/////////////////////////////////////////////////////////////////////////
// $Id: stack32.cc,v 1.33 2006/06/12 16:58:27 sshwarts Exp $
/////////////////////////////////////////////////////////////////////////
//
//  Copyright (C) 2001  MandrakeSoft S.A.
//
//    MandrakeSoft S.A.
//    43, rue d'Aboukir
//    75002 Paris - France
//    http://www.linux-mandrake.com/
//    http://www.mandrakesoft.com/
//
//  This library is free software; you can redistribute it and/or
//  modify it under the terms of the GNU Lesser General Public
//  License as published by the Free Software Foundation; either
//  version 2 of the License, or (at your option) any later version.
//
//  This library is distributed in the hope that it will be useful,
//  but WITHOUT ANY WARRANTY; without even the implied warranty of
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
//  Lesser General Public License for more details.
//
//  You should have received a copy of the GNU Lesser General Public
//  License along with this library; if not, write to the Free Software
//  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA


#define NEED_CPU_REG_SHORTCUTS 1
#include "bochs.h"
#include "cpu.h"
#define LOG_THIS BX_CPU_THIS_PTR

void BX_CPU_C::POP_Ed(bxInstruction_c *i)
{
  Bit32u val32;

  pop_32(&val32);

  if (i->modC0()) {
    BX_WRITE_32BIT_REGZ(i->rm(), val32);
  }
  else {
    // Note: there is one little weirdism here.  When 32bit addressing
    // is used, it is possible to use ESP in the modrm addressing.
    // If used, the value of ESP after the pop is used to calculate
    // the address.
    if (i->as32L() && (!i->modC0()) && (i->rm()==4) && (i->sibBase()==4)) {
      // call method on BX_CPU_C object
      BX_CPU_CALL_METHODR (i->ResolveModrm, (i));
    }
    write_virtual_dword(i->seg(), RMAddr(i), &val32);
  }
}

void BX_CPU_C::PUSH_ERX(bxInstruction_c *i)
{
  push_32(BX_CPU_THIS_PTR gen_reg[i->opcodeReg()].dword.erx);
}

void BX_CPU_C::POP_ERX(bxInstruction_c *i)
{
  Bit32u erx;
  pop_32(&erx);
  BX_CPU_THIS_PTR gen_reg[i->opcodeReg()].dword.erx = erx;
}

void BX_CPU_C::PUSH32_CS(bxInstruction_c *i)
{
  Bit32u eSP;
  decrementESPForPush(4, &eSP);
  write_virtual_word(BX_SEG_REG_SS, eSP,
            &BX_CPU_THIS_PTR sregs[BX_SEG_REG_CS].selector.value);
}

void BX_CPU_C::PUSH32_DS(bxInstruction_c *i)
{
  Bit32u eSP;
  decrementESPForPush(4, &eSP);
  write_virtual_word(BX_SEG_REG_SS, eSP,
           &BX_CPU_THIS_PTR sregs[BX_SEG_REG_DS].selector.value);
}

void BX_CPU_C::PUSH32_ES(bxInstruction_c *i)
{
  Bit32u eSP;
  decrementESPForPush(4, &eSP);
  write_virtual_word(BX_SEG_REG_SS, eSP,
            &BX_CPU_THIS_PTR sregs[BX_SEG_REG_ES].selector.value);
}

void BX_CPU_C::PUSH32_FS(bxInstruction_c *i)
{
  Bit32u eSP;
  decrementESPForPush(4, &eSP);
  write_virtual_word(BX_SEG_REG_SS, eSP,
            &BX_CPU_THIS_PTR sregs[BX_SEG_REG_FS].selector.value);
}

void BX_CPU_C::PUSH32_GS(bxInstruction_c *i)
{
  Bit32u eSP;
  decrementESPForPush(4, &eSP);
  write_virtual_word(BX_SEG_REG_SS, eSP,
            &BX_CPU_THIS_PTR sregs[BX_SEG_REG_GS].selector.value);
}

void BX_CPU_C::PUSH32_SS(bxInstruction_c *i)
{
  Bit32u eSP;
  decrementESPForPush(4, &eSP);
  write_virtual_word(BX_SEG_REG_SS, eSP,
            &BX_CPU_THIS_PTR sregs[BX_SEG_REG_SS].selector.value);
}

