lib: errno: introduce errno_str(): returns errno related message

The functions error's numbers are standarized - but the error
messages are not.

The errors are often handled with unclear error messages,
so why not use an errno standarized messages.

Advantages:
- This could decrease the binary size.
- Appended with a detailed information,
  the error message will be clear.

This commit introduces new function:
- const char *errno_to_str(int errno)

The functions returns a pointer to the errno corresponding text message:
- if errno is null or positive number - a pointer to "Success" message
- if errno is negative - a pointer to errno related message

Signed-off-by: Przemyslaw Marczak <p.marczak@samsung.com>
Reviewed-by: Tom Rini <trini@ti.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/include/errno.h b/include/errno.h
index e24a33b386..14ac3cb10b 100644
--- a/include/errno.h
+++ b/include/errno.h
@@ -6,4 +6,7 @@ extern int errno;
 
 #define __set_errno(val) do { errno = val; } while (0)
 
+#ifdef CONFIG_ERRNO_STR
+const char *errno_str(int errno);
+#endif
 #endif /* _ERRNO_H */