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Bochs/bochs/cpu/protect_ctrl.cc

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/////////////////////////////////////////////////////////////////////////
// $Id: protect_ctrl.cc,v 1.9 2001-10-03 13:10:37 bdenney 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_CPU_C::ARPL_EwGw(BxInstruction_t *i)
{
#if BX_CPU_LEVEL < 2
BX_PANIC(("ARPL_EwRw: not supported on 8086!"));
#else /* 286+ */
Bit16u op2_16, op1_16;
if (protected_mode()) {
/* op1_16 is a register or memory reference */
if (i->mod == 0xc0) {
op1_16 = BX_READ_16BIT_REG(i->rm);
}
else {
/* pointer, segment address pair */
read_RMW_virtual_word(i->seg, i->rm_addr, &op1_16);
}
op2_16 = BX_READ_16BIT_REG(i->nnn);
if ( (op1_16 & 0x03) < (op2_16 & 0x03) ) {
op1_16 = (op1_16 & 0xfffc) | (op2_16 & 0x03);
/* now write back to destination */
if (i->mod == 0xc0) {
if (i->os_32) {
// if 32bit opsize, then 0xff3f is or'd into
// upper 16bits of register
Bit32u op1_32;
op1_32 = BX_READ_32BIT_REG(i->rm);
op1_32 = (op1_32 & 0xffff0000) | op1_16;
op1_32 |= 0xff3f0000;
BX_WRITE_32BIT_REG(i->rm, op1_32);
}
else {
BX_WRITE_16BIT_REG(i->rm, op1_16);
}
}
else {
write_RMW_virtual_word(op1_16);
}
set_ZF(1);
}
else {
set_ZF(0);
}
}
else {
// ARPL not recognized in real or v8086 mode
UndefinedOpcode(i);
return;
}
#endif
}
void
BX_CPU_C::LAR_GvEw(BxInstruction_t *i)
{
/* for 16 bit operand size mode */
Bit16u raw_selector;
bx_descriptor_t descriptor;
bx_selector_t selector;
Bit32u dword1, dword2;
if (v8086_mode()) BX_PANIC(("protect_ctrl: v8086 mode unsupported"));
if (real_mode()) {
BX_PANIC(("LAR_GvEw: not recognized in real mode"));
UndefinedOpcode(i);
return;
}
if (i->mod == 0xc0) {
raw_selector = BX_READ_16BIT_REG(i->rm);
}
else {
/* pointer, segment address pair */
read_virtual_word(i->seg, i->rm_addr, &raw_selector);
}
/* if selector null, clear ZF and done */
if ( (raw_selector & 0xfffc) == 0 ) {
set_ZF(0);
return;
}
parse_selector(raw_selector, &selector);
if ( !fetch_raw_descriptor2(&selector, &dword1, &dword2) ) {
/* not within descriptor table */
set_ZF(0);
return;
}
parse_descriptor(dword1, dword2, &descriptor);
if (descriptor.valid==0) {
set_ZF(0);
//BX_DEBUG(("lar(): descriptor valid bit cleared"));
return;
}
/* if source selector is visible at CPL & RPL,
* within the descriptor table, and of type accepted by LAR instruction,
* then load register with segment limit and set ZF
*/
if ( descriptor.segment ) { /* normal segment */
if ( descriptor.u.segment.executable && descriptor.u.segment.c_ed ) {
/* ignore DPL for conforming segments */
}
else {
if ( (descriptor.dpl<CPL) || (descriptor.dpl<selector.rpl) ) {
set_ZF(0);
return;
}
}
set_ZF(1);
if (i->os_32) {
/* masked by 00FxFF00, where x is undefined */
BX_WRITE_32BIT_REG(i->nnn, dword2 & 0x00ffff00);
}
else {
BX_WRITE_16BIT_REG(i->nnn, dword2 & 0xff00);
}
return;
}
else { /* system or gate segment */
switch ( descriptor.type ) {
case 1: /* available TSS */
case 2: /* LDT */
case 3: /* busy TSS */
case 4: /* 286 call gate */
case 5: /* task gate */
#if BX_CPU_LEVEL >= 3
