1 files changed, 61 insertions, 0 deletions
diff --git a/builtin/stdio.h b/builtin/stdio.h
new file mode 100644
index 0000000000..7536499feb
--- /dev/null
+++ b/builtin/stdio.h
@@ -0,0 +1,61 @@
+/* Copyright 2022 The ChromiumOS Authors
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef __CROS_EC_STDIO_H__
+#define __CROS_EC_STDIO_H__
+
+#include <stddef.h>
+#include <stdarg.h>
+
+#include "common.h"
+
+/**
+ * Print formatted outut to a string.
+ *
+ * Guarantees null-termination if size!=0.
+ *
+ * @param str           Destination string
+ * @param size          Size of destination in bytes
+ * @param format        Format string
+ * @return EC_SUCCESS, or EC_ERROR_OVERFLOW if the output was truncated.
+ */
+__attribute__((__format__(__printf__, 3, 4)))
+__warn_unused_result __stdlib_compat int
+crec_snprintf(char *str, size_t size, const char *format, ...);
+
+/**
+ * Print formatted output to a string.
+ *
+ * Guarantees null-termination if size!=0.
+ *
+ * @param str           Destination string
+ * @param size          Size of destination in bytes
+ * @param format        Format string
+ * @param args          Parameters
+ * @return The string length written to str, or a negative value on error.
+ *         The negative values can be -EC_ERROR_INVAL or -EC_ERROR_OVERFLOW.
+ */
+__warn_unused_result __stdlib_compat int
+crec_vsnprintf(char *str, size_t size, const char *format, va_list args);
+
+/*
+ * Create weak aliases to the crec_* printf functions. This lets us call the
+ * crec_* printf functions in tests that link the C standard library.
+ */
+
+/**
+ * Alias to crec_snprintf.
+ */
+__attribute__((__format__(__printf__, 3, 4)))
+__warn_unused_result __stdlib_compat int
+snprintf(char *str, size_t size, const char *format, ...);
+
+/**
+ * Alias to crec_vsnprintf.
+ */
+__warn_unused_result __stdlib_compat int
+vsnprintf(char *str, size_t size, const char *format, va_list args);
+
+#endif /* __CROS_EC_STDIO_H__ */