rom/dos/runprocess.c

   1 /*
   2     Copyright © 1995-2008, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Desc: RunProcess() - Run a process from an entry point with args
   6     Lang: english
   7 */
   8 #include <aros/asmcall.h>       /* LONG_FUNC */
   9 #ifndef TEST
  10 #   include <dos/dosextens.h>
  11 #   include <proto/exec.h>
  12 #   include <aros/debug.h>
  13 #else
  14 #   include <exec/types.h>
  15 #   include <exec/tasks.h>
  16 #   define D(x) /* eps */
  17
  18 struct Process;
  19
  20 struct DosLibrary
  21 {
  22     struct ExecBase * dl_SysBase;
  23 };
  24
  25 extern void StackSwap (struct StackSwapStruct *, struct ExecBase *);
  26
  27 #define StackSwap(s)    StackSwap(s, SysBase)
  28 #define AROS_SLIB_ENTRY(a,b)    a
  29
  30 #endif /* TEST */
  31
  32 #include <string.h>
  33
  34
  35 /**************************************************************************
  36
  37     NAME */
  38         LONG AROS_SLIB_ENTRY(RunProcess,Dos) (
  39
  40 /*  SYNOPSIS */
  41         struct Process          * proc,
  42         struct StackSwapStruct  * sss,
  43         CONST_STRPTR              argptr,
  44         ULONG                     argsize,
  45         LONG_FUNC                 entry,
  46         struct DosLibrary       * DOSBase)
  47
  48 /* FUNCTION
  49         Sets the stack as specified and calls the routine with the given
  50         arguments.
  51
  52     INPUTS
  53         proc    - Process context
  54         sss     - New Stack
  55         argptr  - Pointer to argument string
  56         argsize - Size of the argument string
  57         entry   - The entry point of the function
  58         DOSBase - Pointer to dos.library structure
  59
  60     RESULT
  61         The return value of (*entry)();
  62
  63     NOTES
  64
  65     EXAMPLE
  66
  67     BUGS
  68
  69     SEE ALSO
  70
  71     INTERNALS
  72
  73 **************************************************************************/
  74 {
  75     APTR *      oldSP;
  76     APTR *      sp;
  77     ULONG *     retptr;
  78     ULONG       ret;
  79     APTR        oldReturnAddr;
  80
  81     retptr = &ret;
  82
  83     sp = (APTR *)(sss->stk_Upper);
  84     oldSP = (APTR *)&DOSBase;
  85     oldReturnAddr = proc->pr_ReturnAddr;
  86
  87     /* Compute argsize automatically */
  88     if (argsize == -1)
  89     {
  90         argsize = strlen(argptr);
  91     }
  92
  93     /* Copy stack + locals + regs + everything */
  94     while ( oldSP != (APTR *)&ret )
  95     {
  96         *--sp = *oldSP--;
  97     }
  98
  99     sss->stk_Pointer = sp;
 100
 101     D(bug("In RunProcess() entry=%lx, *entry=%lx\n", (IPTR)entry, (IPTR)*entry));
 102     StackSwap(sss);
 103
 104     /* Call the function with the new stack */
 105     /*
 106         We have to set the pr_ReturnAddr pointer to the correct value
 107         before we call the entry() otherwise some startup code will
 108         not work.
 109
 110         This can be done rather more easily on the m68k than elsewhere.
 111     */
 112 #ifndef AROS_UFC3R
 113 #error You need to write the AROS_UFC3R macro for your CPU
 114 #endif
 115
 116    /* The AROS_UFC3R() macro doesn't work on my system (gcc 2.95.1, Linux 2.3.50)
 117     * this is the workaround I'm currently using:
 118     */
 119
 120 //    *retptr = entry(argptr,argsize,SysBase);
 121
 122     *retptr = AROS_UFC3R(ULONG, entry,
 123                 AROS_UFCA(CONST_STRPTR, argptr, A0),
 124                 AROS_UFCA(ULONG, argsize, D0),
 125                 AROS_UFCA(struct ExecBase *, SysBase, A6),
 126                 &proc->pr_ReturnAddr, (sss->stk_Upper - (ULONG)sss->stk_Lower)
 127               );
 128
 129     StackSwap(sss);
 130
 131     proc->pr_ReturnAddr = oldReturnAddr;
 132
 133     return ret;
 134 }
 135
 136 #ifdef TEST
 137
 138 #include <stdio.h>
 139
 140 ULONG teststack[4096];
 141
 142 int DemoProc (const char * argstr, int argsize, struct ExecBase * SysBase)
 143 {
 144     printf ("arg=\"%s\" (len=%d\n", argstr, argsize);
 145
 146     return argsize;
 147 } /* DemoProc */
 148
 149 int main (int argc, char ** argv)
 150 {
 151     int ret, len;
 152     char * argstr;
 153     struct StackSwapStruct sss;
 154     struct DosLibrary DosBase;
 155
 156     sss.stk_Lower = teststack;
 157     sss.stk_Upper = &teststack[sizeof(teststack) / sizeof(teststack[0])];
 158     sss.stk_Pointer = sss.stk_Upper;
 159
 160     DosBase.dl_SysBase = (struct ExecBase *)0x0bad0bad;
 161
 162     printf ("Stack=%p\n", &ret);
 163
 164     argstr = "Hello world.";
 165
 166     len = strlen (argstr);
 167
 168     ret = RunProcess (NULL,
 169         &sss,
 170         argstr,
 171         len,
 172         (LONG_FUNC)DemoProc,
 173         &DOSBase
 174     );
 175
 176     printf ("Stack=%p\n", &ret);
 177     printf ("RunProcess=%d\n",ret);
 178
 179     if (len == ret)
 180     {
 181         printf("Test ok.\n");
 182     }
 183     else
 184     {
 185         printf("Test failed.\n");
 186     }
 187
 188     return 0;
 189 }
 190
 191 #endif /* TEST */