case 9: /* available 32bit TSS */
case 11: /* busy 32bit TSS */
case 12: /* 32bit call gate */
#endif
break;
default: /* rest not accepted types to LAR */
set_ZF(0);
BX_DEBUG(("lar(): not accepted type"));
return;
break;
}
if ( (descriptor.dpl<CPL) || (descriptor.dpl<selector.rpl) ) {
set_ZF(0);
return;
}
set_ZF(1);
if (i->os_32) {
/* masked by 00FxFF00, where x is undefined ??? */
BX_WRITE_32BIT_REG(i->nnn, dword2 & 0x00ffff00);
}
else {
BX_WRITE_16BIT_REG(i->nnn, dword2 & 0xff00);
}
return;
}
}
void
BX_CPU_C::LSL_GvEw(BxInstruction_t *i)
{
/* for 16 bit operand size mode */
Bit16u raw_selector;
Bit32u limit32;
//bx_descriptor_t descriptor;
bx_selector_t selector;
Bit32u dword1, dword2;
Bit32u descriptor_dpl;
if (v8086_mode()) BX_PANIC(("protect_ctrl: v8086 mode unsupported"));
if (real_mode()) {
BX_PANIC(("LSL_GvEw: not recognized in real mode"));
UndefinedOpcode(i);
return;
}
if (i->mod == 0xc0) {
raw_selector = BX_READ_16BIT_REG(i->rm);
}
else {
/* pointer, segment address pair */
read_virtual_word(i->seg, i->rm_addr, &raw_selector);
}
/* if selector null, clear ZF and done */
if ( (raw_selector & 0xfffc) == 0 ) {
set_ZF(0);
return;
}
parse_selector(raw_selector, &selector);
if ( !fetch_raw_descriptor2(&selector, &dword1, &dword2) ) {
/* not within descriptor table */
set_ZF(0);
return;
}
//parse_descriptor(dword1, dword2, &descriptor);
descriptor_dpl = (dword2 >> 13) & 0x03;
if ( (dword2 & 0x00001000) == 0 ) { // system segment
Bit32u type;
type = (dword2 >> 8) & 0x0000000f;
switch (type) {
case 1: // 16bit TSS
case 3: // 16bit TSS
case 2: // LDT
case 9: // 32bit TSS G00A
case 11:// 32bit TSS G00A
limit32 = (dword1 & 0x0000ffff) | (dword2 & 0x000f0000);
if ( dword2 & 0x00800000 )
limit32 = (limit32 << 12) | 0x00000fff;
if ( (descriptor_dpl<CPL) || (descriptor_dpl<selector.rpl) ) {
set_ZF(0);
return;
}
goto lsl_ok;
break;
default:
set_ZF(0);
return;
}
}
else { // data & code segment
limit32 = (dword1 & 0x0000ffff) | (dword2 & 0x000f0000);
if ( dword2 & 0x00800000 )
limit32 = (limit32 << 12) | 0x00000fff;
if ( (dword2 & 0x00000c00) == 0x00000c00 ) {
// conforming code segment, no check done
goto lsl_ok;
}
if ( (descriptor_dpl<CPL) || (descriptor_dpl<selector.rpl) ) {
set_ZF(0);
return;
}
goto lsl_ok;
}
lsl_ok:
/* all checks pass, limit32 is now byte granular, write to op1 */
set_ZF(1);
if (i->os_32)
BX_WRITE_32BIT_REG(i->nnn, limit32)
else
// chop off upper 16 bits
BX_WRITE_16BIT_REG(i->nnn, (Bit16u) limit32)
}
void
BX_CPU_C::SLDT_Ew(BxInstruction_t *i)
{
#if BX_CPU_LEVEL < 2
BX_PANIC(("SLDT_Ew: not supported on 8086!"));
#else
if (v8086_mode()) BX_PANIC(("protect_ctrl: v8086 mode unsupported"));
if (real_mode()) {
/* not recognized in real address mode */
BX_ERROR(("SLDT_Ew: encountered in real mode."));
UndefinedOpcode(i);
}
else {
Bit16u val16;
val16 = BX_CPU_THIS_PTR ldtr.selector.value;
if (i->mod == 0xc0) {
BX_WRITE_16BIT_REG(i->rm, val16);
}
else {
write_virtual_word(i->seg, i->rm_addr, &val16);
}
}
#endif
}
void
BX_CPU_C::STR_Ew(BxInstruction_t *i)
{
if (v8086_mode()) BX_PANIC(("protect_ctrl: v8086 mode unsupported"));
