commit 5ff915a9696d37361c0470f29eb26311adea59da
Author: Brandon Bergren <bdragon@FreeBSD.org>
Date:   Sun Sep 6 17:18:24 2020 -0500

    [PowerPC] Fix setting of time in OPAL -- The params use register passing.

diff --git a/sys/powerpc/powernv/opal_dev.c b/sys/powerpc/powernv/opal_dev.c
index 250599c19c36..d70222bd58be 100644
--- a/sys/powerpc/powernv/opal_dev.c
+++ b/sys/powerpc/powernv/opal_dev.c
@@ -321,11 +321,12 @@ opal_settime(device_t dev, struct timespec *ts)
 	hmsm |= ((uint64_t)bin2bcd(ct.min) << 48);
 	hmsm |= ((uint64_t)bin2bcd(ct.hour) << 56);
 
-	hmsm = htobe64(hmsm);
-	ymd = htobe32(ymd);
-
+	/*
+	 * We do NOT swap endian here, because the values are being sent
+	 * via registers instead of indirect via memory.
+	 */
 	do {
-		rv = opal_call(OPAL_RTC_WRITE, vtophys(&ymd), vtophys(&hmsm));
+		rv = opal_call(OPAL_RTC_WRITE, ymd, hmsm);
 		if (rv == OPAL_BUSY_EVENT) {
 			rv = opal_call(OPAL_POLL_EVENTS, 0);
 			pause("opalrtc", 1);