xref: /rk3399_ARM-atf/docs/design/cpu-specific-build-macros.rst (revision 601e2d4325a7def628990f4a25889f374c81ca06)
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_reporting` 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.
121
122-  ``ERRATA_A53_843419``: This applies erratum 843419 workaround at link time
123   to Cortex-A53 CPU.  This needs to be enabled for some variants of revision
124   <= r0p4. This workaround can lead the linker to emit ``*.stub`` sections
125   which are 4kB aligned.
126
127-  ``ERRATA_A53_855873``: This applies errata 855873 workaround to Cortex-A53
128   CPUs. Though the erratum is present in every revision of the CPU,
129   this workaround is only applied to CPUs from r0p3 onwards, which feature
130   a chicken bit in CPUACTLR_EL1 to enable a hardware workaround.
131   Earlier revisions of the CPU have other errata which require the same
132   workaround in software, so they should be covered anyway.
133
134-  ``ERRATA_A53_1530924``: This applies errata 1530924 workaround to all
135   revisions of Cortex-A53 CPU.
136
137For Cortex-A55, the following errata build flags are defined :
138
139-  ``ERRATA_A55_768277``: This applies errata 768277 workaround to Cortex-A55
140   CPU. This needs to be enabled only for revision r0p0 of the CPU.
141
142-  ``ERRATA_A55_778703``: This applies errata 778703 workaround to Cortex-A55
143   CPU. This needs to be enabled only for revision r0p0 of the CPU.
144
145-  ``ERRATA_A55_798797``: This applies errata 798797 workaround to Cortex-A55
146   CPU. This needs to be enabled only for revision r0p0 of the CPU.
147
148-  ``ERRATA_A55_846532``: This applies errata 846532 workaround to Cortex-A55
149   CPU. This needs to be enabled only for revision <= r0p1 of the CPU.
150
151-  ``ERRATA_A55_903758``: This applies errata 903758 workaround to Cortex-A55
152   CPU. This needs to be enabled only for revision <= r0p1 of the CPU.
153
154-  ``ERRATA_A55_1221012``: This applies errata 1221012 workaround to Cortex-A55
155   CPU. This needs to be enabled only for revision <= r1p0 of the CPU.
156
157-  ``ERRATA_A55_1530923``: This applies errata 1530923 workaround to all
158   revisions of Cortex-A55 CPU.
159
160For Cortex-A57, the following errata build flags are defined :
161
162-  ``ERRATA_A57_806969``: This applies errata 806969 workaround to Cortex-A57
163   CPU. This needs to be enabled only for revision r0p0 of the CPU.
164
165-  ``ERRATA_A57_813419``: This applies errata 813419 workaround to Cortex-A57
166   CPU. This needs to be enabled only for revision r0p0 of the CPU.
167
168-  ``ERRATA_A57_813420``: This applies errata 813420 workaround to Cortex-A57
169   CPU. This needs to be enabled only for revision r0p0 of the CPU.
170
171-  ``ERRATA_A57_814670``: This applies errata 814670 workaround to Cortex-A57
172   CPU. This needs to be enabled only for revision r0p0 of the CPU.
173
174-  ``ERRATA_A57_817169``: This applies errata 817169 workaround to Cortex-A57
175   CPU. This needs to be enabled only for revision <= r0p1 of the CPU.
176
177-  ``ERRATA_A57_826974``: This applies errata 826974 workaround to Cortex-A57
178   CPU. This needs to be enabled only for revision <= r1p1 of the CPU.
179
180-  ``ERRATA_A57_826977``: This applies errata 826977 workaround to Cortex-A57
181   CPU. This needs to be enabled only for revision <= r1p1 of the CPU.
182
183-  ``ERRATA_A57_828024``: This applies errata 828024 workaround to Cortex-A57
184   CPU. This needs to be enabled only for revision <= r1p1 of the CPU.
185
186-  ``ERRATA_A57_829520``: This applies errata 829520 workaround to Cortex-A57
187   CPU. This needs to be enabled only for revision <= r1p2 of the CPU.
188
189-  ``ERRATA_A57_833471``: This applies errata 833471 workaround to Cortex-A57
190   CPU. This needs to be enabled only for revision <= r1p2 of the CPU.
191
192-  ``ERRATA_A57_859972``: This applies errata 859972 workaround to Cortex-A57
193   CPU. This needs to be enabled only for revision <= r1p3 of the CPU.
194
195-  ``ERRATA_A57_1319537``: This applies errata 1319537 workaround to all
196   revisions of Cortex-A57 CPU.