void BX_CPU_C::POP32_DS(bxInstruction_c *i)
{
  Bit32u ds;
  pop_32(&ds);
  load_seg_reg(&BX_CPU_THIS_PTR sregs[BX_SEG_REG_DS], (Bit16u) ds);
}

void BX_CPU_C::POP32_ES(bxInstruction_c *i)
{
  Bit32u es;
  pop_32(&es);
  load_seg_reg(&BX_CPU_THIS_PTR sregs[BX_SEG_REG_ES], (Bit16u) es);
}

void BX_CPU_C::POP32_FS(bxInstruction_c *i)
{
  Bit32u fs;
  pop_32(&fs);
  load_seg_reg(&BX_CPU_THIS_PTR sregs[BX_SEG_REG_FS], (Bit16u) fs);
}

void BX_CPU_C::POP32_GS(bxInstruction_c *i)
{
  Bit32u gs;
  pop_32(&gs);
  load_seg_reg(&BX_CPU_THIS_PTR sregs[BX_SEG_REG_GS], (Bit16u) gs);
}

void BX_CPU_C::POP32_SS(bxInstruction_c *i)
{
  Bit32u ss;
  pop_32(&ss);
  load_seg_reg(&BX_CPU_THIS_PTR sregs[BX_SEG_REG_SS], (Bit16u) ss);

  // POP SS inhibits interrupts, debug exceptions and single-step
  // trap exceptions until the execution boundary following the
  // next instruction is reached.
  // Same code as MOV_SwEw()
  BX_CPU_THIS_PTR inhibit_mask |=
    BX_INHIBIT_INTERRUPTS | BX_INHIBIT_DEBUG;
  BX_CPU_THIS_PTR async_event = 1;
}

#if BX_CPU_LEVEL >= 2
void BX_CPU_C::PUSHAD32(bxInstruction_c *i)
{
  Bit32u temp_ESP;
  Bit32u esp;

  if (BX_CPU_THIS_PTR sregs[BX_SEG_REG_SS].cache.u.segment.d_b)
    temp_ESP = ESP;
  else
    temp_ESP = SP;

  if (protected_mode()) {
    if (! can_push(&BX_CPU_THIS_PTR sregs[BX_SEG_REG_SS].cache, temp_ESP, 32)) {
        BX_ERROR(("PUSHAD(): stack doesn't have enough room!"));
        exception(BX_SS_EXCEPTION, 0, 0);
        return;
    }
  }
  else {
    if (temp_ESP < 32)
      BX_PANIC(("pushad: eSP < 32"));
  }

  esp = ESP;

  /* ??? optimize this by using virtual write, all checks passed */
  push_32(EAX);
  push_32(ECX);
  push_32(EDX);
  push_32(EBX);
  push_32(esp);
  push_32(EBP);
  push_32(ESI);
  push_32(EDI);
}

void BX_CPU_C::POPAD32(bxInstruction_c *i)
{
  Bit32u edi, esi, ebp, etmp, ebx, edx, ecx, eax;

  if (protected_mode()) {
    if ( !can_pop(32) ) {
      BX_ERROR(("POPAD: not enough bytes on stack"));
      exception(BX_SS_EXCEPTION, 0, 0);
      return;
    }
  }

  /* ??? optimize this */
  pop_32(&edi);
  pop_32(&esi);
  pop_32(&ebp);
  pop_32(&etmp); /* value for ESP discarded */
  pop_32(&ebx);
  pop_32(&edx);
  pop_32(&ecx);
  pop_32(&eax);

  EDI = edi;
  ESI = esi;
  EBP = ebp;
  EBX = ebx;
  EDX = edx;
  ECX = ecx;
  EAX = eax;
}
#endif

void BX_CPU_C::PUSH_Id(bxInstruction_c *i)
{
  push_32(i->Id());
}

void BX_CPU_C::PUSH_Ed(bxInstruction_c *i)
{
  Bit32u op1_32;

