pcjs/modules/pdp10/lib/bus.js

760 lines
26 KiB
JavaScript

/**
* @fileoverview Implements the PDP-10 Bus component.
* @author <a href="mailto:Jeff@pcjs.org">Jeff Parsons</a>
* @copyright © Jeff Parsons 2012-2017
*
* This file is part of PCjs, a computer emulation software project at <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 modified copy of this work
* and to display that copyright notice when the software starts running; see COPYRIGHT in
* <http://pcjs.org/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 Usr = require("../../shared/lib/usrlib");
var Component = require("../../shared/lib/component");
var State = require("../../shared/lib/state");
var PDP10 = require("./defines");
var MemoryPDP10 = require("./memory");
var MessagesPDP10 = require("./messages");
}
/*
* Data types used by scanMemory()
*/
/**
* This defines the BlockInfo bit fields used by scanMemory() when it creates the aBlocks array.
*
* @typedef {{
* num: BitField,
* count: BitField,
* btmod: BitField,
* type: BitField
* }}
*/
var BlockInfoPDP10 = Usr.defineBitFields({num:20, count:8, btmod:1, type:3});
/**
* BusInfoPDP10 object definition (returned by scanMemory())
*
* cbTotal: total bytes allocated
* cBlocks: total Memory blocks allocated
* aBlocks: array of allocated Memory block numbers
*
* @typedef {{
* cbTotal: number,
* cBlocks: number,
* aBlocks: Array.<BlockInfoPDP10>
* }}
*/
var BusInfoPDP10;
class BusPDP10 extends Component {
/**
* BusPDP10(parmsBus, cpu, dbg)
*
* The BusPDP10 component manages physical memory and I/O address spaces.
*
* The BusPDP10 component has no UI elements, so it does not require an init() handler,
* but it still inherits from the Component class and must be allocated like any
* other device component. It's currently allocated by the Computer's init() handler,
* which then calls the initBus() method of all the other components.
*
* For memory beyond the simple needs of the ROM and RAM components (ie, memory-mapped
* devices), the address space must still be allocated through the BusPDP10 component via
* addMemory(). If the component needs something more than simple read/write storage,
* it must provide a custom controller.
*
* @param {Object} parmsBus
* @param {CPUStatePDP10} cpu
* @param {DebuggerPDP10} dbg
*/
constructor(parmsBus, cpu, dbg)
{
super("Bus", parmsBus, MessagesPDP10.BUS);
this.cpu = cpu;
this.dbg = dbg;
/*
* Supported values for nBusWidth: 18 (default). This represents the maximum size of the bus for the
* life of the machine, regardless what memory management mode the CPU has enabled.
*/
this.nBusWidth = +parmsBus['busWidth'] || 18;
/*
* Compute all BusPDP10 memory block parameters now, based on the width of the bus.
*
* Note that all PCjs machines divide their address space into blocks, using a block size appropriate for
* the machine's bus width. This allows us to efficiently allocate the entire address space, by reusing blocks
* as appropriate, and to define to different address behaviors on a block-granular level.
*/
this.addrTotal = 1 << this.nBusWidth;
this.nBusMask = (this.addrTotal - 1);
this.nBlockSize = 16384;
this.nBlockShift = Math.log2(this.nBlockSize); // ES6 ALERT (alternatively: Math.log(this.nBlockSize) / Math.LN2)
this.nBlockLen = this.nBlockSize >> 2;
this.nBlockLimit = this.nBlockSize - 1;
this.nBlockTotal = (this.addrTotal / this.nBlockSize) | 0;
this.nBlockMask = this.nBlockTotal - 1;
this.assert(this.nBlockMask <= BlockInfoPDP10.num.mask);
this.nDisableFaults = 0;
this.fFault = false;
/*
* Define all the properties to be initialized by initMemory()
*/
this.aBusBlocks = [];
/*
* We're ready to allocate empty Memory blocks to span the entire physical address space.
*/
this.initMemory();
this.setReady();
}
/**
* initMemory()
*
* Allocate enough (empty) Memory blocks to span the entire physical address space.
