arch/ppc-all/exec/execstubs.s

   1 /*
   2     Copyright ? 1995-2007, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Desc: Stubs to call C functions while preserving all registers
   6     Lang: english
   7 */
   8    #include "aros/ppc/asm.h"
   9
  10 /*
  11     Macros:
  12    PUSH - Save all registers on the stack
  13    POP - Restore all registers from the stack
  14
  15    STUB_ARG0(name) - Call a function preserving all registers
  16           which gets no arguments
  17    STUB_ARG1(name) - Call a function preserving all registers
  18           which gets a single argument
  19    STUB_ARG2(name) - Call a function preserving all registers
  20           which gets two arguments
  21 */
  22
  23 #define NUM_REGS   (32 + 2)
  24 #define OFFSET     ((NUM_REGS) * 4)
  25 #define FIRST_ARG  (((NUM_REGS + 0) * 4) + OFFSET)
  26 #define SECOND_ARG (((NUM_REGS + 1) * 4) + OFFSET)
  27
  28 /* 4(1) is used by the called function
  29    to store lr much the same way we do
  30 */
  31 #define PUSH           \
  32     stwu 1,-OFFSET(1) ;\
  33     stw  0,8(1)       ;\
  34     stmw 2,12(1)      ;\
  35     mflr 0            ;\
  36     stw  0,OFFSET-4(1);
  37
  38 #define POP             \
  39     lwz  0,OFFSET-4(1); \
  40     mtlr 0            ; \
  41     lmw  2,12(1)      ; \
  42     lwz  0,8(1)       ; \
  43     lwz  1,0(1);
  44
  45 #define STUB_ARG0(name)\
  46     PUSH            ;  \
  47     lis  9,name@ha  ;  \
  48     la   0,name@l(9);  \
  49     mtlr 0          ;  \
  50     blrl            ;  \
  51     POP             ;  \
  52     blrl
  53
  54 #define STUB_ARG1(name)  \
  55     PUSH               ; \
  56     lwz  0,FIRST_ARG(1); \
  57     stw  0,-4(1)       ; \
  58     lis  9,name@ha     ; \
  59     la   0,name@l(9)   ; \
  60     mtlr 0             ; \
  61     blrl               ; \
  62     POP                ; \
  63     blrl
  64
  65 #define STUB_ARG2(name)   \
  66     PUSH                ; \
  67     lwz  0,SECOND_ARG(1); \
  68     stw  0,-4(1)        ; \
  69     lwz  0,FIRST_ARG(1) ; \
  70     stw  0,-8(1)        ; \
  71     lis  9,name@ha      ; \
  72     la   0,name@l(9)    ; \
  73     mtlr 0              ; \
  74     blrl                ; \
  75     POP                 ; \
  76     blrl
  77
  78 /* To save typing work */
  79 #define STUB0(cname,name)\
  80    .globl   cname      ; \
  81    _FUNCTION(cname)    ; \
  82 cname:                 ; \
  83    STUB_ARG0(name)
  84
  85 #define STUB1(cname,name)\
  86    .globl   cname      ; \
  87    _FUNCTION(cname)    ; \
  88 cname:                 ; \
  89    STUB_ARG1(name)
  90
  91 #define STUB2(cname,name)\
  92    .globl   cname      ; \
  93    _FUNCTION(cname)    ; \
  94 cname:                 ; \
  95    STUB_ARG2(name)
  96
  97    .text
  98    _ALIGNMENT
  99
 100 /* Call functions and preserve registers */
 101 #ifdef  UseExecstubs
 102    STUB1(AROS_SLIB_ENTRY(Forbid,Exec),AROS_CSYMNAME(_Exec_Forbid))
 103    STUB1(AROS_SLIB_ENTRY(Permit,Exec),AROS_CSYMNAME(_Exec_Permit))
 104    STUB1(AROS_SLIB_ENTRY(Disable,Exec),AROS_CSYMNAME(_Exec_Disable))
 105    STUB1(AROS_SLIB_ENTRY(Enable,Exec),AROS_CSYMNAME(_Exec_Enable))
 106
 107    STUB2(AROS_SLIB_ENTRY(ObtainSemaphore,Exec),AROS_CSYMNAME(_Exec_ObtainSemaphore))
 108    STUB2(AROS_SLIB_ENTRY(ReleaseSemaphore,Exec),AROS_CSYMNAME(_Exec_ReleaseSemaphore))
 109    STUB2(AROS_SLIB_ENTRY(ObtainSemaphoreShared,Exec),AROS_CSYMNAME(_Exec_ObtainSemaphoreShared))
 110 #endif
 111