arch/i386-pc/exec/preparecontext.c

   1 /*
   2     Copyright © 1995-2011, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Desc: i386 native 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 "etask.h"
  14 #include "exec_util.h"
  15
  16 #include <aros/libcall.h>
  17 #include <asm/ptrace.h>
  18 #include <asm/segments.h>
  19
  20 #define Regs(t) ((struct pt_regs *)(GetIntETask(t)->iet_Context))
  21
  22 static ULONG *PrepareContext_Common(struct Task *task, APTR entryPoint, APTR fallBack,
  23                                     struct TagItem *tagList, struct ExecBase *SysBase)
  24 {
  25     ULONG *regs;
  26     IPTR  *sp=(IPTR *)task->tc_SPReg;
  27     IPTR args[8] = {0};
  28     WORD numargs = 0;
  29
  30     while(tagList)
  31     {
  32         switch(tagList->ti_Tag)
  33         {
  34             case TAG_MORE:
  35                 tagList = (struct TagItem *)tagList->ti_Data;
  36                 continue;
  37
  38             case TAG_SKIP:
  39                 tagList += tagList->ti_Data;
  40                 break;
  41
  42             case TAG_DONE:
  43                 tagList = NULL;
  44                 break;
  45
  46             #define HANDLEARG(x) \
  47             case TASKTAG_ARG ## x: \
  48                 args[x - 1] = (IPTR)tagList->ti_Data; \
  49                 if (x > numargs) numargs = x; \
  50                 break;
  51
  52             HANDLEARG(1)
  53             HANDLEARG(2)
  54             HANDLEARG(3)
  55             HANDLEARG(4)
  56             HANDLEARG(5)
  57             HANDLEARG(6)
  58             HANDLEARG(7)
  59             HANDLEARG(8)
  60
  61             #undef HANDLEARG
  62         }
  63
  64         if (tagList) tagList++;
  65     }
  66
  67     if (!(task->tc_Flags & TF_ETASK) )
  68         return NULL;
  69
  70     GetIntETask (task)->iet_Context = AllocTaskMem (task
  71         , SIZEOF_ALL_REGISTERS
  72         , MEMF_PUBLIC|MEMF_CLEAR
  73     );
  74
  75     if (!(regs = (ULONG*)GetIntETask (task)->iet_Context))
  76         return NULL;
  77
  78     if (numargs)
  79     {
  80         while(numargs--)
  81         {
  82             *--sp = args[numargs];
  83         }
  84     }
  85
  86     /* Push fallBack address */
  87
  88     *--sp = (IPTR)fallBack;
  89
  90
  91     /* We have to prepare whole context right now so Dispatch()
  92      * would work propertly */
  93
  94     *regs++ = 0;                /* ebx */
  95     *regs++ = 0;                /* ecx */
  96     *regs++ = 0;                /* edx */
  97     *regs++ = 0;                /* esi */
  98     *regs++ = 0;                /* edi */
  99     *regs++ = 0;                /* ebp */
 100     *regs++ = 0;                /* eax */
 101     *regs++ = USER_DS;          /* xds */
 102     *regs++ = USER_DS;          /* xes */
 103     *regs++ = (ULONG)entryPoint;/* eip */
 104     *regs++ = USER_CS;          /* xcs */
 105     *regs++ = 0x3202;           /* eflags */
 106     *regs++ = (ULONG)sp;        /* esp */
 107     *regs++ = USER_DS;          /* xss */
 108
 109     task->tc_SPReg = sp;
 110
 111     return regs;
 112 }
 113
 114 AROS_LH4(BOOL, PrepareContext,
 115     AROS_LHA(struct Task *, task, A0),
 116     AROS_LHA(APTR, entryPoint, A1),
 117     AROS_LHA(APTR, fallBack, A2),
 118     AROS_LHA(struct TagItem *, tagList, A3),
 119     struct ExecBase *, SysBase, 6, Exec)
 120 {
 121     AROS_LIBFUNC_INIT
 122
 123     return PrepareContext_Common(task, entryPoint, fallBack, tagList, SysBase) ? TRUE : FALSE;
 124
 125     AROS_LIBFUNC_EXIT
 126 }
 127
 128 /* FIXME: This needs to be fixed/updated if the way library params are passed is changed */
 129 AROS_LH4(BOOL, PrepareContext_FPU,
 130     AROS_LHA(struct Task *, task, A0),
 131     AROS_LHA(APTR, entryPoint, A1),
 132     AROS_LHA(APTR, fallBack, A2),
 133     AROS_LHA(struct TagItem *, tagList, A3),
 134     struct ExecBase *, SysBase, 6, Exec)
 135 {
 136     AROS_LIBFUNC_INIT
 137
 138     ULONG *regs;
 139     BOOL  retval = FALSE;
 140
 141     if ((regs = PrepareContext_Common(task, entryPoint, fallBack, tagList, SysBase)))
 142     {
 143         UBYTE this_fpustate[SIZEOF_FPU_STATE];
 144
 145         asm volatile("fnsave %1\n\t"
 146                      "fwait\n\t"
 147                      "fninit\n\t"
 148                      "fnsave %0\n\t"
 149                      "fwait\n\t"
 150                      "frstor %1\n\t"
 151                      "fwait\n\t" : "=m" (*regs), "=m" (this_fpustate) : : "memory");
 152
 153         retval = TRUE;
 154     }
 155
 156     return retval;
 157
 158     AROS_LIBFUNC_EXIT
 159 }
 160
 161 AROS_LH4(BOOL, PrepareContext_SSE,
 162     AROS_LHA(struct Task *, task, A0),
 163     AROS_LHA(APTR, entryPoint, A1),
 164     AROS_LHA(APTR, fallBack, A2),
 165     AROS_LHA(struct TagItem *, tagList, A3),
 166     struct ExecBase *, SysBase, 6, Exec)
 167 {
 168     AROS_LIBFUNC_INIT
 169
 170     ULONG *regs;
 171     BOOL  retval = FALSE;
 172
 173     if ((regs = PrepareContext_Common(task, entryPoint, fallBack, tagList, SysBase)))
 174     {
 175         UBYTE this_ssestate[SIZEOF_FPU_STATE + 15], *ptr = this_ssestate;
 176         regs = (ULONG*)(((IPTR)regs+15)&~15);
 177         ptr = (UBYTE*)(((IPTR)ptr+15)&~15);
 178
 179         asm volatile("fxsave (%0)\n\t"
 180                      "fninit\n\t"
 181                      "fwait\n\t"
 182                      "fxsave (%1)\n\t"
 183                      "fxrstor (%0)\n\t"
 184                      :
 185                      : "r" (ptr), "r" (regs)
 186                      : "memory");
 187
 188         retval = TRUE;
 189     }
 190
 191     return retval;
 192
 193     AROS_LIBFUNC_EXIT
 194 }