diff --git a/FreeBSD/sys/dev/hwpmc/hwpmc_logging.c b/FreeBSD/sys/dev/hwpmc/hwpmc_logging.c
--- a/FreeBSD/sys/dev/hwpmc/hwpmc_logging.c
+++ b/FreeBSD/sys/dev/hwpmc/hwpmc_logging.c
@@ -718,7 +718,10 @@
 	/* create a log initialization entry */
 	PMCLOG_RESERVE_WITH_ERROR(po, PMCLOG_TYPE_INITIALIZE,
 	    sizeof(struct pmclog_initialize));
-	PMCLOG_EMIT32(PMC_VERSION);
+	if ((po->po_flags & PMC_PO_LEGACY) != 0)
+		PMCLOG_EMIT32(pmc_compat_version);
+	else
+		PMCLOG_EMIT32(PMC_VERSION);
 	PMCLOG_EMIT32(md->pmd_cputype);
 #if defined(__i386__) || defined(__amd64__)
 	PMCLOG_EMIT64(tsc_freq);
@@ -1098,19 +1101,26 @@
 
 void
 pmclog_process_procexec(struct pmc_owner *po, pmc_id_t pmid, pid_t pid,
-    uintptr_t baseaddr, uintptr_t dynaddr, char *path)
+    uintptr_t baseaddr, uintptr_t dynaddr, uintptr_t entryaddr, char *path)
 {
-	int pathlen, recordlen;
+	int pathlen, recordlen, legacy;
 
 	PMCDBG3(LOG,EXC,1,"po=%p pid=%d path=\"%s\"", po, pid, path);
 
 	pathlen   = strlen(path) + 1;	/* #bytes for the path */
 	recordlen = offsetof(struct pmclog_procexec, pl_pathname) + pathlen;
+	legacy = !!(po->po_flags & PMC_PO_LEGACY);
+	if (legacy)
+		recordlen -= sizeof (uintptr_t);
 	PMCLOG_RESERVE(po, PMCLOG_TYPE_PROCEXEC, recordlen);
 	PMCLOG_EMIT32(pid);
 	PMCLOG_EMIT32(pmid);
-	PMCLOG_EMITADDR(baseaddr);
-	PMCLOG_EMITADDR(dynaddr);
+	if (legacy) {
+		PMCLOG_EMITADDR(entryaddr);
+	} else {
+		PMCLOG_EMITADDR(baseaddr);
+		PMCLOG_EMITADDR(dynaddr);
+	}
 	PMCLOG_EMITSTRING(path,pathlen);
 	PMCLOG_DESPATCH_SYNC(po);
 }
diff --git a/FreeBSD/sys/dev/hwpmc/hwpmc_mod.c b/FreeBSD/sys/dev/hwpmc/hwpmc_mod.c
--- a/FreeBSD/sys/dev/hwpmc/hwpmc_mod.c
+++ b/FreeBSD/sys/dev/hwpmc/hwpmc_mod.c
@@ -392,6 +392,15 @@
     &pmc_unprivileged_syspmcs, 0,
     "allow unprivileged process to allocate system PMCs");
 
+/*
+ * Enable support for legacy profilers, like AMDuProf, that are
+ * built for older version of FreeBSD and use an older ABI.
+ */
+int pmc_compat_version = 0;
+SYSCTL_INT(_kern_hwpmc, OID_AUTO, compat_verson, CTLFLAG_RWTUN,
+    &pmc_compat_version, 0,
+    "Emulate ABI from this older version when an older binary is run");
+
 /*
  * Hash function.  Discard the lower 2 bits of the pointer since
  * these are always zero for our uses.  The hash multiplier is
@@ -1345,7 +1354,8 @@
 	CK_LIST_FOREACH(po, &pmc_ss_owners, po_ssnext) {
 		if ((po->po_flags & PMC_PO_OWNS_LOGFILE) != 0) {
 			pmclog_process_procexec(po, PMC_ID_INVALID, p->p_pid,
-			    pk->pm_baseaddr, pk->pm_dynaddr, fullpath);
+			    pk->pm_baseaddr, pk->pm_dynaddr, pk->pm_entryaddr,
+			    fullpath);
 		}
 	}
 	PMC_EPOCH_EXIT();
@@ -1392,7 +1402,8 @@
 		if (po->po_sscount == 0 &&
 		    (po->po_flags & PMC_PO_OWNS_LOGFILE) != 0) {
 			pmclog_process_procexec(po, pm->pm_id, p->p_pid,
-			    pk->pm_baseaddr, pk->pm_dynaddr, fullpath);
+			    pk->pm_baseaddr, pk->pm_dynaddr,
+			    pk->pm_entryaddr, fullpath);
 		}
 	}
 
@@ -2306,6 +2317,8 @@
 	/* Allocate space for N pointers and one descriptor struct. */
 	po = malloc(sizeof(struct pmc_owner), M_PMC, M_WAITOK | M_ZERO);
 	po->po_owner = p;
+	if (pmc_compat_version != 0 && p->p_osrel == 1200500)
+		po->po_flags |= PMC_PO_LEGACY;
 	LIST_INSERT_HEAD(poh, po, po_next); /* insert into hash table */
 