  /* op1_32 is a register or memory reference */
  if (i->modC0()) {
    op1_32 = BX_READ_32BIT_REG(i->rm());
  }
  else {
    /* pointer, segment address pair */
    read_virtual_dword(i->seg(), RMAddr(i), &op1_32);
  }

  push_32(op1_32);
}

#if BX_CPU_LEVEL >= 2
void BX_CPU_C::ENTER_IwIb(bxInstruction_c *i)
{
  unsigned ss32 = BX_CPU_THIS_PTR sregs[BX_SEG_REG_SS].cache.u.segment.d_b;

  Bit16u imm16 = i->Iw();
  Bit8u level = i->Ib2();
  level &= 0x1F;

  Bit32u ebp; // Use temp copy in case of exception.

  if (i->os32L())
    push_32(EBP);
  else
    push_16(BP);

  Bit32u frame_ptr32 = ESP;

  if (ss32) {
    ebp = EBP;
  }
  else {
    ebp = BP;
  }

  if (level > 0) {
    /* do level-1 times */
    while (--level) {
      if (i->os32L()) {
        Bit32u temp32;

        if (ss32) {
          ebp -= 4;
          read_virtual_dword(BX_SEG_REG_SS, ebp, &temp32);
        }
        else { /* 16bit stacksize */
          ebp -= 4; ebp &= 0xffff;
          read_virtual_dword(BX_SEG_REG_SS, ebp, &temp32);
        }
        push_32(temp32);
      }
      else { /* 16bit opsize */
        Bit16u temp16;

        if (ss32) {
          ebp -= 2;
          read_virtual_word(BX_SEG_REG_SS, ebp, &temp16);
        }
        else { /* 16bit stacksize */
          ebp -= 2; ebp &= 0xffff;
          read_virtual_word(BX_SEG_REG_SS, ebp, &temp16);
        }
        push_16(temp16);
      }
    } /* while (--level) */

    /* push(frame pointer) */
    if (i->os32L()) {
      push_32(frame_ptr32);
    }
    else { /* 16bit opsize */
      push_16((Bit16u)frame_ptr32);
    }
  } /* if (level > 0) ... */

  if (ss32) {
    EBP = frame_ptr32;
    ESP -= imm16;
  }
  else {
    BP = (Bit16u) frame_ptr32;
    SP -= imm16;
  }
}

void BX_CPU_C::LEAVE(bxInstruction_c *i)
{
  Bit32u temp_EBP;

#if BX_CPU_LEVEL >= 3
  if (BX_CPU_THIS_PTR sregs[BX_SEG_REG_SS].cache.u.segment.d_b)
    temp_EBP = EBP;
  else
#endif
    temp_EBP = BP;

  if (protected_mode()) {
    if (IS_DATA_SEGMENT_EXPAND_DOWN(BX_CPU_THIS_PTR sregs[BX_SEG_REG_SS].cache.type)) {
      if (temp_EBP <= BX_CPU_THIS_PTR sregs[BX_SEG_REG_SS].cache.u.segment.limit_scaled) {
        BX_PANIC(("LEAVE: BP > BX_CPU_THIS_PTR sregs[BX_SEG_REG_SS].limit"));
        exception(BX_SS_EXCEPTION, 0, 0);
      }
    }
    else { /* normal */
      if (temp_EBP > BX_CPU_THIS_PTR sregs[BX_SEG_REG_SS].cache.u.segment.limit_scaled) {
        BX_PANIC(("LEAVE: BP > BX_CPU_THIS_PTR sregs[BX_SEG_REG_SS].limit"));
        exception(BX_SS_EXCEPTION, 0, 0);
      }
    }
  }

  // delete frame
#if BX_CPU_LEVEL >= 3
  if (BX_CPU_THIS_PTR sregs[BX_SEG_REG_SS].cache.u.segment.d_b)
    ESP = EBP;
  else
#endif
    SP = BP;

  // restore frame pointer
#if BX_CPU_LEVEL >= 3
  if (i->os32L()) {
    Bit32u temp32;
    pop_32(&temp32);
    EBP = temp32;
  }
  else
#endif
  {
    Bit16u temp16;
    pop_16(&temp16);
    BP = temp16;
  }
}
#endif