From b88271f625e9ad1158954b2b00a4542eba0195a8 Mon Sep 17 00:00:00 2001
From: Matt Hillsdon <44397098+microbit-matt-hillsdon@users.noreply.github.com>
Date: Thu, 13 Oct 2022 11:45:28 +0100
Subject: [PATCH 1/3] Add license and contributing files. (#83)

---
 CONTRIBUTING.md | 13 +++++++++++++
 LICENSE         | 21 +++++++++++++++++++++
 README.md       |  6 ++++++
 3 files changed, 40 insertions(+)
 create mode 100644 CONTRIBUTING.md
 create mode 100644 LICENSE

diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
new file mode 100644
index 00000000..3ccae7b5
--- /dev/null
+++ b/CONTRIBUTING.md
@@ -0,0 +1,13 @@
+Thanks for looking here! We'd love your help. The micro:bit project is only
+possible through contributions of companies and individuals around the world.
+
+This project is managed on GitHub, and the best way to contribute is to jump in
+and fix/file issues.
+
+https://github.com/microbit-foundation/micropython-microbit-v2-simulator
+
+Significant features are best discussed first to make sure everyone is agreed
+on the best direction.
+
+The project uses [Prettier](https://prettier.io/) to format TypeScript code so
+please check out their documentation and set it up with your code editor.
diff --git a/LICENSE b/LICENSE
new file mode 100644
index 00000000..2171dc8d
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,21 @@
+The MIT License (MIT)
+
+Copyright (c) 2022 Damien P. George, Micro:bit Educational Foundation
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
diff --git a/README.md b/README.md
index c4c1c74e..ecaa0251 100644
--- a/README.md
+++ b/README.md
@@ -7,6 +7,12 @@ To try the simulator use the [micro:bit Python Editor](https://python.microbit.o
 The rest of this page explains how to embed the simulator in an application
 and develop the simulator software.
 
+## License
+
+This software is under the MIT open source license.
+
+[SPDX-License-Identifier: MIT](LICENSE)
+
 ## Embedding
 
 The simulator is designed to be embedded into other web applications

From 365bad7863ab4c2e2ac5d1f6437b57501cd8e0ba Mon Sep 17 00:00:00 2001
From: Matt Hillsdon <44397098+microbit-matt-hillsdon@users.noreply.github.com>
Date: Mon, 31 Oct 2022 11:38:25 +0000
Subject: [PATCH 2/3] Set the random number seed. (#87)

It's used in a non-crypto safe RNG in MicroPython so just seed it with a
Math.random-derived value.

Closes https://github.com/microbit-foundation/micropython-microbit-v2-simulator/issues/85
---
 src/demo.html          |  1 +
 src/examples/random.py | 13 +++++++++++++
 src/jshal.h            |  2 ++
 src/jshal.js           |  9 ++++++++-
 src/microbithal_js.c   |  5 ++---
 5 files changed, 26 insertions(+), 4 deletions(-)
 create mode 100644 src/examples/random.py

diff --git a/src/demo.html b/src/demo.html
index cdcbfd44..5889f7cf 100644
--- a/src/demo.html
+++ b/src/demo.html
@@ -93,6 +93,7 @@ <h1>MicroPython-micro:bit simulator example embedding</h1>
               <option value="music">Music</option>
               <option value="pin_logo">Pin logo</option>
               <option value="radio">Radio</option>
+              <option value="random">Random</option>
               <option value="sensors">Sensors</option>
               <option value="sound_effects_builtin">
                 Sound effects (builtin)
diff --git a/src/examples/random.py b/src/examples/random.py
new file mode 100644
index 00000000..d053b81c
--- /dev/null
+++ b/src/examples/random.py
@@ -0,0 +1,13 @@
+from microbit import display, sleep
+import random
+import machine
+
+
+n = random.randrange(0, 100)
+print("Default seed ", n)
+random.seed(1)
+n = random.randrange(0, 100)
+print("Fixed seed ", n)
+print()
+sleep(2000)
+machine.reset()
diff --git a/src/jshal.h b/src/jshal.h
index d0ca73e3..65c81024 100644
--- a/src/jshal.h
+++ b/src/jshal.h
@@ -27,6 +27,8 @@
 void mp_js_hal_init(void);
 void mp_js_hal_deinit(void);
 