*
* @this {BusPDP10}
*/
initMemory()
{
var block = new MemoryPDP10(this);
block.copyBreakpoints(this.dbg);
this.aBusBlocks = new Array(this.nBlockTotal);
for (var iBlock = 0; iBlock < this.nBlockTotal; iBlock++) {
this.aBusBlocks[iBlock] = block;
}
}
/**
* reset()
*
* @this {BusPDP10}
*/
reset()
{
}
/**
* getWidth()
*
* @this {BusPDP10}
* @return {number}
*/
getWidth()
{
return this.nBusWidth;
}
/**
* powerUp(data, fRepower)
*
* @this {BusPDP10}
* @param {Object|null} data (always null because we supply no powerDown() handler)
* @param {boolean} [fRepower]
* @return {boolean} true if successful, false if failure
*/
powerUp(data, fRepower)
{
if (!fRepower) {
if (!data) {
this.reset();
} else {
if (!this.restore(data)) return false;
}
}
return true;
}
/**
* powerDown(fSave, fShutdown)
*
* @this {BusPDP10}
* @param {boolean} [fSave]
* @param {boolean} [fShutdown]
* @return {Object|boolean} component state if fSave; otherwise, true if successful, false if failure
*/
powerDown(fSave, fShutdown)
{
return fSave? this.save() : true;
}
/**
* save()
*
* @this {BusPDP10}
* @return {Object|null}
*/
save()
{
var state = new State(this);
state.set(0, this.saveMemory());
return state.data();
}
/**
* restore(data)
*
* @this {BusPDP10}
* @param {Object} data
* @return {boolean} true if restore successful, false if not
*/
restore(data)
{
return this.restoreMemory(data[0]);
}
/**
* addMemory(addr, size, type)
*
* Adds new Memory blocks to the specified address range. Any Memory blocks previously
* added to that range must first be removed via removeMemory(); otherwise, you'll get
* an allocation conflict error. This helps prevent address calculation errors, redundant
* allocations, etc.
*
* We've relaxed some of the original requirements (ie, that addresses must start at a
* block-granular address, or that sizes must be equal to exactly one or more blocks),
* because machines with large block sizes can make it impossible to load certain ROMs at
* their required addresses. Every allocation still allocates a whole number of blocks.
*
* Even so, BusPDP10 memory management does NOT provide a general-purpose heap. Most memory
* allocations occur during machine initialization and never change. In particular, there
* is NO support for removing partial-block allocations.
*
* Each Memory block keeps track of a start address (addr) and length (used), indicating
* the used space within the block; any free space that precedes or follows that used space
* can be allocated later, by simply extending the beginning or ending of the previously used
* space. However, any holes that might have existed between the original allocation and an
* extension are subsumed by the extension.
*
* @this {BusPDP10}
* @param {number} addr is the starting physical address of the request
* @param {number} size of the request, in bytes
* @param {number} type is one of the MemoryPDP10.TYPE constants
* @return {boolean} true if successful, false if not
*/
addMemory(addr, size, type)
{
var addrNext = addr;
var sizeLeft = size;
var iBlock = addrNext >>> this.nBlockShift;
while (sizeLeft > 0 && iBlock < this.aBusBlocks.length) {
var block = this.aBusBlocks[iBlock];
var addrBlock = iBlock * this.nBlockSize;
var sizeBlock = this.nBlockSize - (addrNext - addrBlock);
if (sizeBlock > sizeLeft) sizeBlock = sizeLeft;
if (block && block.size) {
if (block.type == type) {
/*
* Where there is already a similar block with a non-zero size, we allow the allocation only if:
*
* 1) addrNext + sizeLeft <= block.addr (the request precedes the used portion of the current block), or
* 2) addrNext >= block.addr + block.used (the request follows the used portion of the current block)
*/
if (addrNext + sizeLeft <= block.addr) {
block.used += (block.addr - addrNext);
block.addr = addrNext;
return true;
}
if (addrNext >= block.addr + block.used) {
var sizeAvail = block.size - (addrNext - addrBlock);
if (sizeAvail > sizeLeft) sizeAvail = sizeLeft;
block.used = addrNext - block.addr + sizeAvail;
addrNext = addrBlock + this.nBlockSize;
sizeLeft -= sizeAvail;
iBlock++;
continue;
}
}
return this.reportError(BusPDP10.ERROR.RANGE_INUSE, addrNext, sizeLeft);
}
var blockNew = new MemoryPDP10(this, addrNext, sizeBlock, this.nBlockSize, type);
blockNew.copyBreakpoints(this.dbg, block);
this.aBusBlocks[iBlock++] = blockNew;
addrNext = addrBlock + this.nBlockSize;
sizeLeft -= sizeBlock;
}
if (sizeLeft <= 0) {
this.status("Added " + (size >> 10) + "Kb " + MemoryPDP10.TYPE_NAMES[type] + " at " + Str.toOct(addr));
return true;
}
return this.reportError(BusPDP10.ERROR.RANGE_INVALID, addr, size);
}
/**
* cleanMemory(addr, size)
*
* @this {BusPDP10}
* @param {number} addr
* @param {number} size
* @return {boolean} true if all blocks were clean, false if dirty; all blocks are cleaned in the process
*/
cleanMemory(addr, size)
{
var fClean = true;
var iBlock = addr >>> this.nBlockShift;
while (size > 0 && iBlock < this.aBusBlocks.length) {
if (this.aBusBlocks[iBlock].fDirty) {
this.aBusBlocks[iBlock].fDirty = fClean = false;
this.aBusBlocks[iBlock].fDirtyEver = true;
}
size -= this.nBlockSize;
iBlock++;
}
return fClean;
}
/**
* zeroMemory(addr, size, pattern)
*
* @this {BusPDP10}
* @param {number} addr
* @param {number} size
* @param {number} [pattern]
*/
zeroMemory(addr, size, pattern)
{
var off = addr & this.nBlockLimit;
var iBlock = addr >>> this.nBlockShift;
while (size > 0 && iBlock < this.aBusBlocks.length) {
this.aBusBlocks[iBlock].zero(off, size, pattern);
size -= this.nBlockSize;
iBlock++;
off = 0;
}
}
/**
* scanMemory(info, addr, size)
*
* Returns a BusInfoPDP10 object for the specified address range.
