Index: uspace/drv/char/msim-con/main.c
===================================================================
--- uspace/drv/char/msim-con/main.c	(revision 071a1ddbcc6bb2b9c6f3c1a3acc865f1f23b5fe0)
+++ uspace/drv/char/msim-con/main.c	(revision b7fd2a02e4161f4edd38548e7f8456b8021549be)
@@ -43,9 +43,9 @@
 #define NAME  "msim-con"
 
-static int msim_con_dev_add(ddf_dev_t *dev);
-static int msim_con_dev_remove(ddf_dev_t *dev);
-static int msim_con_dev_gone(ddf_dev_t *dev);
-static int msim_con_fun_online(ddf_fun_t *fun);
-static int msim_con_fun_offline(ddf_fun_t *fun);
+static errno_t msim_con_dev_add(ddf_dev_t *dev);
+static errno_t msim_con_dev_remove(ddf_dev_t *dev);
+static errno_t msim_con_dev_gone(ddf_dev_t *dev);
+static errno_t msim_con_fun_online(ddf_fun_t *fun);
+static errno_t msim_con_fun_offline(ddf_fun_t *fun);
 
 static driver_ops_t driver_ops = {
@@ -62,9 +62,9 @@
 };
 
-static int msim_con_get_res(ddf_dev_t *dev, msim_con_res_t *res)
+static errno_t msim_con_get_res(ddf_dev_t *dev, msim_con_res_t *res)
 {
 	async_sess_t *parent_sess;
 	hw_res_list_parsed_t hw_res;
-	int rc;
+	errno_t rc;
 
 	parent_sess = ddf_dev_parent_sess_get(dev);
@@ -97,9 +97,9 @@
 }
 
-static int msim_con_dev_add(ddf_dev_t *dev)
+static errno_t msim_con_dev_add(ddf_dev_t *dev)
 {
 	msim_con_t *msim_con;
 	msim_con_res_t res;
-	int rc;
+	errno_t rc;
 
         ddf_msg(LVL_DEBUG, "msim_con_dev_add(%p)", dev);
@@ -122,5 +122,5 @@
 }
 
-static int msim_con_dev_remove(ddf_dev_t *dev)
+static errno_t msim_con_dev_remove(ddf_dev_t *dev)
 {
         msim_con_t *msim_con = (msim_con_t *)ddf_dev_data_get(dev);
@@ -131,5 +131,5 @@
 }
 
-static int msim_con_dev_gone(ddf_dev_t *dev)
+static errno_t msim_con_dev_gone(ddf_dev_t *dev)
 {
         msim_con_t *msim_con = (msim_con_t *)ddf_dev_data_get(dev);
@@ -140,5 +140,5 @@
 }
 
-static int msim_con_fun_online(ddf_fun_t *fun)
+static errno_t msim_con_fun_online(ddf_fun_t *fun)
 {
         ddf_msg(LVL_DEBUG, "msim_con_fun_online()");
@@ -146,5 +146,5 @@
 }
 
-static int msim_con_fun_offline(ddf_fun_t *fun)
+static errno_t msim_con_fun_offline(ddf_fun_t *fun)
 {
         ddf_msg(LVL_DEBUG, "msim_con_fun_offline()");
Index: uspace/drv/char/msim-con/msim-con.c
===================================================================
--- uspace/drv/char/msim-con/msim-con.c	(revision 071a1ddbcc6bb2b9c6f3c1a3acc865f1f23b5fe0)
+++ uspace/drv/char/msim-con/msim-con.c	(revision b7fd2a02e4161f4edd38548e7f8456b8021549be)
@@ -43,6 +43,6 @@
 static void msim_con_connection(ipc_callid_t, ipc_call_t *, void *);
 
-static int msim_con_read(chardev_srv_t *, void *, size_t, size_t *);
-static int msim_con_write(chardev_srv_t *, const void *, size_t, size_t *);
+static errno_t msim_con_read(chardev_srv_t *, void *, size_t, size_t *);
+static errno_t msim_con_write(chardev_srv_t *, const void *, size_t, size_t *);
 
 static chardev_ops_t msim_con_chardev_ops = {
@@ -66,5 +66,5 @@
 	msim_con_t *con = (msim_con_t *) arg;
 	uint8_t c;
-	int rc;
+	errno_t rc;
 
 	fibril_mutex_lock(&con->buf_lock);
@@ -80,10 +80,10 @@
 
 /** Add msim console device. */
-int msim_con_add(msim_con_t *con, msim_con_res_t *res)
+errno_t msim_con_add(msim_con_t *con, msim_con_res_t *res)
 {
 	ddf_fun_t *fun = NULL;
 	bool subscribed = false;
 	irq_cmd_t *msim_cmds = NULL;
-	int rc;
+	errno_t rc;
 
 	circ_buf_init(&con->cbuf, con->buf, msim_con_buf_size, 1);
@@ -152,5 +152,5 @@
 
 /** Remove msim console device */
-int msim_con_remove(msim_con_t *con)
+errno_t msim_con_remove(msim_con_t *con)
 {
 	return ENOTSUP;
@@ -158,5 +158,5 @@
 
 /** Msim console device gone */
-int msim_con_gone(msim_con_t *con)
+errno_t msim_con_gone(msim_con_t *con)
 {
 	return ENOTSUP;
@@ -169,5 +169,5 @@
 
 /** Read from msim console device */
-static int msim_con_read(chardev_srv_t *srv, void *buf, size_t size,
+static errno_t msim_con_read(chardev_srv_t *srv, void *buf, size_t size,
     size_t *nread)
 {
@@ -175,5 +175,5 @@
 	size_t p;
 	uint8_t *bp = (uint8_t *) buf;
-	int rc;
+	errno_t rc;
 
 	fibril_mutex_lock(&con->buf_lock);
@@ -197,5 +197,5 @@
 
 /** Write to msim console device */
-static int msim_con_write(chardev_srv_t *srv, const void *data, size_t size,
+static errno_t msim_con_write(chardev_srv_t *srv, const void *data, size_t size,
     size_t *nwr)
 {
Index: uspace/drv/char/msim-con/msim-con.h
===================================================================
--- uspace/drv/char/msim-con/msim-con.h	(revision 071a1ddbcc6bb2b9c6f3c1a3acc865f1f23b5fe0)
+++ uspace/drv/char/msim-con/msim-con.h	(revision b7fd2a02e4161f4edd38548e7f8456b8021549be)
@@ -70,7 +70,7 @@
 } msim_con_t;
 
-extern int msim_con_add(msim_con_t *, msim_con_res_t *);
-extern int msim_con_remove(msim_con_t *);
-extern int msim_con_gone(msim_con_t *);
+extern errno_t msim_con_add(msim_con_t *, msim_con_res_t *);
+extern errno_t msim_con_remove(msim_con_t *);
+extern errno_t msim_con_gone(msim_con_t *);
 
 #endif