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Fixed bug in tasking.cc found by Scott Duplichan. When paging

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if off, we were still reading CR3 from the TSS and reloading
it!  This was causing problems with a DOS extender.  When
paging is turned back on, CR3 would be incorrect.
This commit is contained in:
Kevin Lawton 2002-09-10 01:39:40 +00:00
parent 425ad824c0
commit 112bf27f29
1 changed files with 6 additions and 3 deletions
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9
bochs/cpu/tasking.cc
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@ -1,5 +1,5 @@
/////////////////////////////////////////////////////////////////////////
// $Id: tasking.cc,v 1.11 2002-09-09 21:59:10 kevinlawton Exp $
// $Id: tasking.cc,v 1.12 2002-09-10 01:39:40 kevinlawton Exp $
/////////////////////////////////////////////////////////////////////////
//
// Copyright (C) 2001 MandrakeSoft S.A.
@ -283,7 +283,10 @@ BX_CPU_C::task_switch(bx_selector_t *tss_selector,
trap_word = 0; // keep compiler happy (not used)
}
else {
access_linear(nbase32 + 0x1c, 4, 0, BX_READ, &newCR3);
if (BX_CPU_THIS_PTR cr0.pg)
access_linear(nbase32 + 0x1c, 4, 0, BX_READ, &newCR3);
else
newCR3 = 0; // keep compiler happy (not used)
access_linear(nbase32 + 0x20, 4, 0, BX_READ, &newEIP);
access_linear(nbase32 + 0x24, 4, 0, BX_READ, &newEFLAGS);
access_linear(nbase32 + 0x28, 4, 0, BX_READ, &newEAX);
@ -476,7 +479,7 @@ if ( source==BX_TASK_FROM_CALL_OR_INT ) {
// descriptor parts of the segment registers.
//
if (tss_descriptor->type >= 9) {
if ( (tss_descriptor->type >= 9) && BX_CPU_THIS_PTR cr0.pg) {
CR3_change(newCR3); // Tell paging unit about new cr3 value
BX_DEBUG (("task_switch changing CR3 to 0x%08x\n", newCR3));
BX_INSTR_TLB_CNTRL(BX_INSTR_TASKSWITCH, newCR3);