Playing with NASM

blog/2015/02/23/README.md

@@ -358,7 +358,7 @@ The only other information I have about revision levels comes from a March 30, 1
 
 However, that document does not indicate how a 80386-C0 part was marked, and I've found very little other
 information on the C0 stepping; it may have been quickly superseded by the D0 stepping, which used revision
-identifier 0x05.
+identifier 0x05.  D1 and D2 steppings used identifier 0x08.
 
 ### Errata
 

blog/2015/03/26/README.md

@@ -46,7 +46,7 @@ However, don't use that technique to check for optional parameters:
 
 	if (!parameter) { ... }
 
-because a valid numeric parameter could include 0, a valid string parameter could include "", etc.
+if a valid numeric parameter could include 0, or a valid string parameter could include "", etc.
 
 Problems with type coercion are **NOT** problems caused by a poor choice of operators, so trying to make
 those problems go away by artificially limiting your choice of operators seems like the wrong solution.

devices/pc/bios/compaq/deskpro386/README.md

@@ -62,3 +62,20 @@ the DEVICE OPERATION table indicated that, for a READ operation, /CE and /OE pin
 while the /PGM should be connected to INPUT HIGH VOLTAGE.  So I wired pin 27 (/PGM) to +5V instead of GND, and the dump
 worked perfectly.  The NYC Resistor article implied that every *active low* pin should be connected to GND, but apparently
 there are exceptions to that general rule.
+
+Producing Source Code with NDISASM
+---
+From the current directory, I ran:
+
+	ndisasm -o0x8000 private/1988-01-28.rom > 1988-01-28.nasm
+
+Then I massaged the output with a regex:
+
+	^([0-9A-F]+)\s+([0-9A-F]+)\s+(o32 |a32 |)([^\s]*) *(.*)$  -->  \t$3$4\t$5\t\t\t; $1  $2
+
+Then I ran a TextOut command to vertically align all the comments:
+
+	node ~/Sites/pcjs/modules/textout/bin/textout --file=1988-01-28.nasm --alignvert > t.nasm
+	mv t.nasm 1988-01-28.nasm
+
+To be continued....

modules/textout/bin/textout

@@ -0,0 +1,40 @@
+#!/usr/bin/env node
+/**
+ * @fileoverview Provides miscellaneous text-munging services
+ * @author <a href="mailto:Jeff@pcjs.org">Jeff Parsons</a>
+ * @version 1.0
+ * @suppress {missingProperties}
+ * Created 2015-Apr-04
+ *
+ * Copyright © 2012-2015 Jeff Parsons <Jeff@pcjs.org>
+ *
+ * This file is part of the JavaScript Machines Project (aka JSMachines) at <http://jsmachines.net/>
+ * and <http://pcjs.org/>.
+ *
+ * JSMachines 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.
+ *
+ * JSMachines 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 JSMachines.
+ * 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 JSMachines 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
+ * JSMachines Project for purposes of the GNU General Public License, and the author does not claim
+ * any copyright as to their contents.
+ */
+
+"use strict";
+var path = require("path");
+var fs = require("fs");
+var lib = path.join(path.dirname(fs.realpathSync(__filename)), "../lib/");
+
+require(lib + "textout.js").CLI();

