fix(pe016): Correct SVE2 check for non-Armv9 platforms #94
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* Moved `ID_AA64ZFR0_EL1.SVEver` check before Armv9 family check to avoid false failures * Validates `SVEver > 0` directly to confirm FEAT\_SVE2 or greater is present Signed-off-by: Balaji Gontumukkala <balaji.gontumukkala@arm.com> Change-Id: I6c2d43af40b1c76f835decf790e06151bf82d657
chetan-rathore
approved these changes
Sep 4, 2025
hrw
reviewed
Sep 4, 2025
| /* For Armv9, the ID_AA64ZFR0_EL1.SVEver, bits [3:0] value 0b0000 is not permitted */ | ||
| /* ID_AA64ZFR0_EL1.SVEver > 0 indicates FEAT_SVE2 or grater is implemented*/ | ||
| /* If PE implements SVE2, it's a pass. No need to check architecture family, as | ||
| * SVE2 is required from v9 onwards. */ |
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I would rewrite that comment.
ArmArm L.b, page A2-158:
FEAT_SVE2 is OPTIONAL from Armv9.0.
It is completely legal to have Armv9.0 cpu without any SVE. In such case ID_AA64ZFR0_EL1 register should not be present.
On the other side, BSA 1.2 mandates SVE2 for Armv9 cpus:
Implementation of SVE is optional. Implementation of SVE2 (FEAT_SVE2) is required for PEs that are based on the Armv9 architecture (see FEAT_SVE2 in [3]).
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ID_AA64ZFR0_EL1.SVEvercheck before Armv9 family check to avoid false failuresSVEver > 0directly to confirm FEAT_SVE2 or greater is presentChange-Id: I6c2d43af40b1c76f835decf790e06151bf82d657