*
* @this {BusPDP10}
* @param {BusInfoPDP10} [info] previous BusInfoPDP10, if any
* @param {number} [addr] starting address of range (0 if none provided)
* @param {number} [size] size of range, in bytes (up to end of address space if none provided)
* @return {BusInfoPDP10} updated info (or new info if no previous info provided)
*/
scanMemory(info, addr, size)
{
if (addr == null) addr = 0;
if (size == null) size = (this.addrTotal - addr) | 0;
if (info == null) info = {cbTotal: 0, cBlocks: 0, aBlocks: []};
var iBlock = addr >>> this.nBlockShift;
var iBlockMax = ((addr + size - 1) >>> this.nBlockShift);
info.cbTotal = 0;
info.cBlocks = 0;
while (iBlock <= iBlockMax) {
var block = this.aBusBlocks[iBlock];
info.cbTotal += block.size;
if (block.size) {
info.aBlocks.push(/** @type {BlockInfoPDP10} */ (Usr.initBitFields(BlockInfoPDP10, iBlock, 0, 0, block.type)));
info.cBlocks++
}
iBlock++;
}
return info;
}
/**
* removeMemory(addr, size)
*
* Replaces every block in the specified address range with empty Memory blocks that ignore all reads/writes.
*
* TODO: Update the removeMemory() interface to reflect the relaxed requirements of the addMemory() interface.
*
* @this {BusPDP10}
* @param {number} addr
* @param {number} size
* @return {boolean} true if successful, false if not
*/
removeMemory(addr, size)
{
if (!(addr & this.nBlockLimit) && size && !(size & this.nBlockLimit)) {
var iBlock = addr >>> this.nBlockShift;
while (size > 0) {
var blockOld = this.aBusBlocks[iBlock];
var blockNew = new MemoryPDP10(this, addr);
blockNew.copyBreakpoints(this.dbg, blockOld);
this.aBusBlocks[iBlock++] = blockNew;
addr = iBlock * this.nBlockSize;
size -= this.nBlockSize;
}
return true;
}
return this.reportError(BusPDP10.ERROR.RANGE_INVALID, addr, size);
}
/**
* getMemoryBlocks(addr, size)
*
* @this {BusPDP10}
* @param {number} addr is the starting physical address
* @param {number} size of the request, in bytes
* @return {Array} of Memory blocks
*/
getMemoryBlocks(addr, size)
{
var aBlocks = [];
var iBlock = addr >>> this.nBlockShift;
while (size > 0 && iBlock < this.aBusBlocks.length) {
aBlocks.push(this.aBusBlocks[iBlock++]);
size -= this.nBlockSize;
}
return aBlocks;
}
/**
* setMemoryBlocks(addr, size, aBlocks, type)
*
* If no type is specified, then specified address range uses all the provided blocks as-is;
* this form of setMemoryBlocks() is used for complete physical aliases.
*
* Otherwise, new blocks are allocated with the specified type; the underlying memory from the
* provided blocks is still used, but the new blocks may have different access to that memory.
