diff --git a/host/simtrace_usb.h b/host/simtrace_usb.h
deleted file mode 120000
index 4f8fb46..0000000
--- a/host/simtrace_usb.h
+++ /dev/null
@@ -1 +0,0 @@
-../../openpcd/firmware/include/simtrace_usb.h
\ No newline at end of file
diff --git a/host/simtrace_usb.h b/host/simtrace_usb.h
new file mode 100644
index 0000000..c020093
--- /dev/null
+++ b/host/simtrace_usb.h
@@ -0,0 +1,24 @@
+#ifndef SIMTRACE_USB_H
+#define SIMTRACE_USB_H
+
+//#include <stdint.h>
+
+/* this is kept compatible with OpenPCD protocol */
+struct simtrace_hdr {
+	u_int8_t cmd;
+	u_int8_t flags;
+	u_int8_t res[2];
+	u_int8_t data[0];
+} __attribute__ ((packed));
+
+enum simtrace_usb_msgt {
+	SIMTRACE_MSGT_NULL,
+	SIMTRACE_MSGT_DATA,
+	SIMTRACE_MSGT_RESET,		/* reset was asserted, no more data */
+};
+
+/* flags for MSGT_DATA */
+#define SIMTRACE_FLAG_ATR		0x01	/* ATR immediately after reset */
+#define SIMTRACE_FLAG_WTIME_EXP		0x04	/* work waiting time expired */
+
+#endif /* SIMTRACE_USB_H */