197
198For Cortex-A72, the following errata build flags are defined :
199
200-  ``ERRATA_A72_859971``: This applies errata 859971 workaround to Cortex-A72
201   CPU. This needs to be enabled only for revision <= r0p3 of the CPU.
202
203-  ``ERRATA_A72_1319367``: This applies errata 1319367 workaround to all
204   revisions of Cortex-A72 CPU.
205
206For Cortex-A73, the following errata build flags are defined :
207
208-  ``ERRATA_A73_852427``: This applies errata 852427 workaround to Cortex-A73
209   CPU. This needs to be enabled only for revision r0p0 of the CPU.
210
211-  ``ERRATA_A73_855423``: This applies errata 855423 workaround to Cortex-A73
212   CPU. This needs to be enabled only for revision <= r0p1 of the CPU.
213
214For Cortex-A75, the following errata build flags are defined :
215
216-  ``ERRATA_A75_764081``: This applies errata 764081 workaround to Cortex-A75
217   CPU. This needs to be enabled only for revision r0p0 of the CPU.
218
219-  ``ERRATA_A75_790748``: This applies errata 790748 workaround to Cortex-A75
220    CPU. This needs to be enabled only for revision r0p0 of the CPU.
221
222For Cortex-A76, the following errata build flags are defined :
223
224-  ``ERRATA_A76_1073348``: This applies errata 1073348 workaround to Cortex-A76
225   CPU. This needs to be enabled only for revision <= r1p0 of the CPU.
226
227-  ``ERRATA_A76_1130799``: This applies errata 1130799 workaround to Cortex-A76
228   CPU. This needs to be enabled only for revision <= r2p0 of the CPU.
229
230-  ``ERRATA_A76_1220197``: This applies errata 1220197 workaround to Cortex-A76
231   CPU. This needs to be enabled only for revision <= r2p0 of the CPU.
232
233-  ``ERRATA_A76_1257314``: This applies errata 1257314 workaround to Cortex-A76
234   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
235
236-  ``ERRATA_A76_1262606``: This applies errata 1262606 workaround to Cortex-A76
237   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
238
239-  ``ERRATA_A76_1262888``: This applies errata 1262888 workaround to Cortex-A76
240   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
241
242-  ``ERRATA_A76_1275112``: This applies errata 1275112 workaround to Cortex-A76
243   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
244
245-  ``ERRATA_A76_1791580``: This applies errata 1791580 workaround to Cortex-A76
246   CPU. This needs to be enabled only for revision <= r4p0 of the CPU.
247
248-  ``ERRATA_A76_1165522``: This applies errata 1165522 workaround to all
249   revisions of Cortex-A76 CPU. This errata is fixed in r3p0 but due to
250   limitation of errata framework this errata is applied to all revisions
251   of Cortex-A76 CPU.
252
253-  ``ERRATA_A76_1868343``: This applies errata 1868343 workaround to Cortex-A76
254   CPU. This needs to be enabled only for revision <= r4p0 of the CPU.
255
256-  ``ERRATA_A76_1946160``: This applies errata 1946160 workaround to Cortex-A76
257   CPU. This needs to be enabled only for revisions r3p0 - r4p1 of the CPU.
258
259-  ``ERRATA_A76_2743102``: This applies errata 2743102 workaround to Cortex-A76
260   CPU. This needs to be enabled for all revisions <= r4p1 of the CPU and is
261   still open.
262
263For Cortex-A77, the following errata build flags are defined :
264
265-  ``ERRATA_A77_1508412``: This applies errata 1508412 workaround to Cortex-A77
266   CPU. This needs to be enabled only for revision <= r1p0 of the CPU.
267
268-  ``ERRATA_A77_1925769``: This applies errata 1925769 workaround to Cortex-A77
269   CPU. This needs to be enabled only for revision <= r1p1 of the CPU.
270
271-  ``ERRATA_A77_1946167``: This applies errata 1946167 workaround to Cortex-A77
272   CPU. This needs to be enabled only for revision <= r1p1 of the CPU.
273
274-  ``ERRATA_A77_1791578``: This applies errata 1791578 workaround to Cortex-A77
275   CPU. This needs to be enabled for r0p0, r1p0, and r1p1, it is still open.
276
277-  ``ERRATA_A77_2356587``: This applies errata 2356587 workaround to Cortex-A77
