Index: head/sys/arm/include/elf.h
===================================================================
--- head/sys/arm/include/elf.h
+++ head/sys/arm/include/elf.h
@@ -85,8 +85,9 @@
 #define	AT_TIMEKEEP	22	/* Pointer to timehands. */
 #define	AT_STACKPROT	23	/* Initial stack protection. */
 #define	AT_EHDRFLAGS	24	/* e_flags field from elf hdr */
+#define	AT_HWCAP	25	/* CPU feature flags. */
 
-#define	AT_COUNT	25	/* Count of defined aux entry types. */
+#define	AT_COUNT	26	/* Count of defined aux entry types. */
 
 #define	R_ARM_COUNT	33	/* Count of defined relocation types. */
 
Index: head/sys/arm64/include/elf.h
===================================================================
--- head/sys/arm64/include/elf.h
+++ head/sys/arm64/include/elf.h
@@ -90,8 +90,10 @@
 #define	AT_PAGESIZESLEN	21	/* Number of pagesizes. */
 #define	AT_TIMEKEEP	22	/* Pointer to timehands. */
 #define	AT_STACKPROT	23	/* Initial stack protection. */
+#define	AT_EHDRFLAGS	24	/* e_flags field from elf hdr */
+#define	AT_HWCAP	25	/* CPU feature flags. */
 
-#define	AT_COUNT	24	/* Count of defined aux entry types. */
+#define	AT_COUNT	26	/* Count of defined aux entry types. */
 
 /* Define "machine" characteristics */
 #define	ELF_TARG_CLASS	ELFCLASS64
Index: head/sys/kern/imgact_elf.c
===================================================================
--- head/sys/kern/imgact_elf.c
+++ head/sys/kern/imgact_elf.c
@@ -1110,9 +1110,7 @@
 	AUXARGS_ENTRY(pos, AT_FLAGS, args->flags);
 	AUXARGS_ENTRY(pos, AT_ENTRY, args->entry);
 	AUXARGS_ENTRY(pos, AT_BASE, args->base);
-#ifdef AT_EHDRFLAGS
 	AUXARGS_ENTRY(pos, AT_EHDRFLAGS, args->hdr_eflags);
-#endif
 	if (imgp->execpathp != 0)
 		AUXARGS_ENTRY(pos, AT_EXECPATH, imgp->execpathp);
 	AUXARGS_ENTRY(pos, AT_OSRELDATE,
@@ -1133,6 +1131,8 @@
 	AUXARGS_ENTRY(pos, AT_STACKPROT, imgp->sysent->sv_shared_page_obj
 	    != NULL && imgp->stack_prot != 0 ? imgp->stack_prot :
 	    imgp->sysent->sv_stackprot);
+	if (imgp->sysent->sv_hwcap != NULL)
+		AUXARGS_ENTRY(pos, AT_HWCAP, *imgp->sysent->sv_hwcap);
 	AUXARGS_ENTRY(pos, AT_NULL, 0);
 
 	free(imgp->auxargs, M_TEMP);
Index: head/sys/mips/include/elf.h
===================================================================
--- head/sys/mips/include/elf.h
+++ head/sys/mips/include/elf.h
@@ -144,8 +144,10 @@
 #define	AT_PAGESIZESLEN	21	/* Number of pagesizes. */
 #define	AT_TIMEKEEP	22	/* Pointer to timehands. */
 #define	AT_STACKPROT	23	/* Initial stack protection. */
+#define	AT_EHDRFLAGS	24	/* e_flags field from elf hdr */
+#define	AT_HWCAP	25	/* CPU feature flags. */
 
-#define	AT_COUNT	24	/* Count of defined aux entry types. */
+#define	AT_COUNT	26	/* Count of defined aux entry types. */
 
 #define	ET_DYN_LOAD_ADDR 0x0120000
 
Index: head/sys/powerpc/include/elf.h
===================================================================
--- head/sys/powerpc/include/elf.h
+++ head/sys/powerpc/include/elf.h
@@ -107,8 +107,10 @@
 #define	AT_PAGESIZESLEN	19	/* Number of pagesizes. */
 #define	AT_STACKPROT	21	/* Initial stack protection. */
 #define	AT_TIMEKEEP	22	/* Pointer to timehands. */
+#define	AT_EHDRFLAGS	24	/* e_flags field from elf hdr */
+#define	AT_HWCAP	25	/* CPU feature flags. */
 
-#define	AT_COUNT	23	/* Count of defined aux entry types. */
+#define	AT_COUNT	26	/* Count of defined aux entry types. */
 
 /*
  * Relocation types.
Index: head/sys/riscv/include/elf.h
===================================================================
--- head/sys/riscv/include/elf.h
+++ head/sys/riscv/include/elf.h
@@ -90,8 +90,10 @@
 #define	AT_PAGESIZESLEN	21	/* Number of pagesizes. */
 #define	AT_TIMEKEEP	22	/* Pointer to timehands. */
 #define	AT_STACKPROT	23	/* Initial stack protection. */
+#define	AT_EHDRFLAGS	24	/* e_flags field from elf hdr */
+#define	AT_HWCAP	25	/* CPU feature flags. */
 
-#define	AT_COUNT	24	/* Count of defined aux entry types. */
+#define	AT_COUNT	26	/* Count of defined aux entry types. */
 
 /* Define "machine" characteristics */
 #define	ELF_TARG_CLASS	ELFCLASS64
Index: head/sys/sparc64/include/elf.h
===================================================================
--- head/sys/sparc64/include/elf.h
+++ head/sys/sparc64/include/elf.h
@@ -92,8 +92,10 @@
 #define	AT_PAGESIZESLEN	21	/* Number of pagesizes. */
 #define	AT_TIMEKEEP	22	/* Pointer to timehands. */
 #define	AT_STACKPROT	23	/* Initial stack protection. */
+#define	AT_EHDRFLAGS	24	/* e_flags field from elf hdr */
+#define	AT_HWCAP	25	/* CPU feature flags. */
 
-#define	AT_COUNT	24	/* Count of defined aux entry types. */
+#define	AT_COUNT	26	/* Count of defined aux entry types. */
 
 /* Define "machine" characteristics */
 #if __ELF_WORD_SIZE == 32
Index: head/sys/sys/sysent.h
===================================================================
--- head/sys/sys/sysent.h
+++ head/sys/sys/sysent.h
@@ -129,6 +129,7 @@
 	void		(*sv_schedtail)(struct thread *);
 	void		(*sv_thread_detach)(struct thread *);
 	int		(*sv_trap)(struct thread *);
+	u_long		*sv_hwcap;	/* Value passed in AT_HWCAP. */
 };
 
 #define	SV_ILP32	0x000100	/* 32-bit executable. */
Index: head/sys/x86/include/elf.h
===================================================================
--- head/sys/x86/include/elf.h
+++ head/sys/x86/include/elf.h
@@ -100,8 +100,10 @@
 #define	AT_PAGESIZESLEN	21	/* Number of pagesizes. */
 #define	AT_TIMEKEEP	22	/* Pointer to timehands. */
 #define	AT_STACKPROT	23	/* Initial stack protection. */
+#define	AT_EHDRFLAGS	24	/* e_flags field from elf hdr */
+#define	AT_HWCAP	25	/* CPU feature flags. */
 
-#define	AT_COUNT	24	/* Count of defined aux entry types. */
+#define	AT_COUNT	26	/* Count of defined aux entry types. */
 
 /*
  * Relocation types.