arch/ppc-all/exec/newstackswap.c

   1 /*
   2     Copyright © 1995-2013, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Desc: NewStackSwap() - Call a function with swapped stack.
   6     Lang: english
   7 */
   8
   9 #define __AROS_GIMME_DEPRECATED_STACKSWAP__
  10
  11 #include <aros/debug.h>
  12 #include <exec/tasks.h>
  13 #include <proto/exec.h>
  14
  15 /* See rom/exec/newstackswap.c for documentation */
  16
  17 AROS_LH3(IPTR, NewStackSwap,
  18     AROS_LHA(struct StackSwapStruct *,  sss, A0),
  19     AROS_LHA(LONG_FUNC, entry, A1),
  20     AROS_LHA(struct StackSwapArgs *, args, A2),
  21     struct ExecBase *, SysBase, 134, Exec)
  22 {
  23     AROS_LIBFUNC_INIT
  24
  25     ULONG *     retptr;
  26     ULONG       ret;
  27     register ULONG real_sp asm("r1");
  28     ULONG *sp;
  29     ULONG *src;
  30     ULONG *dst;
  31
  32     /* Get the real stack pointer */
  33     asm volatile ("mr %0,%1":"=r"(sp):"r"(real_sp));
  34
  35     /* Go one stack frame upper - now src points to the stackframe of caller */
  36     src = (ULONG*)*sp;
  37
  38     /* Go one more stack frame up. Now you may copy from src to dst (src - sp) IPTR's */
  39     src = (ULONG*)*src;
  40
  41     dst = (ULONG*)((IPTR)sss->stk_Upper - SP_OFFSET);
  42
  43     /* Copy the two stack frames */
  44     while (src != sp)
  45     {
  46         *--dst = *--src;
  47     }
  48
  49     sss->stk_Pointer = dst;
  50
  51     retptr = &ret;
  52
  53     D(bug("In NewStackSwap() entry=%lx, *entry=%lx\n", (IPTR)entry, (IPTR)*entry));
  54     D(bug("[sss] %08x %08x %08x\n", sss->stk_Lower, sss->stk_Pointer, sss->stk_Upper));
  55
  56     StackSwap(sss);
  57
  58     D(bug("[sss] %08x %08x %08x\n", sss->stk_Lower, sss->stk_Pointer, sss->stk_Upper));
  59
  60     /* Call the function with the new stack */
  61     if (args != NULL)
  62     {
  63         *retptr = entry(args->Args[0], args->Args[1], args->Args[2],
  64             args->Args[3], args->Args[4], args->Args[5], args->Args[6],
  65             args->Args[7]);
  66     }
  67     else
  68         *retptr = entry();
  69
  70     StackSwap(sss);
  71
  72     return ret;
  73
  74     AROS_LIBFUNC_EXIT
  75 } /* NewStackSwap() */