278   CPU. This needs to be enabled for r0p0, r1p0, and r1p1, it is still open.
279
280 -  ``ERRATA_A77_1800714``: This applies errata 1800714 workaround to Cortex-A77
281    CPU. This needs to be enabled for revisions <= r1p1 of the CPU.
282
283 -  ``ERRATA_A77_2743100``: This applies errata 2743100 workaround to Cortex-A77
284    CPU. This needs to be enabled for r0p0, r1p0, and r1p1, it is still open.
285
286For Cortex-A78, the following errata build flags are defined :
287
288-  ``ERRATA_A78_1688305``: This applies errata 1688305 workaround to Cortex-A78
289   CPU. This needs to be enabled only for revision r0p0 - r1p0 of the CPU.
290
291-  ``ERRATA_A78_1941498``: This applies errata 1941498 workaround to Cortex-A78
292   CPU. This needs to be enabled for revisions r0p0, r1p0, and r1p1 of the CPU.
293
294-  ``ERRATA_A78_1951500``: This applies errata 1951500 workaround to Cortex-A78
295   CPU. This needs to be enabled for revisions r1p0 and r1p1, r0p0 has the same
296   issue but there is no workaround for that revision.
297
298-  ``ERRATA_A78_1821534``: This applies errata 1821534 workaround to Cortex-A78
299   CPU. This needs to be enabled for revisions r0p0 and r1p0.
300
301-  ``ERRATA_A78_1952683``: This applies errata 1952683 workaround to Cortex-A78
302   CPU. This needs to be enabled for revision r0p0, it is fixed in r1p0.
303
304-  ``ERRATA_A78_2132060``: This applies errata 2132060 workaround to Cortex-A78
305   CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1, and r1p2. It
306   is still open.
307
308-  ``ERRATA_A78_2242635``: This applies errata 2242635 workaround to Cortex-A78
309   CPU. This needs to be enabled for revisions r1p0, r1p1, and r1p2. The issue
310   is present in r0p0 but there is no workaround. It is still open.
311
312-  ``ERRATA_A78_2376745``: This applies errata 2376745 workaround to Cortex-A78
313   CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1, and r1p2, and
314   it is still open.
315
316-  ``ERRATA_A78_2395406``: This applies errata 2395406 workaround to Cortex-A78
317   CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1, and r1p2, and
318   it is still open.
319
320-  ``ERRATA_A78_2772019``: This applies errata 2772019 workaround to Cortex-A78
321   CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1, and r1p2, and
322   it is still open.
323
324For Cortex-A78 AE, the following errata build flags are defined :
325
326- ``ERRATA_A78_AE_1941500`` : This applies errata 1941500 workaround to
327   Cortex-A78 AE CPU. This needs to be enabled for revisions r0p0 and r0p1.
328   This erratum is still open.
329
330- ``ERRATA_A78_AE_1951502`` : This applies errata 1951502 workaround to
331  Cortex-A78 AE CPU. This needs to be enabled for revisions r0p0 and r0p1. This
332  erratum is still open.
333
334- ``ERRATA_A78_AE_2376748`` : This applies errata 2376748 workaround to
335  Cortex-A78 AE CPU. This needs to be enabled for revisions r0p0 and r0p1. This
336  erratum is still open.
337
338- ``ERRATA_A78_AE_2395408`` : This applies errata 2395408 workaround to
339  Cortex-A78 AE CPU. This needs to be enabled for revisions r0p0 and r0p1. This
340  erratum is still open.
341
342For Cortex-A78C, the following errata build flags are defined :
343
344- ``ERRATA_A78C_2132064`` : This applies errata 2132064 workaround to
345  Cortex-A78C CPU. This needs to be enabled for revisions r0p1, r0p2 and
346  it is still open.
347
348- ``ERRATA_A78C_2242638`` : This applies errata 2242638 workaround to
349  Cortex-A78C CPU. This needs to be enabled for revisions r0p1, r0p2 and
350  it is still open.
351
352- ``ERRATA_A78C_2376749`` : This applies errata 2376749 workaround to
353  Cortex-A78C CPU. This needs to be enabled for revisions r0p1 and r0p2. This
354  erratum is still open.
355
356- ``ERRATA_A78C_2395411`` : This applies errata 2395411 workaround to
357  Cortex-A78C CPU. This needs to be enabled for revisions r0p1 and r0p2. This
358  erratum is still open.