*
* @this {BusPDP10}
* @param {number} addr is the starting physical address
* @param {number} size of the request, in bytes
* @param {Array} aBlocks as returned by getMemoryBlocks()
* @param {number} [type] is one of the MemoryPDP10.TYPE constants
*/
setMemoryBlocks(addr, size, aBlocks, type)
{
var i = 0;
var iBlock = addr >>> this.nBlockShift;
while (size > 0 && iBlock < this.aBusBlocks.length) {
var block = aBlocks[i++];
this.assert(block);
if (!block) break;
if (type !== undefined) {
var blockNew = new MemoryPDP10(this, addr);
blockNew.clone(block, type, this.dbg);
block = blockNew;
}
this.aBusBlocks[iBlock++] = block;
size -= this.nBlockSize;
}
}
/**
* getWord(addr)
*
* @this {BusPDP10}
* @param {number} addr is a physical address
* @return {number} word (36-bit) value at that address
*/
getWord(addr)
{
var off = addr & this.nBlockLimit;
var iBlock = (addr & this.nBusMask) >>> this.nBlockShift;
return this.aBusBlocks[iBlock].readWord(off, addr);
}
/**
* setWord(addr, w)
*
* @this {BusPDP10}
* @param {number} addr is a physical address
* @param {number} w is the word (36-bit) value to write
*/
setWord(addr, w)
{
var off = addr & this.nBlockLimit;
var iBlock = (addr & this.nBusMask) >>> this.nBlockShift;
this.aBusBlocks[iBlock].writeWord(w, off, addr);
}
/**
* getBlockDirect(addr)
*
* @this {BusPDP10}
* @param {number} addr is a physical address
* @return {MemoryPDP10}
*/
getBlockDirect(addr)
{
return this.aBusBlocks[(addr & this.nBusMask) >>> this.nBlockShift];
}
/**
* getWordDirect(addr)
*
* This is used for device I/O and Debugger physical memory requests, not the CPU.
*
* @this {BusPDP10}
* @param {number} addr is a physical address
* @return {number} word (36-bit) value at that address
*/
getWordDirect(addr)
{
var w;
var off = addr & this.nBlockLimit;
var block = this.getBlockDirect(addr);
this.nDisableFaults++;
w = block.readWordDirect(off, addr);
this.nDisableFaults--;
return w;
}
/**
* setWordDirect(addr, w)
*
* This is used for device I/O and Debugger physical memory requests, not the CPU.
*
* @this {BusPDP10}
* @param {number} addr is a physical address
* @param {number} w is the word (36-bit) value to write (we truncate it to 16 bits to be safe)
*/
setWordDirect(addr, w)
{
var off = addr & this.nBlockLimit;
var block = this.getBlockDirect(addr);
this.nDisableFaults++;
block.writeWordDirect(w, off, addr);
this.nDisableFaults--;
}
/**
* addMemBreak(addr, fWrite)
*
* @this {BusPDP10}
* @param {number} addr
* @param {boolean} fWrite is true for a memory write breakpoint, false for a memory read breakpoint
*/
addMemBreak(addr, fWrite)
{
if (DEBUGGER) {
var iBlock = addr >>> this.nBlockShift;
this.aBusBlocks[iBlock].addBreakpoint(addr & this.nBlockLimit, fWrite);
}
}
/**
* removeMemBreak(addr, fWrite)
*
* @this {BusPDP10}
* @param {number} addr
* @param {boolean} fWrite is true for a memory write breakpoint, false for a memory read breakpoint
*/
removeMemBreak(addr, fWrite)
{
if (DEBUGGER) {
var iBlock = addr >>> this.nBlockShift;
this.aBusBlocks[iBlock].removeBreakpoint(addr & this.nBlockLimit, fWrite);
}
}
/**
* saveMemory(fAll)
*
* The only memory blocks we save are those marked as dirty, but most likely all of RAM will have been marked dirty,
* and even if our dirty-memory flags were as smart as our dirty-sector flags (ie, were set only when a write changed
* what was already there), it's unlikely that would reduce the number of RAM blocks we must save/restore. At least
* all the ROM blocks should be clean (except in the unlikely event that the Debugger was used to modify them).
*
* All dirty blocks will be stored in a single array, as pairs of block numbers and data arrays, like so:
*
* [iBlock0, [dw0, dw1, ...], iBlock1, [dw0, dw1, ...], ...]
*
* In a normal 4Kb block, there will be 1K DWORD values in the data array. Remember that each DWORD is a signed 32-bit
* integer (because they are formed using bit-wise operator rather than floating-point math operators), so don't be
* surprised to see negative numbers in the data.
*
* The above example assumes "uncompressed" data arrays. If we choose to use "compressed" data arrays, the data arrays
* will look like:
*
* [count0, dw0, count1, dw1, ...]
