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

Fixed the fallback logic for IOPAGE ranges where only byte handlers exist (ie, the readROMByte() case)

Browse source
This commit is contained in:
Jeff 2016-11-06 09:48:12 -08:00 • committed by Jeff Parsons
commit 8188554875
6 changed files with 489 additions and 468 deletions
Download patch file Download diff file Expand all files Collapse all files

27
modules/pdp11/lib/bus.js
View file

@ -219,7 +219,7 @@ BusPDP11.IOHANDLER = {
* Unlike regular Memory blocks, IOPAGE accesses permit word accesses on ODD addresses; that works
* just fine by registering WORD handlers for the appropriate ODD addresses. For BYTE accesses, it
* depends. For CPU register addresses, addIOHandlers() installs special byte handlers that perform
* either a simple word read or write. Other addresses must be handled on case-by-case basis.
* either a simple word read or write. Other addresses must be handled on a case-by-case basis.
*
* TODO: Another small potential improvement would be for addIOHandlers() to install fallbacks for ALL
* missing handlers, in both the ODD and EVEN cases, so there's never a need to check each function index
@ -265,6 +265,13 @@ BusPDP11.IOController = {
if (afn) {
if (afn[BusPDP11.IOHANDLER.READ_WORD]) {
b = afn[BusPDP11.IOHANDLER.READ_WORD](addrMasked & ~0x1) >> 8;
} else if (afn[BusPDP11.IOHANDLER.READ_BYTE]) {
/*
* WARNING: This is an unusual fall-back, because we're trying to read an ODD byte
* access using a BYTE handler registered for EVEN bytes. But if that's all we've got,
* then presumably the handler is prepared for it (certainly, readROMByte() is).
*/
b = afn[BusPDP11.IOHANDLER.READ_BYTE](addrMasked)
}
}
}
@ -346,6 +353,13 @@ BusPDP11.IOController = {
w = afn[BusPDP11.IOHANDLER.READ_WORD]? afn[BusPDP11.IOHANDLER.READ_WORD](0) : 0;
afn[BusPDP11.IOHANDLER.WRITE_WORD]((w & 0xff) | (b << 8), addrMasked);
fWrite = true;
} else if (afn[BusPDP11.IOHANDLER.WRITE_BYTE]) {
/*
* WARNING: This is an unusual fall-back, because we're trying to write an ODD byte
* access using a BYTE handler registered for EVEN bytes. But if that's all we've got,
* then presumably the handler is prepared for it (certainly, writeROMByte() is).
*/
afn[BusPDP11.IOHANDLER.WRITE_BYTE](b, addrMasked);
}
}
}
@ -1239,7 +1253,7 @@ BusPDP11.prototype.restoreMemory = function(a)
* getMemorySize(type)
*
* NOTE: The original pdp11.js defined MAX_MEMORY as IOBASE_UNIBUS - 16384, where IOBASE_UNIBUS
* is 4Mb less 256Kb, and then subtracted another 16Kb so that BSD 2.9 could boot.
* is 4Mb less 256Kb, and then it subtracted another 16Kb so that BSD 2.9 could boot.
*
* @this {BusPDP11}
* @param {number} type is one of the MemoryPDP11.TYPE constants (only RAM is currently supported)
@ -1263,6 +1277,11 @@ BusPDP11.prototype.getMemorySize = function(type)
* relative to the starting IOPAGE address, but they can also be absolute; we simply mask all addresses with
* IOPAGE_MASK.
*
* CAVEATS: If a conflict is reported, a partial set of handlers may still have been added. There is no mechanism
* for removing handlers, since this is considered an initialization function. And finally, when a range of addresses
* is used, each successive address is advanced by 2, so if you really want to add a handler for a "+1" (usually odd)
* address, then you must add it individually.
*
* @this {BusPDP11}
* @param {number} start address
* @param {number} end address
@ -1319,8 +1338,8 @@ BusPDP11.prototype.addIOTable = function(component, table, msgCategory, sName)
var nRegs = afn[5] || 1;
/*
* As discussed in the IOController comments above, when handlers are being registered for the following
* addresses, we must install different fallback handlers for all BYTE accesses.
* As discussed in the IOController comments above, when handlers are being registered for these
* BYTE-granular UNIBUS addresses, we must install custom fallback handlers for all BYTE accesses.
*/
if (addr >= PDP11.UNIBUS.R0SET0 && addr <= PDP11.UNIBUS.R6USER) {
if (!fnReadByte && fnReadWord) {

4
modules/pdp11/lib/defines.js
View file

@ -507,8 +507,10 @@ var PDP11 = {
R6USER: 0o177717,
/*
* This next group of registers is largely ignored; all accesses are routed to regsControl[]
* This next group of registers is largely ignored; all accesses are routed to regsControl[],
* and therefore are managed as a block of 8 "CTRL" registers.
*/
CTRL: 0o177740,
LAERR: 0o177740, // Low Address Error (11/70 only)
HAERR: 0o177742, // High Address Error (11/70 only)
MEMERR: 0o177744, // Memory System Error (11/70 only)