359
360For Cortex-X1 CPU, the following errata build flags are defined:
361
362- ``ERRATA_X1_1821534`` : This applies errata 1821534 workaround to Cortex-X1
363   CPU. This needs to be enabled only for revision <= r1p0 of the CPU.
364
365- ``ERRATA_X1_1688305`` : This applies errata 1688305 workaround to Cortex-X1
366   CPU. This needs to be enabled only for revision <= r1p0 of the CPU.
367
368- ``ERRATA_X1_1827429`` : This applies errata 1827429 workaround to Cortex-X1
369   CPU. This needs to be enabled only for revision <= r1p0 of the CPU.
370
371For Neoverse N1, the following errata build flags are defined :
372
373-  ``ERRATA_N1_1073348``: This applies errata 1073348 workaround to Neoverse-N1
374   CPU. This needs to be enabled only for revision r0p0 and r1p0 of the CPU.
375
376-  ``ERRATA_N1_1130799``: This applies errata 1130799 workaround to Neoverse-N1
377   CPU. This needs to be enabled only for revision <= r2p0 of the CPU.
378
379-  ``ERRATA_N1_1165347``: This applies errata 1165347 workaround to Neoverse-N1
380   CPU. This needs to be enabled only for revision <= r2p0 of the CPU.
381
382-  ``ERRATA_N1_1207823``: This applies errata 1207823 workaround to Neoverse-N1
383   CPU. This needs to be enabled only for revision <= r2p0 of the CPU.
384
385-  ``ERRATA_N1_1220197``: This applies errata 1220197 workaround to Neoverse-N1
386   CPU. This needs to be enabled only for revision <= r2p0 of the CPU.
387
388-  ``ERRATA_N1_1257314``: This applies errata 1257314 workaround to Neoverse-N1
389   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
390
391-  ``ERRATA_N1_1262606``: This applies errata 1262606 workaround to Neoverse-N1
392   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
393
394-  ``ERRATA_N1_1262888``: This applies errata 1262888 workaround to Neoverse-N1
395   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
396
397-  ``ERRATA_N1_1275112``: This applies errata 1275112 workaround to Neoverse-N1
398   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
399
400-  ``ERRATA_N1_1315703``: This applies errata 1315703 workaround to Neoverse-N1
401   CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
402
403-  ``ERRATA_N1_1542419``: This applies errata 1542419 workaround to Neoverse-N1
404   CPU. This needs to be enabled only for revisions r3p0 - r4p0 of the CPU.
405
406-  ``ERRATA_N1_1868343``: This applies errata 1868343 workaround to Neoverse-N1
407   CPU. This needs to be enabled only for revision <= r4p0 of the CPU.
408
409-  ``ERRATA_N1_1946160``: This applies errata 1946160 workaround to Neoverse-N1
410   CPU. This needs to be enabled for revisions r3p0, r3p1, r4p0, and r4p1, for
411   revisions r0p0, r1p0, and r2p0 there is no workaround.
412
413-  ``ERRATA_N1_2743102``: This applies errata 2743102 workaround to Neoverse-N1
414   CPU. This needs to be enabled for all revisions <= r4p1 of the CPU and is
415   still open.
416
417For Neoverse V1, the following errata build flags are defined :
418
419-  ``ERRATA_V1_1618635``: This applies errata 1618635 workaround to Neoverse-V1
420   CPU. This needs to be enabled for revision r0p0 of the CPU, it is fixed in
421   r1p0.
422
423-  ``ERRATA_V1_1774420``: This applies errata 1774420 workaround to Neoverse-V1
424   CPU. This needs to be enabled only for revisions r0p0 and r1p0, it is fixed
425   in r1p1.
426
427-  ``ERRATA_V1_1791573``: This applies errata 1791573 workaround to Neoverse-V1
428   CPU. This needs to be enabled only for revisions r0p0 and r1p0, it is fixed
429   in r1p1.
430
431-  ``ERRATA_V1_1852267``: This applies errata 1852267 workaround to Neoverse-V1
432   CPU. This needs to be enabled only for revisions r0p0 and r1p0, it is fixed
433   in r1p1.
434
435-  ``ERRATA_V1_1925756``: This applies errata 1925756 workaround to Neoverse-V1
436   CPU. This needs to be enabled for r0p0, r1p0, and r1p1, it is still open.
437
438-  ``ERRATA_V1_1940577``: This applies errata 1940577 workaround to Neoverse-V1
439   CPU. This needs to be enabled only for revision r1p0 and r1p1 of the
440   CPU.
441
442-  ``ERRATA_V1_1966096``: This applies errata 1966096 workaround to Neoverse-V1
443   CPU. This needs to be enabled for revisions r1p0 and r1p1 of the CPU, the
444   issue is present in r0p0 as well but there is no workaround for that
445   revision.  It is still open.
