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 = 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 #warning This needs to be fixed/updated if the way library params are passed is changed
 130
 131 BOOL Exec_PrepareContext_FPU(struct Task *task, APTR entryPoint, APTR fallBack, struct TagItem *tagList, struct ExecBase *SysBase)
 132 {
 133     ULONG *regs;
 134     BOOL  retval = FALSE;
 135
 136     if ((regs = PrepareContext_Common(task, entryPoint, fallBack, tagList, SysBase)))
 137     {
 138         UBYTE this_fpustate[SIZEOF_FPU_STATE];
 139
 140         asm volatile("fnsave %1\n\t"
 141                      "fwait\n\t"
 142                      "fninit\n\t"
 143                      "fnsave %0\n\t"
 144                      "fwait\n\t"
 145                      "frstor %1\n\t"
 146                      "fwait\n\t" : "=m" (*regs), "=m" (this_fpustate) : : "memory");
 147
 148         retval = TRUE;
 149     }
 150
 151     return retval;
 152
 153 }
 154
 155 BOOL Exec_PrepareContext_SSE(struct Task *task, APTR entryPoint, APTR fallBack, struct TagItem *tagList, struct ExecBase *SysBase)
 156 {
 157     ULONG *regs;
 158     BOOL  retval = FALSE;
 159
 160     if ((regs = PrepareContext_Common(task, entryPoint, fallBack, tagList, SysBase)))
 161     {
 162         UBYTE this_ssestate[SIZEOF_FPU_STATE + 15], *ptr = this_ssestate;
 163         regs = (ULONG*)(((IPTR)regs+15)&~15);
 164         ptr = (UBYTE*)(((IPTR)ptr+15)&~15);
 165
 166         asm volatile("fxsave (%0)\n\t"
 167                      "fninit\n\t"
 168                      "fwait\n\t"
 169                      "fxsave (%1)\n\t"
 170                      "fxrstor (%0)\n\t"
 171                      :
 172                      : "r" (ptr), "r" (regs)
 173                      : "memory");
 174
 175         retval = TRUE;
 176     }
 177
 178     return retval;
 179
 180 }