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Restructured ModRM decoding

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This commit is contained in:
Jeff Parsons 2015-01-20 20:10:48 -08:00 • committed by jeffpar
commit 418f3bd603
13 changed files with 6175 additions and 6516 deletions
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26
modules/pcjs/lib/x86seg.js
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@ -58,6 +58,7 @@ function X86Seg(cpu, id, sName, fProt)
this.base = 0;
this.limit = 0xffff;
this.acc = 0;
this.ext = 0;
this.addrDesc = X86.ADDR_INVALID;
this.cpl = 0;
this.dpl = 0;
@ -117,7 +118,8 @@ X86Seg.ID = {
X86Seg.loadReal = function loadReal(sel, fSuppress)
{
this.sel = sel;
this.ext = 0;
this.opSize = this.addrSize = 2;
this.opMask = this.addrMask = 0xffff;
return this.base = sel << 4;
};
@ -204,11 +206,10 @@ X86Seg.loadRealIDT = function loadRealIDT(nIDT)
*
* TODO: Verify that 80286 real-mode actually enforces the above. See http://localhost:8088/pubs/pc/reference/intel/80286/progref/#page-260
*/
var offIDT = cpu.addrIDT + (nIDT << 2);
cpu.regIP = cpu.getWord(offIDT);
this.sel = cpu.getWord(offIDT + 2);
var addrIDT = cpu.addrIDT + (nIDT << 2);
cpu.regEIP = cpu.getWord(addrIDT);
cpu.regPS &= ~(X86.PS.TF | X86.PS.IF);
return this.base = this.sel << 4;
return this.load(cpu.getWord(addrIDT + 2));
};
/**
@ -422,7 +423,7 @@ X86Seg.switchTSS = function switchTSS(selNew, fNest)
cpu.setWord(cpu.segTSS.addrDesc + X86.DESC.ACC.OFFSET, cpu.segTSS.acc |= X86.DESC.ACC.TYPE.TSS_BUSY);
cpu.segTSS.type = X86.DESC.ACC.TYPE.TSS_BUSY;
}
cpu.setWord(addrOld + X86.TSS.TASK_IP, cpu.regIP);
cpu.setWord(addrOld + X86.TSS.TASK_IP, cpu.regEIP);
cpu.setWord(addrOld + X86.TSS.TASK_PS, cpu.getPS());
cpu.setWord(addrOld + X86.TSS.TASK_AX, cpu.regEAX);
cpu.setWord(addrOld + X86.TSS.TASK_CX, cpu.regECX);
@ -640,7 +641,7 @@ X86Seg.prototype.loadDesc8 = function(addrDesc, sel, fSuppress)
base = X86.ADDR_INVALID;
break;
}
cpu.regIP = limit;
cpu.regEIP = limit;
if (this.cpl < cplPrev) {
if (fCall !== true) {
cpu.assert(false);
@ -846,6 +847,13 @@ X86Seg.prototype.updateMode = function(fProt)
}
this.cpl = this.sel & X86.SEL.RPL;
this.dpl = (this.acc & X86.DESC.ACC.DPL.MASK) >> X86.DESC.ACC.DPL.SHIFT;
if (this.cpu.model < X86.MODEL_80386 || !(this.ext & X86.DESC.EXT.BIG)) {
this.opSize = 2;
this.opMask = 0xffff;
} else {
this.opSize = 4;
this.opMask = 0xffffffff;
}
} else {
this.load = X86Seg.loadReal;
this.loadIDT = X86Seg.loadRealIDT;
@ -854,7 +862,11 @@ X86Seg.prototype.updateMode = function(fProt)
this.limit = 0xffff;
this.cpl = this.dpl = 0;
this.addrDesc = X86.ADDR_INVALID;
this.opSize = 2;
this.opMask = 0xffff;
}
this.addrSize = this.opSize;
this.addrMask = this.opMask;
return fProt;
};