Added MR #define place holders so that these are used instead of real register names

include/l4/glue/arm/message.h

@@ -16,4 +16,8 @@
 #define MR_UNUSED_TOTAL		(MR_TOTAL - MR_UNUSED_START)
 #define MR_USABLE_TOTAL		MR_UNUSED_TOTAL
 
+/* These are defined so that we don't hard-code register names */
+#define MR0_REGISTER		r3
+#define MR_RETURN_REGISTER	r3
+
 #endif /* __GLUE_ARM_MESSAGE_H__ */

include/l4/glue/arm/syscall.h

@@ -8,6 +8,7 @@
 #define __ARM_GLUE_SYSCALL_H__
 
 #include <l4/types.h>
+#include INC_GLUE(message.h)
 
 /* Only specific call is the trap that gives back the kip address
  * from which other system calls can be discovered. */
@@ -57,7 +58,7 @@ typedef struct msg_regs {
  * that imitates a page fault ipc etc.
  */
 #define KTCB_REF_ARG0(ktcb)	(&(ktcb)->syscall_regs->r0)
-#define KTCB_REF_MR0(ktcb)	(&(ktcb)->syscall_regs->r3)
+#define KTCB_REF_MR0(ktcb)	(&(ktcb)->syscall_regs->MR0_REGISTER)
 
 /* Represents each syscall. We get argument registers
  * from stack for now. This is slower but the simplest. */