if (real_mode()) {
// not recognized in real address mode
BX_PANIC(("STR_Ew: encountered in real mode."));
UndefinedOpcode(i);
}
else {
Bit16u val16;
val16 = BX_CPU_THIS_PTR tr.selector.value;
if (i->mod == 0xc0) {
BX_WRITE_16BIT_REG(i->rm, val16);
}
else {
write_virtual_word(i->seg, i->rm_addr, &val16);
}
}
}
void
BX_CPU_C::LLDT_Ew(BxInstruction_t *i)
{
#if BX_CPU_LEVEL < 2
BX_PANIC(("LLDT_Ew: not supported on 8086!"));
#else
if (v8086_mode()) BX_PANIC(("protect_ctrl: v8086 mode unsupported"));
invalidate_prefetch_q();
if (real_mode()) {
BX_PANIC(("lldt: not recognized in real mode"));
UndefinedOpcode(i);
return;
}
else { /* protected mode */
bx_descriptor_t descriptor;
bx_selector_t selector;
Bit16u raw_selector;
Bit32u dword1, dword2;
/* #GP(0) if the current privilege level is not 0 */
if (CPL != 0) {
BX_PANIC(("LLDT: CPL != 0"));
exception(BX_GP_EXCEPTION, 0, 0);
return;
}
if (i->mod == 0xc0) {
raw_selector = BX_READ_16BIT_REG(i->rm);
}
else {
read_virtual_word(i->seg, i->rm_addr, &raw_selector);
}
/* if selector is NULL, invalidate and done */
if ((raw_selector & 0xfffc) == 0) {
BX_CPU_THIS_PTR ldtr.selector.value = raw_selector;
BX_CPU_THIS_PTR ldtr.cache.valid = 0;
return;
}
/* parse fields in selector */
parse_selector(raw_selector, &selector);
// #GP(selector) if the selector operand does not point into GDT
if (selector.ti != 0) {
BX_ERROR(("LLDT: selector.ti != 0"));
exception(BX_GP_EXCEPTION, raw_selector & 0xfffc, 0);
}
if ((selector.index*8 + 7) > BX_CPU_THIS_PTR gdtr.limit) {
BX_PANIC(("lldt: GDT: index > limit"));
exception(BX_GP_EXCEPTION, raw_selector & 0xfffc, 0);
return;
}
access_linear(BX_CPU_THIS_PTR gdtr.base + selector.index*8, 4, 0,
BX_READ, &dword1);
access_linear(BX_CPU_THIS_PTR gdtr.base + selector.index*8 + 4, 4, 0,
BX_READ, &dword2);
parse_descriptor(dword1, dword2, &descriptor);
/* if selector doesn't point to an LDT descriptor #GP(selector) */
if ( (descriptor.valid==0) ||
descriptor.segment ||
(descriptor.type!=2) ) {
BX_ERROR(("lldt: doesn't point to an LDT descriptor!"));
exception(BX_GP_EXCEPTION, raw_selector & 0xfffc, 0);
}
/* #NP(selector) if LDT descriptor is not present */
if (descriptor.p==0) {
BX_ERROR(("lldt: LDT descriptor not present!"));
exception(BX_NP_EXCEPTION, raw_selector & 0xfffc, 0);
}
if (descriptor.u.ldt.limit < 7) {
BX_ERROR(("lldt: ldtr.limit < 7"));
}
BX_CPU_THIS_PTR ldtr.selector = selector;
BX_CPU_THIS_PTR ldtr.cache = descriptor;
BX_CPU_THIS_PTR ldtr.cache.valid = 1;
return;
}
#endif
}
void
BX_CPU_C::LTR_Ew(BxInstruction_t *i)
{
#if BX_CPU_LEVEL < 2
BX_PANIC(("LTR_Ew: not supported on 8086!"));
#else
if (v8086_mode()) BX_PANIC(("protect_ctrl: v8086 mode unsupported"));
invalidate_prefetch_q();
if (protected_mode()) {
bx_descriptor_t descriptor;
bx_selector_t selector;
Bit16u raw_selector;
Bit32u dword1, dword2;
/* #GP(0) if the current privilege level is not 0 */
if (CPL != 0) {
BX_PANIC(("LTR: CPL != 0"));
exception(BX_GP_EXCEPTION, 0, 0);
return;
}
if (i->mod == 0xc0) {
raw_selector = BX_READ_16BIT_REG(i->rm);
}
else {
