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|
/////////////////////////////////////////////////////////////////////////
// $Id: ctrl_xfer16.cc,v 1.36 2006/06/09 22:29:06 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::RETnear16_Iw(bxInstruction_c *i)
{
Bit16u return_IP;
#if BX_DEBUGGER
BX_CPU_THIS_PTR show_flag |= Flag_ret;
#endif
pop_16(&return_IP);
if (return_IP > BX_CPU_THIS_PTR sregs[BX_SEG_REG_CS].cache.u.segment.limit_scaled)
{
BX_ERROR(("retnear_iw: IP > limit"));
exception(BX_GP_EXCEPTION, 0, 0);
}
EIP = return_IP;
Bit16u imm16 = i->Iw();
if (BX_CPU_THIS_PTR sregs[BX_SEG_REG_SS].cache.u.segment.d_b) /* 32bit stack */
ESP += imm16;
else
SP += imm16;
BX_INSTR_UCNEAR_BRANCH(BX_CPU_ID, BX_INSTR_IS_RET, EIP);
}
void BX_CPU_C::RETnear16(bxInstruction_c *i)
{
Bit16u return_IP;
#if BX_DEBUGGER
BX_CPU_THIS_PTR show_flag |= Flag_ret;
#endif
pop_16(&return_IP);
if (return_IP > BX_CPU_THIS_PTR sregs[BX_SEG_REG_CS].cache.u.segment.limit_scaled)
{
BX_ERROR(("retnear: IP > limit"));
exception(BX_GP_EXCEPTION, 0, 0);
}
EIP = return_IP;
BX_INSTR_UCNEAR_BRANCH(BX_CPU_ID, BX_INSTR_IS_RET, EIP);
}
void BX_CPU_C::RETfar16_Iw(bxInstruction_c *i)
{
Bit16s imm16;
Bit16u ip, cs_raw;
invalidate_prefetch_q();
#if BX_DEBUGGER
BX_CPU_THIS_PTR show_flag |= Flag_ret;
#endif
imm16 = i->Iw();
#if BX_CPU_LEVEL >= 2
if (protected_mode()) {
BX_CPU_THIS_PTR return_protected(i, imm16);
goto done;
}
#endif
pop_16(&ip);
pop_16(&cs_raw);
EIP = (Bit32u) ip;
load_seg_reg(&BX_CPU_THIS_PTR sregs[BX_SEG_REG_CS], cs_raw);
if (BX_CPU_THIS_PTR sregs[BX_SEG_REG_SS].cache.u.segment.d_b)
ESP += imm16;
else
SP += imm16;
done:
BX_INSTR_FAR_BRANCH(BX_CPU_ID, BX_INSTR_IS_RET,
BX_CPU_THIS_PTR sregs[BX_SEG_REG_CS].selector.value, EIP);
}
void BX_CPU_C::RETfar16(bxInstruction_c *i)
{
Bit16u ip, cs_raw;
invalidate_prefetch_q();
#if BX_DEBUGGER
BX_CPU_THIS_PTR show_flag |= Flag_ret;
#endif
#if BX_CPU_LEVEL >= 2
if ( protected_mode() ) {
BX_CPU_THIS_PTR return_protected(i, 0);
goto done;
}
#endif
pop_16(&ip);
pop_16(&cs_raw);
EIP = (Bit32u) ip;
load_seg_reg(&BX_CPU_THIS_PTR sregs[BX_SEG_REG_CS], cs_raw);
done:
BX_INSTR_FAR_BRANCH(BX_CPU_ID, BX_INSTR_IS_RET,
BX_CPU_THIS_PTR sregs[BX_SEG_REG_CS].selector.value, EIP);
}
void BX_CPU_C::CALL_Aw(bxInstruction_c *i)
{
Bit32u new_EIP;
#if BX_DEBUGGER
BX_CPU_THIS_PTR show_flag |= Flag_call;
#endif
new_EIP = EIP + (Bit32s) i->Id();
new_EIP &= 0x0000ffff;
#if BX_CPU_LEVEL >= 2
if (new_EIP > BX_CPU_THIS_PTR sregs[BX_SEG_REG_CS].cache.u.segment.limit_scaled)
{
BX_ERROR(("CALL_Aw: new_IP > BX_CPU_THIS_PTR sregs[BX_SEG_REG_CS].limit"));
exception(BX_GP_EXCEPTION, 0, 0);
}
#endif
/* push 16 bit EA of next instruction */
push_16(IP);
EIP = new_EIP;
BX_INSTR_UCNEAR_BRANCH(BX_CPU_ID, BX_INSTR_IS_CALL, EIP);
}
void BX_CPU_C::CALL16_Ap(bxInstruction_c *i)
{
Bit16u cs_raw;
Bit16u disp16;
invalidate_prefetch_q();
#if BX_DEBUGGER
BX_CPU_THIS_PTR show_flag |= Flag_call;
#endif
disp16 = i->Iw();
