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Memory can now be explicitly "zeroed" with any byte pattern (but the default is still zero); note that memory blocks are still always zero-initialized when first created

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Jeff 2016-11-03 15:50:19 -07:00 • committed by Jeff Parsons
commit 3b88e4c53c
5 changed files with 18 additions and 10 deletions
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7
modules/pdp11/lib/bus.js
View file

@ -664,13 +664,14 @@ BusPDP11.prototype.cleanMemory = function(addr, size)
};
/**
* zeroMemory(addr, size)
* zeroMemory(addr, size, pattern)
*
* @this {BusPDP11}
* @param {number} addr
* @param {number} size
* @param {number} [pattern]
*/
BusPDP11.prototype.zeroMemory = function(addr, size)
BusPDP11.prototype.zeroMemory = function(addr, size, pattern)
{
var off = addr & this.nBlockLimit;
var iBlock = addr >>> this.nBlockShift;
@ -682,7 +683,7 @@ BusPDP11.prototype.zeroMemory = function(addr, size)
if (i >= 0) block = this.aIOPrevBlocks[i];
}
}
if (block) block.zero(off, size);
if (block) block.zero(off, size, pattern);
size -= this.nBlockSize;
iBlock++;
off = 0;

10
modules/pdp11/lib/memory.js
View file

@ -385,7 +385,7 @@ MemoryPDP11.prototype = {
return false;
},
/**
* zero(off, len)
* zero(off, len, pattern)
*
* Zeros the block. Supporting off and len parameters is probably overkill, and makes more
* work in the non-TYPEDARRAY, non-BYTEARRAY case, but that's not the typical case. The other
@ -394,19 +394,21 @@ MemoryPDP11.prototype = {
* @this {MemoryPDP11}
* @param {number} [off] (optional starting byte offset within block)
* @param {number} [len] (optional maximum number of bytes; default is the entire block)
* @param {number} [pattern]
*/
zero: function(off, len) {
zero: function(off, len, pattern) {
var i;
off = off || 0;
pattern &= 0xff;
/*
* NOTE: If len happens to be larger than the block, that's OK, because we also bounds-check the index.
*/
if (len === undefined) len = this.size;
Component.assert(off >= 0 && off < this.size);
if ((TYPEDARRAYS || BYTEARRAYS) && this.ab) {
for (i = off; len-- && i < this.ab.length; i++) this.ab[i] = 0;
for (i = off; len-- && i < this.ab.length; i++) this.ab[i] = pattern;
} else {
for (i = off; len-- && i < this.size; i++) this.writeByteDirect(off, 0, this.addr + off);
for (i = off; len-- && i < this.size; i++) this.writeByteDirect(off, pattern, this.addr + off);
}
},
/**

7
modules/pdp11/lib/ram.js
View file

@ -239,7 +239,12 @@ RAMPDP11.prototype.initRAM = function()
RAMPDP11.prototype.reset = function()
{
if (this.fAllocated) {
this.bus.zeroMemory(this.addrRAM, this.sizeRAM);
/*
* TODO: Add a configuration parameter for selecting the byte pattern on reset?
* Note that when memory blocks are originally created, they are currently always
* zero-initialized, so this would only affect resets.
*/
this.bus.zeroMemory(this.addrRAM, this.sizeRAM, 0);
if (this.abInit) {
this.loadImage(this.abInit, this.addrLoad, this.addrExec, this.addrRAM, true);
}