446
447-  ``ERRATA_V1_2139242``: This applies errata 2139242 workaround to Neoverse-V1
448   CPU. This needs to be enabled for revisions r0p0, r1p0, and r1p1 of the
449   CPU.  It is still open.
450
451-  ``ERRATA_V1_2108267``: This applies errata 2108267 workaround to Neoverse-V1
452   CPU. This needs to be enabled for revisions r0p0, r1p0, and r1p1 of the CPU.
453   It is still open.
454
455-  ``ERRATA_V1_2216392``: This applies errata 2216392 workaround to Neoverse-V1
456   CPU. This needs to be enabled for revisions r1p0 and r1p1 of the CPU, the
457   issue is present in r0p0 as well but there is no workaround for that
458   revision.  It is still open.
459
460-  ``ERRATA_V1_2294912``: This applies errata 2294912 workaround to Neoverse-V1
461   CPU. This needs to be enabled for revisions r0p0, r1p0, and r1p1 of the CPU.
462
463-  ``ERRATA_V1_2372203``: This applies errata 2372203 workaround to Neoverse-V1
464   CPU. This needs to be enabled for revisions r0p0, r1p0 and r1p1 of the CPU.
465   It is still open.
466
467-  ``ERRATA_V1_2743093``: This applies errata 2743093 workaround to Neoverse-V1
468   CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1 and r1p2 of the
469   CPU. It is still open.
470
471For Cortex-A710, the following errata build flags are defined :
472
473-  ``ERRATA_A710_1987031``: This applies errata 1987031 workaround to
474   Cortex-A710 CPU. This needs to be enabled only for revisions r0p0, r1p0 and
475   r2p0 of the CPU. It is still open.
476
477-  ``ERRATA_A710_2081180``: This applies errata 2081180 workaround to
478   Cortex-A710 CPU. This needs to be enabled only for revisions r0p0, r1p0 and
479   r2p0 of the CPU. It is still open.
480
481-  ``ERRATA_A710_2055002``: This applies errata 2055002 workaround to
482   Cortex-A710 CPU. This needs to be enabled for revisions r1p0, r2p0 of the CPU
483   and is still open.
484
485-  ``ERRATA_A710_2017096``: This applies errata 2017096 workaround to
486   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
487   of the CPU and is still open.
488
489-  ``ERRATA_A710_2083908``: This applies errata 2083908 workaround to
490   Cortex-A710 CPU. This needs to be enabled for revision r2p0 of the CPU and
491   is still open.
492
493-  ``ERRATA_A710_2058056``: This applies errata 2058056 workaround to
494   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
495   of the CPU and is still open.
496
497-  ``ERRATA_A710_2267065``: This applies errata 2267065 workaround to
498   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
499   of the CPU and is fixed in r2p1.
500
501-  ``ERRATA_A710_2136059``: This applies errata 2136059 workaround to
502   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
503   of the CPU and is fixed in r2p1.
504
505-  ``ERRATA_A710_2147715``: This applies errata 2147715 workaround to
506   Cortex-A710 CPU. This needs to be enabled for revision r2p0 of the CPU
507   and is fixed in r2p1.
508
509-  ``ERRATA_A710_2216384``: This applies errata 2216384 workaround to
510   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
511   of the CPU and is fixed in r2p1.
512
513-  ``ERRATA_A710_2282622``: This applies errata 2282622 workaround to
514   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
515   of the CPU and is fixed in r2p1.
516
517- ``ERRATA_A710_2291219``: This applies errata 2291219 workaround to
518   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
519   of the CPU and is fixed in r2p1.
520
521-  ``ERRATA_A710_2008768``: This applies errata 2008768 workaround to
522   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
523   of the CPU and is fixed in r2p1.
524
525-  ``ERRATA_A710_2371105``: This applies errata 2371105 workaround to
526   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
527   of the CPU and is fixed in r2p1.
528
529-  ``ERRATA_A710_2768515``: This applies errata 2768515 workaround to
530   Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and
531   r2p1 of the CPU and is still open.
