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Some cleanup involving invalid addresses

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Jeff Parsons 2014-12-01 13:31:23 -08:00 • committed by jeffpar
commit c85398db6b
7 changed files with 124 additions and 82 deletions
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22
modules/pcjs/lib/x86cpu.js
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@ -901,7 +901,7 @@ X86CPU.prototype.resetRegs = function()
* The next few initializations mirror what we must do prior to each instruction (ie, inside the stepCPU() function);
* note that opPrefixes, along with segData and segStack, are reset only after we've executed a non-prefix instruction.
*/
this.regEA = this.regEAWrite = -1;
this.regEA = this.regEAWrite = X86.ADDR_INVALID;
this.segData = this.segDS;
this.segStack = this.segSS;
this.opFlags = this.opPrefixes = 0;
@ -1295,8 +1295,8 @@ X86CPU.prototype.setIP = function(off)
* never set without an accompanying IP (well, except for a few undocumented instructions, like POP CS, which
* were available ONLY on the 8086/8088/80186/80188; see setCS() for details).
*
* NOTE: Unlike setIP(), which is often passed a computation, the offsets passed to setCSIP() are strictly
* 16-bit values, so there's never any need to mask them with 0xffff (although it doesn't hurt to assert that).
* NOTE: Unlike setIP(), which is often passed a computation, the offsets passed to setCSIP() are assumed to
* be 16-bit values, so there's no need to mask them with 0xffff (although it doesn't hurt to assert that).
*
* And even though this function is called setCSIP(), please note the order of the parameters is IP,CS,
* which matches the order that CS:IP values are normally stored in memory, allowing us to make calls like this:
@ -1306,8 +1306,8 @@ X86CPU.prototype.setIP = function(off)
* @this {X86CPU}
* @param {number} off
* @param {number} sel
* @param {boolean} [fCall] is true if CALLF in progress, false if RETF in progress, null/undefined otherwise
* @return {boolean|null} true if a stack switch occurred; the only opcode that really needs to care is opRETFn()
* @param {boolean} [fCall] is true if CALLF in progress, false if RETF/IRET in progress, null/undefined otherwise
* @return {boolean|null} true if a stack switch occurred; the only opcode that really needs to pay attention is opRETFn()
*/
X86CPU.prototype.setCSIP = function(off, sel, fCall)
{
@ -1319,12 +1319,12 @@ X86CPU.prototype.setCSIP = function(off, sel, fCall)
*/
this.regIP = off;
var base = this.segCS.load(sel);
if (base == null) {
return null;
if (base != X86.ADDR_INVALID) {
this.regEIP = base + this.regIP;
if (PREFETCH) this.flushPrefetch(this.regEIP);
return this.segCS.fStackSwitch;
}
this.regEIP = base + this.regIP;
if (PREFETCH) this.flushPrefetch(this.regEIP);
return this.segCS.fStackSwitch;
return null;
};
/**
@ -2510,7 +2510,7 @@ X86CPU.prototype.stepCPU = function(nMinCycles)
this.opPrefixes |= opPrefixes;
} else {
this.opEA = this.regEIP;
this.regEA = this.regEAWrite = -1;
this.regEA = this.regEAWrite = X86.ADDR_INVALID;
this.segData = this.segDS;
this.segStack = this.segSS;
this.opPrefixes = this.opFlags & X86.OPFLAG.REPEAT;