arch/i386-pc/exec/preparecontext.c

   1 /*
   2     Copyright © 1995-2001, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Desc: i386unix version of PrepareContext().
   6     Lang: english
   7 */
   8
   9 #include <exec/types.h>
  10 #include <exec/execbase.h>
  11 #include <exec/memory.h>
  12 #include <utility/tagitem.h>
  13 #include <sigcore.h>
  14 #include "etask.h"
  15 #include "exec_util.h"
  16
  17 #include <aros/libcall.h>
  18 #include <asm/ptrace.h>
  19 #include <asm/segments.h>
  20
  21 #define Regs(t) ((struct pt_regs *)(GetIntETask(t)->iet_Context))
  22
  23 static ULONG *PrepareContext_Common(struct Task *task, APTR entryPoint, APTR fallBack,
  24                                     struct TagItem *tagList, struct ExecBase *SysBase)
  25 {
  26     ULONG *regs;
  27     IPTR  *sp=(IPTR *)task->tc_SPReg;
  28     IPTR args[8] = {0};
  29     WORD numargs = 0;
  30
  31     while(tagList)
  32     {
  33         switch(tagList->ti_Tag)
  34         {
  35             case TAG_MORE:
  36                 tagList = (struct TagItem *)tagList->ti_Data;
  37                 continue;
  38
  39             case TAG_SKIP:
  40                 tagList += tagList->ti_Data;
  41                 break;
  42
  43             case TAG_DONE:
  44                 tagList = NULL;
  45                 break;
  46
  47             #define HANDLEARG(x) \
  48             case TASKTAG_ARG ## x: \
  49                 args[x - 1] = (IPTR)tagList->ti_Data; \
  50                 if (x > numargs) numargs = x; \
  51                 break;
  52
  53             HANDLEARG(1)
  54             HANDLEARG(2)
  55             HANDLEARG(3)
  56             HANDLEARG(4)
  57             HANDLEARG(5)
  58             HANDLEARG(6)
  59             HANDLEARG(7)
  60             HANDLEARG(8)
  61
  62             #undef HANDLEARG
  63         }
  64
  65         if (tagList) tagList++;
  66     }
  67
  68     if (!(task->tc_Flags & TF_ETASK) )
  69         return NULL;
  70
  71     GetIntETask (task)->iet_Context = AllocTaskMem (task
  72         , SIZEOF_ALL_REGISTERS
  73         , MEMF_PUBLIC|MEMF_CLEAR
  74     );
  75
  76     if (!(regs = (ULONG*)GetIntETask (task)->iet_Context))
  77         return NULL;
  78
  79     if (numargs)
  80     {
  81         while(numargs--)
  82         {
  83             *--sp = args[numargs];
  84         }
  85     }
  86
  87     /* Push fallBack address */
  88
  89     *--sp = (IPTR)fallBack;
  90
  91
  92     /* We have to prepare whole context right now so Dispatch()
  93      * would work propertly */
  94
  95     *regs++ = 0;                /* ebx */
  96     *regs++ = 0;                /* ecx */
  97     *regs++ = 0;                /* edx */
  98     *regs++ = 0;                /* esi */
  99     *regs++ = 0;                /* edi */
 100     *regs++ = 0;                /* ebp */
 101     *regs++ = 0;                /* eax */
 102     *regs++ = USER_DS;          /* xds */
 103     *regs++ = USER_DS;          /* xes */
 104     *regs++ = (ULONG)entryPoint;/* eip */
 105     *regs++ = USER_CS;          /* xcs */
 106     *regs++ = 0x3202;           /* eflags */
 107     *regs++ = (ULONG)sp;        /* esp */
 108     *regs++ = USER_DS;          /* xss */
 109
 110     task->tc_SPReg = sp;
 111
 112     return regs;
 113 }
 114
 115 AROS_LH4(BOOL, PrepareContext,
 116     AROS_LHA(struct Task *, task, A0),
 117     AROS_LHA(APTR, entryPoint, A1),
 118     AROS_LHA(APTR, fallBack, A2),
 119     AROS_LHA(struct TagItem *, tagList, A3),
 120     struct ExecBase *, SysBase, 6, Exec)
 121 {
 122     AROS_LIBFUNC_INIT
 123
 124     return PrepareContext_Common(task, entryPoint, fallBack, tagList, SysBase) ? TRUE : FALSE;
 125
 126     AROS_LIBFUNC_EXIT
 127 }
 128
 129 /* FIXME: This needs to be fixed/updated if the way library params are passed is changed */
 130 AROS_LH4(BOOL, PrepareContext_FPU,
 131     AROS_LHA(struct Task *, task, A0),
 132     AROS_LHA(APTR, entryPoint, A1),
 133     AROS_LHA(APTR, fallBack, A2),
 134     AROS_LHA(struct TagItem *, tagList, A3),
 135     struct ExecBase *, SysBase, 6, Exec)
 136 {
 137     AROS_LIBFUNC_INIT
 138
 139     ULONG *regs;
 140     BOOL  retval = FALSE;
 141
 142     if ((regs = PrepareContext_Common(task, entryPoint, fallBack, tagList, SysBase)))
 143     {
 144         UBYTE this_fpustate[SIZEOF_FPU_STATE];
 145
 146         asm volatile("fnsave %1\n\t"
 147                      "fwait\n\t"
 148                      "fninit\n\t"
 149                      "fnsave %0\n\t"
 150                      "fwait\n\t"
 151                      "frstor %1\n\t"
 152                      "fwait\n\t" : "=m" (*regs), "=m" (this_fpustate) : : "memory");
 153
 154         retval = TRUE;
 155     }
 156
 157     return retval;
 158
 159     AROS_LIBFUNC_EXIT
 160 }
 161
 162 AROS_LH4(BOOL, PrepareContext_SSE,
 163     AROS_LHA(struct Task *, task, A0),
 164     AROS_LHA(APTR, entryPoint, A1),
 165     AROS_LHA(APTR, fallBack, A2),
 166     AROS_LHA(struct TagItem *, tagList, A3),
 167     struct ExecBase *, SysBase, 6, Exec)
 168 {
 169     AROS_LIBFUNC_INIT
 170
 171     ULONG *regs;
 172     BOOL  retval = FALSE;
 173
 174     if ((regs = PrepareContext_Common(task, entryPoint, fallBack, tagList, SysBase)))
 175     {
 176         UBYTE this_ssestate[SIZEOF_FPU_STATE + 15], *ptr = this_ssestate;
 177         regs = (ULONG*)(((IPTR)regs+15)&~15);
 178         ptr = (UBYTE*)(((IPTR)ptr+15)&~15);
 179
 180         asm volatile("fxsave (%0)\n\t"
 181                      "fninit\n\t"
 182                      "fwait\n\t"
 183                      "fxsave (%1)\n\t"
 184                      "fxrstor (%0)\n\t"
 185                      :
 186                      : "r" (ptr), "r" (regs)
 187                      : "memory");
 188
 189         retval = TRUE;
 190     }
 191
 192     return retval;
 193
 194     AROS_LIBFUNC_EXIT
 195 }