neoverse-N2
632   CPU. This needs to be enabled for revision r0p0 of the CPU and is fixed in r0p1.
633
634-  ``ERRATA_N2_2025414``: This applies errata 2025414 workaround to Neoverse-N2
635   CPU. This needs to be enabled for revision r0p0 of the CPU and is fixed in r0p1.
636
637-  ``ERRATA_N2_2189731``: This applies errata 2189731 workaround to Neoverse-N2
638   CPU. This needs to be enabled for revision r0p0 of the CPU and is fixed in r0p1.
639
640-  ``ERRATA_N2_2138956``: This applies errata 2138956 workaround to Neoverse-N2
641   CPU. This needs to be enabled for revision r0p0 of the CPU and is fixed in r0p1.
642
643-  ``ERRATA_N2_2138953``: This applies errata 2138953 workaround to Neoverse-N2
644   CPU. This needs to be enabled for revisions r0p0, r0p1, r0p2, r0p3 and is still open.
645
646-  ``ERRATA_N2_2242415``: This applies errata 2242415 workaround to Neoverse-N2
647   CPU. This needs to be enabled for revision r0p0 of the CPU and is fixed in r0p1.
648
649-  ``ERRATA_N2_2138958``: This applies errata 2138958 workaround to Neoverse-N2
650   CPU. This needs to be enabled for revision r0p0 of the CPU and is fixed in r0p1.
651
652-  ``ERRATA_N2_2242400``: This applies errata 2242400 workaround to Neoverse-N2
653   CPU. This needs to be enabled for revision r0p0 of the CPU and is fixed in r0p1.
654
655-  ``ERRATA_N2_2280757``: This applies errata 2280757 workaround to Neoverse-N2
656   CPU. This needs to be enabled for revision r0p0 of the CPU and is fixed in r0p1.
657
658-  ``ERRATA_N2_2326639``: This applies errata 2326639 workaround to Neoverse-N2
659   CPU. This needs to be enabled for revision r0p0 of the CPU, it is fixed in
660   r0p1.
661
662-  ``ERRATA_N2_2340933``: This applies errata 2340933 workaround to Neoverse-N2
663   CPU. This needs to be enabled for revision r0p0 of the CPU, it is fixed in
664   r0p1.
665
666-  ``ERRATA_N2_2346952``: This applies errata 2346952 workaround to Neoverse-N2
667   CPU. This needs to be enabled for revisions r0p0, r0p1 and r0p2 of the CPU,
668   it is fixed in r0p3.
669
670-  ``ERRATA_N2_2376738``: This applies errata 2376738 workaround to Neoverse-N2
671   CPU. This needs to be enabled for revision r0p0, r0p1, r0p2, r0p3 and is still open.
672
673-  ``ERRATA_N2_2388450``: This applies errata 2388450 workaround to Neoverse-N2
674   CPU. This needs to be enabled for revision r0p0 of the CPU, it is fixed in
675   r0p1.
676
677-  ``ERRATA_N2_2743014``: This applies errata 2743014 workaround to Neoverse-N2
678   CPU. This needs to be enabled for revisions r0p0, r0p1 and r0p2. It is fixed
679   in r0p3.
680
681-  ``ERRATA_N2_2743089``: This applies errata 2743089 workaround to Neoverse-N2
682   CPU. This needs to be enabled for revisions r0p0, r0p1 and r0p2. It is fixed
683   in r0p3.
684
685- ``ERRATA_N2_2728475``: This applies erratum 2728475 workaround to Neoverse-N2
686   CPU, this erratum affects system configurations that do not use and ARM
687   interconnect IP. This needs to be enabled for revisions r0p0, r0p1 and r0p2.
688   It is fixed in r0p3.
689
690-  ``ERRATA_N2_2779511``: This applies errata 2779511 workaround to Neoverse-N2
691   CPU. This needs to be enabled for revisions r0p0, r0p1 and r0p2. It is fixed
692   in r0p3.
693
694For Cortex-X2, the following errata build flags are defined :
695
696-  ``ERRATA_X2_2002765``: This applies errata 2002765 workaround to Cortex-X2
697   CPU. This needs to be enabled for revisions r0p0, r1p0, and r2p0 of the CPU,
698   it is still open.
