Bochs/bochs/cpu/flag_ctrl_pro.cc
2005-07-01 14:06:02 +00:00

148 lines
3.9 KiB
C++

/////////////////////////////////////////////////////////////////////////
// $Id: flag_ctrl_pro.cc,v 1.18 2005-07-01 14:05:56 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"
#define LOG_THIS BX_CPU_THIS_PTR
void BX_CPP_AttrRegparmN(2)
BX_CPU_C::writeEFlags(Bit32u flags, Bit32u changeMask)
{
Bit32u supportMask, newEFlags;
// Build a mask of the non-reserved bits:
// x,x,x,x,VM,RF,x,NT,IOPL,OF,DF,IF,TF,SF,ZF,x,AF,x,PF,x,CF
supportMask = 0x00037fd5;
#if BX_CPU_LEVEL >= 4
supportMask |= ((1<<21) | (1<<18)); // ID/AC
#endif
// Screen out changing of any unsupported bits.
changeMask &= supportMask;
newEFlags = (BX_CPU_THIS_PTR eflags.val32 & ~changeMask) |
(flags & changeMask);
BX_CPU_THIS_PTR setEFlags( newEFlags );
BX_CPU_THIS_PTR lf_flags_status = 0; // OSZAPC flags are known.
if (newEFlags & (1 << 8)) {
BX_CPU_THIS_PTR async_event = 1; // TF = 1
}
}
void BX_CPP_AttrRegparmN(3)
BX_CPU_C::write_flags(Bit16u flags, bx_bool change_IOPL, bx_bool change_IF)
{
Bit32u changeMask = 0x0dd5;
#if BX_CPU_LEVEL >= 3
changeMask |= (1<<14); // NT is modified as requested.
if (change_IOPL)
changeMask |= (3<<12); // IOPL is modified as requested.
#endif
if (change_IF)
changeMask |= (1<<9);
writeEFlags(Bit32u(flags), changeMask);
}
#if BX_CPU_LEVEL >= 3
void BX_CPU_C::write_eflags(Bit32u eflags_raw, bx_bool change_IOPL,
bx_bool change_IF, bx_bool change_VM, bx_bool change_RF)
{
Bit32u changeMask = 0x4dd5;
#if BX_CPU_LEVEL >= 4
changeMask |= ((1<<21) | (1<<18)); // ID/AC
#endif
if (change_IOPL)
changeMask |= (3<<12);
if (change_IF)
changeMask |= (1<<9);
if (change_VM)
changeMask |= (1<<17);
if (change_RF)
changeMask |= (1<<16);
writeEFlags(eflags_raw, changeMask);
}
#endif /* BX_CPU_LEVEL >= 3 */
// Cause arithmetic flags to be in known state and cached in val32.
Bit32u BX_CPU_C::force_flags(void)
{
if (BX_CPU_THIS_PTR lf_flags_status) {
(void) get_CF();
(void) get_PF();
(void) get_AF();
(void) get_ZF();
(void) get_SF();
(void) get_OF();
}
return BX_CPU_THIS_PTR eflags.val32;
}
Bit16u BX_CPU_C::read_flags(void)
{
Bit16u flags16 = (Bit16u) BX_CPU_THIS_PTR force_flags();
/* 8086: bits 12-15 always set to 1.
* 286: in real mode, bits 12-15 always cleared.
* 386+: real-mode: bit15 cleared, bits 14..12 are last loaded value
* protected-mode: bit 15 clear, bit 14 = last loaded, IOPL?
*/
#if BX_CPU_LEVEL < 2
flags16 |= 0xF000; /* 8086 nature */
#elif BX_CPU_LEVEL == 2
if (real_mode()) {
flags16 &= 0x0FFF; /* 80286 in real mode nature */
}
#endif
return(flags16);
}
#if BX_CPU_LEVEL >= 3
Bit32u BX_CPU_C::read_eflags(void)
{
Bit32u flags32 = BX_CPU_THIS_PTR force_flags();
#if 0
/*
* 386+: real-mode: bit15 cleared, bits 14..12 are last loaded value
* protected-mode: bit 15 clear, bit 14 = last loaded, IOPL?
*/
#endif
return(flags32);
}
#endif