532
533For Neoverse N2, the following errata build flags are defined :
534
535-  ``ERRATA_N2_2002655``: This applies errata 2002655 workaround to Neoverse-N2
536   CPU. This needs to be enabled for revision r0p0 of the CPU, it is still open.
537
538-  ``ERRATA_N2_2067956``: This applies errata 2067956 workaround to Neoverse-N2
539   CPU. This needs to be enabled for revision r0p0 of the CPU and is still open.
540
541-  ``ERRATA_N2_2025414``: This applies errata 2025414 workaround to Neoverse-N2
542   CPU. This needs to be enabled for revision r0p0 of the CPU and is still open.
543
544-  ``ERRATA_N2_2189731``: This applies errata 2189731 workaround to Neoverse-N2
545   CPU. This needs to be enabled for revision r0p0 of the CPU and is still open.
546
547-  ``ERRATA_N2_2138956``: This applies errata 2138956 workaround to Neoverse-N2
548   CPU. This needs to be enabled for revision r0p0 of the CPU and is still open.
549
550-  ``ERRATA_N2_2138953``: This applies errata 2138953 workaround to Neoverse-N2
551   CPU. This needs to be enabled for revision r0p0 of the CPU and is still open.
552
553-  ``ERRATA_N2_2242415``: This applies errata 2242415 workaround to Neoverse-N2
554   CPU. This needs to be enabled for revision r0p0 of the CPU and is still open.
555
556-  ``ERRATA_N2_2138958``: This applies errata 2138958 workaround to Neoverse-N2
557   CPU. This needs to be enabled for revision r0p0 of the CPU and is still open.
558
559-  ``ERRATA_N2_2242400``: This applies errata 2242400 workaround to Neoverse-N2
560   CPU. This needs to be enabled for revision r0p0 of the CPU and is still open.
561
562-  ``ERRATA_N2_2280757``: This applies errata 2280757 workaround to Neoverse-N2
563   CPU. This needs to be enabled for revision r0p0 of the CPU and is still open.
564
565-  ``ERRATA_N2_2326639``: This applies errata 2326639 workaround to Neoverse-N2
566   CPU. This needs to be enabled for revision r0p0 of the CPU, it is fixed in
567   r0p1.
568
569-  ``ERRATA_N2_2376738``: This applies errata 2376738 workaround to Neoverse-N2
570   CPU. This needs to be enabled for revision r0p0 of the CPU, it is fixed in
571   r0p1.
572
573-  ``ERRATA_N2_2388450``: This applies errata 2388450 workaround to Neoverse-N2
574   CPU. This needs to be enabled for revision r0p0 of the CPU, it is fixed in
575   r0p1.
576
577-  ``ERRATA_N2_2743089``: This applies errata 2743089 workaround to Neoverse-N2
578   CPU. This needs to be enabled for revisions r0p0, r0p1 and r0p2. It is fixed
579   in r0p3.
580
581For Cortex-X2, the following errata build flags are defined :
582
583-  ``ERRATA_X2_2002765``: This applies errata 2002765 workaround to Cortex-X2
584   CPU. This needs to be enabled for revisions r0p0, r1p0, and r2p0 of the CPU,
585   it is still open.
586
587-  ``ERRATA_X2_2058056``: This applies errata 2058056 workaround to Cortex-X2
588   CPU. This needs to be enabled for revisions r0p0, r1p0, and r2p0 of the CPU,
589   it is still open.
590
591-  ``ERRATA_X2_2083908``: This applies errata 2083908 workaround to Cortex-X2
592   CPU. This needs to be enabled for revision r2p0 of the CPU, it is still open.
593
594-  ``ERRATA_X2_2017096``: This applies errata 2017096 workaround to
595   Cortex-X2 CPU. This needs to be enabled only for revisions r0p0, r1p0 and
596   r2p0 of the CPU, it is fixed in r2p1.
597
598-  ``ERRATA_X2_2081180``: This applies errata 2081180 workaround to
599   Cortex-X2 CPU. This needs to be enabled only for revisions r0p0, r1p0 and
600   r2p0 of the CPU, it is fixed in r2p1.
601
602-  ``ERRATA_X2_2216384``: This applies errata 2216384 workaround to
603   Cortex-X2 CPU. This needs to be enabled only for revisions r0p0, r1p0 and
604   r2p0 of the CPU, it is fixed in r2p1.
605
606-  ``ERRATA_X2_2147715``: This applies errata 2147715 workaround to
607   Cortex-X2 CPU. This needs to be enabled only for revision r2p0 of the CPU,
608   it is fixed in r2p1.
609
610-  ``ERRATA_X2_2371105``: This applies errata 2371105 workaround to
611   Cortex-X2 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
612   of the CPU and is fixed in r2p1.
613
614-  ``ERRATA_X2_2768515``: This applies errata 2768515 workaround to
615   Cortex-X2 CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0
616   and r2p1 of the CPU and is still open.