699
700-  ``ERRATA_X2_2058056``: This applies errata 2058056 workaround to Cortex-X2
701   CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and r2p1 of the CPU,
702   it is still open.
703
704-  ``ERRATA_X2_2083908``: This applies errata 2083908 workaround to Cortex-X2
705   CPU. This needs to be enabled for revision r2p0 of the CPU, it is still open.
706
707-  ``ERRATA_X2_2017096``: This applies errata 2017096 workaround to Cortex-X2
708   CPU. This needs to be enabled only for revisions r0p0, r1p0 and r2p0 of the
709   CPU, it is fixed in r2p1.
710
711-  ``ERRATA_X2_2081180``: This applies errata 2081180 workaround to Cortex-X2
712   CPU. This needs to be enabled only for revisions r0p0, r1p0 and r2p0 of the
713   CPU, it is fixed in r2p1.
714
715-  ``ERRATA_X2_2216384``: This applies errata 2216384 workaround to Cortex-X2
716   CPU. This needs to be enabled only for revisions r0p0, r1p0 and r2p0 of the
717   CPU, it is fixed in r2p1.
718
719-  ``ERRATA_X2_2147715``: This applies errata 2147715 workaround to Cortex-X2
720   CPU. This needs to be enabled only for revision r2p0 of the CPU, it is fixed
721   in r2p1.
722
723-  ``ERRATA_X2_2282622``: This applies errata 2282622 workaround to Cortex-X2
724   CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and r2p1 of the
725   CPU and is still open.
726
727-  ``ERRATA_X2_2371105``: This applies errata 2371105 workaround to Cortex-X2
728   CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0 of the CPU
729   and is fixed in r2p1.
730
731- ``ERRATA_X2_2701952``: This applies erratum 2701952 workaround to Cortex-X2
732   CPU and affects system configurations that do not use an ARM interconnect IP.
733   This needs to be enabled for revisions r0p0, r1p0, r2p0 and r2p1 and is
734   still open.
735
736-  ``ERRATA_X2_2742423``: This applies errata 2742423 workaround to Cortex-X2
737   CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and r2p1 of the
738   CPU and is still open.
739
740-  ``ERRATA_X2_2768515``: This applies errata 2768515 workaround to Cortex-X2
741   CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and r2p1 of the
742   CPU and is still open.
743
744For Cortex-X3, the following errata build flags are defined :
745
746- ``ERRATA_X3_2070301``: This applies errata 2070301 workaround to the Cortex-X3
747  CPU. This needs to be enabled only for revisions r0p0, r1p0, r1p1 and r1p2 of
748  the CPU and is still open.
749
750- ``ERRATA_X3_2313909``: This applies errata 2313909 workaround to
751  Cortex-X3 CPU. This needs to be enabled only for revisions r0p0 and r1p0
752  of the CPU, it is fixed in r1p1.
753
754- ``ERRATA_X3_2615812``: This applies errata 2615812 workaround to Cortex-X3
755  CPU. This needs to be enabled only for revisions r0p0, r1p0 and r1p1 of the
756  CPU, it is still open.
757
758- ``ERRATA_X3_2742421``: This applies errata 2742421 workaround to
759  Cortex-X3 CPU. This needs to be enabled only for revisions r0p0, r1p0 and
760  r1p1. It is fixed in r1p2.
761
762For Cortex-A510, the following errata build flags are defined :
763
764-  ``ERRATA_A510_1922240``: This applies errata 1922240 workaround to
765   Cortex-A510 CPU. This needs to be enabled only for revision r0p0, it is
766   fixed in r0p1.
767
768-  ``ERRATA_A510_2288014``: This applies errata 2288014 workaround to
769   Cortex-A510 CPU. This needs to be enabled only for revisions r0p0, r0p1,
770   r0p2, r0p3 and r1p0, it is fixed in r1p1.
771
772-  ``ERRATA_A510_2042739``: This applies errata 2042739 workaround to
773   Cortex-A510 CPU. This needs to be enabled only for revisions r0p0, r0p1 and
774   r0p2, it is fixed in r0p3.
