initial commit

Signed-off-by: Sean Cross <sean@xobs.io>

css/theme/fossasia2020.css

@@ -0,0 +1,514 @@
+/**
+ * Black theme for reveal.js. This is the opposite of the 'white' theme.
+ *
+ * By Hakim El Hattab, http://hakim.se
+ */
+
+@import url(../../lib/font/space-mono/space-mono.css);
+
+section.has-light-background,
+section.has-light-background h1,
+section.has-light-background h2,
+section.has-light-background h3,
+section.has-light-background h4,
+section.has-light-background h5,
+section.has-light-background h6 {
+    color: #222;
+}
+
+/*********************************************
+  * GLOBAL STYLES
+  *********************************************/
+/* rgb(250, 166, 26); */
+body {
+    background: #fff;
+    background-color: #fff;
+}
+
+.reveal .commentary {
+    bottom: 100px;
+    right: 0em;
+    padding-bottom: 1em;
+    padding-right: 1em;
+    position: absolute;
+    background-color: rgba(0, 0, 0, 0.50);
+    font-size: 12pt;
+    font-family: serif;
+    z-index: 10;
+    color: white;
+    display: none;
+}
+
+.reveal .footer {
+    position: absolute;
+    bottom: 0em;
+    right: 0em;
+    padding-bottom: 1em;
+    padding-right: 1em;
+    text-align: right;
+    font-size: 0.5em;
+    width: 100%;
+    height: 68px;
+    background-image: url("lca2020-logo-cropped.svg");
+    background-repeat: no-repeat;
+    background-color: rgb(0, 177, 197);
+    display: flex;
+    justify-content: flex-end;
+    align-items: flex-end;
+    z-index: 1;
+}
+
+.reveal .footer .url {
+    position: absolute;
+    padding-bottom: 30px;
+}
+
+.reveal .footer .theme {
+    padding-right: 80px;
+}
+
+.reveal .footer .hashtag {
+    padding-right: 80px;
+}
+
+@media only screen and (max-width:800px) {
+    .reveal .footer .url {
+        display: none;
+    }
+}
+
+@media only screen and (max-width:550px) {
+    .reveal .footer {
+        background-image: none;
+    }
+}
+
+@media only screen and (max-width:750px) {
+    .reveal .footer .twitter {
+        display: none;
+    }
+}
+
+@media only screen and (max-width:1050px) {
+    .reveal .footer .theme {
+        display: none;
+    }
+}
+
+@media only screen and (max-width:1300px) {
+    .reveal .footer .hashtag {
+        display: none;
+    }
+}
+
+.reveal {
+    font-family: "IBM Plex Mono", "Space Mono", Helvetica, sans-serif;
+    font-size: 42pt;
+    font-weight: normal;
+    color: #212529;
+}
+
+::selection {
+    color: #212529;
+    background: #bee4fd;
+    text-shadow: none;
+}
+
+::-moz-selection {
+    color: #212529;
+    background: #bee4fd;
+    text-shadow: none;
+}
+
+.reveal .slides section,
+.reveal .slides section>section {
+    line-height: 1.3;
+    font-weight: inherit;
+}
+
+/*********************************************
+  * HEADERS
+  *********************************************/
+@font-face {
+    font-family: "Brix Sans Medium Firefox";
+    src: url("HVD_Fonts_-_BrixSlab-Medium.otf") format("opentype");
+}
+
+.reveal h1,
+.reveal h2,
+.reveal h3,
+.reveal h4,
+.reveal h5,
+.reveal h6 {
+    margin: 0 0 20px 0;
+    color: #212529;
+    font-family: "Brix Sans Medium Firefox", "Brix Sans Medium", "Montserrat", Helvetica, sans-serif;
+    font-weight: 300;
+    line-height: 1.2;
+    letter-spacing: normal;
+    /* text-transform: uppercase; */
+    /* text-shadow: 1px 1px 2px black;  */
+    text-shadow: none;
+    word-wrap: break-word;
+    background-color: rgb(250, 166, 26);
+    width: 100%;
+}
+
+.reveal h1 {
+    font-size: 2.5em;
+}
+
+.reveal h2 {
+    font-size: 1.6em;
+}
+
+.reveal h3 {
+    font-size: 1.3em;
+}
+
+.reveal h4 {
+    font-size: 1em;
+}
+
+.reveal h1 {
+    text-shadow: none;
+}
+
+/*********************************************
+  * OTHER
+  *********************************************/
+
+.reveal p {
+    margin: 20px 0;
+    line-height: 1.3;
+}
+
+/* Ensure certain elements are never larger than the slide itself */
+
+.reveal img,
+.reveal video,
+.reveal iframe {
+    max-width: 95%;
+    max-height: 95%;
+}
+
+.reveal strong,
+.reveal b {
+    font-weight: bold;
+}
+
+.reveal em {