modules/textout/lib/textout.js

@@ -0,0 +1,309 @@
+/**
+ * @fileoverview Provides miscellaneous text-munging services
+ * @author <a href="mailto:Jeff@pcjs.org">Jeff Parsons</a> (@jeffpar)
+ * @version 1.0
+ * Created 2015-Apr-04
+ *
+ * Copyright © 2012-2015 Jeff Parsons <Jeff@pcjs.org>
+ *
+ * This file is part of the JavaScript Machines Project (aka JSMachines) at <http://jsmachines.net/>
+ * and <http://pcjs.org/>.
+ *
+ * JSMachines 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.
+ *
+ * JSMachines 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 JSMachines.
+ * 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 JSMachines 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
+ * JSMachines Project for purposes of the GNU General Public License, and the author does not claim
+ * any copyright as to their contents.
+ */
+
+"use strict";
+
+var fs      = require("fs");
+var path    = require("path");
+var mkdirp  = require("mkdirp");
+var net     = require("../../shared/lib/netlib");
+var proc    = require("../../shared/lib/proclib");
+
+/**
+ * TextOut()
+ *
+ * @constructor
+ */
+function TextOut()
+{
+    this.fDebug = false;
+    this.sServerRoot = process.cwd();
+    this.sText = null;
+    this.nTabWidth = 8;
+    this.sTarget = "; ";
+}
+
+/*
+ * Class methods
+ */
+
+/**
+ * CLI()
+ *
+ * Provides the command-line interface for the TextOut module.
+ *
+ * Usage
+ * ---
+ *      textout --file=({path}|{URL}) [--alignvert]
+ *
+ * Arguments
+ * ---
+ *      --alignvert looks for tabs preceding certain characters (eg, ';') in the first line, and endeavors
+ *      to ensure that the same tab+character combination(s) in all subsequent lines start at the same column.
+ *
+ *      For now, all output is written to stdout only.
+ *
+ * Examples
+ * ---
+ *      node modules/textout/bin/textout --file=devices/pc/bios/compaq/deskpro386/1988-01-28.nasm --alignvert
+ */
+TextOut.CLI = function()
+{
+    var args = proc.getArgs();
+
+    if (!args.argc) {
+        console.log("usage: textout --file=({path}|{URL}) [--alignvert]");
+        return;
+    }
+
+    var argv = args.argv;
+    var sFile = argv['file'];
+    if (!sFile) {
+        TextOut.logError(new Error("bad or missing input filename"));
+        return;
+    }
+
+    var text = new TextOut();
+    text.loadFile(sFile, function(err) {
+        if (!err) {
+            if (argv['alignvert']) {
+                text.alignVertical();
+            }
+            text.outputText();
+        }
+    });
+};
+
+/**
+ * logError(err)
+ *
+ * Conditionally logs an error to the console.
+ *
+ * @param {Error} err
+ * @return {string} the error message that was logged (or that would have been logged had logging been enabled)
+ */
+TextOut.logError = function(err)
+{
+    var sError = "";
+    if (err) {
+        sError = "textout error: " + err.message;
+        console.log(sError);
+    }
+    return sError;
+};
+
+/*
+ * Object methods
+ */
+
+/**
+ * loadFile(sFile, done)
+ *
+ * @this {TextOut}
+ * @param {string} sFile
+ * @param {function(Error)} done
+ */
+TextOut.prototype.loadFile = function(sFile, done)
+{
+    var obj = this;
+    var options = {encoding: "utf8"};
+    var sFilePath = net.isRemote(sFile)? sFile : path.join(this.sServerRoot, sFile);
+
+    if (!this.sFilePath) this.sFilePath = sFilePath;
+
+    if (this.fDebug) console.log("loadFile(" + sFilePath + ")");
+
+    if (net.isRemote(sFilePath)) {
+        net.getFile(sFilePath, options.encoding, function(err, status, buf) {
+            if (err) {
+                TextOut.logError(err);
+                done(err);
+                return;
+            }
+            obj.setText(buf);
+            done(null);
+        });
+    } else {
+        fs.readFile(sFilePath, options, function(err, buf) {
+            if (err) {
+                TextOut.logError(err);
+                done(err);
+                return;
+            }
+            obj.setText(buf);
+            done(null);
+        });
+    }
+};
+
+/**
+ * setText(buf)
+ *
+ * Records the given file data in the TextOut's buffer
+ *
+ * @this {TextOut}
+ * @param {Buffer|string} buf
+ * @return {boolean}
+ */
+TextOut.prototype.setText = function(buf)
+{
+    var b, i, j, s;
+    if (typeof buf == "string") {
+        this.sText = buf;