*
* where each count indicates how many times the following DWORD value occurs. A data array length less than 1K indicates
* that it's compressed, since we'll only store them in compressed form if they actually shrank, and we'll use State
* helper methods compress() and decompress() to create and expand the compressed data arrays.
*
* @this {BusPDP10}
* @param {boolean} [fAll] (true to save all non-ROM memory blocks, regardless of their dirty flags)
* @return {Array} a
*/
saveMemory(fAll)
{
var i = 0;
var a = [];
for (var iBlock = 0; iBlock < this.nBlockTotal; iBlock++) {
var block = this.aBusBlocks[iBlock];
/*
* We have to check both fDirty and fDirtyEver, because we may have called cleanMemory() on some of
* the memory blocks (eg, video memory), and while cleanMemory() will clear a dirty block's fDirty flag,
* it also sets the dirty block's fDirtyEver flag, which is left set for the lifetime of the machine.
*/
if (fAll && block.type != MemoryPDP10.TYPE.ROM || block.fDirty || block.fDirtyEver) {
a[i++] = iBlock;
a[i++] = State.compress(block.save());
}
}
return a;
}
/**
* restoreMemory(a)
*
* This restores the contents of all Memory blocks; called by CPUState.restore().
*
* In theory, we ONLY have to save/restore block contents. Other block attributes,
* like the type, the memory controller (if any), and the active memory access functions,
* should already be restored, since every component (re)allocates all the memory blocks
* it was using when it's restored. And since the CPU is guaranteed to be the last
* component to be restored, all those blocks (and their attributes) should be in place now.
*
* See saveMemory() for more information on how the memory block contents are saved.
*
* @this {BusPDP10}
* @param {Array} a
* @return {boolean} true if successful, false if not
*/
restoreMemory(a)
{
var i;
for (i = 0; i < a.length - 1; i += 2) {
var iBlock = a[i];
var adw = a[i+1];
if (adw && adw.length < this.nBlockLen) {
adw = State.decompress(adw, this.nBlockLen);
}
var block = this.aBusBlocks[iBlock];
if (!block || !block.restore(adw)) {
/*
* Either the block to restore hasn't been allocated, indicating a change in the machine
* configuration since it was last saved (the most likely explanation) or there's some internal
* inconsistency (eg, the block size is wrong).
*/
Component.error("Unable to restore memory block " + iBlock);
return false;
}
}
return true;
}
/**
* getMemoryLimit(type)
*
* @this {BusPDP10}
* @param {number} type is one of the MemoryPDP10.TYPE constants
* @return {number} (the limiting address of the specified memory type, zero if none)
*/
getMemoryLimit(type)
{
var addr = 0;
for (var iBlock = 0; iBlock < this.aBusBlocks.length; iBlock++) {
var block = this.aBusBlocks[iBlock];
if (block.type == type) {
addr = block.addr + block.used;
}
}
return addr;
}
/**
* fault(addr, err, access)
*
* Bus interface for signaling alignment errors, invalid memory, etc.
*
* @this {BusPDP10}
* @param {number} addr
* @param {number} [err]
* @param {number} [access] (for diagnostic purposes only)
*/
fault(addr, err, access)
{
this.fFault = true;
if (!this.nDisableFaults) {
if (DEBUGGER && this.dbg && this.dbg.messageEnabled(MessagesPDP10.FAULT)) {
this.dbg.printMessage("memory fault on " + this.dbg.toStrBase(addr), true, true);
this.dbg.stopCPU();
}
}
}
/**
* checkFault()
*
* This also serves as a clearFault() function.
*
* @this {BusPDP10}
* @return {boolean}
*/
checkFault()
{
var f = this.fFault;
this.fFault = false;
return f;
}
/**
* reportError(errNum, addr, size, fQuiet)
*
* @this {BusPDP10}
* @param {number} errNum
* @param {number} addr
* @param {number} size
* @param {boolean} [fQuiet] (true if any error should be quietly logged)
* @return {boolean} false
*/
reportError(errNum, addr, size, fQuiet)
{
var sError = "Memory block error (" + errNum + ": " + Str.toHex(addr) + "," + Str.toHex(size) + ")";
if (fQuiet) {
if (this.dbg) {
this.dbg.message(sError);
} else {
this.log(sError);
}
} else {
Component.error(sError);
}
return false;
}
}
BusPDP10.ERROR = {
RANGE_INUSE: 1,
RANGE_INVALID: 2
};
if (NODE) module.exports = BusPDP10;