read_virtual_word(i->seg, i->rm_addr, &raw_selector);
}
/* if selector is NULL, invalidate and done */
if ((raw_selector & 0xfffc) == 0) {
BX_PANIC(("ltr: loading with NULL selector!"));
/* if this is OK, then invalidate and load selector & descriptor cache */
/* load here */
BX_CPU_THIS_PTR tr.selector.value = raw_selector;
BX_CPU_THIS_PTR tr.cache.valid = 0;
return;
}
/* parse fields in selector, then check for null selector */
parse_selector(raw_selector, &selector);
if (selector.ti) {
BX_PANIC(("ltr: selector.ti != 0"));
return;
}
/* fetch 2 dwords of descriptor; call handles out of limits checks */
fetch_raw_descriptor(&selector, &dword1, &dword2, BX_GP_EXCEPTION);
parse_descriptor(dword1, dword2, &descriptor);
/* #GP(selector) if object is not a TSS or is already busy */
if ( (descriptor.valid==0) || descriptor.segment ||
(descriptor.type!=1 && descriptor.type!=9) ) {
BX_PANIC(("ltr: doesn't point to an available TSS descriptor!"));
exception(BX_GP_EXCEPTION, raw_selector & 0xfffc, 0); /* 0 ??? */
return;
}
/* #NP(selector) if TSS descriptor is not present */
if (descriptor.p==0) {
BX_PANIC(("ltr: LDT descriptor not present!"));
exception(BX_NP_EXCEPTION, raw_selector & 0xfffc, 0); /* 0 ??? */
return;
}
if (descriptor.type==1 && descriptor.u.tss286.limit<43) {
BX_PANIC(("ltr:286TSS: loading tr.limit < 43"));
}
else if (descriptor.type==9 && descriptor.u.tss386.limit_scaled<103) {
BX_PANIC(("ltr:386TSS: loading tr.limit < 103"));
}
BX_CPU_THIS_PTR tr.selector = selector;
BX_CPU_THIS_PTR tr.cache = descriptor;
BX_CPU_THIS_PTR tr.cache.valid = 1;
/* mark as busy */
dword2 |= 0x00000200; /* set busy bit */
access_linear(BX_CPU_THIS_PTR gdtr.base + selector.index*8 + 4, 4, 0,
BX_WRITE, &dword2);
return;
}
else {
BX_PANIC(("ltr_ew: not recognized in real-mode!"));
UndefinedOpcode(i);
return;
}
#endif
}
void
BX_CPU_C::VERR_Ew(BxInstruction_t *i)
{
/* for 16 bit operand size mode */
Bit16u raw_selector;
bx_descriptor_t descriptor;
bx_selector_t selector;
Bit32u dword1, dword2;
if (v8086_mode()) BX_PANIC(("protect_ctrl: v8086 mode unsupported"));
if (real_mode()) {
BX_PANIC(("VERR_Ew: not recognized in real mode"));
UndefinedOpcode(i);
return;
}
if (i->mod == 0xc0) {
raw_selector = BX_READ_16BIT_REG(i->rm);
}
else {
/* pointer, segment address pair */
read_virtual_word(i->seg, i->rm_addr, &raw_selector);
}
/* if selector null, clear ZF and done */
if ( (raw_selector & 0xfffc) == 0 ) {
set_ZF(0);
BX_ERROR(("VERR: null selector"));
return;
}
/* if source selector is visible at CPL & RPL,
* within the descriptor table, and of type accepted by VERR instruction,
* then load register with segment limit and set ZF */
parse_selector(raw_selector, &selector);
if ( !fetch_raw_descriptor2(&selector, &dword1, &dword2) ) {
/* not within descriptor table */
set_ZF(0);
BX_ERROR(("VERR: not in table"));
return;
}
parse_descriptor(dword1, dword2, &descriptor);
if ( descriptor.segment==0 ) { /* system or gate descriptor */
set_ZF(0); /* inaccessible */
BX_ERROR(("VERR: system descriptor"));
return;
}
if ( descriptor.valid==0 ) {
set_ZF(0);
BX_INFO(("VERR: valid bit cleared"));