+uint32_t mp_js_rng_generate_random_word();
+
 uint32_t mp_js_hal_ticks_ms(void);
 void mp_js_hal_stdout_tx_strn(const char *ptr, size_t len);
 int mp_js_hal_stdin_pop_char(void);
diff --git a/src/jshal.js b/src/jshal.js
index c4cec674..39d3cf08 100644
--- a/src/jshal.js
+++ b/src/jshal.js
@@ -36,6 +36,10 @@ mergeInto(LibraryManager.library, {
     Module.board.stopComponents();
   },
 
+  mp_js_rng_generate_random_word: function () {
+    return (Math.random() * 0x100000000) >>> 0;
+  },
+
   mp_js_hal_ticks_ms: function () {
     return Module.board.ticksMilliseconds();
   },
@@ -131,7 +135,10 @@ mergeInto(LibraryManager.library, {
     return Module.board.pins[pin].getAnalogPeriodUs();
   },
 
-  mp_js_hal_pin_set_analog_period_us: function (/** @type {number} */ pin, /** @type {number} */ period) {
+  mp_js_hal_pin_set_analog_period_us: function (
+    /** @type {number} */ pin,
+    /** @type {number} */ period
+  ) {
     return Module.board.pins[pin].setAnalogPeriodUs(period);
   },
 
diff --git a/src/microbithal_js.c b/src/microbithal_js.c
index f9d2460f..4d656341 100644
--- a/src/microbithal_js.c
+++ b/src/microbithal_js.c
@@ -389,10 +389,9 @@ int microbit_hal_log_data(const char *key, const char *value) {
     return mp_js_hal_log_data(key, value);
 }
 
-// This is needed by the microbitfs implementation.
+// This is used to seed the random number generator.
 uint32_t rng_generate_random_word(void) {
-    //return uBit.random(65536) << 16 | uBit.random(65536);
-    return 0;
+    return mp_js_rng_generate_random_word();
 }
 
 void microbit_hal_audio_select_pin(int pin) {

From 7c5b2e62d3d9ef365294bad5a5874a42e16a4401 Mon Sep 17 00:00:00 2001
From: Matt Hillsdon <44397098+microbit-matt-hillsdon@users.noreply.github.com>
Date: Mon, 31 Oct 2022 17:01:53 +0000
Subject: [PATCH 3/3] Fix for reset/panic overriding the user's stop (#88)

Switch to an enum to make the possible states easier to follow and so we
can check we're in the default state before committing to a reset or
panic.

Closes https://github.com/microbit-foundation/micropython-microbit-v2-simulator/issues/86
---
 src/board/index.ts | 112 +++++++++++++++++++++++++++++++++++----------
 1 file changed, 87 insertions(+), 25 deletions(-)

diff --git a/src/board/index.ts b/src/board/index.ts
index 9cf57b4c..9f662c61 100644
--- a/src/board/index.ts
+++ b/src/board/index.ts
@@ -35,6 +35,32 @@ import { Radio } from "./radio";
 import { RangeSensor, State } from "./state";
 import { ModuleWrapper } from "./wasm";
 
+enum StopKind {
+  /**
+   * The main Wasm function returned control to us in a normal way.
+   */
+  Default = "default",
+  /**
+   * The program called panic.
+   */
+  Panic = "panic",
+  /**
+   * The program requested a reset.
+   */
+  Reset = "reset",
+  /**
+   * An internal mode where we do not display the stop state UI as we plan to immediately reset.
+   * Used for user-requested flash or reset.
+   */
+  BriefStop = "brief",
+  /**
+   * The user requested the program be interrupted.
+   *
+   * Note the program could finish for other reasons, but should always count as a user stop.
+   */
+  UserStop = "user",
+}
+
 export class PanicError extends Error {
   constructor(public code: number) {
     super("panic");
@@ -74,8 +100,6 @@ export class Board {
   radio: Radio;
   dataLogging: DataLogging;
 
