diff --git a/src/system/boot/platform/atari_m68k/bios.h b/src/system/boot/platform/atari_m68k/bios.h
deleted file mode 100644
index cfdbcdb549..0000000000
--- a/src/system/boot/platform/atari_m68k/bios.h
+++ /dev/null
@@ -1,42 +0,0 @@
-/*
- * Copyright 2007, Haiku, Inc. All Rights Reserved.
- * Distributed under the terms of the MIT license.
- *
- * Author:
- *		François Revol, revol@free.fr.
- */
-#ifndef _BIOS_H
-#define _BIOS_H
-
-/* 
- * Atari BIOS calls
- */
-
-#define BIOS_TRAP XXX
-
-// BIOSxxx...: x: param type {W|L}
-
-#define BIOS(nr) \
-({ uint32 ret; \
-asm volatile ( \
-"	move	#%0,-(sp)\n" \
-"	trap	#" #BIOS_TRAP "\n" \
-"	add.l	#2,sp" \
-:: "=r"(ret)); \
-ret; })
-
-#define BIOSW(nr, w0) \
-({ uint32 ret; \
-asm volatile ( \
-"	move.w	%1,-(sp)\n" \
-"	move	#" #nr ",-(sp)\n" \
-"	trap	#" #BIOS_TRAP "\n" \
-"	add.l	#2,sp" \
-:: "=r"(ret)); \
-ret; })
-
-#define Bconin(p0) (uint32)BIOSW(2, p0)
-//XXX nparams ?
-#define Kbshift(p0) (uint32)BIOSW(11, p0)
-
-#endif /* _BIOS_H */
diff --git a/src/system/boot/platform/atari_m68k/gemdos.h b/src/system/boot/platform/atari_m68k/gemdos.h
deleted file mode 100644
index ba29b4ea9e..0000000000
--- a/src/system/boot/platform/atari_m68k/gemdos.h
+++ /dev/null
@@ -1,24 +0,0 @@
-/*
- * Copyright 2007, Haiku, Inc. All Rights Reserved.
- * Distributed under the terms of the MIT license.
- *
- * Author:
- *		François Revol, revol@free.fr.
- */
-#ifndef _GEMDOS_H
-#define _GEMDOS_H
-
-/* 
- * Atari GEMDOS calls
- */
-
-#define GEMDOS_TRAP 1
-
-// official names
-#define Cconin() GEMDOS(1)
-
-// check for names
-#define supexec() GEMDOS(0x20)
-#define terminate() GEMDOS(0)
-
-#endif /* _GEMDOS_H */
diff --git a/src/system/boot/platform/atari_m68k/toscalls.S b/src/system/boot/platform/atari_m68k/toscalls.S
new file mode 100644
index 0000000000..246f180735
--- /dev/null
+++ b/src/system/boot/platform/atari_m68k/toscalls.S
@@ -0,0 +1,46 @@
+/*
+ * Copyright 2007, Haiku, Inc. All Rights Reserved.
+ * Distributed under the terms of the MIT license.
+ *
+ * Author:
+ *		François Revol, revol@free.fr.
+ */
+
+#define FUNCTION(x) .global x; .type x,@function; x
+
+/* non reentrant but that's enough
+ * idea taken from
+ * http://www.fortunecity.com/skyscraper/apple/308/html/chap4.htm
+ */
+
+_trap_ret_addr:
+	.long	0
+
+/*	uint32 bios(uint16 nr, ...); */
+FUNCTION(bios):
+	move.l	(%a7)+,_trap_ret_addr
+	trap	#
+	move.l	_trap_ret_addr,-(%a7)
+	rts
+
+/*	uint32 xbios(uint16 nr, ...); */
+FUNCTION(xbios):
+	move.l	(%a7)+,_trap_ret_addr
+	trap	#14
+	move.l	_trap_ret_addr,-(%a7)
+	rts
+
+/*	uint32 gemdos(uint16 nr, ...); */
+FUNCTION(gemdos):
+	move.l	(%a7)+,_trap_ret_addr
+	trap	#1
+	move.l	_trap_ret_addr,-(%a7)
+	rts
+
+/*	uint32 vdi(uint16 nr, ...); */
+FUNCTION(vdi):
+	move.l	(%a7)+,_trap_ret_addr
+	trap	#14
+	move.l	_trap_ret_addr,-(%a7)
+	rts
+
diff --git a/src/system/boot/platform/atari_m68k/toscalls.h b/src/system/boot/platform/atari_m68k/toscalls.h
new file mode 100644
index 0000000000..4faf78e070
--- /dev/null
+++ b/src/system/boot/platform/atari_m68k/toscalls.h
@@ -0,0 +1,50 @@
+/*
+ * Copyright 2007, Haiku, Inc. All Rights Reserved.
+ * Distributed under the terms of the MIT license.
+ *
+ * Author:
+ *		François Revol, revol@free.fr.
+ */
+
+#ifndef _TOSCALLS_H
+#define _TOSCALLS_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* 
+ * Atari BIOS calls
+ */
+
+extern uint32 bios(uint16 nr, ...);
+
+#define Bconin(p0) bios(2, p0)
+//XXX nparams ?
+#define Kbshift(p0) bios(11, p0)
+
+/* 
+ * Atari XBIOS calls
+ */
+
+extern uint32 bios(uint16 nr, ...);
+
+
+/* 
+ * Atari GEMDOS calls
+ */
+
+extern uint32 gemdos(uint16 nr, ...);
+
+// official names
+#define Cconin() gemdos(1)
+#define Super(a) gemdos(0x20, (uint32)a)
+
+// check for names
+#define terminate() GEMDOS(0)
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _TOSCALLS_H */
diff --git a/src/system/boot/platform/atari_m68k/xbios.h b/src/system/boot/platform/atari_m68k/xbios.h
deleted file mode 100644
index 97245b5208..0000000000
--- a/src/system/boot/platform/atari_m68k/xbios.h
+++ /dev/null
@@ -1,18 +0,0 @@
-/*
- * Copyright 2007, Haiku, Inc. All Rights Reserved.
- * Distributed under the terms of the MIT license.
- *
- * Author:
- *		François Revol, revol@free.fr.
- */
-#ifndef _XBIOS_H
-#define _XBIOS_H
-
-/* 
- * Atari XBIOS calls
- */
-
-#define BIOS_TRAP 14
-//#define GEMDOS_TRAP 1
-
-#endif /* _XBIOS_H */