 	TAILQ_INIT(&po->po_logbuffers);
@@ -3418,6 +3431,8 @@
 	(pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_pmc == NULL)
 
 	if (PMC_IS_SYSTEM_MODE(mode)) {
+		if (pmc_compat_version != 0 && curproc->p_osrel == 1200500)
+			pa->pm_flags |= PMC_F_EV_PMU;
 		pmc_select_cpu(cpu);
 		for (n = pcd->pcd_ri; n < md->pmd_npmc; n++) {
 			pcd = pmc_ri_to_classdep(md, n, &adjri);
@@ -3819,6 +3834,10 @@
 			break;
 		}
 
+		/* zero out flags on legacy apps */
+		if (pmc_compat_version != 0 && curproc->p_osrel == 1200500)
+			cl.pm_flags = 0;
+
 		/* No flags currently implemented */
 		if (cl.pm_flags != 0) {
 			pmclog_proc_ignite(pmclog_proc_handle, NULL);
@@ -4011,6 +4030,13 @@
 			break;
 		/* don't service clients newer than our driver */
 		modv = PMC_VERSION;
+		if (cv == 0 && pmc_compat_version != 0 &&
+		    curproc->p_osrel == 1200500) {
+                       /* work around AMDuProf support ending at FreeBSD 13 */
+                       printf("%s %d: overriding hwpmc version to 0x%x\n",
+                           curproc->p_comm, curproc->p_osrel, pmc_compat_version);
+                       modv = pmc_compat_version;
+               }
 		if ((cv & 0xFFFF0000) > (modv & 0xFFFF0000)) {
 			error = EPROGMISMATCH;
 			break;
diff --git a/FreeBSD/sys/kern/kern_exec.c b/FreeBSD/sys/kern/kern_exec.c
--- a/FreeBSD/sys/kern/kern_exec.c
+++ b/FreeBSD/sys/kern/kern_exec.c
@@ -932,6 +932,7 @@
 		pe.pm_credentialschanged = credential_changing;
 		pe.pm_baseaddr = imgp->reloc_base;
 		pe.pm_dynaddr = imgp->et_dyn_addr;
+		pe.pm_entryaddr = imgp->entry_addr;
 
 		PMC_CALL_HOOK_X(td, PMC_FN_PROCESS_EXEC, (void *) &pe);
 		vn_lock(imgp->vp, LK_SHARED | LK_RETRY);
diff --git a/FreeBSD/sys/sys/pmc.h b/FreeBSD/sys/sys/pmc.h
--- a/FreeBSD/sys/sys/pmc.h
+++ b/FreeBSD/sys/sys/pmc.h
@@ -874,6 +874,7 @@
 #define	PMC_PO_OWNS_LOGFILE		0x00000001 /* has a log file */
 #define	PMC_PO_SHUTDOWN			0x00000010 /* in the process of shutdown */
 #define	PMC_PO_INITIAL_MAPPINGS_DONE	0x00000020
+#define	PMC_PO_LEGACY			0x00000040
 
 /*
  * struct pmc_hw -- describe the state of the PMC hardware
@@ -1072,6 +1073,9 @@
 /* driver statistics */
 extern struct pmc_driverstats pmc_stats;
 
+/* compat version */
+extern int pmc_compat_version;
+
 #if	defined(HWPMC_DEBUG)
 
 /* HWPMC_DEBUG without KTR will compile but is a no-op. */
diff --git a/FreeBSD/sys/sys/pmckern.h b/FreeBSD/sys/sys/pmckern.h
--- a/FreeBSD/sys/sys/pmckern.h
+++ b/FreeBSD/sys/sys/pmckern.h
@@ -76,6 +76,7 @@
 	int		pm_credentialschanged;
 	uintptr_t	pm_baseaddr;
 	uintptr_t	pm_dynaddr;
+	uintptr_t	pm_entryaddr;
 };
 
 struct pmckern_map_in {
diff --git a/FreeBSD/sys/sys/pmclog.h b/FreeBSD/sys/sys/pmclog.h
--- a/FreeBSD/sys/sys/pmclog.h
+++ b/FreeBSD/sys/sys/pmclog.h
@@ -315,7 +315,7 @@
 void	pmclog_process_proccsw(struct pmc *_pm, struct pmc_process *_pp,
     pmc_value_t _v, struct thread *);
 void	pmclog_process_procexec(struct pmc_owner *_po, pmc_id_t _pmid, pid_t _pid,
-    uintfptr_t _baseaddr, uintptr_t _dynaddr, char *_path);
+    uintfptr_t _baseaddr, uintptr_t _dynaddr, uintptr_t _entryaddr, char *_path);
 void	pmclog_process_procexit(struct pmc *_pm, struct pmc_process *_pp);
 void	pmclog_process_procfork(struct pmc_owner *_po, pid_t _oldpid, pid_t _newpid);
 void	pmclog_process_sysexit(struct pmc_owner *_po, pid_t _pid);