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More 80286 testing

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This commit is contained in:
Jeff Parsons 2015-05-15 09:08:42 -07:00 • committed by jeffpar
commit a28fa95d25
25 changed files with 107 additions and 36 deletions
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26
modules/pcjs/lib/x86seg.js
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@ -185,16 +185,14 @@ X86Seg.prototype.loadProt = function loadProt(sel, fSuppress)
* which has no bearing on the ROM's own code, because it never loads any LDT selectors, but if at the same
* time our Debugger attempts to validate a selector in one of its breakpoints, that could cause some
* grief here. We avoid that grief by 1) relying on the Debugger setting fSuppress to true, and 2) skipping
* segment lookup if the descriptor table being referenced is zero.
*
* TODO: This could probably be simplified to a test of addrDT; however, there's nothing in the design
* of the CPU that prevents the GDT or LDT being located at linear address zero.
* segment lookup if the descriptor table being referenced is zero. Both tests are required, because
* there's nothing in the design of the CPU that prevents the GDT or LDT being at linear address zero.
*/
if (!fSuppress || addrDT) {
var addrDesc = (addrDT + (sel & X86.SEL.MASK))|0;
if ((addrDTLimit - addrDesc)|0 >= 7) {
/*
* TODO: This is only the first of many steps toward accurately counting cycles in protected mode;
* TODO: This is the first of many steps toward accurately counting cycles in protected mode;
* I simply noted that "POP segreg" takes 5 cycles in real mode and 20 in protected mode, so I'm
* starting with a 15-cycle difference. Obviously the difference will vary with the instruction,
* and will be much greater whenever the load fails.
@ -563,7 +561,7 @@ X86Seg.prototype.loadDesc6 = function(addrDesc, sel)
this.base = base;
this.limit = limit;
this.offMax = (limit >>> 0) + 1;
this.acc = acc & X86.DESC.ACC.MASK;
this.acc = acc;
this.type = (acc & X86.DESC.ACC.TYPE.MASK);
this.ext = 0;
this.addrDesc = addrDesc;
@ -641,7 +639,7 @@ X86Seg.prototype.loadDesc8 = function(addrDesc, sel, fSuppress)
* Otherwise, we must be dealing with a CALLF or JMPF to a less privileged segment, in which
* case either DPL == CPL *or* the new segment is conforming and DPL <= CPL.
*/
if (fCall !== false && !(dpl == this.cpl || (acc & X86.DESC.ACC.TYPE.CONFORMING) && dpl <= this.cpl)) {
if (fCall !== false && !(dpl == this.cpl || (type & X86.DESC.ACC.TYPE.CONFORMING) && dpl <= this.cpl)) {
base = addrDesc = X86.ADDR_INVALID;
break;
}
@ -793,7 +791,7 @@ X86Seg.prototype.loadDesc8 = function(addrDesc, sel, fSuppress)
/*
* For LSL, we must support any descriptor marked X86.DESC.ACC.TYPE.SEG, as well as TSS and LDT descriptors.
*/
if (!(acc & X86.DESC.ACC.TYPE.SEG) && type > X86.DESC.ACC.TYPE.TSS_BUSY) {
if (!(type & X86.DESC.ACC.TYPE.SEG) && type > X86.DESC.ACC.TYPE.TSS_BUSY) {
base = addrDesc = X86.ADDR_INVALID;
break;
}
@ -937,23 +935,23 @@ X86Seg.prototype.updateMode = function(fLoad, fProt)
this.checkWrite = this.checkWriteProtDisallowed;
}
else if (this.acc & X86.DESC.ACC.TYPE.SEG) {
else if (this.type & X86.DESC.ACC.TYPE.SEG) {
/*
* If the READABLE bit of CODE_READABLE is not set, then disallow reads.
*/
if ((this.acc & X86.DESC.ACC.TYPE.CODE_READABLE) == X86.DESC.ACC.TYPE.CODE_EXECONLY) {
if ((this.type & X86.DESC.ACC.TYPE.CODE_READABLE) == X86.DESC.ACC.TYPE.CODE_EXECONLY) {
this.checkRead = this.checkReadProtDisallowed;
}
/*
* If the CODE bit is set, or the the WRITABLE bit is not set, then disallow writes.
*/
if ((this.acc & X86.DESC.ACC.TYPE.CODE) || !(this.acc & X86.DESC.ACC.TYPE.WRITABLE)) {
if ((this.type & X86.DESC.ACC.TYPE.CODE) || !(this.type & X86.DESC.ACC.TYPE.WRITABLE)) {
this.checkWrite = this.checkWriteProtDisallowed;
}
/*
* If the CODE bit is not set *and* the EXPDOWN bit is set, then invert the limit check.
*/
if ((this.acc & (X86.DESC.ACC.TYPE.CODE | X86.DESC.ACC.TYPE.EXPDOWN)) == X86.DESC.ACC.TYPE.EXPDOWN) {
if ((this.type & (X86.DESC.ACC.TYPE.CODE | X86.DESC.ACC.TYPE.EXPDOWN)) == X86.DESC.ACC.TYPE.EXPDOWN) {
if (this.checkRead == this.checkReadProt) this.checkRead = this.checkReadProtDown;
if (this.checkWrite == this.checkWriteProt) this.checkWrite = this.checkWriteProtDown;
this.fExpDown = true;
@ -983,8 +981,8 @@ X86Seg.prototype.updateMode = function(fLoad, fProt)
* for other purposes, on the assumption that that descriptor is completely unused.
*/
if ((this.sel & ~X86.SEL.RPL) && this.addrDesc !== X86.ADDR_INVALID) {
var addrACC = this.addrDesc + X86.DESC.ACC.TYPE.OFFSET;
this.cpu.setByte(addrACC, this.cpu.getByte(addrACC) | (X86.DESC.ACC.TYPE.ACCESSED >> 8));
var addrType = this.addrDesc + X86.DESC.ACC.TYPE.OFFSET;
this.cpu.setByte(addrType, this.cpu.getByte(addrType) | (X86.DESC.ACC.TYPE.ACCESSED >> 8));
}
this.cpl = this.sel & X86.SEL.RPL;
this.dpl = (this.acc & X86.DESC.ACC.DPL.MASK) >> X86.DESC.ACC.DPL.SHIFT;