+        return true;
+    }
+    TextOut.logError(new Error("setText(): invalid data"));
+    return false;
+};
+
+/**
+ * alignVertical()
+ *
+ * @this {TextOut}
+ */
+TextOut.prototype.alignVertical = function()
+{
+    if (!this.sText) return;
+
+    var asLines = this.sText.split('\n');
+
+    var iTarget = -1;
+    if (asLines.length) {
+        iTarget = this.findTarget(asLines[0]);
+    }
+    if (iTarget < 0) return;
+
+    if (this.fDebug) console.log("target vertical alignment: " + (iTarget + 1));
+
+    var iLine, fModified = false;
+
+    for (iLine = 1; iLine < asLines.length; iLine++) {
+        var iVictim;
+        var sLine = asLines[iLine];
+        var fModifiedLine = false;
+        while ((iVictim = this.findTarget(sLine)) != iTarget) {
+            if (iVictim < 0) break;
+
+            if (this.fDebug) console.log("line " + (iLine + 1) + ": current vertical alignment: " + (iVictim + 1));
+
+            if (iVictim > iTarget) {
+                if (!this.iTargetIndex) break;
+                var ch = sLine.charAt(this.iTargetIndex-1);
+                if (ch != ' ' && ch != '\t') break;
+                sLine = sLine.substr(0, this.iTargetIndex-1) + sLine.substr(this.iTargetIndex);
+            } else {
+                sLine = sLine.substr(0, this.iTargetIndex) + ' ' + sLine.substr(this.iTargetIndex);
+            }
+            fModifiedLine = true;
+        }
+        if (fModifiedLine) {
+            asLines[iLine] = sLine;
+            fModified = true;
+        }
+    }
+
+    if (fModified) {
+        this.sText = "";
+        for (iLine = 0; iLine < asLines.length; iLine++) {
+            if (this.sText) this.sText += '\n';
+            this.sText += asLines[iLine];
+        }
+    }
+};
+
+/**
+ * findTarget(sSrc, fDebug)
+ *
+ * This does not return the physical 0-based index of sTarget within sSrc, but rather the logical
+ * 0-based position, taking into account tab stops, based on the current nTabWidth setting.
+ *
+ * @this {TextOut}
+ * @param {string} sSrc
+ * @param {boolean} [fDebug]
+ * @return {number} logical position of sTarget within sSrc, -1 if not found
+ */
+TextOut.prototype.findTarget = function(sSrc, fDebug)
+{
+    var i = 0, iPos = 0, iTarget;
+
+    if (fDebug) console.log('findTarget("' + sSrc + '")');
+
+    if ((iTarget = sSrc.indexOf(this.sTarget, i)) >= 0) {
+        /*
+         * i is a physical position, whereas iPos is the logical position (ie, taking into account tab stops),
+         * so we have to walk i up to iTarget, advancing iPos as we go.
+         */
+        while (i < iTarget) {
+            var ch = sSrc.charAt(i++);
+            if (ch != '\t') {
+                iPos++;
+            } else {
+                iPos = iPos + (this.nTabWidth - (iPos % this.nTabWidth));
+            }
+            if (fDebug) console.log('\t"' + ch + '": index=' + (i - 1) + ', pos=' + iPos);
+        }
+        this.iTargetIndex = iTarget;
+        iTarget = iPos;
+    }
+    return iTarget;
+};
+
+/**
+ * outputText(sOutputFile, fOverwrite)
+ *
+ * @this {TextOut}
+ * @param {string} [sOutputFile]
+ * @param {boolean} [fOverwrite]
+ */
+TextOut.prototype.outputText = function(sOutputFile, fOverwrite)
+{
+    if (this.sText) {
+        if (sOutputFile) {
+            try {
+                if (fs.existsSync(sOutputFile) && !fOverwrite) {
+                    console.log(sOutputFile + " exists, use --overwrite to rewrite");
+                } else {
+                    var sDirName = path.dirname(sOutputFile);
+                    if (!fs.existsSync(sDirName)) mkdirp.sync(sDirName);
+                    fs.writeFileSync(sOutputFile, this.sText);
+                    console.log(this.sText.length + "-byte file saved as " + sOutputFile);
+                }
+            } catch(err) {
+                TextOut.logError(err);
+            }
+        } else {
+            console.log(this.sText);
+        }
+    }
+};
+
+module.exports = TextOut;

tests/pc/80386/makefile

@@ -0,0 +1,4 @@
+all: tests.rom
+
+tests.rom: tests.nasm
+	nasm -f bin tests.nasm -l tests.lst -o tests.rom

tests/pc/80386/tests.nasm

@@ -0,0 +1,14 @@
+	cpu	386
+
+	org	0x0000
+	section .text
+
+	bits	16
+
+start:	mov	eax,0x11223344
+	mov	edx,0x55667788
+
+	times	0xfff0-($-$$) db 0
+
+	bits	16
+	jmp	0xf000:start