git: 48da01ad0b16 - main - arm64: Add a comment about HWCAP values

The branch main has been updated by andrew:

URL: https://cgit.FreeBSD.org/src/commit/?id=48da01ad0b165b4dd38a4c22449216c1babc068b

commit 48da01ad0b165b4dd38a4c22449216c1babc068b
Author:     Andrew Turner <andrew@FreeBSD.org>
AuthorDate: 2026-05-14 15:04:32 +0000
Commit:     Andrew Turner <andrew@FreeBSD.org>
CommitDate: 2026-05-27 15:22:25 +0000

    arm64: Add a comment about HWCAP values
    
    They must be identical to Linux. Document this requirement to allow
    userspace to depend on this.
    
    Sponsored by:   Arm Ltd
---
 sys/arm64/include/elf.h | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/sys/arm64/include/elf.h b/sys/arm64/include/elf.h
index a5a90f8c7712..7940bb259256 100644
--- a/sys/arm64/include/elf.h
+++ b/sys/arm64/include/elf.h
@@ -96,6 +96,12 @@ __ElfType(Auxinfo);
 /* First __FreeBSD_version that supports Top Byte Ignore (TBI) */
 #define	TBI_VERSION	1500058
 
+/*
+ * The HWCAP values must be identical to Linux. Many userspace programs
+ * will define missing HWCAP values to the Linux version. To keep these
+ * working when we add the HWCAP it must be the same.
+ */
+
 /* HWCAP */
 #define	HWCAP_FP		(1 << 0)
 #define	HWCAP_ASIMD		(1 << 1)