Index: sys/powerpc/powernv/opal.h
===================================================================
--- sys/powerpc/powernv/opal.h
+++ sys/powerpc/powernv/opal.h
@@ -138,15 +138,37 @@
 #define	OPAL_SUCCESS			0
 #define	OPAL_PARAMETER			-1
 #define	OPAL_BUSY			-2
+#define OPAL_PARTIAL			-3
+#define OPAL_CONSTRAINED		-4
 #define	OPAL_CLOSED			-5
 #define	OPAL_HARDWARE			-6
 #define	OPAL_UNSUPPORTED		-7
+#define OPAL_PERMISSION			-8
+#define OPAL_NO_MEM			-9
 #define	OPAL_RESOURCE			-10
+#define OPAL_INTERNAL_ERROR		-11
 #define	OPAL_BUSY_EVENT			-12
+#define OPAL_HARDWARE_FROZEN		-13
+#define OPAL_WRONG_STATE		-14
 #define	OPAL_ASYNC_COMPLETION		-15
 #define	OPAL_EMPTY			-16
+#define OPAL_I2C_TIMEOUT		-17
+#define OPAL_I2C_INVALID_CMD		-18
+#define OPAL_I2C_LBUS_PARITY		-19
+#define OPAL_I2C_BKEND_OVERRUN		-20
+#define OPAL_I2C_BKEND_ACCESS		-21
+#define OPAL_I2C_ARBT_LOST		-22
+#define OPAL_I2C_NACK_RCVD		-23
+#define OPAL_I2C_STOP_ERR		-24
+#define OPAL_XSCOM_PARTIAL_GOOD		-25
+#define OPAL_XSCOM_ADDR_ERROR		-26
+#define OPAL_XSCOM_CLOCK_ERROR		-27
+#define OPAL_XSCOM_PARITY_ERROR		-28
+#define OPAL_XSCOM_TIMEOUT		-29
+#define OPAL_XSCOM_CTR_OFFLINED		-30
 #define	OPAL_XIVE_PROVISIONING		-31
 #define	OPAL_XIVE_FREE_ACTIVE		-32
+#define OPAL_TIMEOUT			-33
 
 #define	OPAL_TOKEN_ABSENT		0
 #define	OPAL_TOKEN_PRESENT		1
Index: sys/powerpc/powernv/opal_dev.c
===================================================================
--- sys/powerpc/powernv/opal_dev.c
+++ sys/powerpc/powernv/opal_dev.c
@@ -382,8 +382,22 @@
 
 	rv = opal_call(OPAL_GET_MSG, vtophys(&msg), sizeof(msg));
 
-	if (rv != OPAL_SUCCESS)
+	switch (rv) {
+	case OPAL_SUCCESS:
+		break;
+	case OPAL_RESOURCE:
+		/* no available messages - return */
+		return;
+	case OPAL_PARAMETER:
+		printf("%s error: invalid buffer. Please file a bug report.\n", __func__);
+		return;
+	case OPAL_PARTIAL:
+		printf("%s error: buffer is too small and messages was discarded. Please file a bug report.\n", __func__);
 		return;
+	default:
+		printf("%s opal_call returned unknown result <%lu>\n", __func__, rv);
+		return;
+	}
 
 	type = be32toh(msg.msg_type);
 	switch (type) {
@@ -406,7 +420,7 @@
 		EVENTHANDLER_DIRECT_INVOKE(OPAL_OCC, &msg);
 		break;
 	default:
-		printf("Unknown OPAL message type %d\n", type);
+		printf("%s Unknown OPAL message type %d\n", __func__, type);
 	}
 }
 
@@ -418,7 +432,7 @@
 	opal_call(OPAL_HANDLE_INTERRUPT, (uint32_t)(uint64_t)xintr,
 	    vtophys(&events));
 	/* Wake up the heartbeat, if it's been setup. */
-	if (events != 0 && opal_hb_proc != NULL)
+	if (be64toh(events) != 0 && opal_hb_proc != NULL)
 		wakeup(opal_hb_proc);
 
 }
Index: sys/powerpc/powernv/opal_sensor.c
===================================================================
--- sys/powerpc/powernv/opal_sensor.c
+++ sys/powerpc/powernv/opal_sensor.c
@@ -33,6 +33,7 @@
 #include <sys/proc.h>
 #include <sys/sysctl.h>
 #include <sys/systm.h>
+#include <sys/endian.h>
 
 #include <vm/vm.h>
 #include <vm/pmap.h>
@@ -114,7 +115,7 @@
 	SENSOR_UNLOCK(sc);
 
 	if (rv == OPAL_SUCCESS)
-		*val = val32;
+		*val = be32toh(val32);
 	else
 		rv = EIO;
 
@@ -218,7 +219,7 @@
 	SYSCTL_ADD_STRING(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, "label",
 	    CTLFLAG_RD, sc->sc_label, 0, "");
 
-	if (OF_getprop(node, "sensor-data-min",
+	if (OF_getencprop(node, "sensor-data-min",
 	    &sensor_id, sizeof(sensor_id)) > 0) {
 		sc->sc_min_handle = sensor_id;
 		SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
@@ -228,7 +229,7 @@
 		    "minimum value");
 	}
 
-	if (OF_getprop(node, "sensor-data-max",
+	if (OF_getencprop(node, "sensor-data-max",
 	    &sensor_id, sizeof(sensor_id)) > 0) {
 		sc->sc_max_handle = sensor_id;
 		SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,