617
618For Cortex-X3, the following errata build flags are defined :
619
620- ``ERRATA_X3_2313909``: This applies errata 2313909 workaround to
621  Cortex-X3 CPU. This needs to be enabled only for revisions r0p0 and r1p0
622  of the CPU, it is fixed in r1p1.
623
624- ``ERRATA_X3_2615812``: This applies errata 2615812 workaround to Cortex-X3
625  CPU. This needs to be enabled only for revisions r0p0, r1p0 and r1p1 of the
626  CPU, it is still open.
627
628For Cortex-A510, the following errata build flags are defined :
629
630-  ``ERRATA_A510_1922240``: This applies errata 1922240 workaround to
631   Cortex-A510 CPU. This needs to be enabled only for revision r0p0, it is
632   fixed in r0p1.
633
634-  ``ERRATA_A510_2288014``: This applies errata 2288014 workaround to
635   Cortex-A510 CPU. This needs to be enabled only for revisions r0p0, r0p1,
636   r0p2, r0p3 and r1p0, it is fixed in r1p1.
637
638-  ``ERRATA_A510_2042739``: This applies errata 2042739 workaround to
639   Cortex-A510 CPU. This needs to be enabled only for revisions r0p0, r0p1 and
640   r0p2, it is fixed in r0p3.
641
642-  ``ERRATA_A510_2041909``: This applies errata 2041909 workaround to
643   Cortex-A510 CPU. This needs to be enabled only for revision r0p2 and is fixed
644   in r0p3. The issue is also present in r0p0 and r0p1 but there is no
645   workaround for those revisions.
646
647-  ``ERRATA_A510_2250311``: This applies errata 2250311 workaround to
648   Cortex-A510 CPU. This needs to be enabled for revisions r0p0, r0p1, r0p2,
649   r0p3 and r1p0, it is fixed in r1p1. This workaround disables MPMM even if
650   ENABLE_MPMM=1.
651
652-  ``ERRATA_A510_2218950``: This applies errata 2218950 workaround to
653   Cortex-A510 CPU. This needs to be enabled for revisions r0p0, r0p1, r0p2,
654   r0p3 and r1p0, it is fixed in r1p1.
655
656-  ``ERRATA_A510_2172148``: This applies errata 2172148 workaround to
657   Cortex-A510 CPU. This needs to be enabled for revisions r0p0, r0p1, r0p2,
658   r0p3 and r1p0, it is fixed in r1p1.
659
660- ``ERRATA_A510_2347730``: This applies errata 2347730 workaround to
661   Cortex-A510 CPU. This needs to be enabled for revisions r0p0, r0p1, r0p2,
662   r0p3, r1p0 and r1p1. It is fixed in r1p2.
663
664-  ``ERRATA_A510_2371937``: This applies errata 2371937 workaround to
665   Cortex-A510 CPU. This needs to applied for revisions r0p0, r0p1, r0p2,
666   r0p3, r1p0, r1p1, and is fixed in r1p2.
667
668-  ``ERRATA_A510_2666669``: This applies errata 2666669 workaround to
669   Cortex-A510 CPU. This needs to applied for revisions r0p0, r0p1, r0p2,
670   r0p3, r1p0, r1p1. It is fixed in r1p2.
671
672DSU Errata Workarounds
673----------------------
674
675Similar to CPU errata, TF-A also implements workarounds for DSU (DynamIQ
676Shared Unit) errata. The DSU errata details can be found in the respective Arm
677documentation:
678
679- `Arm DSU Software Developers Errata Notice`_.
680
681Each erratum is identified by an ``ID``, as defined in the DSU errata notice
682document. Thus, the build flags which enable/disable the errata workarounds
683have the format ``ERRATA_DSU_<ID>``. The implementation and application logic
684of DSU errata workarounds are similar to `CPU errata workarounds`_.
685
686For DSU errata, the following build flags are defined:
687
688-  ``ERRATA_DSU_798953``: This applies errata 798953 workaround for the
689   affected DSU configurations. This errata applies only for those DSUs that
690   revision is r0p0 (on r0p1 it is fixed). However, please note that this
691   workaround results in increased DSU power consumption on idle.
692
693-  ``ERRATA_DSU_936184``: This applies errata 936184 workaround for the
694   affected DSU configurations. This errata applies only for those DSUs that
695   contain the ACP interface **and** the DSU revision is older than r2p0 (on
696   r2p0 it is fixed). However, please note that this workaround results in
697   increased DSU power consumption on idle.
