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OS/2 1.0 boots!

Browse source 
(at least through the first couple of screens)
This commit is contained in:
Jeff Parsons 2014-11-30 14:37:34 -08:00 • committed by jeffpar
commit 019ce280f6
25 changed files with 6130 additions and 13 deletions
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15
modules/pcjs/lib/x86cpu.js
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@ -1622,8 +1622,9 @@ X86CPU.prototype.getPS = function()
*
* @this {X86CPU}
* @param {number} regPS
* @param {number} [cpl]
*/
X86CPU.prototype.setPS = function(regPS)
X86CPU.prototype.setPS = function(regPS, cpl)
{
this.resultSize = X86.RESULT.SIZE_BYTE; // NOTE: We could have chosen SIZE_WORD, too; it's irrelevant
this.resultValue = this.resultParitySign = this.resultAuxOverflow = 0;
@ -1638,7 +1639,7 @@ X86CPU.prototype.setPS = function(regPS)
/*
* OS/2 1.0 discriminates between an 80286 and an 80386 based on whether an IRET in real-mode that
* pops 0xF000 into the flags is able to set *any* of flag bits 12-15: if it can, then OS/2 declares
* the the CPU an 80386. Therefore, in real-mode, we must zero all incoming bits 12-15.
* the CPU an 80386. Therefore, in real-mode, we must zero all incoming bits 12-15.
*
* This has the added benefit of relieving us from having to zero the effective IOPL (this.nIOPL)
* whenever we're in real-mode, since we're zeroing the IOPL bits up front now.
@ -1647,19 +1648,25 @@ X86CPU.prototype.setPS = function(regPS)
regPS &= ~(X86.PS.IOPL.MASK | X86.PS.NT | X86.PS.BIT15);
}
/*
* There are some cases (eg, an IRET returning to a less privileged code segment) where the CPL
* we compare against should come from the outgoing code segment, so if the caller provided it, use it.
*/
if (cpl === undefined) cpl = this.segCS.cpl;
/*
* Since PS.IOPL and PS.IF are part of PS_DIRECT, we need to take care of any 80286-specific behaviors
* before setting the PS_DIRECT bits from the incoming regPS bits.
*
* Specifically, PS.IOPL is unchanged if CPL > 0, and PS.IF is unchanged if CPL > IOPL.
*/
if (!this.segCS.cpl) {
if (!cpl) {
this.nIOPL = (regPS & X86.PS.IOPL.MASK) >> X86.PS.IOPL.SHIFT; // IOPL allowed to change
} else {
regPS = (regPS & ~X86.PS.IOPL.MASK) | (this.regPS & X86.PS.IOPL.MASK); // IOPL not allowed to change
}
if (this.segCS.cpl > this.nIOPL) {
if (cpl > this.nIOPL) {
regPS = (regPS & ~X86.PS.IF) | (this.regPS & X86.PS.IF); // IF not allowed to change
}