Add logging framework

src/kernel/log.h

@@ -0,0 +1,48 @@
+#pragma once
+#include <stdarg.h>
+#include <stdint.h>
+
+class console;
+
+
+enum class logs
+{
+	boot,
+	memory,
+	interrupt,
+	devices,
+
+	max
+};
+
+
+class log
+{
+public:
+	enum class level {debug, info, warn, error, fatal, max};
+
+	static void init(console *cons);
+	static void enable(logs type, level at_level);
+
+	template <level L>
+	static void trylog(logs area, const char *fmt, ...);
+	using trylog_p = void (*)(logs area, const char *fmt, ...);
+
+	static const trylog_p debug;
+	static const trylog_p info;
+	static const trylog_p warn;
+	static const trylog_p error;
+	static const trylog_p fatal;
+
+private:
+	void output(level severity, logs area, const char *fmt, va_list args);
+
+	/// Bitmasks for what categories are enabled. fatal is
+	/// always enabled, so leave it out.
+	uint64_t m_enabled[static_cast<uint64_t>(level::max) - 1];
+	console *m_cons;
+
+	log();
+	log(console *cons);
+	static log s_log;
+};