diff --git a/board/astro/mcf5373l/astro.h b/board/astro/mcf5373l/astro.h
new file mode 100644
index 0000000..b55a6f7
--- /dev/null
+++ b/board/astro/mcf5373l/astro.h
@@ -0,0 +1,44 @@
+#ifndef __ASTRO_H__
+#define __ASTRO_H__
+
+/* in mcf5373l.c */
+int rs_serial_init(int port, int baud);
+void astro_put_char(char ch);
+int astro_is_char(void);
+int astro_get_char(void);
+
+/* in fpga.c */
+int astro5373l_altera_load(void);
+int astro5373l_xilinx_load(void);
+
+/* data structures used for communication (update.c) */
+typedef struct card_id {
+	char card_type;
+	char hardware_version;
+	char software_version;
+	char software_subversion;	/* " ","a".."z" */
+	char fpga_version_altera;
+	char fpga_version_xilinx;
+} card_id_t;
+
+typedef struct {
+	unsigned char mode;
+	unsigned char deviation;
+	unsigned short freq;
+} __attribute__ ((packed)) output_params_t;
+
+typedef struct {
+	unsigned short satfreq;
+	unsigned char satdatallg;
+	unsigned short symbolrate;
+	unsigned char viterbirate;
+	unsigned char symbolrate_l;
+	output_params_t output_params;
+	unsigned char reserve;
+	unsigned char card_error;
+	unsigned short dummy_ts_id;
+	unsigned char dummy_pat_ver;
+	unsigned char dummy_sdt_ver;
+} __attribute__ ((packed)) parameters_t;
+
+#endif /* __ASTRO_H__ */