cs_raw = i->Iw2();
#if BX_CPU_LEVEL >= 2
if (protected_mode()) {
BX_CPU_THIS_PTR call_protected(i, cs_raw, disp16);
goto done;
}
#endif
push_16(BX_CPU_THIS_PTR sregs[BX_SEG_REG_CS].selector.value);
push_16((Bit16u) EIP);
EIP = (Bit32u) disp16;
load_seg_reg(&BX_CPU_THIS_PTR sregs[BX_SEG_REG_CS], cs_raw);
done:
BX_INSTR_FAR_BRANCH(BX_CPU_ID, BX_INSTR_IS_CALL,
BX_CPU_THIS_PTR sregs[BX_SEG_REG_CS].selector.value, EIP);
}
void BX_CPU_C::CALL_Ew(bxInstruction_c *i)
{
Bit16u op1_16;
#if BX_DEBUGGER
BX_CPU_THIS_PTR show_flag |= Flag_call;
#endif
if (i->modC0()) {
op1_16 = BX_READ_16BIT_REG(i->rm());
}
else {
read_virtual_word(i->seg(), RMAddr(i), &op1_16);
}
#if BX_CPU_LEVEL >= 2
if (op1_16 > BX_CPU_THIS_PTR sregs[BX_SEG_REG_CS].cache.u.segment.limit_scaled)
{
BX_ERROR(("CALL_Ew: IP out of CS limits!"));
exception(BX_GP_EXCEPTION, 0, 0);
}
#endif
push_16(IP);
EIP = op1_16;
BX_INSTR_UCNEAR_BRANCH(BX_CPU_ID, BX_INSTR_IS_CALL, EIP);
}
void BX_CPU_C::CALL16_Ep(bxInstruction_c *i)
{
Bit16u cs_raw;
Bit16u op1_16;
invalidate_prefetch_q();
#if BX_DEBUGGER
BX_CPU_THIS_PTR show_flag |= Flag_call;
#endif
if (i->modC0()) {
BX_INFO(("CALL_Ep: op1 is a register"));
exception(BX_UD_EXCEPTION, 0, 0);
}
read_virtual_word(i->seg(), RMAddr(i), &op1_16);
read_virtual_word(i->seg(), RMAddr(i)+2, &cs_raw);
if ( protected_mode() ) {
BX_CPU_THIS_PTR call_protected(i, cs_raw, op1_16);
goto done;
}
push_16(BX_CPU_THIS_PTR sregs[BX_SEG_REG_CS].selector.value);
push_16(IP);
EIP = op1_16;
load_seg_reg(&BX_CPU_THIS_PTR sregs[BX_SEG_REG_CS], cs_raw);
done:
BX_INSTR_FAR_BRANCH(BX_CPU_ID, BX_INSTR_IS_CALL,
BX_CPU_THIS_PTR sregs[BX_SEG_REG_CS].selector.value, EIP);
}
void BX_CPU_C::JMP_Jw(bxInstruction_c *i)
{
Bit32u new_EIP = EIP + (Bit32s) i->Id();
new_EIP &= 0x0000ffff;
branch_near32(new_EIP);
BX_INSTR_UCNEAR_BRANCH(BX_CPU_ID, BX_INSTR_IS_JMP, new_EIP);
}
void BX_CPU_C::JCC_Jw(bxInstruction_c *i)
{
bx_bool condition;
switch (i->b1() & 0x0f) {
case 0x00: /* JO */ condition = get_OF(); break;
case 0x01: /* JNO */ condition = !get_OF(); break;
case 0x02: /* JB */ condition = get_CF(); break;
case 0x03: /* JNB */ condition = !get_CF(); break;
case 0x04: /* JZ */ condition = get_ZF(); break;
case 0x05: /* JNZ */ condition = !get_ZF(); break;
case 0x06: /* JBE */ condition = get_CF() || get_ZF(); break;
case 0x07: /* JNBE */ condition = !get_CF() && !get_ZF(); break;
case 0x08: /* JS */ condition = get_SF(); break;
case 0x09: /* JNS */ condition = !get_SF(); break;
case 0x0A: /* JP */ condition = get_PF(); break;
case 0x0B: /* JNP */ condition = !get_PF(); break;
case 0x0C: /* JL */ condition = getB_SF() != getB_OF(); break;
case 0x0D: /* JNL */ condition = getB_SF() == getB_OF(); break;
case 0x0E: /* JLE */ condition = get_ZF() || (getB_SF() != getB_OF()); break;
case 0x0F: /* JNLE */ condition = (getB_SF() == getB_OF()) && !get_ZF(); break;
default:
condition = 0; // For compiler...all targets should set condition.
