1 files changed, 17 insertions, 2 deletions
diff --git a/os/src/write.c b/os/src/write.c
index 50fadc6..268c0f1 100644
--- a/os/src/write.c
+++ b/os/src/write.c
@@ -1,7 +1,22 @@
 #include <reent.h>
 #include <osdebug.h>
+#include <errno.h>
+#include "fio.h"
 
 _ssize_t _write_r(struct _reent * reent, int fd, const void * buf, size_t size) {
-    DBGOUT("_write_r(%p, %d, %p, %u)\r\n", reent, fd, buf, size);
-    return 0;
+    int r;
+    
+    if (!fio_is_open(fd)) {
+        reent->_errno = EBADF;
+        return -1;
+    }
+    
+    r = fio_write(fd, buf, size);
+    
+    if (r < 0) {
+        reent->_errno = EINVAL;
+        return -1;
+    }
+    
+    return r;
 }