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Honor TRAP exceptions in a CPU-appropriate manner

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This commit is contained in:
Jeff Parsons 2015-04-10 08:08:49 -07:00 • committed by jeffpar
commit b063387357
4 changed files with 43 additions and 18 deletions
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39
modules/pcjs/lib/x86cpu.js
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@ -3291,6 +3291,8 @@ X86CPU.prototype.pushWord = function(w)
* by a coprocessor). As of the 80286, those priorities were inverted, giving the Trap interrupt higher priority
* than external interrupts.
*
* TODO: Determine the priorities for the 80186.
*
* @this {X86CPU}
* @return {boolean} true if h/w interrupt (or trap) has just been acknowledged, false if not
*/
@ -3299,23 +3301,34 @@ X86CPU.prototype.checkINTR = function()
this.assert(this.intFlags);
if (!(this.opFlags & X86.OPFLAG.NOINTR)) {
/*
* TODO: Reverse the order of the INTR and TRAP tests if the processor is an 80286 or higher.
* As discussed above, the 8086/8088 give hardware interrupts higher priority than the TRAP interrupt,
* whereas the 80286 and up give TRAPs higher priority.
*/
if ((this.intFlags & X86.INTFLAG.INTR) && (this.regPS & X86.PS.IF)) {
var nIDT = this.chipset.getIRRVector();
if (nIDT >= -1) {
this.intFlags &= ~X86.INTFLAG.INTR;
if (nIDT >= 0) {
this.intFlags &= ~X86.INTFLAG.HALT;
X86.fnINT.call(this, nIDT, null, 11);
var iPriority = (this.model < X86.MODEL_80286? 0 : 1);
for (var nPriorities = 0; nPriorities < 2; nPriorities++) {
switch(iPriority) {
case 0:
if ((this.intFlags & X86.INTFLAG.INTR) && (this.regPS & X86.PS.IF)) {
var nIDT = this.chipset.getIRRVector();
if (nIDT >= -1) {
this.intFlags &= ~X86.INTFLAG.INTR;
if (nIDT >= 0) {
this.intFlags &= ~X86.INTFLAG.HALT;
X86.fnINT.call(this, nIDT, null, 11);
return true;
}
}
}
break;
case 1:
if ((this.intFlags & X86.INTFLAG.TRAP)) {
this.intFlags &= ~X86.INTFLAG.TRAP;
X86.fnINT.call(this, X86.EXCEPTION.TRAP, null, 11);
return true;
}
break;
}
}
else if ((this.intFlags & X86.INTFLAG.TRAP)) {
this.intFlags &= ~X86.INTFLAG.TRAP;
X86.fnINT.call(this, X86.EXCEPTION.TRAP, null, 11);
return true;
iPriority = 1 - iPriority;
}
}
if (this.intFlags & X86.INTFLAG.DMA) {