break;
}
if (condition) {
Bit32u new_EIP = EIP + (Bit32s) i->Id();
new_EIP &= 0x0000ffff;
branch_near32(new_EIP);
BX_INSTR_CNEAR_BRANCH_TAKEN(BX_CPU_ID, new_EIP);
}
#if BX_INSTRUMENTATION
else {
BX_INSTR_CNEAR_BRANCH_NOT_TAKEN(BX_CPU_ID);
}
#endif
}
void BX_CPU_C::JZ_Jw(bxInstruction_c *i)
{
if (get_ZF()) {
Bit32u new_EIP = EIP + (Bit32s) i->Id();
new_EIP &= 0x0000ffff;
branch_near32(new_EIP);
BX_INSTR_CNEAR_BRANCH_TAKEN(BX_CPU_ID, new_EIP);
}
#if BX_INSTRUMENTATION
else {
BX_INSTR_CNEAR_BRANCH_NOT_TAKEN(BX_CPU_ID);
}
#endif
}
void BX_CPU_C::JNZ_Jw(bxInstruction_c *i)
{
if (!get_ZF()) {
Bit32u new_EIP = EIP + (Bit32s) i->Id();
new_EIP &= 0x0000ffff;
branch_near32(new_EIP);
BX_INSTR_CNEAR_BRANCH_TAKEN(BX_CPU_ID, new_EIP);
}
#if BX_INSTRUMENTATION
else {
BX_INSTR_CNEAR_BRANCH_NOT_TAKEN(BX_CPU_ID);
}
#endif
}
void BX_CPU_C::JMP_Ew(bxInstruction_c *i)
{
Bit16u op1_16;
if (i->modC0()) {
op1_16 = BX_READ_16BIT_REG(i->rm());
}
else {
read_virtual_word(i->seg(), RMAddr(i), &op1_16);
}
Bit32u new_EIP = op1_16;
branch_near32(new_EIP);
BX_INSTR_UCNEAR_BRANCH(BX_CPU_ID, BX_INSTR_IS_JMP, new_EIP);
}
/* Far indirect jump */
void BX_CPU_C::JMP16_Ep(bxInstruction_c *i)
{
Bit16u cs_raw;
Bit16u op1_16;
invalidate_prefetch_q();
if (i->modC0()) {
/* far indirect must specify a memory address */
BX_INFO(("JMP_Ep(): op1 is a register"));
exception(BX_UD_EXCEPTION, 0, 0);
}
read_virtual_word(i->seg(), RMAddr(i), &op1_16);
read_virtual_word(i->seg(), RMAddr(i)+2, &cs_raw);
#if BX_CPU_LEVEL >= 2
if ( protected_mode() ) {
BX_CPU_THIS_PTR jump_protected(i, cs_raw, op1_16);
goto done;
}
#endif
EIP = op1_16;
load_seg_reg(&BX_CPU_THIS_PTR sregs[BX_SEG_REG_CS], cs_raw);
done:
BX_INSTR_FAR_BRANCH(BX_CPU_ID, BX_INSTR_IS_JMP,
BX_CPU_THIS_PTR sregs[BX_SEG_REG_CS].selector.value, EIP);
}
void BX_CPU_C::IRET16(bxInstruction_c *i)
{
Bit16u ip, cs_raw, flags;
invalidate_prefetch_q();
#if BX_DEBUGGER
BX_CPU_THIS_PTR show_flag |= Flag_iret;
#endif
BX_CPU_THIS_PTR nmi_disable = 0;
if (v8086_mode()) {
// IOPL check in stack_return_from_v86()
iret16_stack_return_from_v86(i);
goto done;
}
#if BX_CPU_LEVEL >= 2
if (BX_CPU_THIS_PTR cr0.pe) {
iret_protected(i);
goto done;
}
#endif
if (! can_pop(6)) {
BX_ERROR(("IRET: top 6 bytes of stack not within stack limits"));
exception(BX_SS_EXCEPTION, 0, 0);
}
pop_16(&ip);
pop_16(&cs_raw);
pop_16(&flags);
load_seg_reg(&BX_CPU_THIS_PTR sregs[BX_SEG_REG_CS], cs_raw);
EIP = (Bit32u) ip;
write_flags(flags, /* change IOPL? */ 1, /* change IF? */ 1);
done:
BX_INSTR_FAR_BRANCH(BX_CPU_ID, BX_INSTR_IS_IRET,
BX_CPU_THIS_PTR sregs[BX_SEG_REG_CS].selector.value, EIP);
}
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