Merge all libs into libu

libu/debugconsole.c

@@ -0,0 +1,40 @@
+#include <debugconsole.h>
+#include <devices.h>
+#include <printf.h>
+#include <stdatomic.h>
+#include <stddef.h>
+#include <system.h>
+
+static char debug_printf_buffer[DEBUG_PRINTF_MAX];
+static atomic_flag debug_printf_buffer_lock = ATOMIC_FLAG_INIT;
+
+static void debugconsole_printf_buffer_lock (void) {
+  while (atomic_flag_test_and_set_explicit (&debug_printf_buffer_lock, memory_order_acquire)) {
+#if defined(__x86_64__)
+    __asm__ volatile ("pause" ::: "memory");
+#endif
+  }
+}
+
+static void debugconsole_printf_buffer_unlock (void) {
+  atomic_flag_clear_explicit (&debug_printf_buffer_lock, memory_order_release);
+}
+
+int debugconsole_print (const char* string, size_t len) {
+  return device_do ("debugconsole", DEBUGCONSOLE_PUTSTR, (void*)string, (void*)&len, NULL, NULL);
+}
+
+void debug_printf (const char* fmt, ...) {
+  va_list args;
+  va_start (args, fmt);
+
+  debugconsole_printf_buffer_lock ();
+
+  int len = vsnprintf (debug_printf_buffer, DEBUG_PRINTF_MAX, fmt, args);
+
+  va_end (args);
+
+  debugconsole_print (debug_printf_buffer, len);
+
+  debugconsole_printf_buffer_unlock ();
+}