775
776-  ``ERRATA_A510_2041909``: This applies errata 2041909 workaround to
777   Cortex-A510 CPU. This needs to be enabled only for revision r0p2 and is fixed
778   in r0p3. The issue is also present in r0p0 and r0p1 but there is no
779   workaround for those revisions.
780
781-  ``ERRATA_A510_2080326``: This applies errata 2080326 workaround to
782   Cortex-A510 CPU. This needs to be enabled only for revision r0p2 and is
783   fixed in r0p3. This issue is also present in r0p0 and r0p1 but there is no
784   workaround for those revisions.
785
786-  ``ERRATA_A510_2250311``: This applies errata 2250311 workaround to
787   Cortex-A510 CPU. This needs to be enabled for revisions r0p0, r0p1, r0p2,
788   r0p3 and r1p0, it is fixed in r1p1. This workaround disables MPMM even if
789   ENABLE_MPMM=1.
790
791-  ``ERRATA_A510_2218950``: This applies errata 2218950 workaround to
792   Cortex-A510 CPU. This needs to be enabled for revisions r0p0, r0p1, r0p2,
793   r0p3 and r1p0, it is fixed in r1p1.
794
795-  ``ERRATA_A510_2172148``: This applies errata 2172148 workaround to
796   Cortex-A510 CPU. This needs to be enabled for revisions r0p0, r0p1, r0p2,
797   r0p3 and r1p0, it is fixed in r1p1.
798
799-  ``ERRATA_A510_2347730``: This applies errata 2347730 workaround to
800   Cortex-A510 CPU. This needs to be enabled for revisions r0p0, r0p1, r0p2,
801   r0p3, r1p0 and r1p1. It is fixed in r1p2.
802
803-  ``ERRATA_A510_2371937``: This applies errata 2371937 workaround to
804   Cortex-A510 CPU. This needs to applied for revisions r0p0, r0p1, r0p2,
805   r0p3, r1p0, r1p1, and is fixed in r1p2.
806
807-  ``ERRATA_A510_2666669``: This applies errata 2666669 workaround to
808   Cortex-A510 CPU. This needs to applied for revisions r0p0, r0p1, r0p2,
809   r0p3, r1p0, r1p1. It is fixed in r1p2.
810
811-  ``ERRATA_A510_2684597``: This applies erratum 2684597 workaround to
812   Cortex-A510 CPU. This needs to be applied to revision r0p0, r0p1, r0p2,
813   r0p3, r1p0, r1p1 and r1p2. It is fixed in r1p3.
814
815For Cortex-A715, the following errata build flags are defined :
816
817-  ``ERRATA_A715_2701951``: This applies erratum 2701951 workaround to Cortex-A715
818   CPU and affects system configurations that do not use an ARM interconnect
819   IP. This needs to be applied to revisions r0p0, r1p0 and r1p1. It is fixed
820   in r1p2.
821
822DSU Errata Workarounds
823----------------------
824
825Similar to CPU errata, TF-A also implements workarounds for DSU (DynamIQ
826Shared Unit) errata. The DSU errata details can be found in the respective Arm
827documentation:
828
829- `Arm DSU Software Developers Errata Notice`_.
830
831Each erratum is identified by an ``ID``, as defined in the DSU errata notice
832document. Thus, the build flags which enable/disable the errata workarounds
833have the format ``ERRATA_DSU_<ID>``. The implementation and application logic
834of DSU errata workarounds are similar to `CPU errata workarounds`_.
835
836For DSU errata, the following build flags are defined:
837
838-  ``ERRATA_DSU_798953``: This applies errata 798953 workaround for the
839   affected DSU configurations. This errata applies only for those DSUs that
840   revision is r0p0 (on r0p1 it is fixed). However, please note that this
841   workaround results in increased DSU power consumption on idle.
842
843-  ``ERRATA_DSU_936184``: This applies errata 936184 workaround for the
844   affected DSU configurations. This errata applies only for those DSUs that
845   contain the ACP interface **and** the DSU revision is older than r2p0 (on
846   r2p0 it is fixed). However, please note that this workaround results in
847   increased DSU power consumption on idle.
848
849-  ``ERRATA_DSU_2313941``: This applies errata 2313941 workaround for the
850   affected DSU configurations. This errata applies for those DSUs with
851   revisions r0p0, r1p0, r2p0, r2p1, r3p0, r3p1 and is still open. However,
852   please note that this workaround results in increased DSU power consumption
853   on idle.
