Index: abi/include/abi/fourcc.h
===================================================================
--- abi/include/abi/fourcc.h	(revision 6a8ce16e9d7ca696b63ae994c87911928c450d62)
+++ abi/include/abi/fourcc.h	(revision 6a8ce16e9d7ca696b63ae994c87911928c450d62)
@@ -0,0 +1,52 @@
+/*
+ * Copyright (c) 2011 Martin Decky
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ * - Redistributions in binary form must reproduce the above copyright
+ *   notice, this list of conditions and the following disclaimer in the
+ *   documentation and/or other materials provided with the distribution.
+ * - The name of the author may not be used to endorse or promote products
+ *   derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/** @addtogroup libc
+ * @{
+ */
+/** @file
+ */
+
+#ifndef ABI_FOURCC_H_
+#define ABI_FOURCC_H_
+
+#define FOURCC(a, b, c, d) \
+	(((UINT32_T) (a)) | (((UINT32_T) (b)) << 8) | \
+	    (((UINT32_T) (c)) << 16) | (((UINT32_T) (d)) << 24))
+
+#define CC_COMPACT(a) \
+	((((UINT32_T) (a)) & 0x7c) >> 2)
+
+#define FOURCC_COMPACT(a, b, c, d) \
+	((CC_COMPACT(a) << 12) | (CC_COMPACT(b) << 17) | \
+	    (CC_COMPACT(c) << 22) | (CC_COMPACT(d) << 27))
+
+#endif
+
+/** @}
+ */
Index: abi/include/abi/ipc/interfaces.h
===================================================================
--- abi/include/abi/ipc/interfaces.h	(revision 6a8ce16e9d7ca696b63ae994c87911928c450d62)
+++ abi/include/abi/ipc/interfaces.h	(revision 6a8ce16e9d7ca696b63ae994c87911928c450d62)
@@ -0,0 +1,88 @@
+/*
+ * Copyright (c) 2014 Martin Decky
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ * - Redistributions in binary form must reproduce the above copyright
+ *   notice, this list of conditions and the following disclaimer in the
+ *   documentation and/or other materials provided with the distribution.
+ * - The name of the author may not be used to endorse or promote products
+ *   derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/** @addtogroup genericipc
+ * @{
+ */
+/**
+ * @file interface.h
+ * @brief List of all known interfaces and their codes.
+ */
+
+#ifndef ABI_IPC_INTERFACES_H_
+#define ABI_IPC_INTERFACES_H_
+
+#include <abi/fourcc.h>
+
+#define IFACE_EXCHANGE_MASK  0x03
+#define IFACE_MOD_MASK       0x04
+
+/** Interface exchange management style
+ *
+ */
+typedef enum {
+	/** No explicit exchange management
+	 *
+	 * Suitable for protocols which use a single
+	 * IPC message per exchange only.
+	 */
+	IFACE_EXCHANGE_ATOMIC = 0x00,
+	
+	/** Exchange management via mutual exclusion
+	 *
+	 * Suitable for any kind of client/server
+	 * communication, but with possibly limited
+	 * parallelism.
+	 */
+	IFACE_EXCHANGE_SERIALIZE = 0x01,
+	
+	/** Exchange management via connection cloning
+	 *
+	 * Suitable for servers which support client
+	 * connection tracking and connection cloning.
+	 */
+	IFACE_EXCHANGE_PARALLEL = 0x02
+} iface_exch_mgmt_t;
+
+/** Interface modifiers
+ *
+ */
+typedef enum {
+	IFACE_MOD_NONE = 0x00,
+	IFACE_MOD_CALLBACK = 0x04
+} iface_mod_t;
+
+typedef enum {
+	INTERFACE_LOADER =
+	    FOURCC_COMPACT('l', 'o', 'a', 'd') | IFACE_EXCHANGE_PARALLEL
+} iface_t;
+
+#endif
+
+/** @}
+ */