sandbox: add function os_printf()
Before setting up the devices U-Boot's printf() function cannot be used
for console output. Provide function os_printf() to print to stderr.
Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
diff --git a/include/os.h b/include/os.h
index 10e198c..1481787 100644
--- a/include/os.h
+++ b/include/os.h
@@ -17,6 +17,13 @@
struct sandbox_state;
/**
+ * os_printf() - print directly to OS console
+ *
+ * @format: format string
+ */
+int os_printf(const char *format, ...);
+
+/**
* Access to the OS read() system call
*
* @fd: File descriptor as returned by os_open()