Bochs/bochs/cpu/io_pro.cc

/////////////////////////////////////////////////////////////////////////
// $Id: io_pro.cc,v 1.20 2006-06-09 22:29:07 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

#include "iodev/iodev.h"

  Bit16u BX_CPP_AttrRegparmN(1)
BX_CPU_C::inp16(Bit16u addr)
{
  Bit16u ret16;

  if (BX_CPU_THIS_PTR cr0.pe && (BX_CPU_THIS_PTR get_VM() || (CPL>BX_CPU_THIS_PTR get_IOPL()))) {
    if (! BX_CPU_THIS_PTR allow_io(addr, 2)) {
      BX_DEBUG(("inp16(): I/O access not allowed !"));
      exception(BX_GP_EXCEPTION, 0, 0);
      return(0);
    }
  }

  ret16 = BX_INP(addr, 2);
  return ret16;
}

  void BX_CPP_AttrRegparmN(2)
BX_CPU_C::outp16(Bit16u addr, Bit16u value)
{
  /* If CPL <= IOPL, then all IO addresses are accessible.
   * Otherwise, must check the IO permission map on >286.
   * On the 286, there is no IO permissions map */

  if (BX_CPU_THIS_PTR cr0.pe && (BX_CPU_THIS_PTR get_VM() || (CPL>BX_CPU_THIS_PTR get_IOPL()))) {
    if (! BX_CPU_THIS_PTR allow_io(addr, 2)) {
      BX_DEBUG(("outp16(): I/O access not allowed !"));
      exception(BX_GP_EXCEPTION, 0, 0);
      return;
    }
  }

  BX_OUTP(addr, value, 2);
}

  Bit32u BX_CPP_AttrRegparmN(1)
BX_CPU_C::inp32(Bit16u addr)
{
  Bit32u ret32;

  if (BX_CPU_THIS_PTR cr0.pe && (BX_CPU_THIS_PTR get_VM() || (CPL>BX_CPU_THIS_PTR get_IOPL()))) {
    if (! BX_CPU_THIS_PTR allow_io(addr, 4)) {
      BX_DEBUG(("inp32(): I/O access not allowed !"));
      exception(BX_GP_EXCEPTION, 0, 0);
      return(0);
    }
  }

  ret32 = BX_INP(addr, 4);
  return ret32;
}

  void BX_CPP_AttrRegparmN(2)
BX_CPU_C::outp32(Bit16u addr, Bit32u value)
{
  /* If CPL <= IOPL, then all IO addresses are accessible.
   * Otherwise, must check the IO permission map on >286.
   * On the 286, there is no IO permissions map */

  if (BX_CPU_THIS_PTR cr0.pe && (BX_CPU_THIS_PTR get_VM() || (CPL>BX_CPU_THIS_PTR get_IOPL()))) {
    if (! BX_CPU_THIS_PTR allow_io(addr, 4)) {
      BX_DEBUG(("outp32(): I/O access not allowed !"));
      exception(BX_GP_EXCEPTION, 0, 0);
      return;
    }
  }

  BX_OUTP(addr, value, 4);
}

  Bit8u BX_CPP_AttrRegparmN(1)
BX_CPU_C::inp8(Bit16u addr)
{
  Bit8u ret8;

  if (BX_CPU_THIS_PTR cr0.pe && (BX_CPU_THIS_PTR get_VM() || (CPL>BX_CPU_THIS_PTR get_IOPL()))) {
    if (! BX_CPU_THIS_PTR allow_io(addr, 1)) {
      BX_DEBUG(("inp8(): I/O access not allowed !"));
      exception(BX_GP_EXCEPTION, 0, 0);
      return(0);
    }
  }

  ret8 = BX_INP(addr, 1);
  return ret8;
}


  void BX_CPP_AttrRegparmN(2)
BX_CPU_C::outp8(Bit16u addr, Bit8u value)
{
  /* If CPL <= IOPL, then all IO addresses are accessible.
   * Otherwise, must check the IO permission map on >286.
   * On the 286, there is no IO permissions map */

  if (BX_CPU_THIS_PTR cr0.pe && (BX_CPU_THIS_PTR get_VM() || (CPL>BX_CPU_THIS_PTR get_IOPL()))) {
    if (! BX_CPU_THIS_PTR allow_io(addr, 1)) {
      BX_DEBUG(("outp8(): I/O access not allowed !"));
      exception(BX_GP_EXCEPTION, 0, 0);
      return;
    }
  }

  BX_OUTP(addr, value, 1);
}

bx_bool BX_CPU_C::allow_io(Bit16u addr, unsigned len)
{
  Bit16u io_base, permission16;
  unsigned bit_index, i;

  if (BX_CPU_THIS_PTR tr.cache.valid==0 || 
      BX_CPU_THIS_PTR tr.cache.type != BX_SYS_SEGMENT_AVAIL_386_TSS)
  {
    BX_ERROR(("allow_io(): TR doesn't point to a valid 32bit TSS"));
    return(0);
  }

  if (BX_CPU_THIS_PTR tr.cache.u.tss.limit_scaled < 103) {
    BX_ERROR(("allow_io(): TR.limit < 103"));
    return(0);
  }

  access_linear(BX_CPU_THIS_PTR tr.cache.u.tss.base + 102, 
                   2, 0, BX_READ, &io_base);

  if (io_base <= 103) {
     BX_PANIC(("allow_io(): TR:io_base (%u) <= 103",io_base));
     return(0);
  }

  if ( (Bit32s) (addr/8) >= (Bit32s) (BX_CPU_THIS_PTR tr.cache.u.tss.limit_scaled - io_base)) {
    BX_INFO(("allow_io(): IO addr %x (len %d) outside TSS IO permission map (base=%x, limit=%x) #GP(0)",
      addr, len, io_base, BX_CPU_THIS_PTR tr.cache.u.tss.limit_scaled));
    return(0);
  }

  access_linear(BX_CPU_THIS_PTR tr.cache.u.tss.base + io_base + addr/8,
                   2, 0, BX_READ, &permission16);

  bit_index = addr & 0x07;
  permission16 >>= bit_index;
  for (i=0; i<len; i++) {
    if (permission16 & 0x01)
      return(0);
    permission16 >>= 1;
  }

  return(1);
}