diff --git a/aos/ftrace.cc b/aos/ftrace.cc
new file mode 100644
index 0000000..af4964c
--- /dev/null
+++ b/aos/ftrace.cc
@@ -0,0 +1,45 @@
+#include "aos/ftrace.h"
+
+#include <stdarg.h>
+#include <stdio.h>
+
+namespace aos {
+
+Ftrace::~Ftrace() {
+  if (message_fd_ != -1) {
+    PCHECK(close(message_fd_) == 0);
+  }
+  if (message_fd_ != -1) {
+    PCHECK(close(on_fd_) == 0);
+  }
+}
+
+void Ftrace::FormatMessage(const char *format, ...) {
+  if (message_fd_ == -1) {
+    return;
+  }
+  char buffer[512];
+  va_list ap;
+  va_start(ap, format);
+  const int result = vsnprintf(buffer, sizeof(buffer), format, ap);
+  va_end(ap);
+  CHECK_LE(static_cast<size_t>(result), sizeof(buffer))
+      << ": Format string ended up too long: " << format;
+  WriteMessage(std::string_view(buffer, result));
+}
+
+void Ftrace::WriteMessage(std::string_view content) {
+  if (message_fd_ == -1) {
+    return;
+  }
+  const int result = write(message_fd_, content.data(), content.size());
+  if (result == -1 && errno == EBADF) {
+    // This just means tracing is turned off. Ignore it.
+    return;
+  }
+  PCHECK(result >= 0) << ": Failed to write ftrace message: " << content;
+  CHECK_EQ(static_cast<size_t>(result), content.size())
+      << ": Failed to write complete ftrace message: " << content;
+}
+
+}  // namespace aos