14
modules/pdp11/lib/device.js
View file

@ -835,7 +835,7 @@ DevicePDP11.prototype.writeR6USER = function(data, addr)
*/
DevicePDP11.prototype.readCTRL = function(addr)
{
var reg = (addr - PDP11.UNIBUS.LAERR) >> 1;
var reg = (addr - PDP11.UNIBUS.CTRL) >> 1;
return this.cpu.regsControl[reg];
};
@ -848,7 +848,7 @@ DevicePDP11.prototype.readCTRL = function(addr)
*/
DevicePDP11.prototype.writeCTRL = function(data, addr)
{
var reg = (addr - PDP11.UNIBUS.LAERR) >> 1;
var reg = (addr - PDP11.UNIBUS.CTRL) >> 1;
this.cpu.regsControl[reg] = data;
};
@ -1090,7 +1090,7 @@ DevicePDP11.UNIBUS_IOTABLE = {
[PDP11.UNIBUS.R5SET1]: /* 177715 */ [null, null, DevicePDP11.prototype.readRSET1, DevicePDP11.prototype.writeRSET1, "R5SET1", 1, PDP11.MODEL_1145],
[PDP11.UNIBUS.R6SUPER]: /* 177716 */ [null, null, DevicePDP11.prototype.readR6SUPER, DevicePDP11.prototype.writeR6SUPER, "R6SUPER", 1, PDP11.MODEL_1145],
[PDP11.UNIBUS.R6USER]: /* 177717 */ [null, null, DevicePDP11.prototype.readR6USER, DevicePDP11.prototype.writeR6USER, "R6USER", 1, PDP11.MODEL_1145],
[PDP11.UNIBUS.LAERR]: /* 177740 */ [null, null, DevicePDP11.prototype.readCTRL, DevicePDP11.prototype.writeCTRL, "CTRL", 1, PDP11.MODEL_1170],
[PDP11.UNIBUS.CTRL]: /* 177740 */ [null, null, DevicePDP11.prototype.readCTRL, DevicePDP11.prototype.writeCTRL, "CTRL", 8, PDP11.MODEL_1170],
[PDP11.UNIBUS.LSIZE]: /* 177760 */ [null, null, DevicePDP11.prototype.readSIZE, DevicePDP11.prototype.writeSIZE, "LSIZE", 1, PDP11.MODEL_1170],
[PDP11.UNIBUS.HSIZE]: /* 177762 */ [null, null, DevicePDP11.prototype.readSIZE, DevicePDP11.prototype.writeSIZE, "HSIZE", 1, PDP11.MODEL_1170],
[PDP11.UNIBUS.SYSID]: /* 177764 */ [null, null, DevicePDP11.prototype.readSYSID, DevicePDP11.prototype.writeSYSID, "SYSID", 1, PDP11.MODEL_1170],
@ -1101,14 +1101,6 @@ DevicePDP11.UNIBUS_IOTABLE = {
[PDP11.UNIBUS.PSW]: /* 177776 */ [null, null, DevicePDP11.prototype.readPSW, DevicePDP11.prototype.writePSW, "PSW"]
};
DevicePDP11.UNIBUS_IOTABLE[PDP11.UNIBUS.HAERR] = DevicePDP11.UNIBUS_IOTABLE[PDP11.UNIBUS.LAERR];
DevicePDP11.UNIBUS_IOTABLE[PDP11.UNIBUS.MEMERR] = DevicePDP11.UNIBUS_IOTABLE[PDP11.UNIBUS.LAERR];
DevicePDP11.UNIBUS_IOTABLE[PDP11.UNIBUS.CACHEC] = DevicePDP11.UNIBUS_IOTABLE[PDP11.UNIBUS.LAERR];
DevicePDP11.UNIBUS_IOTABLE[PDP11.UNIBUS.MAINT] = DevicePDP11.UNIBUS_IOTABLE[PDP11.UNIBUS.LAERR];
DevicePDP11.UNIBUS_IOTABLE[PDP11.UNIBUS.HITMISS]= DevicePDP11.UNIBUS_IOTABLE[PDP11.UNIBUS.LAERR];
DevicePDP11.UNIBUS_IOTABLE[PDP11.UNIBUS.UNDEF1] = DevicePDP11.UNIBUS_IOTABLE[PDP11.UNIBUS.LAERR];
DevicePDP11.UNIBUS_IOTABLE[PDP11.UNIBUS.UNDEF2] = DevicePDP11.UNIBUS_IOTABLE[PDP11.UNIBUS.LAERR];
/**
* DevicePDP11.init()
*

8
modules/pdp11/lib/rom.js
View file

@ -288,7 +288,7 @@ ROMPDP11.prototype.addROM = function(addr)
* This code has been added as a work-around to effectively allow us to install small ROMs into portions
* of the IOPAGE address space, by installing I/O handlers for the entire range that return the corresponding
* bytes of the current ROM image on reads, and ignore any writes (which I'm only assuming is how a typical
* ROM "device" deals with writes; if we remove the write handler, then writes will cause a fault).
* ROM "device" deals with writes; if we remove the write handler, then writes will fault).
*/
var IOTable = {
[addr]: [ROMPDP11.prototype.readROMByte, ROMPDP11.prototype.writeROMByte, null, null, null, this.sizeROM >> 1]
@ -348,6 +348,12 @@ ROMPDP11.prototype.readROMByte = function(addr)
/**
* writeROMByte(data, addr)
*
* This handler exists simply to ignore any writes, so that they don't cause faults.
*
* TODO: Another possible use for this would be to allow the Debugger to alter ROM contents,
* if the Debugger were to provide an interface indicating whether or not it was responsible
* for this write.
*
* @this {ROMPDP11}
* @param {number} data
* @param {number} addr