-  private panicTimeout: any;
-
   public serialInputBuffer: number[] = [];
 
   private stoppedOverlay: HTMLDivElement;
@@ -108,10 +132,19 @@ export class Board {
    */
   private module: ModuleWrapper | undefined;
   /**
-   * If undefined, then when main finishes we stay stopped.
-   * Otherwise we perform the action then clear this field.
+   * Controls the action after the user program completes.
+   *
+   * Determined by a combination of user actions (stop, reset etc) and program actions.
    */
-  private afterStopped: (() => void) | undefined;
+  private stopKind: StopKind = StopKind.Default;
+  /**
+   * Timeout for a pending start call due to StopKind.Reset.
+   */
+  private pendingRestartTimeout: any;
+  /**
+   * Timeout for the next frame of the panic animation.
+   */
+  private panicTimeout: any;
 
   constructor(
     private notifications: Notifications,
@@ -356,6 +389,8 @@ export class Board {
     if (this.modulePromise || this.module) {
       throw new Error("Module already exists!");
     }
+    clearTimeout(this.pendingRestartTimeout);
+    this.pendingRestartTimeout = null;
 
     this.modulePromise = this.createModule();
     const module = await this.modulePromise;
@@ -365,11 +400,17 @@ export class Board {
       this.displayRunningState();
       await module.start();
     } catch (e: any) {
+      // Take care not to overwrite another kind of stop just because the program
+      // called restart or panic.
       if (e instanceof PanicError) {
-        panicCode = e.code;
+        if (this.stopKind === StopKind.Default) {
+          this.stopKind = StopKind.Panic;
+          panicCode = e.code;
+        }
       } else if (e instanceof ResetError) {
-        const noChangeRestart = () => {};
-        this.afterStopped = noChangeRestart;
+        if (this.stopKind === StopKind.Default) {
+          this.stopKind = StopKind.Reset;
+        }
       } else {
         this.notifications.onInternalError(e);
       }
@@ -386,30 +427,52 @@ export class Board {
     this.modulePromise = undefined;
     this.module = undefined;
 
-    if (panicCode !== undefined) {
-      this.displayPanic(panicCode);
-    } else {
-      if (this.afterStopped) {
-        this.afterStopped();
-        this.afterStopped = undefined;
-        setTimeout(() => this.start(), 0);
-      } else {
+    switch (this.stopKind) {
+      case StopKind.Panic: {
+        if (panicCode === undefined) {
+          throw new Error("Must be set");
+        }
+        this.displayPanic(panicCode);
+        break;
+      }
+      case StopKind.Reset: {
+        this.pendingRestartTimeout = setTimeout(() => this.start(), 0);
+        break;
+      }
+      case StopKind.BriefStop: {
+        // Skip the stopped state.
+        break;
+      }
+      case StopKind.UserStop: /* Fall through */
+      case StopKind.Default: {
         this.displayStoppedState();
+        break;
+      }
+      default: {
+        throw new Error("Unknown stop kind: " + this.stopKind);
       }
     }
+    this.stopKind = StopKind.Default;
   }
 
-  async stop(
-    afterStopped: (() => void) | undefined = undefined
-  ): Promise<void> {
-    this.afterStopped = afterStopped;
+  async stop(brief: boolean = false): Promise<void> {
     if (this.panicTimeout) {
       clearTimeout(this.panicTimeout);
       this.panicTimeout = null;
       this.display.clear();
-      this.displayStoppedState();
+      if (!brief) {
+        this.displayStoppedState();
+      }
+    }
+    if (this.pendingRestartTimeout) {
+      clearTimeout(this.pendingRestartTimeout);
+      this.pendingRestartTimeout = null;
+      if (!brief) {
+        this.displayStoppedState();
+      }
     }
     if (this.modulePromise) {
+      this.stopKind = brief ? StopKind.BriefStop : StopKind.UserStop;
       // Avoid this.module as we might still be creating it (async).
       const module = await this.modulePromise;
       module.requestStop();
@@ -422,11 +485,10 @@ export class Board {
 
   /**
    * An external reset.
-   * reset() in MicroPython code throws ResetError.
    */
   async reset(): Promise<void> {
-    const noChangeRestart = () => {};
-    this.stop(noChangeRestart);
+    await this.stop(true);
+    return this.start();
   }
 
   async flash(filesystem: Record<string, Uint8Array>): Promise<void> {
@@ -440,7 +502,7 @@ export class Board {
     };
     if (this.modulePromise) {
       // If it's running then we need to stop before flash.
-      return this.stop(flashFileSystem);
+      await this.stop(true);
     }
     flashFileSystem();
     return this.start();