1 files changed, 11 insertions, 9 deletions

diff --git a/firmware/libc/include/fcntl.h b/firmware/libc/include/fcntl.h
index 34740c9ca2..ec53d728cf 100644
--- a/firmware/libc/include/fcntl.h
+++ b/firmware/libc/include/fcntl.h
@@ -23,18 +23,20 @@
 #define __FCNTL_H__
 
 #ifndef O_RDONLY
-#define O_RDONLY 0
-#define O_WRONLY 1
-#define O_RDWR   2
-#define O_CREAT  4
-#define O_APPEND 8
-#define O_TRUNC  0x10
+#define O_RDONLY    0x0000      /* open for reading only */
+#define O_WRONLY    0x0001      /* open for writing only */
+#define O_RDWR      0x0002      /* open for reading and writing */
+#define O_ACCMODE   0x0003      /* mask for above modes */
+#define O_APPEND    0x0008      /* set append mode */
+#define O_CREAT     0x0200      /* create if nonexistent */
+#define O_TRUNC     0x0400      /* truncate to zero length */
+#define O_EXCL      0x0800      /* error if already exists */
 #endif
 
 #ifndef SEEK_SET
-#define SEEK_SET 0
-#define SEEK_CUR 1
-#define SEEK_END 2
+#define SEEK_SET    0           /* set file offset to offset */
+#define SEEK_CUR    1           /* set file offset to current plus offset */
+#define SEEK_END    2           /* set file offset to EOF plus offset */
 #endif
 
 #endif /* __FCNTL_H__ */