Index: boot/arch/sparc64/include/arch.h
===================================================================
--- boot/arch/sparc64/include/arch.h	(revision 2550b6ee56039c2e3278e3526d558819090513e9)
+++ boot/arch/sparc64/include/arch.h	(revision b9c229bbaa51496ffe548c034b12a1d2eff12892)
@@ -41,4 +41,5 @@
 #define STACK_BIAS                   2047
 #define STACK_WINDOW_SAVE_AREA_SIZE  (16 * 8)
+#define STACK_ARG_SAVE_AREA_SIZE     (6 * 8)
 
 #define NWINDOWS  8
Index: boot/arch/sparc64/src/asm.S
===================================================================
--- boot/arch/sparc64/src/asm.S	(revision 2550b6ee56039c2e3278e3526d558819090513e9)
+++ boot/arch/sparc64/src/asm.S	(revision b9c229bbaa51496ffe548c034b12a1d2eff12892)
@@ -152,5 +152,5 @@
 .global ofw
 ofw:
-	save %sp, -STACK_WINDOW_SAVE_AREA_SIZE, %sp
+	save %sp, -(STACK_WINDOW_SAVE_AREA_SIZE + STACK_ARG_SAVE_AREA_SIZE), %sp
 	set ofw_cif, %l0
 	ldx [%l0], %l0