698
699-  ``ERRATA_DSU_2313941``: This applies errata 2313941 workaround for the
700   affected DSU configurations. This errata applies for those DSUs with
701   revisions r0p0, r1p0, r2p0, r2p1, r3p0, r3p1 and is still open. However,
702   please note that this workaround results in increased DSU power consumption
703   on idle.
704
705CPU Specific optimizations
706--------------------------
707
708This section describes some of the optimizations allowed by the CPU micro
709architecture that can be enabled by the platform as desired.
710
711-  ``SKIP_A57_L1_FLUSH_PWR_DWN``: This flag enables an optimization in the
712   Cortex-A57 cluster power down sequence by not flushing the Level 1 data
713   cache. The L1 data cache and the L2 unified cache are inclusive. A flush
714   of the L2 by set/way flushes any dirty lines from the L1 as well. This
715   is a known safe deviation from the Cortex-A57 TRM defined power down
716   sequence. Each Cortex-A57 based platform must make its own decision on
717   whether to use the optimization.
718
719-  ``A53_DISABLE_NON_TEMPORAL_HINT``: This flag disables the cache non-temporal
720   hint. The LDNP/STNP instructions as implemented on Cortex-A53 do not behave
721   in a way most programmers expect, and will most probably result in a
722   significant speed degradation to any code that employs them. The Armv8-A
723   architecture (see Arm DDI 0487A.h, section D3.4.3) allows cores to ignore
724   the non-temporal hint and treat LDNP/STNP as LDP/STP instead. Enabling this
725   flag enforces this behaviour. This needs to be enabled only for revisions
726   <= r0p3 of the CPU and is enabled by default.
727
728-  ``A57_DISABLE_NON_TEMPORAL_HINT``: This flag has the same behaviour as
729   ``A53_DISABLE_NON_TEMPORAL_HINT`` but for Cortex-A57. This needs to be
730   enabled only for revisions <= r1p2 of the CPU and is enabled by default,
731   as recommended in section "4.7 Non-Temporal Loads/Stores" of the
732   `Cortex-A57 Software Optimization Guide`_.
733
734- ''A57_ENABLE_NON_CACHEABLE_LOAD_FWD'': This flag enables non-cacheable
735   streaming enhancement feature for Cortex-A57 CPUs. Platforms can set
736   this bit only if their memory system meets the requirement that cache
737   line fill requests from the Cortex-A57 processor are atomic. Each
738   Cortex-A57 based platform must make its own decision on whether to use
739   the optimization. This flag is disabled by default.
740
741-  ``NEOVERSE_Nx_EXTERNAL_LLC``: This flag indicates that an external last
742   level cache(LLC) is present in the system, and that the DataSource field
743   on the master CHI interface indicates when data is returned from the LLC.
744   This is used to control how the LL_CACHE* PMU events count.
745   Default value is 0 (Disabled).
746
747GIC Errata Workarounds
748----------------------
749-  ``GIC600_ERRATA_WA_2384374``: This flag applies part 2 of errata 2384374
750   workaround for the affected GIC600 and GIC600-AE implementations. It applies
751   to implementations of GIC600 and GIC600-AE with revisions less than or equal
752   to r1p6 and r0p2 respectively. If the platform sets GICV3_SUPPORT_GIC600,
753   then this flag is enabled; otherwise, it is 0 (Disabled).
754
755--------------
756
757*Copyright (c) 2014-2022, Arm Limited and Contributors. All rights reserved.*
758
759.. _CVE-2017-5715: http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-5715
760.. _CVE-2018-3639: http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-3639
761.. _CVE-2022-23960: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-23960
762.. _Cortex-A53 MPCore Software Developers Errata Notice: http://infocenter.arm.com/help/topic/com.arm.doc.epm048406/index.html
763.. _Cortex-A57 MPCore Software Developers Errata Notice: http://infocenter.arm.com/help/topic/com.arm.doc.epm049219/index.html
764.. _Cortex-A72 MPCore Software Developers Errata Notice: http://infocenter.arm.com/help/topic/com.arm.doc.epm012079/index.html
765.. _Cortex-A57 Software Optimization Guide: http://infocenter.arm.com/help/topic/com.arm.doc.uan0015b/Cortex_A57_Software_Optimization_Guide_external.pdf
766.. _Arm DSU Software Developers Errata Notice: http://infocenter.arm.com/help/topic/com.arm.doc.epm138168/index.html
767