Index: hal/arm/arch/current/src/vectors.S
===================================================================
--- hal/arm/arch/current/src/vectors.S	(revision 3391)
+++ hal/arm/arch/current/src/vectors.S	(working copy)
@@ -539,7 +539,8 @@
         tst     r1,#CPSR_THUMB_ENABLE
         subeq   r0,lr,#4                // PC at time of SWI (ARM)
         subne   r0,lr,#2                // PC at time of SWI (thumb)
-        mov     r2,#CYGNUM_HAL_EXCEPTION_INTERRUPT
+        mov     r2,#CYGNUM_HAL_EXCEPTION_SOFTWARE_INTERRUPT
+        mov     r3,sp
         b       call_exception_handler
 
         .code   32