Implement dbg log interface

exosphere/src/dbg/log.h

@@ -0,0 +1,25 @@
+#ifndef EXOSPHERE_DBG_LOG_H
+#define EXOSPHERE_DBG_LOG_H
+
+#include "../utils.h"
+
+#define DBG_LOG_BUF_SIZE    256
+
+typedef enum {
+    DEBUGLOGDEVICE_NULL = 0,
+    DEBUGLOGDEVICE_UART = 1,
+
+    DEBUGLOGDEVICE_MAX = 2,
+} DebugLogDevice;
+
+typedef struct debug_log_device_t {
+    void (*initialize)(struct debug_log_device_t *this, ...);
+    void (*write_string)(struct debug_log_device_t *this, const char *str, size_t len);
+    void (*finalize)(struct debug_log_device_t *this);
+} debug_log_device_t;
+
+void dbg_log_initialize(DebugLogDevice device);
+void dbg_log_write(const char *fmt, ...);
+void dbg_log_finalize(void);
+
+#endif