return;
}
/* normal data/code segment */
if ( descriptor.u.segment.executable ) { /* code segment */
/* ignore DPL for readable conforming segments */
if ( descriptor.u.segment.c_ed &&
descriptor.u.segment.r_w) {
set_ZF(1); /* accessible */
BX_INFO(("VERR: conforming code, OK"));
return;
}
if ( descriptor.u.segment.r_w==0 ) {
set_ZF(0); /* inaccessible */
BX_INFO(("VERR: code not readable"));
return;
}
/* readable, non-conforming code segment */
if ( (descriptor.dpl<CPL) || (descriptor.dpl<selector.rpl) ) {
set_ZF(0); /* inaccessible */
BX_INFO(("VERR: non-coforming code not withing priv level"));
return;
}
set_ZF(1); /* accessible */
BX_INFO(("VERR: code seg readable"));
return;
}
else { /* data segment */
if ( (descriptor.dpl<CPL) || (descriptor.dpl<selector.rpl) ) {
set_ZF(0); /* not accessible */
BX_INFO(("VERR: data seg not withing priv level"));
return;
}
set_ZF(1); /* accessible */
BX_ERROR(("VERR: data segment OK"));
return;
}
}
void
BX_CPU_C::VERW_Ew(BxInstruction_t *i)
{
/* for 16 bit operand size mode */
Bit16u raw_selector;
bx_descriptor_t descriptor;
bx_selector_t selector;
Bit32u dword1, dword2;
if (v8086_mode()) BX_PANIC(("protect_ctrl: v8086 mode unsupported"));
if (real_mode()) {
BX_PANIC(("VERW_Ew: not recognized in real mode"));
UndefinedOpcode(i);
return;
}
if (i->mod == 0xc0) {
raw_selector = BX_READ_16BIT_REG(i->rm);
}
else {
/* pointer, segment address pair */
read_virtual_word(i->seg, i->rm_addr, &raw_selector);
}
/* if selector null, clear ZF and done */
if ( (raw_selector & 0xfffc) == 0 ) {
set_ZF(0);
BX_ERROR(("VERW: null selector"));
return;
}
/* if source selector is visible at CPL & RPL,
* within the descriptor table, and of type accepted by VERW instruction,
* then load register with segment limit and set ZF */
parse_selector(raw_selector, &selector);
if ( !fetch_raw_descriptor2(&selector, &dword1, &dword2) ) {
/* not within descriptor table */
set_ZF(0);
BX_ERROR(("VERW: not in table"));
return;
}
parse_descriptor(dword1, dword2, &descriptor);
/* rule out system segments & code segments */
if ( descriptor.segment==0 || descriptor.u.segment.executable ) {
set_ZF(0);
BX_ERROR(("VERW: system seg or code"));
return;
}
if ( descriptor.valid==0 ) {
set_ZF(0);
BX_INFO(("VERW: valid bit cleared"));
return;
}
/* data segment */
if ( descriptor.u.segment.r_w ) { /* writable */
if ( (descriptor.dpl<CPL) || (descriptor.dpl<selector.rpl) ) {
set_ZF(0); /* not accessible */
BX_INFO(("VERW: writable data seg not within priv level"));
return;
}
set_ZF(1); /* accessible */
BX_ERROR(("VERW: data seg writable"));
return;
}
set_ZF(0); /* not accessible */
BX_INFO(("VERW: data seg not writable"));
return;
}
void
BX_CPU_C::SGDT_Ms(BxInstruction_t *i)
{
#if BX_CPU_LEVEL < 2
BX_PANIC(("SGDT_Ms: not supported on 8086!"));
#else
Bit16u limit_16;
Bit32u base_32;
if (v8086_mode()) BX_PANIC(("protect_ctrl: v8086 mode unsupported"));
/* op1 is a register or memory reference */
if (i->mod == 0xc0) {
/* undefined opcode exception */
BX_PANIC(("SGDT_Ms: use of register is undefined opcode."));
UndefinedOpcode(i);
