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Bochs/bochs/cpu/stack_pro.cc

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// Copyright (C) 2000 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
#include "bochs.h"
void
BX_CPU_C::push_16(Bit16u value16)
{
Bit32u temp_ESP;
#if BX_CPU_LEVEL >= 2
if (protected_mode()) {
#if BX_CPU_LEVEL >= 3
if (BX_CPU_THIS_PTR sregs[BX_SEG_REG_SS].cache.u.segment.d_b)
temp_ESP = ESP;
else
#endif
temp_ESP = SP;
if (!can_push(&BX_CPU_THIS_PTR sregs[BX_SEG_REG_SS].cache, temp_ESP, 2)) {
bx_panic("push_16(): can't push on stack\n");
exception(BX_SS_EXCEPTION, 0, 0);
return;
}
/* access within limits */
write_virtual_word(BX_SEG_REG_SS, temp_ESP - 2, &value16);
if (BX_CPU_THIS_PTR sregs[BX_SEG_REG_SS].cache.u.segment.d_b)
ESP -= 2;
else
SP -= 2;
return;
}
else
#endif
{ /* real mode */
if (BX_CPU_THIS_PTR sregs[BX_SEG_REG_SS].cache.u.segment.d_b) {
if (ESP == 1)
bx_panic("CPU shutting down due to lack of stack space, ESP==1\n");
ESP -= 2;
temp_ESP = ESP;
}
else {
if (SP == 1)
bx_panic("CPU shutting down due to lack of stack space, SP==1\n");
SP -= 2;
temp_ESP = SP;
}
write_virtual_word(BX_SEG_REG_SS, temp_ESP, &value16);
return;
}
}
#if BX_CPU_LEVEL >= 3
/* push 32 bit operand size */
void
BX_CPU_C::push_32(Bit32u value32)
{
/* must use StackAddrSize, and either ESP or SP accordingly */
if (BX_CPU_THIS_PTR sregs[BX_SEG_REG_SS].cache.u.segment.d_b) { /* StackAddrSize = 32 */
/* 32bit stack size: pushes use SS:ESP */
if (protected_mode()) {
if (!can_push(&BX_CPU_THIS_PTR sregs[BX_SEG_REG_SS].cache, ESP, 4)) {
bx_panic("push_32(): push outside stack limits\n");
/* #SS(0) */
}
}
else { /* real mode */
if ((ESP>=1) && (ESP<=3)) {
bx_panic("push_32: ESP=%08x\n", (unsigned) ESP);
}
}
write_virtual_dword(BX_SEG_REG_SS, ESP-4, &value32);
ESP -= 4;
/* will return after error anyway */
return;
}
else { /* 16bit stack size: pushes use SS:SP */
if (protected_mode()) {
if (!can_push(&BX_CPU_THIS_PTR sregs[BX_SEG_REG_SS].cache, SP, 4)) {
bx_panic("push_32(): push outside stack limits\n");
/* #SS(0) */
}
}
else { /* real mode */
if ((SP>=1) && (SP<=3)) {
bx_panic("push_32: SP=%08x\n", (unsigned) SP);
}
}
write_virtual_dword(BX_SEG_REG_SS, (Bit16u) (SP-4), &value32);
SP -= 4;
/* will return after error anyway */
return;
}
}
#endif /* BX_CPU_LEVEL >= 3 */
void
BX_CPU_C::pop_16(Bit16u *value16_ptr)
{
Bit32u temp_ESP;
#if BX_CPU_LEVEL >= 3
if (BX_CPU_THIS_PTR sregs[BX_SEG_REG_SS].cache.u.segment.d_b)
temp_ESP = ESP;
else
#endif
temp_ESP = SP;
#if BX_CPU_LEVEL >= 2
if (protected_mode()) {
if ( !can_pop(2) ) {
bx_printf("pop_16(): can't pop from stack\n");
exception(BX_SS_EXCEPTION, 0, 0);
return;
}
}
#endif
/* access within limits */
read_virtual_word(BX_SEG_REG_SS, temp_ESP, value16_ptr);
if (BX_CPU_THIS_PTR sregs[BX_SEG_REG_SS].cache.u.segment.d_b)
ESP += 2;
else
SP += 2;
}
#if BX_CPU_LEVEL >= 3
void
BX_CPU_C::pop_32(Bit32u *value32_ptr)
{
Bit32u temp_ESP;
/* 32 bit stack mode: use SS:ESP */
if (BX_CPU_THIS_PTR sregs[BX_SEG_REG_SS].cache.u.segment.d_b)
temp_ESP = ESP;
else
temp_ESP = SP;
/* 16 bit stack mode: use SS:SP */
if (protected_mode()) {
if ( !can_pop(4) ) {
bx_panic("pop_32(): can't pop from stack\n");
exception(BX_SS_EXCEPTION, 0, 0);
return;
}
}
/* access within limits */
read_virtual_dword(BX_SEG_REG_SS, temp_ESP, value32_ptr);
if (BX_CPU_THIS_PTR sregs[BX_SEG_REG_SS].cache.u.segment.d_b==1)
ESP += 4;