854
855CPU Specific optimizations
856--------------------------
857
858This section describes some of the optimizations allowed by the CPU micro
859architecture that can be enabled by the platform as desired.
860
861-  ``SKIP_A57_L1_FLUSH_PWR_DWN``: This flag enables an optimization in the
862   Cortex-A57 cluster power down sequence by not flushing the Level 1 data
863   cache. The L1 data cache and the L2 unified cache are inclusive. A flush
864   of the L2 by set/way flushes any dirty lines from the L1 as well. This
865   is a known safe deviation from the Cortex-A57 TRM defined power down
866   sequence. Each Cortex-A57 based platform must make its own decision on
867   whether to use the optimization.
868
869-  ``A53_DISABLE_NON_TEMPORAL_HINT``: This flag disables the cache non-temporal
870   hint. The LDNP/STNP instructions as implemented on Cortex-A53 do not behave
871   in a way most programmers expect, and will most probably result in a
872   significant speed degradation to any code that employs them. The Armv8-A
873   architecture (see Arm DDI 0487A.h, section D3.4.3) allows cores to ignore
874   the non-temporal hint and treat LDNP/STNP as LDP/STP instead. Enabling this
875   flag enforces this behaviour. This needs to be enabled only for revisions
876   <= r0p3 of the CPU and is enabled by default.
877
878-  ``A57_DISABLE_NON_TEMPORAL_HINT``: This flag has the same behaviour as
879   ``A53_DISABLE_NON_TEMPORAL_HINT`` but for Cortex-A57. This needs to be
880   enabled only for revisions <= r1p2 of the CPU and is enabled by default,
881   as recommended in section "4.7 Non-Temporal Loads/Stores" of the
882   `Cortex-A57 Software Optimization Guide`_.
883
884- ''A57_ENABLE_NON_CACHEABLE_LOAD_FWD'': This flag enables non-cacheable
885   streaming enhancement feature for Cortex-A57 CPUs. Platforms can set
886   this bit only if their memory system meets the requirement that cache
887   line fill requests from the Cortex-A57 processor are atomic. Each
888   Cortex-A57 based platform must make its own decision on whether to use
889   the optimization. This flag is disabled by default.
890
891-  ``NEOVERSE_Nx_EXTERNAL_LLC``: This flag indicates that an external last
892   level cache(LLC) is present in the system, and that the DataSource field
893   on the master CHI interface indicates when data is returned from the LLC.
894   This is used to control how the LL_CACHE* PMU events count.
895   Default value is 0 (Disabled).
896
897GIC Errata Workarounds
898----------------------
899-  ``GIC600_ERRATA_WA_2384374``: This flag applies part 2 of errata 2384374
900   workaround for the affected GIC600 and GIC600-AE implementations. It applies
901   to implementations of GIC600 and GIC600-AE with revisions less than or equal
902   to r1p6 and r0p2 respectively. If the platform sets GICV3_SUPPORT_GIC600,
903   then this flag is enabled; otherwise, it is 0 (Disabled).
904
905--------------
906
907*Copyright (c) 2014-2023, Arm Limited and Contributors. All rights reserved.*
908
909.. _CVE-2017-5715: http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-5715
910.. _CVE-2018-3639: http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-3639
911.. _CVE-2022-23960: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-23960
912.. _Cortex-A53 MPCore Software Developers Errata Notice: http://infocenter.arm.com/help/topic/com.arm.doc.epm048406/index.html
913.. _Cortex-A57 MPCore Software Developers Errata Notice: http://infocenter.arm.com/help/topic/com.arm.doc.epm049219/index.html
914.. _Cortex-A72 MPCore Software Developers Errata Notice: http://infocenter.arm.com/help/topic/com.arm.doc.epm012079/index.html
915.. _Cortex-A57 Software Optimization Guide: http://infocenter.arm.com/help/topic/com.arm.doc.uan0015b/Cortex_A57_Software_Optimization_Guide_external.pdf
916.. _Arm DSU Software Developers Errata Notice: http://infocenter.arm.com/help/topic/com.arm.doc.epm138168/index.html
917