return;
}
limit_16 = BX_CPU_THIS_PTR gdtr.limit;
base_32 = BX_CPU_THIS_PTR gdtr.base;
#if BX_CPU_LEVEL == 2
base_32 |= 0xff000000; /* ??? */
#else /* 386+ */
/* 32bit processors always write 32bits of base */
#endif
write_virtual_word(i->seg, i->rm_addr, &limit_16);
write_virtual_dword(i->seg, i->rm_addr+2, &base_32);
#endif
}
void
BX_CPU_C::SIDT_Ms(BxInstruction_t *i)
{
#if BX_CPU_LEVEL < 2
BX_PANIC(("SIDT_Ms: not supported on 8086!"));
#else
Bit16u limit_16;
Bit32u base_32;
if (v8086_mode()) BX_PANIC(("protect_ctrl: v8086 mode unsupported"));
/* op1 is a register or memory reference */
if (i->mod == 0xc0) {
/* undefined opcode exception */
BX_PANIC(("SIDT: use of register is undefined opcode."));
UndefinedOpcode(i);
return;
}
limit_16 = BX_CPU_THIS_PTR idtr.limit;
base_32 = BX_CPU_THIS_PTR idtr.base;
#if BX_CPU_LEVEL == 2
base_32 |= 0xff000000;
#else /* 386+ */
/* ??? regardless of operand size, all 32bits of base are stored */
#endif
write_virtual_word(i->seg, i->rm_addr, &limit_16);
write_virtual_dword(i->seg, i->rm_addr+2, &base_32);
#endif
}
void
BX_CPU_C::LGDT_Ms(BxInstruction_t *i)
{
#if BX_CPU_LEVEL < 2
BX_PANIC(("LGDT_Ms: not supported on 8086!"));
#else
if (v8086_mode()) BX_PANIC(("protect_ctrl: v8086 mode unsupported"));
invalidate_prefetch_q();
if (protected_mode() && (CPL!=0)) {
BX_PANIC(("LGDT: protected mode: CPL!=0"));
exception(BX_GP_EXCEPTION, 0, 0);
return;
}
/* op1 is a register or memory reference */
if (i->mod == 0xc0) {
BX_PANIC(("LGDT generating exception 6"));
UndefinedOpcode(i);
return;
}
#if BX_CPU_LEVEL >= 3
if (i->os_32) {
Bit16u limit_16;
Bit32u base0_31;
read_virtual_word(i->seg, i->rm_addr, &limit_16);
read_virtual_dword(i->seg, i->rm_addr + 2, &base0_31);
BX_CPU_THIS_PTR gdtr.limit = limit_16;
BX_CPU_THIS_PTR gdtr.base = base0_31;
}
else
#endif
{
Bit16u limit_16, base0_15;
Bit8u base16_23;
read_virtual_word(i->seg, i->rm_addr, &limit_16);
read_virtual_word(i->seg, i->rm_addr + 2, &base0_15);
read_virtual_byte(i->seg, i->rm_addr + 4, &base16_23);
/* ignore high 8 bits */
BX_CPU_THIS_PTR gdtr.limit = limit_16;
BX_CPU_THIS_PTR gdtr.base = (base16_23 << 16) | base0_15;
}
#endif
}
void
BX_CPU_C::LIDT_Ms(BxInstruction_t *i)
{
#if BX_CPU_LEVEL < 2
BX_PANIC(("LIDT_Ms: not supported on 8086!"));
#else
Bit16u limit_16;
Bit32u base_32;
if (v8086_mode()) BX_PANIC(("protect_ctrl: v8086 mode unsupported"));
invalidate_prefetch_q();
if (protected_mode()) {
if (CPL != 0) {
BX_PANIC(("LIDT(): CPL(%u) != 0", (unsigned) CPL));
exception(BX_GP_EXCEPTION, 0, 0);
return;
}
}
/* op1 is a register or memory reference */
if (i->mod == 0xc0) {
/* undefined opcode exception */
BX_PANIC(("LIDT generating exception 6"));
UndefinedOpcode(i);
return;
}
read_virtual_word(i->seg, i->rm_addr, &limit_16);
read_virtual_dword(i->seg, i->rm_addr + 2, &base_32);
BX_CPU_THIS_PTR idtr.limit = limit_16;
#if BX_CPU_LEVEL >= 3
if (i->os_32)
BX_CPU_THIS_PTR idtr.base = base_32;
else
#endif
BX_CPU_THIS_PTR idtr.base = base_32 & 0x00ffffff; /* ignore upper 8 bits */
#endif
}
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