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Fixed a few more MMU bugs uncovered by the EKBEE1 diagnostics; the end is in sight

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This commit is contained in:
Jeff 2016-11-17 23:51:30 -08:00 • committed by Jeff Parsons
commit 7088a185fd
5 changed files with 116 additions and 112 deletions
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18
modules/pdp11/lib/cpustate.js
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@ -1552,6 +1552,8 @@ CPUStatePDP11.prototype.mapVirtualToPhysical = function(virtualAddress, accessFl
pdr = this.mmuPDR[this.mmuMode][page];
physicalAddress = ((this.mmuPAR[this.mmuMode][page] << 6) + (virtualAddress & 0x1fff)) & this.mmuMask;
if (this.nDisableTraps) return physicalAddress;
var newMMR0 = 0;
switch (pdr & PDP11.PDR.ACF.MASK) {
@ -1620,16 +1622,16 @@ CPUStatePDP11.prototype.mapVirtualToPhysical = function(virtualAddress, accessFl
newMMR0 |= PDP11.MMR0.COMPLETED;
}
if (!(this.regMMR0 & PDP11.MMR0.ABORT)) {
newMMR0 |= (this.mmuLastMode << 5) | (this.mmuLastPage << 1);
newMMR0 |= (this.regMMR0 & PDP11.MMR0.TRAP_MMU) | (this.mmuLastMode << 5) | (this.mmuLastPage << 1);
this.assert(!(newMMR0 & ~PDP11.MMR0.UPDATE));
this.setMMR0((this.regMMR0 & ~PDP11.MMR0.UPDATE) | newMMR0);
/*
* I've decided to NOT abort if MMR0 already indicates an ABORT condition,
* because otherwise we run the risk of infinitely looping; eg, we call trap(), which
* calls mapVirtualToPhysical() on the trap vector, which faults again, etc.
*/
this.trap(PDP11.TRAP.MMU, PDP11.OPFLAG.TRAP_MMU, PDP11.REASON.ABORT);
this.setMMR0((this.regMMR0 & ~PDP11.MMR0.UPDATE) | (newMMR0 & PDP11.MMR0.UPDATE));
}
/*
* TODO: In unusual circumstances, if regMMR0 already indicated an ABORT condition above,
* we run the risk of infinitely looping; eg, we call trap(), which calls mapVirtualToPhysical()
* on the trap vector, which faults again, etc. We should add some safeguards against that.
*/
this.trap(PDP11.TRAP.MMU, PDP11.OPFLAG.TRAP_MMU, PDP11.REASON.ABORT);
}
if (!(this.regMMR0 & (PDP11.MMR0.ABORT | PDP11.MMR0.TRAP_MMU))) {
/*