feat: add logging infra w/ backend support
Add functions to support logging. This enables a user specifying their
own logging format for all functions. TF-A's logging format is supported
out of the box by specifying the `DEBUG_BACKEND_HEADER` as
`log_backed_tf.h`.
Implement digest helpers that avoid heap/libc as some end projects don't
have access to this.
Change-Id: I55410ab963ea4d0c1956ba41f94b67eced8621d5
Signed-off-by: Harrison Mutai <harrison.mutai@arm.com>
diff --git a/include/private/debug.h b/include/private/debug.h
new file mode 100644
index 0000000..da10529
--- /dev/null
+++ b/include/private/debug.h
@@ -0,0 +1,72 @@
+/*
+ * Copyright (c) 2025, Arm Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef DEBUG_H
+#define DEBUG_H
+
+#include DEBUG_BACKEND_HEADER
+
+/*
+ * The log output macros print output to the console. These macros produce
+ * compiled log output only if the EVLOG_LOG_LEVEL defined in the makefile (or the
+ * make command line) is greater or equal than the level required for that
+ * type of log output.
+ *
+ * The format expected is the same as for printf(). For example:
+ * INFO("Info %s.\n", "message") -> INFO: Info message.
+ * WARN("Warning %s.\n", "message") -> WARNING: Warning message.
+ */
+
+#define EVLOG_LEVEL_NONE 0
+#define EVLOG_LEVEL_ERROR 10
+#define EVLOG_LEVEL_NOTICE 20
+#define EVLOG_LEVEL_WARNING 30
+#define EVLOG_LEVEL_INFO 40
+#define EVLOG_LEVEL_VERBOSE 50
+
+/*
+ * If the log output is too low then this macro is used in place of evlog_log()
+ * below. The intent is to get the compiler to evaluate the function call for
+ * type checking and format specifier correctness but let it optimize it out.
+ */
+#define no_evlog_log(fmt, ...) \
+ do { \
+ if (false) { \
+ evlog_log(fmt, ##__VA_ARGS__); \
+ } \
+ } while (false)
+
+#if EVLOG_LOG_LEVEL >= EVLOG_LEVEL_ERROR
+#define ERROR(...) evlog_log(EVLOG_MARKER_ERROR __VA_ARGS__)
+#else
+#define ERROR(...) no_evlog_log(EVLOG_MARKER_ERROR __VA_ARGS__)
+#endif
+
+#if EVLOG_LOG_LEVEL >= EVLOG_LEVEL_NOTICE
+#define NOTICE(...) evlog_log(EVLOG_MARKER_NOTICE __VA_ARGS__)
+#else
+#define NOTICE(...) no_evlog_log(EVLOG_MARKER_NOTICE __VA_ARGS__)
+#endif
+
+#if EVLOG_LOG_LEVEL >= EVLOG_LEVEL_WARNING
+#define WARN(...) evlog_log(EVLOG_MARKER_WARNING __VA_ARGS__)
+#else
+#define WARN(...) no_evlog_log(EVLOG_MARKER_WARNING __VA_ARGS__)
+#endif
+
+#if EVLOG_LOG_LEVEL >= EVLOG_LEVEL_INFO
+#define INFO(...) evlog_log(EVLOG_MARKER_INFO __VA_ARGS__)
+#else
+#define INFO(...) no_evlog_log(EVLOG_MARKER_INFO __VA_ARGS__)
+#endif
+
+#if EVLOG_LOG_LEVEL >= EVLOG_LEVEL_VERBOSE
+#define VERBOSE(...) evlog_log(EVLOG_MARKER_VERBOSE __VA_ARGS__)
+#else
+#define VERBOSE(...) no_evlog_log(EVLOG_MARKER_VERBOSE __VA_ARGS__)
+#endif
+
+#endif /* DEBUG_H */