else
SP += 4;
}
#endif
#if BX_CPU_LEVEL >= 2
Boolean
BX_CPU_C::can_push(bx_descriptor_t *descriptor, Bit32u esp, Bit32u bytes)
{
if ( real_mode() ) { /* code not needed ??? */
bx_panic("can_push(): called in real mode\n");
return(0); /* never gets here */
}
// small stack compares against 16-bit SP
if (!descriptor->u.segment.d_b)
esp &= 0x0000ffff;
if (descriptor->valid==0) {
bx_panic("can_push(): SS invalidated.\n");
return(0);
}
if (descriptor->p==0) {
bx_panic("can_push(): not present\n");
return(0);
}
if (descriptor->u.segment.c_ed) { /* expand down segment */
Bit32u expand_down_limit;
if (descriptor->u.segment.d_b)
expand_down_limit = 0xffffffff;
else
expand_down_limit = 0x0000ffff;
if (esp==0) {
bx_panic("can_push(): esp=0, wraparound?\n");
return(0);
}
if (esp < bytes) {
bx_panic("can_push(): expand-down: esp < N\n");
return(0);
}
if ( (esp - bytes) <= descriptor->u.segment.limit_scaled ) {
bx_panic("can_push(): expand-down: esp-N < limit\n");
return(0);
}
if ( esp > expand_down_limit ) {
bx_panic("can_push(): esp > expand-down-limit\n");
return(0);
}
return(1);
}
else { /* normal (expand-up) segment */
if (descriptor->u.segment.limit_scaled==0) {
bx_panic("can_push(): found limit of 0\n");
return(0);
}
// Look at case where esp==0. Possibly, it's an intentional wraparound
// If so, limit must be the maximum for the given stack size
if (esp==0) {
if (descriptor->u.segment.d_b && (descriptor->u.segment.limit_scaled==0xffffffff))
return(1);
if ((descriptor->u.segment.d_b==0) && (descriptor->u.segment.limit_scaled>=0xffff))
return(1);
bx_panic("can_push(): esp=0, normal, wraparound? limit=%08x\n",
descriptor->u.segment.limit_scaled);
return(0);
}
if (esp < bytes) {
bx_printf("can_push(): expand-up: esp < N\n");
return(0);
}
if ((esp-1) > descriptor->u.segment.limit_scaled) {
bx_printf("can_push(): expand-up: SP > limit\n");
return(0);
}
/* all checks pass */
return(1);
}
}
#endif
#if BX_CPU_LEVEL >= 2
Boolean
BX_CPU_C::can_pop(Bit32u bytes)
{
Bit32u temp_ESP, expand_down_limit;
/* ??? */
if (real_mode()) bx_panic("can_pop(): called in real mode?\n");
if (BX_CPU_THIS_PTR sregs[BX_SEG_REG_SS].cache.u.segment.d_b) { /* Big bit set: use ESP */
temp_ESP = ESP;
expand_down_limit = 0xFFFFFFFF;
}
else { /* Big bit clear: use SP */
temp_ESP = SP;
expand_down_limit = 0xFFFF;
}
if (BX_CPU_THIS_PTR sregs[BX_SEG_REG_SS].cache.valid==0) {
bx_panic("can_pop(): SS invalidated.\n");
return(0); /* never gets here */
}
if (BX_CPU_THIS_PTR sregs[BX_SEG_REG_SS].cache.p==0) { /* ??? */
bx_panic("can_pop(): SS.p = 0\n");
return(0);
}
if (BX_CPU_THIS_PTR sregs[BX_SEG_REG_SS].cache.u.segment.c_ed) { /* expand down segment */
if ( temp_ESP == expand_down_limit ) {
bx_panic("can_pop(): found SP=ffff\n");
return(0);
}
if ( ((expand_down_limit - temp_ESP) + 1) >= bytes )
return(1);
return(0);
}
else { /* normal (expand-up) segment */
if (BX_CPU_THIS_PTR sregs[BX_SEG_REG_SS].cache.u.segment.limit_scaled==0) {
bx_panic("can_pop(): SS.limit = 0\n");
}
if ( temp_ESP == expand_down_limit ) {
bx_panic("can_pop(): found SP=ffff\n");
return(0);
}
if ( temp_ESP > BX_CPU_THIS_PTR sregs[BX_SEG_REG_SS].cache.u.segment.limit_scaled ) {
bx_panic("can_pop(): eSP > SS.limit\n");
return(0);
}
if ( ((BX_CPU_THIS_PTR sregs[BX_SEG_REG_SS].cache.u.segment.limit_scaled - temp_ESP) + 1) >= bytes )
return(1);
return(0);
}
}
#endif
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