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OS/2 1.0 boots!

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(at least through the first couple of screens)
This commit is contained in:
Jeff Parsons 2014-11-30 14:37:34 -08:00 • committed by jeffpar
commit 019ce280f6
25 changed files with 6130 additions and 13 deletions
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24
modules/pcjs/lib/x86seg.js
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@ -677,7 +677,29 @@ X86Seg.prototype.loadDesc8 = function(addrDesc, sel, fSuppress)
else if (this.id == X86Seg.ID.DATA) {
if (selMasked) {
if (type < X86.DESC.ACC.TYPE.DATA_READONLY || (type & (X86.DESC.ACC.TYPE.CODE | X86.DESC.ACC.TYPE.READABLE)) == X86.DESC.ACC.TYPE.CODE) {
if (!fSuppress) X86Help.opHelpFault.call(cpu, X86.EXCEPTION.GP_FAULT, sel, true);
/*
* OS/2 1.0 triggers this GP fault (what I'll call the "Empty Descriptor" GP fault) multiple times
* during boot; eg:
*
* Fault 0D (002F) on opcode 0x8E at 3190:3A05 (%112625)
* stopped (11315208 ops, 41813627 cycles, 498270 ms, 83918 hz)
* AX=0000 BX=0970 CX=0300 DX=0300 SP=0ABE BP=0ABA SI=0000 DI=001A
* DS=19C0[177300,2C5F] ES=001F[1743A0,07FF] SS=0038[175CE0,0B5F]
* CS=3190[10EC20,B89F] IP=3A05 V0 D0 I1 T0 S0 Z1 A0 P1 C0 PS=3246 MS=FFF3
* LD=0028[174BC0,003F] GD=[11A4E0,490F] ID=[11F61A,03FF] TR=0010 A20=ON
* 3190:3A05 8E4604 MOV ES,[BP+04]
* 0038:0ABE 002F 19C0 0000 067C - 07FC 0AD2 0010 C420 /.....|....... .
* dumpDesc(002F): %174BE8
* base=000000 limit=0000 dpl=00 type=00 (undefined)
*
* If we allow the GP fault to be dispatched, it recovers, so until I'm able to investigate this
* further, I'm going to assume this is normal behavior. If the segment (0x002F in the example)
* simply needed to be "faulted" into memory, I would have expected OS/2 to build a descriptor
* with the PRESENT bit clear, and rely on NP faults rather than GP faults, but maybe this was simpler.
*
* So, if acc is zero, we won't set fHalt on the following call.
*/
if (!fSuppress) X86Help.opHelpFault.call(cpu, X86.EXCEPTION.GP_FAULT, sel, acc != 0);
base = null;
break;
}