Retro/pcjs
Watch
1
0
Fork
You've already forked pcjs
 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Phase 1 of consolidating descriptor processing in x86seg.js (TSS descriptors are next)

Browse source
This commit is contained in:
Jeff Parsons 2014-11-27 09:28:12 -08:00 • committed by jeffpar
commit 6194aac5af
4 changed files with 132 additions and 45 deletions
Download patch file Download diff file Expand all files Collapse all files

58
modules/pcjs/lib/x86help.js
View file

@ -448,9 +448,10 @@ var X86Help = {
opHelpCallF: function(off, sel) {
var regCS = this.segCS.sel;
var regIP = this.regIP;
this.setCSIP(off, sel, true);
this.pushWord(regCS);
this.pushWord(regIP);
if (this.setCSIP(off, sel, true) != null) {
this.pushWord(regCS);
this.pushWord(regIP);
}
},
/**
* opHelpDIVOverflow()
@ -474,10 +475,22 @@ var X86Help = {
*/
opHelpINT: function(nIDT, nError, nCycles) {
/*
* TODO: We assess the cycle cost up front, because otherwise, if opHelpLoadIDT() fails and we end up in
* opHelpFault(), no cost may be assessed. Ultimately, opHelpFault() needs to determine an appropriate cost.
* TODO: We assess the cycle cost up front, because otherwise, if loadIDT() fails, no cost may be assessed.
*/
this.nStepCycles -= this.CYCLES.nOpCyclesInt + nCycles;
var regPS = this.getPS();
var regCS = this.segCS.sel;
var regIP = this.regIP;
var base = this.segCS.loadIDT(nIDT);
if (base != null) {
this.regEIP = base + this.regIP;
this.pushWord(regPS);
this.pushWord(regCS);
this.pushWord(regIP);
if (nError != null) this.pushWord(nError);
this.nFault = -1;
}
/*
if (X86Help.opHelpLoadIDT.call(this, nIDT)) {
if (this.descIDT.maskPS) {
X86Help.opHelpPushPS.call(this, nError);
@ -487,6 +500,7 @@ var X86Help = {
return;
}
X86Help.opHelpFault.call(this, X86.EXCEPTION.GP_FAULT, (nIDT << 3) | X86.ERRCODE.IDT | X86.ERRCODE.EXT, true);
*/
},
/**
* opHelpIRET()
@ -506,9 +520,13 @@ var X86Help = {
return;
}
}
this.setCSIP(this.popWord(), this.popWord(), false);
this.setPS(this.popWord());
if (this.cIntReturn) this.checkIntReturn(this.regEIP);
var regIP = this.popWord();
var regCS = this.popWord();
var regPS = this.popWord();
if (this.setCSIP(regIP, regCS, false) != null) {
this.setPS(regPS);
if (this.cIntReturn) this.checkIntReturn(this.regEIP);
}
},
/**
* opHelpLoadIDT(nIDT)
@ -568,30 +586,6 @@ var X86Help = {
this.descIDT.maskPS = ~(X86.PS.TF | X86.PS.IF);
return true;
},
/**
* opHelpPushPS(nError)
*
* Helper to push processor state, CS:IP, and optional error code onto the stack, and then jump
* to whatever CS:IP was fetched into descIDT by opHelpLoadIDT().
*
* For protected-mode, this function must attempt to load the new code segment first, because if the new segment
* requires a change in privilege level, the return address must be pushed on the NEW stack, not the current stack.
*
* @this {X86CPU}
* @param {number|null|undefined} nError
*/
opHelpPushPS: function(nError) {
var regPS = this.getPS();
var regCS = this.segCS.sel;
var regIP = this.regIP;
this.regPS &= this.descIDT.maskPS;
this.setCSIP(this.descIDT.off, this.descIDT.sel, true);
this.pushWord(regPS);
this.pushWord(regCS);
this.pushWord(regIP);
if (nError != null) this.pushWord(nError);
this.nFault = -1;
},
/**
* opHelpSwitchTSS(selNew, fNest)
*