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Added MMU dump command ("d mmu [filter]"), fixed byte updates of PDRs, masked 18-bit UNIBUS addresses when UNIBUS relocation map not enabled, and fixed reads of MMR0 when ABORT bits are set

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This commit is contained in:
Jeff 2016-11-17 13:22:25 -08:00 • committed by Jeff Parsons
commit 9148cec085
8 changed files with 424 additions and 360 deletions
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46
modules/pdp11/lib/cpustate.js
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@ -318,11 +318,11 @@ CPUStatePDP11.prototype.setMemoryAccess = function()
*/
CPUStatePDP11.prototype.getMMR0 = function()
{
/*
* Technically, we never allow the UNUSED bits to be set, so there's no point going out of our way
* to clear them, but it doesn't hurt to include them in the mask.
*/
return (this.regMMR0 & ~(PDP11.MMR0.UNUSED | PDP11.MMR0.PAGE | PDP11.MMR0.MODE)) | (this.mmuLastMode << 5) | (this.mmuLastPage << 1);
var data = this.regMMR0;
if (!(data & PDP11.MMR0.ABORT)) {
data = (data & ~(PDP11.MMR0.UNUSED | PDP11.MMR0.PAGE | PDP11.MMR0.MODE)) | (this.mmuLastMode << 5) | (this.mmuLastPage << 1);
}
return data;
};
/**
@ -1278,19 +1278,6 @@ CPUStatePDP11.prototype.updateSubFlags = function(result, src, dst)
}
};
/**
* panic(reason)
*
* TODO: Something.
*
* @this {CPUStatePDP11}
* @param {number} reason
*/
CPUStatePDP11.prototype.panic = function(reason)
{
console.log("panic(" + reason + ")");
};
/**
* trap(vector, flag, reason)
*
@ -1433,7 +1420,7 @@ CPUStatePDP11.prototype.getTrapStatus = function()
/**
* mapUnibus(addr)
*
* If bits 18-21 of addr are all set (which is implied by addr >= BusPDP11.IOPAGE_UNIBUS aka 0x3C0000),
* If bits 18-21 of addr are all set (which is implied by addr >= BusPDP11.UNIBUS_22BIT aka 0x3C0000),
* then we have a 22-bit address pointing to the top 256Kb range, so if the UNIBUS relocation map is enabled,
* we must pass the lower 18 bits of that address through the map.
*
@ -1470,8 +1457,19 @@ CPUStatePDP11.prototype.mapUnibus = function(addr)
var idx = (addr >> 13) & 0x1f;
if (idx < 31) {
if (this.regMMR3 & PDP11.MMR3.UNIBUS_MAP) {
/*
* The UNIBUS map relocation is enabled
*/
addr = (this.unibusMap[idx] + (addr & 0x1ffe)) & 0x3ffffe;
if (addr >= BusPDP11.IOPAGE_UNIBUS && addr < BusPDP11.IOPAGE_22BIT) this.panic(898);
this.assert(addr < BusPDP11.UNIBUS_22BIT || addr >= BusPDP11.IOPAGE_22BIT);
} else {
/*
* Since UNIBUS map relocation is NOT enabled, then as explained above:
*
* If the UNIBUS map relocation is not enabled, an incoming 18-bit UNIBUS address has 4 leading zeroes added for
* referencing a 22-bit physical address. The lower 18 bits are the same. No relocation is performed.
*/
addr &= ~BusPDP11.UNIBUS_22BIT;
}
}
return addr;
@ -1607,7 +1605,6 @@ CPUStatePDP11.prototype.mapVirtualToPhysical = function(virtualAddress, accessFl
this.mmuLastPage = page;
}
var fAbort = false;
if (newMMR0) {
if (newMMR0 & PDP11.MMR0.ABORT) {
if (this.trapPSW >= 0) {
@ -1618,11 +1615,11 @@ CPUStatePDP11.prototype.mapVirtualToPhysical = function(virtualAddress, accessFl
this.assert(!(newMMR0 & ~PDP11.MMR0.UPDATE));
this.setMMR0((this.regMMR0 & ~PDP11.MMR0.UPDATE) | newMMR0);
/*
* I've decided to NOT set fAbort if MMR0 already indicates an ABORT condition,
* I've decided to NOT abort if MMR0 already indicates an ABORT condition,
* because otherwise we run the risk of infinitely looping; eg, we call trap(), which
* calls mapVirtualToPhysical() on the trap vector, which faults again, etc.
*/
fAbort = true;
this.trap(PDP11.TRAP.MMU, 0, PDP11.REASON.ABORT);
}
}
if (!(this.regMMR0 & (PDP11.MMR0.ABORT | PDP11.MMR0.TRAP_MMU))) {
@ -1637,9 +1634,6 @@ CPUStatePDP11.prototype.mapVirtualToPhysical = function(virtualAddress, accessFl
}
}
}
if (fAbort) { // don't abort until the end, because it throws an exception
this.trap(PDP11.TRAP.MMU, 0, PDP11.REASON.ABORT);
}
}
return physicalAddress;
};