pcjs/modules/pdp11/lib/rom.js

390 lines
15 KiB
JavaScript

/**
* @fileoverview Implements the PDP11 ROM component.
* @author <a href="mailto:Jeff@pcjs.org">Jeff Parsons</a>
* @version 1.0
* Created 2016-Sep-03
*
* This file is part of PCjs, a computer emulation software project at <http://pcjs.org/>.
*
* It has been adapted from the JavaScript PDP 11/70 Emulator v1.3 written by Paul Nankervis
* (paulnank@hotmail.com) as of August 2016 from http://skn.noip.me/pdp11/pdp11.html. This code
* may be used freely provided the original author name is acknowledged in any modified source code.
*
* PCjs is free software: you can redistribute it and/or modify it under the terms of the
* GNU General Public License as published by the Free Software Foundation, either version 3
* of the License, or (at your option) any later version.
*
* PCjs is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without
* even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along with PCjs. If not,
* see <http://www.gnu.org/licenses/gpl.html>.
*
* You are required to include the above copyright notice in every source code file of every
* copy or modified version of this work, and to display that copyright notice on every screen
* that loads or runs any version of this software (see COPYRIGHT in /modules/shared/lib/defines.js).
*
* Some PCjs files also attempt to load external resource files, such as character-image files,
* ROM files, and disk image files. Those external resource files are not considered part of PCjs
* for purposes of the GNU General Public License, and the author does not claim any copyright
* as to their contents.
*/
"use strict";
if (NODE) {
var str = require("../../shared/lib/strlib");
var web = require("../../shared/lib/weblib");
var DumpAPI = require("../../shared/lib/dumpapi");
var Component = require("../../shared/lib/component");
var PDP11 = require("./defines");
var MemoryPDP11 = require("./memory");
}
/**
* ROMPDP11(parmsROM)
*
* The ROMPDP11 component expects the following (parmsROM) properties:
*
* addr: physical address of ROM
* size: amount of ROM, in bytes
* alias: physical alias address (null if none)
* file: name of ROM data file
* writable: true to make ROM writable (default is false)
*
* NOTE: The ROM data will not be copied into place until the Bus is ready (see initBus()) AND the
* ROM data file has finished loading (see doneLoad()).
*
* Also, while the size parameter may seem redundant, I consider it useful to confirm that the ROM you received
* is the ROM you expected.
*
* Finally, while making ROM "writable" may seem a contradiction in terms, I want to be able to load selected
* CP/M binary files into memory purely for testing purposes, and the RAM component has no "file" option, so the
* simplest solution was to add the option to load binary files into memory as "writable" ROMs.
*
* Moreover, if a "writable" ROM is installed at addr 0x100, that triggers our "Fake CP/M" support, providing
* a quick-and-dirty means of loading simple CP/M test binaries. See addROM() for details.
*
* @constructor
* @extends Component
* @param {Object} parmsROM
*/
function ROMPDP11(parmsROM)
{
Component.call(this, "ROM", parmsROM, ROMPDP11);
this.abROM = null;
this.addrROM = parmsROM['addr'];
this.sizeROM = parmsROM['size'];
this.fWritable = parmsROM['writable'];
/*
* The new 'alias' property can now be EITHER a single physical address (like 'addr') OR an array of
* physical addresses; eg:
*
* [0xf0000,0xffff0000,0xffff8000]
*
* We could have overloaded 'addr' to accomplish the same thing, but I think it's better to have any
* aliased locations listed under a separate property.
*
* Most ROMs are not aliased, in which case the 'alias' property should have the default value of null.
*/
this.addrAlias = parmsROM['alias'];
this.sFilePath = parmsROM['file'];
this.sFileName = str.getBaseName(this.sFilePath);
if (this.sFilePath) {
var sFileURL = this.sFilePath;
if (DEBUG) this.log('load("' + sFileURL + '")');
/*
* If the selected ROM file has a ".json" extension, then we assume it's pre-converted
* JSON-encoded ROM data, so we load it as-is; ditto for ROM files with a ".hex" extension.
* Otherwise, we ask our server-side ROM converter to return the file in a JSON-compatible format.
*/
var sFileExt = str.getExtension(this.sFileName);
if (sFileExt != DumpAPI.FORMAT.JSON && sFileExt != DumpAPI.FORMAT.HEX) {
sFileURL = web.getHost() + DumpAPI.ENDPOINT + '?' + DumpAPI.QUERY.FILE + '=' + this.sFilePath + '&' + DumpAPI.QUERY.FORMAT + '=' + DumpAPI.FORMAT.BYTES + '&' + DumpAPI.QUERY.DECIMAL + '=true';
}
var rom = this;
web.getResource(sFileURL, null, true, function(sURL, sResponse, nErrorCode) {
rom.doneLoad(sURL, sResponse, nErrorCode);
});
}
}
Component.subclass(ROMPDP11);
/*
* NOTE: There's currently no need for this component to have a reset() function, since
* once the ROM data is loaded, it can't be changed, so there's nothing to reinitialize.
