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Initial commit (a clone of the jsmachines project as of v1.15.3)

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jeffpar 2014-09-27 14:52:57 -07:00
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/**
* @fileoverview Implements the PCjs RAM component.
* @author <a href="mailto:Jeff@pcjs.org">Jeff Parsons</a>
* @version 1.0
* @suppress {missingProperties}
* Created 2012-Jun-15
*
* Copyright © 2012-2014 Jeff Parsons <Jeff@pcjs.org>
*
* This file is part of PCjs, which is part of the JavaScript Machines Project (aka JSMachines)
* at <http://jsmachines.net/> and <http://pcjs.org/>.
*
* 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 Computer.sCopyright).
*
* 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 the
* PCjs program for purposes of the GNU General Public License, and the author does not claim
* any copyright as to their contents.
*/
"use strict";
if (typeof module !== 'undefined') {
var web = require("../../shared/lib/weblib");
var Component = require("../../shared/lib/component");
var ROM = require("./rom");
}
/**
* RAM(parmsRAM)
*
* The RAM component expects the following (parmsRAM) properties:
*
* addr: starting physical address of RAM
* size: amount of RAM, in bytes (optional)
*
* NOTE: We make a note of the specified size, but no memory is initially allocated
* for the RAM until the Computer component calls setPower().
*
* @constructor
* @extends Component
* @param {Object} parmsRAM
*/
function RAM(parmsRAM) {
Component.call(this, "RAM", parmsRAM, RAM);
this.addrRAM = parmsRAM['addr'];
this.sizeRAM = parmsRAM['size'];
this.fTestRAM = parmsRAM['test'];
this.fInstalled = (!!this.sizeRAM); // 0 is the default value for 'size' when none is specified
this.fAllocated = false;
}
Component.subclass(Component, RAM);
/**
* initBus(cmp, bus, cpu, dbg)
*
* @this {RAM}
* @param {Computer} cmp
* @param {Bus} bus
* @param {X86CPU} cpu
* @param {Debugger} dbg
*/
RAM.prototype.initBus = function(cmp, bus, cpu, dbg) {
this.bus = bus;
this.cpu = cpu;
this.cmp = cmp;
this.chipset = cmp.getComponentByType("ChipSet");
this.setReady();
};
/**
* powerUp(data, fRepower)
*
* @this {RAM}
* @param {Object|null} data
* @param {boolean} [fRepower]
* @return {boolean} true if successful, false if failure
*/
RAM.prototype.powerUp = function(data, fRepower) {
if (!fRepower) {
/*
* The Computer powers up the CPU last, at which point the X86 state is restored,
* which includes the Bus state, and since we use the Bus to allocate all our memory,
* memory contents are already restored for us, so we don't need the usual restore
* logic. We just need to call reset(), to allocate memory for the RAM.
*
if (!data || !this.restore) {
this.reset();
} else {
if (!this.restore(data)) return false;
}
*/
this.reset();
}
return true;
};
/**
* powerDown(fSave)
*
* @this {RAM}
* @param {boolean} fSave
* @return {Object|boolean}
*/
RAM.prototype.powerDown = function(fSave) {
/*
* The Computer powers down the CPU first, at which point the X86 state is saved,
* which includes the Bus state, and since we use the Bus component to allocate all
* our memory, memory contents are already saved for us, so we don't need the usual
* save logic.
*
return fSave && this.save ? this.save() : true;
*/
return true;
};
/**
* reset()
*
* NOTE: When we were initialized, we were given an amount of INSTALLED memory (see sizeRAM above).
* The ChipSet component, on the other hand, tells us how much SPECIFIED memory there is -- which,
* like a real PC, may not match the amount of installed memory (due to either user error or perhaps
* an attempt to prevent some portion of the installed memory from being used).
*
* However, since we're a virtual machine, we can defer allocation of RAM until we're able to query the
* ChipSet component, and then allocate an amount of memory that matches the SPECIFIED memory, making
* it easy to reconfigure the machine on the fly and prevent mismatches.
*
* But, we do that ONLY for the RAM instance configured with an addrRAM of 0x0000, and ONLY if that RAM
* object was not given a specific size (see fInstalled). If there are other RAM objects in the system,
* they must necessarily specify a non-conflicting, non-zero start address, in which case their sizeRAM
* value will never be affected by the ChipSet settings.
*
* @this {RAM}
*/
RAM.prototype.reset = function() {
if (!this.addrRAM && !this.fInstalled && this.chipset) {
var baseRAM = this.chipset.getSWMemorySize() * 1024;
if (this.sizeRAM && baseRAM != this.sizeRAM) {
this.bus.removeMemory(this.addrRAM, this.sizeRAM);
this.fAllocated = false;
}
this.sizeRAM = baseRAM;
}
if (!this.fAllocated && this.sizeRAM) {
if (this.bus.addMemory(this.addrRAM, this.sizeRAM)) {
this.fAllocated = true;
this.status(Math.floor(this.sizeRAM / 1024) + "Kb");
/*
* NOTE: I'm specifying MAXDEBUG for status() messages because I'm not yet sure I want these
* messages buried in the app, since they're seen only when a Control Panel is active. Another
* and perhaps better alternative is to add "comment" attributes to the XML configuration file
* for these components, which the Computer component will display as it "powers up" components.
*/
if (MAXDEBUG && this.fInstalled) this.status("specified size overrides SW1");
}
}
if (this.fAllocated) {
if (!this.fTestRAM) {
/*
* HACK: Set the word at 40:72 in the ROM BIOS Data Area (RBDA) to 0x1234 to bypass the ROM BIOS
* memory storage tests. See rom.js for all RBDA definitions.
*/
if (MAXDEBUG) this.status("ROM BIOS memory test has been disabled");
this.bus.setWordDirect(ROM.BIOS.RESET_FLAG, ROM.BIOS.RESET_FLAG_WARMBOOT);
}
} else {
this.error("No RAM allocated");
}
};
/**
* RAM.init()
*
* This function operates on every element (e) of class "ram", and initializes
* all the necessary HTML to construct the RAM module(s) as spec'ed.
*
* Note that each element (e) of class "ram" is expected to have a "data-value"
* attribute containing the same JSON-encoded parameters that the RAM constructor
* expects.
*/
RAM.init = function() {
var aeRAM = Component.getElementsByClass(window.document, PCJSCLASS, "ram");
for (var iRAM = 0; iRAM < aeRAM.length; iRAM++) {
var eRAM = aeRAM[iRAM];
var parmsRAM = Component.getComponentParms(eRAM);
var ram = new RAM(parmsRAM);
Component.bindComponentControls(ram, eRAM, PCJSCLASS);
}
};
/*
* Initialize all the RAM modules on the page.
*/
web.onInit(RAM.init);
if (typeof APP_PCJS !== 'undefined') APP_PCJS.RAM = RAM;
if (typeof module !== 'undefined') module.exports = RAM;