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

Initial v1.18.2 delta: added support for ROM notification parameters that the Video component will accept

Browse source
This commit is contained in:
Jeff Parsons 2015-05-22 12:33:33 -07:00 • committed by jeffpar
commit 0639e8cbd2
151 changed files with 8239 additions and 1383 deletions
Download patch file Download diff file Expand all files Collapse all files

42
modules/pcjs/lib/x86cpu.js
View file

@ -2069,14 +2069,18 @@ X86CPU.prototype.advanceIP = function(inc)
* TR=0010 MS=FFF3 PS=3202 V0 D0 I1 T0 S0 Z0 A0 P0 C0
* 02E0:06F9 C20400 RET 0004
*
* After fetching the 3rd byte of the "RET 0004" opcode at CS:06FB, the CPU wants to automatically
* After fetching the 3rd byte of the "RET 0004" instruction at CS:06FB, the CPU wants to automatically
* advance IP to 06FC, which of course, exceeds the limit, but that doesn't matter unless we actually
* fetch a byte from 06FC, which won't happen. I'm working around this for now by applying a -1
* fudge factor to the fault check.
* fudge factor to the fault check below.
*/
var off = (this.regLIPLimit - this.regLIP)|0;
if (off < 0 && (this.regLIPLimit ^ this.regLIP) >= 0) {
if (this.model <= X86.MODEL_8088) {
/*
* There's no such thing as a GP fault on the 8086/8088, and I'm assuming that, on newer
* processors, when the segment limit is set to the maximum, it's OK for IP to wrap.
*/
if (this.model <= X86.MODEL_8088 || this.segCS.limit == this.segCS.addrMask) {
this.setIP(this.regLIP - this.segCS.base);
} else if (off < -1) { // fudge factor
X86.fnFault.call(this, X86.EXCEPTION.GP_FAULT, 0);
@ -2095,21 +2099,10 @@ X86CPU.prototype.rewindIP = function(dec)
this.assert(dec < 0);
this.regLIP = (this.regLIP + dec)|0;
/*
* Properly comparing regLIP to regLIPLimit would normally require coercing both to unsigned
* (ie, floating-point) values. But instead, we do a subtraction, (regLIPLimit - regLIP), and
* if the result is negative, we need only be concerned if the signs of both numbers are the same
* (ie, the sign of their XOR'ed union is positive).
* Since rewindIP() is used only for discrete "intra-instruction" IP adjustments, there should be no need
* to perform all the same limit checks as advanceIP().
*/
if (((this.regLIPLimit - this.regLIP)|0) >= 0) {
if (PREFETCH) this.advancePrefetch(dec);
}
else if ((this.regLIPLimit ^ this.regLIP) >= 0) {
if (this.model <= X86.MODEL_8088) {
this.setIP(this.regLIP - this.segCS.base);
} else {
X86.fnFault.call(this, X86.EXCEPTION.GP_FAULT, 0);
}
}
if (PREFETCH) this.advancePrefetch(dec);
};
/**
@ -3541,11 +3534,15 @@ X86CPU.prototype.popWord = function()
*
* TODO: I'm combining the old 8088 address-wrap check with the new segment-limit check,
* even though the correct time to do the latter is immediately BEFORE the fetch, not AFTER;
* I'm working around this for now by applying a -1 fudge factor to the fault check.
* I'm working around this for now by applying a -1 fudge factor to the fault check below.
*/
var off = ((this.regLSPLimit - this.regLSP)|0);
if (off < 0 && (this.regLSPLimit ^ this.regLSP) >= 0) {
if (this.model <= X86.MODEL_8088) {
/*
* There's no such thing as an SS fault on the 8086/8088, and I'm assuming that, on newer
* processors, when the stack segment limit is set to the maximum, it's OK for the stack to wrap.
*/
if (this.model <= X86.MODEL_8088 || this.segSS.limit == this.segSS.addrMask) {
this.setSP(this.regLSP - this.segSS.base);
} else if (off < -1) { // fudge factor
X86.fnFault.call(this, X86.EXCEPTION.SS_FAULT, 0);
@ -3571,7 +3568,12 @@ X86CPU.prototype.pushWord = function(w)
* (ie, the sign of their XOR'ed union is positive).
*/
if (((this.regLSP - this.regLSPLimitLow)|0) < 0 && (this.regLSPLimitLow ^ this.regLSP) >= 0) {
if (this.model <= X86.MODEL_8088) {
/*
* There's no such thing as an SS fault on the 8086/8088, and I'm assuming that, on newer
* processors, when the stack segment is expand-down and the limit is set to the "maximum" of
* zero, it's OK for the stack to wrap.
*/
if (this.model <= X86.MODEL_8088 || this.segSS.fExpDown && !this.segSS.limit) {
this.setSP(this.regLSP - this.segSS.base);
} else {
X86.fnFault.call(this, X86.EXCEPTION.SS_FAULT, 0);