*
* OK, well, I take that back, because the Debugger, if installed, has the ability to modify
* ROM contents, so in that case, having a reset() function that restores the original ROM data
* might be useful; then again, it might not, depending on what you're trying to debug.
*
* If we do add reset(), then we'll want to change copyROM() to hang onto the original
* ROM data; currently, we release it after copying it into the read-only memory allocated
* via bus.addMemory().
*/
/**
* initBus(cmp, bus, cpu, dbg)
*
* @this {ROMPDP11}
* @param {ComputerPDP11} cmp
* @param {BusPDP11} bus
* @param {CPUStatePDP11} cpu
* @param {DebuggerPDP11} dbg
*/
ROMPDP11.prototype.initBus = function(cmp, bus, cpu, dbg)
{
this.bus = bus;
this.cpu = cpu;
this.dbg = dbg;
this.copyROM();
};
/**
* powerUp(data, fRepower)
*
* @this {ROMPDP11}
* @param {Object|null} data
* @param {boolean} [fRepower]
* @return {boolean} true if successful, false if failure
*/
ROMPDP11.prototype.powerUp = function(data, fRepower)
{
if (this.aSymbols) {
if (this.dbg) {
this.dbg.addSymbols(this.id, this.addrROM, this.sizeROM, this.aSymbols);
}
/*
* Our only role in the handling of symbols is to hand them off to the Debugger at our
* first opportunity. Now that we've done that, our copy of the symbols, if any, are toast.
*/
delete this.aSymbols;
}
return true;
};
/**
* powerDown(fSave, fShutdown)
*
* Since we have nothing to do on powerDown(), and no state to return, we could simply omit
* this function. But it doesn't hurt anything, and maybe we'll use our state to save something
* useful down the road, like user-defined symbols (ie, symbols that the Debugger may have
* created, above and beyond those symbols we automatically loaded, if any, along with the ROM).
*
* @this {ROMPDP11}
* @param {boolean} [fSave]
* @param {boolean} [fShutdown]
* @return {Object|boolean} component state if fSave; otherwise, true if successful, false if failure
*/
ROMPDP11.prototype.powerDown = function(fSave, fShutdown)
{
return true;
};
/**
* doneLoad(sURL, sROMData, nErrorCode)
*
* @this {ROMPDP11}
* @param {string} sURL
* @param {string} sROMData
* @param {number} nErrorCode (response from server if anything other than 200)
*/
ROMPDP11.prototype.doneLoad = function(sURL, sROMData, nErrorCode)
{
if (nErrorCode) {
this.notice("Unable to load system ROM (error " + nErrorCode + ": " + sURL + ")");
return;
}
Component.addMachineResource(this.idMachine, sURL, sROMData);
if (sROMData.charAt(0) == "[" || sROMData.charAt(0) == "{") {
try {
/*
* The most likely source of any exception will be here: parsing the JSON-encoded ROM data.
*/
var rom = eval("(" + sROMData + ")");
var ab = rom['bytes'];
var adw = rom['data'];
if (ab) {
this.abROM = ab;
}
else if (adw) {
/*
* Convert all the DWORDs into BYTEs, so that subsequent code only has to deal with abROM.
*/
this.abROM = new Array(adw.length * 4);
for (var idw = 0, ib = 0; idw < adw.length; idw++) {
this.abROM[ib++] = adw[idw] & 0xff;
this.abROM[ib++] = (adw[idw] >> 8) & 0xff;
this.abROM[ib++] = (adw[idw] >> 16) & 0xff;
this.abROM[ib++] = (adw[idw] >> 24) & 0xff;
}
}
else {
this.abROM = rom;
}
this.aSymbols = rom['symbols'];
if (!this.abROM.length) {
Component.error("Empty ROM: " + sURL);
return;
}
else if (this.abROM.length == 1) {
Component.error(this.abROM[0]);
return;
}
} catch (e) {
this.notice("ROM data error: " + e.message);
return;
}
}
else {
/*
* Parse the ROM data manually; we assume it's in "simplified" hex form (a series of hex byte-values
* separated by whitespace).
