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linux: export AT_HWCAP and AT_HWCAP2 on aarch64
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Authored by trasz on May 29 2021, 6:25 AM.

Details

Summary

The flag values seem to be the same between Linux and FreeBSD.
Comparing to a Linux VM on the same hardware, we're missing
HWCAP_EVTSTRM, HWCAP_CPUID, HWCAP_DCPOP, HWCAP_USCAT, HWCAP_PACA,
and HWCAP_PACG.

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Repository
rG FreeBSD src repository
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Event Timeline

trasz requested review of this revision.May 29 2021, 6:25 AM

It's intentional that the same bits are used, but IMO we should have some way to help ensure that remains so, even if just a more explicit comment in sys/arm64/include/elf.h.

This revision is now accepted and ready to land.May 31 2021, 8:00 PM

It already suggests that's the case, though: "XXX: The following bits (from CPUID to FLAGM) were originally incorrect, but later changed to match the Linux definitions."

Indeed, hence "a more explicit comment" - it's only after this change that they must match.