From 30de876a6c004b953ffe6beba02faf79f7283bc9 Mon Sep 17 00:00:00 2001
From: Bahadir Balban <bbalban@b-labs.co.uk>
Date: Mon, 15 Sep 2008 18:27:41 +0300
Subject: [PATCH] Added MR #define place holders so that these are used instead
 of real register names

---
 include/l4/glue/arm/message.h  | 4 ++++
 include/l4/glue/arm/syscall.h  | 3 ++-
 tasks/libl4/src/arm/exregs.c   | 4 ++--
 tasks/libl4/src/arm/syscalls.S | 9 ++++-----
 4 files changed, 12 insertions(+), 8 deletions(-)

diff --git a/include/l4/glue/arm/message.h b/include/l4/glue/arm/message.h
index 5ceb86e..de3e1e4 100644
--- a/include/l4/glue/arm/message.h
+++ b/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__ */
diff --git a/include/l4/glue/arm/syscall.h b/include/l4/glue/arm/syscall.h
index 73fd6dd..169d7f1 100644
--- a/include/l4/glue/arm/syscall.h
+++ b/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. */
diff --git a/tasks/libl4/src/arm/exregs.c b/tasks/libl4/src/arm/exregs.c
index 72928e5..0947289 100644
--- a/tasks/libl4/src/arm/exregs.c
+++ b/tasks/libl4/src/arm/exregs.c
@@ -12,7 +12,7 @@
 void exregs_set_mr(struct exregs_data *s, int offset, unsigned long val)
 {
 	/* Get MR0 */
-	u32 *mr = &s->context.r3;
+	u32 *mr = &s->context.MR0_REGISTER;
 
 	/* Sanity check */
 	BUG_ON(offset > MR_TOTAL || offset < 0);
@@ -21,7 +21,7 @@ void exregs_set_mr(struct exregs_data *s, int offset, unsigned long val)
 	mr[offset] = val;
 
 	/* Set valid bit for mr register */
-	s->valid_vect |= FIELD_TO_BIT(exregs_context_t, r3) << offset;
+	s->valid_vect |= FIELD_TO_BIT(exregs_context_t, MR0_REGISTER) << offset;
 }
 
 void exregs_set_pager(struct exregs_data *s, l4id_t pagerid)
diff --git a/tasks/libl4/src/arm/syscalls.S b/tasks/libl4/src/arm/syscalls.S
index 8b964a7..31ab29b 100644
--- a/tasks/libl4/src/arm/syscalls.S
+++ b/tasks/libl4/src/arm/syscalls.S
@@ -6,6 +6,8 @@
 #include <l4lib/arch/asm.h>
 #include <l4lib/arch/utcb.h>
 #include <l4/generic/space.h>
+#include <l4/macros.h>
+#include INC_GLUE(message.h)
 
 	.macro	utcb_address	rx
 		ldr	\rx, =utcb
@@ -43,10 +45,7 @@ END_PROC(l4_kread)
  * For clone() we need special assembler handling
  * Same signature as ipc(): @r0 = to, @r1 = from
  *
- * NOTE: MR_RETURN register is hardcoded here.
- * It must be updated if MR_RETURN offset is changed!
- *
- * NOTE: Note that this also breaks l4 system call interface,
+ * NOTE: Note that this breaks l4 system call interface,
  * this should be moved elsewhere and modified using existing l4 mechanisms.
  */
 BEGIN_PROC(arch_clone)
@@ -65,7 +64,7 @@ BEGIN_PROC(arch_clone)
 	 */
 	cmp	r0, #0			@ Check ipc success
 	blt	ipc_failed
-	cmp	r3, #0			@ Check ipc return register MR_RETURN.
+	cmp	MR_RETURN_REGISTER, #0	@ Check ipc return register MR_RETURN.
 	blt	clone_failed		@ Ipc was ok but clone() failed.
 	bgt	parent_return		@ It has child pid, goto parent return.
 child: