Create initial scaffolding for JS WASM assembler

README.md

@@ -1,24 +1,31 @@
 # Wipforth
 
-Wipforth is a Forth implementation that runs in the WebAssembly
-virtual machine.  The system is bootstrapped from source on page load:
-the only non-text file is the favicon :)
+Wipforth is a simple Forth implementation that runs in the WebAssembly
+virtual machine.  It does I/O via memory-mapped peripherals, which are
+emulated in JavaScript.
 
-I/O is done via memory-mapped peripherals, which are emulated in
-JavaScript.
-
-- For the Forth kernel, see [wipforth.ws](./wipforth.ws)
-- For the emulator, see [emu.js](./emu.js)
-- For the assembler, see [asm.js](./asm.js)
-- For the prelude (Forth code loaded right after the kernel boots),
-  see [prelude.f](./prelude.f)
+- For the Forth kernel, see [wipforth.wat](./wipforth.wat)
+- For the JavaScript emulator, see [emu.js](./emu.js)
+- For the Forth prelude, which is loaded at start-up, see
+  [prelude.f](./prelude.f)
 - For a description of the peripherals, see the
   [Peripherals](#peripherals) section below.
 
 ## Building and Running Locally
 
-There's a [Guile](https://www.gnu.org/software/guile/) script in the
-repo you can use for this:
+You'll need:
+
+- [WABT](https://github.com/WebAssembly/wabt) (not for long mwahaha)
+- [Guile](https://www.gnu.org/software/guile/) (or bring your own HTTP
+  server -- see note below)
+
+To run, first compile the WebAssembly module:
+
+```
+wat2wasm --enable-threads wipforth.wat
+```
+
+Then run the development server:
 
 ```
 guile server.scm
@@ -27,20 +34,14 @@ guile server.scm
 You should then be able to open <http://localhost:8080> in a browser
 and use the system from there.
 
-However, since everything is bootstrapped on the client, basically any
-HTTP server will do as long as it sets the appropriate response
-headers for `SharedArrayBuffer` use:
+**NOTE**: The server is very simple and just serves the files with the
+cross-origin isolation headers required for `SharedMemoryBuffer` use.
+You could use any HTTP server that sets these headers.
 
-- `Cross-Origin-Opener-Policy: same-origin`
-- `Cross-Origin-Embedder-Policy: require-corp`
-
-So, if you don't have Guile on your system you can use something else
-like Python's `http.server`.
-
-**NOTE**: You should **definitely not** use `server.scm` to serve the
-application on the open internet or anything like that; I just hacked
-it together for testing on localhost during development and it's
-probably hilariously insecure.
+You should **definitely not** use the development server to serve the
+application on the open internet; I just hacked it together for
+testing on localhost during development and it's probably hilariously
+insecure.
 
 ## End-to-End Tests
 
@@ -61,34 +62,36 @@ Given that's all sorted, you should be able to run:
 guile tests.scm
 ```
 
-It will print a JUnit XML report to standard out.  You can
-pretty-print it with `xmllint` if you have it installed:
+It will print a JUnit XML report to standard out, you can pretty-print
+it with:
 
 ```
 guile tests.scm | xmllint --format -
 ```
 
+Though, of course, this will require that you have `xmllint` on your
+system.
+
 ## Peripherals
 
 ### Terminal
 
 | Name   | Address | Size / B | Access       |
 |--------|---------|----------|--------------|
-| TXBUF  | 000h    | 32       | write        |
-| RXBUF  | 080h    | 32       | read         |
-| TXHEAD | 100h    | 4        | atomic read  |
-| TXTAIL | 104h    | 4        | atomic write |
-| RXHEAD | 108h    | 4        | atomic write |
-| RXTAIL | 10Ch    | 4        | atomic read  |
+| TXBUF  | 00h     | 32       | write        |
+| RXBUF  | 20h     | 32       | read         |
+| TXHEAD | 40h     | 4        | atomic read  |
+| TXTAIL | 44h     | 4        | atomic write |
+| RXHEAD | 48h     | 4        | atomic write |
+| RXTAIL | 4Ch     | 4        | atomic read  |
 
 For both sending (`TX`) and receiving (`RX`), there are three
 registers: `xBUF`, `xHEAD` and `xTAIL`:
 
-- `xBUF` registers are 128-byte FIFO ring buffers used for data
+- `xBUF` registers are 32-byte FIFO ring buffers used for data
 - The `xHEAD` and `xTAIL` registers specify the start and end of data
   in the ring buffer, `xHEAD` being the offset of the first byte of
-  data, and `xTAIL` being the offset of the first byte *after* the
-  data.
+  data, and `xTAIL` being the offset of the first byte *after* the data.
 
 In order to be distinguishable from the empty state, the ring buffers
 must never be completely full -- there must always be *at least one*
@@ -98,10 +101,7 @@ unoccupied byte between the tail and the head.
 
 | Name     | Address | Size / B | Access       |
 |----------|---------|----------|--------------|
-| SYSREADY | 110h    | 4        | atomic write |
-| SYSINTER | 114h    | 4        | atomic read  |
+| SYSREADY | 50h     | 1        | atomic write |
 
 The `SYSREADY` register is used to indicate when the system has booted
-up and is ready for user input.  `SYSINTER` is set (and notified on)
-once the emulator has enabled user input and the system is
-interactive.
+up and is ready for user input.

boot.js

@@ -1,26 +1,7 @@
-import { Assembler } from './asm.js';
-
-const assemble = (async () => {
-	const asm = new Assembler();
-	const resp = await fetch('wipforth.ws');
-	for await (const chunk of resp.body) {
-		asm.push(chunk);
-	}
-	return asm.wasm();
-})();
-
 self.onmessage = async (e) => {
-	switch (e.data.type) {
-	case "load":
-		const exports = { emu: { mem: e.data.mem } };
-		const wasm = await assemble;
-		self.mod = await WebAssembly.instantiate(wasm, exports);
-		await self.postMessage('ready');
-		break;
-
-	case "boot":
-		self.mod.instance.exports.reset();
-		console.log('System halt');
-		break;
-	}
+	const exports = { emu: { mem: e.data } };
+	const mod = await WebAssembly.instantiateStreaming(
+		fetch('wipforth.wasm'), exports)
+	mod.instance.exports.reset();
+	console.log('System halt');
 };

deploy-manifest.conf

@@ -1,8 +1,6 @@
-asm.js
 boot.js
 emu.js
-favicon.png
 index.html
 prelude.f
 styles.css
-wipforth.ws
+wipforth.wasm

emu.js

@@ -1,17 +1,16 @@
-const TXBUF = 0x000;
-const RXBUF = 0x080;
-const TXHEAD = 0x100;
-const TXTAIL = 0x104;
-const RXHEAD = 0x108;
-const RXTAIL = 0x10c;
+const TXBUF = 0x00;
+const RXBUF = 0x20;
+const TXHEAD = 0x40;
+const TXTAIL = 0x44;
+const RXHEAD = 0x48;
+const RXTAIL = 0x4c;
+const SYSREADY = 0x50;
 
-const SYSREADY = 0x110;
-const SYSINTER = 0x114;
+const TXBUF_SIZE = 32;
+const RXBUF_SIZE = 32;
+const PERIPHS_SIZE = 81;
 
-const PERIPHS_SIZE = 0x200;
-
-const POLL_INTERVAL_MS = 5;
-const DOT_INTERVAL_MS = 25;
+const POLL_INTERVAL_MS = 20;
 
 const COLS = 80;
 const TAB_WIDTH = 8;
@@ -51,19 +50,8 @@ class Emulator {
 		document.addEventListener('keydown', (e) => this.handle_keydown(e));
 		window.addEventListener('resize', () => this.handle_resize());
 
-		this.forth = new Worker('boot.js', { type: 'module' });
-
-		this.print("Assembling kernel ");
-		this.dots = setInterval(() => this.print("."), DOT_INTERVAL_MS);
-		this.forth.postMessage({ type: "load", mem: this.mem });
-		this.forth.onmessage = (e) => {
-			clearInterval(this.dots);
-			this.print(" done\n");
-
-			this.print("Loading prelude ");
-			this.forth.postMessage({ type: "boot" });
-			this.dots = setInterval(() => this.print("."), DOT_INTERVAL_MS);
-		};
+		this.worker = new Worker('boot.js');
+		this.worker.postMessage(this.mem);
 
 		fetch('prelude.f')
 			.then(res => res.text())
@@ -89,21 +77,15 @@ class Emulator {
 		if (!this.input_enable) {
 			const sysready = Atomics.load(this.mem_u8, SYSREADY);
 			if (sysready != 0) {
-				clearInterval(this.dots);
-				this.print(" done\n");
-
-				Atomics.store(this.mem_u8, SYSINTER, 1);
-				Atomics.notify(this.mem_i32, SYSINTER / 4);
-
 				this.input_enable = true;
-				this.blink = true;
 				this.flush_output();
+				document.getElementById('cursor').classList.add('blinking');
 			}
 		}
 	}
 
 	fifo_next(idx) {
-		return (idx + 1) & 0x7f;
+		return (idx + 1) & 0x1f;
 	}
 
 	handle_tx_data(head, tail) {
@@ -191,14 +173,12 @@ class Emulator {
 		}
 
 		e.preventDefault();
-		this.blink = false;
 		this.flush_output();
 
 		document.getElementById('cursor').classList.remove('blinking');
 		if (this.idle_timer)
 			clearTimeout(this.idle_timer);
 		this.idle_timer = setTimeout(() => {
-			this.blink = true;
 			document.getElementById('cursor').classList.add('blinking');
 		}, CURSOR_IDLE_TIME_MS);
 	}
@@ -285,12 +265,10 @@ class Emulator {
 			return row.map((c, x) => {
 				const ec = this.html_escape(c);
 				if (this.input_enable
-					&& x == this.cursor.x && y == this.cursor.y) {
-					const cl = this.blink ? 'class="blinking"' : '';
-					return `<span id="cursor" ${cl}>` + ec + '</span>';
-				} else {
+					&& x == this.cursor.x && y == this.cursor.y)
+					return '<span id="cursor">' + ec + '</span>';
+				else
 					return ec;
-				}
 			}).join('').trimEnd();
 		}).join('\n');
 		this.output.innerHTML = html;
@@ -347,16 +325,6 @@ class Emulator {
 }
 
 window.addEventListener('DOMContentLoaded', () => {
-	const output = document.getElementById('output');
-	output.innerText = '';
-
-	if (!self.crossOriginIsolated) {
-		output.innerText = "Yeah so there's this thing where Chromium ends "
-			+ "up ignoring COOP/COEP\nheaders after a hard reload "
-			+ "sometimes, and I haven't been able to\nfigure out how to "
-			+ "work around it yet.  If you just wait a little while\nand "
-			+ "then reload normally then hopefully it should work haha";
-	} else {
-		window.emu = new Emulator();
-	}
+	document.getElementById('output').innerText = '';
+	window.emu = new Emulator();
 });

index.html

@@ -7,7 +7,8 @@
   </head>
   <body>
 	<script type="text/javascript" src="emu.js"></script>
-	<div id="output"><noscript>I'm afraid you need javascript enabled for this to work :(
+	<div id="output">I'm afraid you need javascript enabled for this to work :(
 
-cringe, I know... but I promise there are no frameworks&#8482;</noscript></div></body>
+cringe, I know... but I promise there are no frameworks&#8482;</div>
+  </body>
 </html>

prelude.f

@@ -1,5 +1,12 @@
+76 EMIT 111 EMIT 97 EMIT 100 EMIT 105 EMIT 110 EMIT 103 EMIT 32 EMIT
+112 EMIT 114 EMIT 101 EMIT 108 EMIT 117 EMIT 100 EMIT 101 EMIT 32 EMIT
+
 : \ KEY 10 = 0BRANCH [ -20 , ] ; IMMEDIATE \ Now we have line comments :)
 
+\ We'll periodically sprinkle these in so that it's clear to the user
+\ that things are happening.
+46 EMIT
+
 \ Conditionals
 
 : IF
@@ -20,6 +27,8 @@
   SWAP !
 ; IMMEDIATE
 
+46 EMIT
+
 \ Loops
 
 : BEGIN HERE @ ; IMMEDIATE
@@ -34,6 +43,8 @@
   HERE @ - ,
 ; IMMEDIATE
 
+46 EMIT
+
 \ Recursive calls
 
 : RECURSE LATEST @ >CFA , ; IMMEDIATE
@@ -50,6 +61,8 @@
 
 ( ( Take that, C ) )
 
+46 EMIT
+
 \ Printing utilities
 
 : CR 10 EMIT ;
@@ -67,6 +80,8 @@
   + EMIT
 ;
 
+CHAR . EMIT
+
 : .
   \ Handle negatives
   DUP 0< IF CHAR - EMIT NEGATE THEN
@@ -95,6 +110,8 @@
   2DROP
 ;
 
+CHAR . EMIT
+
 : TYPE ( addr len -- )
   BEGIN
 	DUP 0= IF 2DROP EXIT THEN
@@ -103,6 +120,8 @@
   AGAIN
 ;
 
+CHAR . EMIT
+
 : C, HERE @ C! 1 HERE +! ;
 
 : ."
@@ -132,6 +151,8 @@
   THEN
 ; IMMEDIATE
 
+CHAR . EMIT
+
 \ Misc utilities
 
 : NIP SWAP DROP ;
@@ -150,6 +171,8 @@
 
 : [COMPILE] ' , ; IMMEDIATE
 
+CHAR . EMIT
+
 \ Constants, variables and values
 
 : CONSTANT
@@ -181,21 +204,24 @@
   THEN
 ; IMMEDIATE
 
+CHAR . EMIT
+
 \ Peripheral register addresses
 
 HEX
 
-000 CONSTANT TXBUF
-080 CONSTANT RXBUF
-100 CONSTANT TXHEAD
-104 CONSTANT TXTAIL
-108 CONSTANT RXHEAD
-10C CONSTANT RXTAIL
-110 CONSTANT SYSREADY
-114 CONSTANT SYSINTER
+00 CONSTANT TXBUF
+20 CONSTANT RXBUF
+40 CONSTANT TXHEAD
+44 CONSTANT TXTAIL
+48 CONSTANT RXHEAD
+4C CONSTANT RXTAIL
+50 CONSTANT SYSREADY
 
 DECIMAL
 
+46 EMIT
+
 \ A better word-not-found handler
 
 : ANY-RX? RXHEAD AC@ RXTAIL AC@ <> ;
@@ -218,11 +244,13 @@ DECIMAL
 
 ' WNF-HANDLER TO WNFHOOK
 
+CHAR . EMIT
+
 \ Version number
 
 0 CONSTANT VERSION-MAJOR
-2 CONSTANT VERSION-MINOR
-2 CONSTANT VERSION-PATCH
+1 CONSTANT VERSION-MINOR
+0 CONSTANT VERSION-PATCH
 
 : PRINT-VERSION
   CHAR v EMIT VERSION-MAJOR .
@@ -230,6 +258,8 @@ DECIMAL
   CHAR . EMIT VERSION-PATCH .
 ;
 
+CHAR . EMIT
+
 \ Welcome banner
 
 : BANNER
@@ -239,7 +269,7 @@ DECIMAL
   ." |__,__/_/ .__(_)___/_//_/" CR
   ."        /_/               " CR
   CR
-  ." Welcome to Wipforth " PRINT-VERSION  ." !" CR
+  ." Wipforth " PRINT-VERSION CR
   ." Copyright (c) Camden Dixie O'Brien" CR
   CR
   ." Wipforth is freely available to use, modify and distribute for personal use" CR
@@ -247,8 +277,8 @@ DECIMAL
   CR
 ;
 
-\ Set SYSREADY high and wait until interactive
-1 SYSREADY AC!
-SYSINTER WAIT DROP
-
+."  done" CR
 BANNER
+
+\ Set SYSREADY high to enable user input
+1 SYSREADY AC!

server.scm

@@ -16,8 +16,9 @@
   '(("html" . (text/html))
 	("css"  . (text/css))
 	("js"   . (application/javascript))
+	("wasm" . (application/wasm))
 	("f"    . (text/plain))
-	("ws"   . (text/plain))
+	("wat"  . (text/plain))
 	("png"  . (image/png))))
 
 (define (mime-type path)

tests.scm

@@ -19,19 +19,13 @@
 (define client (client-setup))
 
 (navigate client "http://localhost:8080")
-(sleep 1)
-
-(define-test kernel-assembles-successfully
-  (let* ((display (get-display client))
-		 (line (first (lines display))))
-	(assert (string-match "Assembling kernel \\.+ done" line)
-			(format #f "Kernel assemble line: ~s" line))))
+(sleep 5)
 
 (define-test prelude-loads-successfully
   (let* ((display (get-display client))
-		 (line (second (lines display))))
-	(assert (string-match "Loading prelude \\.+ done" line)
-			(format #f "Prelude load line: ~s" line))))
+		 (first-line (first (lines display))))
+	(assert (string-match "Loading prelude \\.+ done" first-line)
+			(format #f "Prelude load line: ~s" first-line))))
 
 (define-test six-seven-times-dot-cr-yields-42
   (input-line client "6 7 * . CR")