rom/exec/newstackswap.c

   1 /*
   2     Copyright © 1995-2009, 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 /*****************************************************************************
  10
  11     NAME */
  12 #include <exec/tasks.h>
  13 #include <proto/exec.h>
  14
  15         AROS_LH3(IPTR, NewStackSwap,
  16
  17 /*  SYNOPSIS */
  18         AROS_LHA(struct StackSwapStruct *,  sss, A0),
  19         AROS_LHA(LONG_FUNC, entry, A1),
  20         AROS_LHA(struct StackSwapArgs *, args, A2),
  21
  22 /*  LOCATION */
  23         struct ExecBase *, SysBase, 134, Exec)
  24
  25 /*  FUNCTION
  26         Calls a function with a new stack.
  27
  28     INPUTS
  29         sss     -   A structure containing the values for the upper, lower
  30                     and current bounds of the stack you wish to use.
  31         entry   -   Address of the function to call.
  32         args    -   A structure (actually an array) containing up to 8
  33                     function arguments
  34
  35     RESULT
  36         A value actually returned by your function. The function will be
  37         running on a new stack.
  38
  39     NOTES
  40
  41     EXAMPLE
  42
  43     BUGS
  44         Do not attempt to pass in a prebuilt stack - it will be erased.
  45
  46     SEE ALSO
  47         StackSwap()
  48
  49     INTERNALS
  50         This function MUST be replaced in $(KERNEL) or $(ARCH).
  51
  52 ******************************************************************************/
  53 {
  54     AROS_LIBFUNC_INIT
  55
  56     /* For an example see the NewStackSwap() function in either i386 or
  57        m68k-native.
  58
  59        Note that you must save any state information on the stack that is
  60        used in the current process, for example you should really save
  61        return addresses.
  62
  63        Note that even if you do save that information, it is not a good
  64        idea to return from the procedure that StackSwap() was invoked in
  65        as the stack will be quite incorrect.
  66     */
  67
  68 #ifndef __CXREF__
  69 #error The function NewStackSwap() has not been implemented in the kernel.
  70 #endif
  71
  72     return 0;
  73
  74     AROS_LIBFUNC_EXIT
  75 } /* NewStackSwap() */