It is the ACPI processor UID that is stored here.
ok guenther@
-/* $OpenBSD: acpireg.h,v 1.35 2016/05/07 18:03:36 kettenis Exp $ */
+/* $OpenBSD: acpireg.h,v 1.36 2016/07/10 20:36:41 kettenis Exp $ */
/*
* Copyright (c) 2005 Thorsten Lockert <tholo@sigmasoft.com>
* Copyright (c) 2005 Marco Peereboom <marco@openbsd.org>
u_int8_t reserved[2];
u_int32_t apic_id;
u_int32_t flags; /* Same flags as acpi_madt_lapic */
- u_int32_t apic_proc_uid;
+ u_int32_t acpi_proc_uid;
} __packed;
struct acpi_madt_x2apic_nmi {