*/
var sHexData = sROMData.replace(/\n/gm, " ").replace(/ +$/, "");
var asHexData = sHexData.split(" ");
this.abROM = new Array(asHexData.length);
for (var i = 0; i < asHexData.length; i++) {
this.abROM[i] = str.parseInt(asHexData[i], 16);
}
}
this.copyROM();
};
/**
* copyROM()
*
* This function is called by both initBus() and doneLoad(), but it cannot copy the the ROM data into place
* until after initBus() has received the Bus component AND doneLoad() has received the abROM data. When both
* those criteria are satisfied, the component becomes "ready".
*
* @this {ROMPDP11}
*/
ROMPDP11.prototype.copyROM = function()
{
if (!this.isReady()) {
if (!this.sFilePath) {
this.setReady();
}
else if (this.abROM && this.bus) {
/*
* If no explicit size was specified, then use whatever the actual size is.
*/
if (!this.sizeROM) {
this.sizeROM = this.abROM.length;
}
if (this.abROM.length != this.sizeROM) {
/*
* Note that setError() sets the component's fError flag, which in turn prevents setReady() from
* marking the component ready. TODO: Revisit this decision. On the one hand, it sounds like a
* good idea to stop the machine in its tracks whenever a setError() occurs, but there may also be
* times when we'd like to forge ahead anyway.
*/
this.setError("ROM size (" + str.toHexLong(this.abROM.length) + ") does not match specified size (" + str.toHexLong(this.sizeROM) + ")");
}
else if (this.addROM(this.addrROM)) {
var aliases = [];
if (typeof this.addrAlias == "number") {
aliases.push(this.addrAlias);
} else if (this.addrAlias != null && this.addrAlias.length) {
aliases = this.addrAlias;
}
for (var i = 0; i < aliases.length; i++) {
this.cloneROM(aliases[i]);
}
/*
* We used to hang onto the original ROM data so that we could restore any bytes the CPU overwrote,
* using memory write-notification handlers, but with the introduction of read-only memory blocks, that's
* no longer necessary.
*
* TODO: Consider an option to retain the ROM data, and give the user some way of restoring ROMs.
* That may be useful for "resumable" machines that save/restore all dirty block of memory, regardless
* whether they're ROM or RAM. However, the only way to modify a machine's ROM is with the Debugger,
* and Debugger users should know better.
*/
delete this.abROM;
}
this.setReady();
}
}
};
/**
* addROM(addr)
*
* @this {ROMPDP11}
* @param {number} addr
* @return {boolean}
*/
ROMPDP11.prototype.addROM = function(addr)
{
if (this.bus.addMemory(addr, this.sizeROM, this.fWritable? MemoryPDP11.TYPE.RAM : MemoryPDP11.TYPE.ROM)) {
if (DEBUG) this.log("addROM(): copying ROM to " + str.toHexLong(addr) + " (" + str.toHexLong(this.abROM.length) + " bytes)");
var i;
for (i = 0; i < this.abROM.length; i++) {
this.bus.setByteDirect(addr + i, this.abROM[i]);
}
return true;
}
/*
* We don't need to report an error here, because addMemory() already takes care of that.
*/
return false;
};
/**
* cloneROM(addr)
*
* For ROMs with one or more alias addresses, we used to call addROM() for each address. However,
* that obviously wasted memory, since each alias was an independent copy, and if you used the
* Debugger to edit the ROM in one location, the changes would not appear in the other location(s).
*
* Now that the Bus component provides low-level getMemoryBlocks() and setMemoryBlocks() methods
* to manually get and set the blocks of any memory range, it is now possible to create true aliases.
*
* @this {ROMPDP11}
* @param {number} addr
*/
ROMPDP11.prototype.cloneROM = function(addr)
{
var aBlocks = this.bus.getMemoryBlocks(this.addrROM, this.sizeROM);
this.bus.setMemoryBlocks(addr, this.sizeROM, aBlocks);
};
/**
* ROMPDP11.init()
*
* This function operates on every HTML element of class "rom", extracting the
* JSON-encoded parameters for the ROMPDP11 constructor from the element's "data-value"
* attribute, invoking the constructor to create a ROMPDP11 component, and then binding
* any associated HTML controls to the new component.
*/
ROMPDP11.init = function()
{
var aeROM = Component.getElementsByClass(document, PDP11.APPCLASS, "rom");
for (var iROM = 0; iROM < aeROM.length; iROM++) {
var eROM = aeROM[iROM];
var parmsROM = Component.getComponentParms(eROM);
var rom = new ROMPDP11(parmsROM);
Component.bindComponentControls(rom, eROM, PDP11.APPCLASS);
}
};
/*
* Initialize all the ROMPDP11 modules on the page.
*/
web.onInit(ROMPDP11.init);
if (NODE) module.exports = ROMPDP11;