+    font-style: italic;
+}
+
+.reveal ol,
+.reveal dl,
+.reveal ul {
+    display: inline-block;
+    text-align: left;
+    margin: 0 0 0 1em;
+}
+
+.reveal ol {
+    list-style-type: decimal;
+}
+
+.reveal ul {
+    list-style-type: disc;
+}
+
+.reveal ul ul {
+    list-style-type: square;
+}
+
+.reveal ul ul ul {
+    list-style-type: circle;
+}
+
+.reveal ul ul,
+.reveal ul ol,
+.reveal ol ol,
+.reveal ol ul {
+    display: block;
+    margin-left: 40px;
+}
+
+.reveal dt {
+    font-weight: bold;
+}
+
+.reveal dd {
+    margin-left: 40px;
+}
+
+.reveal blockquote {
+    display: block;
+    position: relative;
+    width: 70%;
+    margin: 20px auto;
+    padding: 5px;
+    font-style: italic;
+    background: rgba(255, 255, 255, 0.05);
+    box-shadow: 0px 0px 2px rgba(0, 0, 0, 0.2);
+}
+
+.reveal blockquote p:first-child,
+.reveal blockquote p:last-child {
+    display: inline-block;
+}
+
+.reveal q {
+    font-style: italic;
+}
+
+.reveal pre {
+    display: block;
+    position: relative;
+    width: 90%;
+    margin: 20px auto;
+    text-align: left;
+    font-size: 0.55em;
+    font-family: monospace;
+    line-height: 1.2em;
+    word-wrap: break-word;
+    box-shadow: 0px 0px 6px rgba(0, 0, 0, 0.3);
+}
+
+.reveal code {
+    font-family: monospace;
+    text-transform: none;
+}
+
+.reveal pre code {
+    display: block;
+    padding: 5px;
+    overflow: auto;
+    max-height: 400px;
+    word-wrap: normal;
+}
+
+.reveal table {
+    margin: auto;
+    border-collapse: collapse;
+    border-spacing: 0;
+}
+
+.reveal table th {
+    font-weight: bold;
+}
+
+.reveal table th,
+.reveal table td {
+    text-align: left;
+    padding: 0.2em 0.5em 0.2em 0.5em;
+    border-bottom: 1px solid;
+}
+
+.reveal table th[align="center"],
+.reveal table td[align="center"] {
+    text-align: center;
+}
+
+.reveal table th[align="right"],
+.reveal table td[align="right"] {
+    text-align: right;
+}
+
+.reveal table tbody tr:last-child th,
+.reveal table tbody tr:last-child td {
+    border-bottom: none;
+}
+
+.reveal sup {
+    vertical-align: super;
+    font-size: smaller;
+}
+
+.reveal sub {
+    vertical-align: sub;
+    font-size: smaller;
+}
+
+.reveal small {
+    display: inline-block;
+    font-size: 0.6em;
+    line-height: 1.2em;
+    vertical-align: top;
+}
+
+.reveal small * {
+    vertical-align: top;
+}
+
+/*********************************************
+  * LINKS
+  *********************************************/
+
+.reveal a {
+    color: #190047;
+    text-decoration: none;
+    -webkit-transition: color .15s ease;
+    -moz-transition: color .15s ease;
+    transition: color .15s ease;
+}
+
+.reveal a:hover {
+    color: #4205b4;
+    text-shadow: none;
+    border: none;
+}
+
+.reveal .roll span:after {
+    color: #fff;
+    background: #068de9;
+}
+
+/*********************************************
+  * IMAGES
+  *********************************************/
+
+.reveal section img {
+    margin: 15px 0px;
+    background: rgba(255, 255, 255, 0.12);
+    border: 4px solid #fff;
+    box-shadow: 0 0 10px rgba(0, 0, 0, 0.15);
+}
+
+.reveal section img.plain {
+    border: 0;
+    box-shadow: none;
+}
+
+.reveal a img {
+    -webkit-transition: all .15s linear;
+    -moz-transition: all .15s linear;
+    transition: all .15s linear;
+}
+
+.reveal a:hover img {
+    background: rgba(255, 255, 255, 0.2);
+    border-color: #42affa;
+    box-shadow: 0 0 20px rgba(0, 0, 0, 0.55);
+}
+
+/*********************************************
+  * VIDEOS
+  *********************************************/
+
+.reveal section video {
+    margin: 15px 0px;
+    background: rgba(255, 255, 255, 0.12);
+    border: 4px solid #fff;
+    box-shadow: 0 0 10px rgba(0, 0, 0, 0.15);
+}
+
+.reveal section video.plain {
+    border: 0;
+    box-shadow: none;
+}
+
+.reveal a video {
+    -webkit-transition: all .15s linear;
+    -moz-transition: all .15s linear;
+    transition: all .15s linear;
+}
+
+/* Fragment additions */
+.reveal .slides section .fragment.fade-semi-out {
+    opacity: 1;
+    visibility: inherit;
+}
+
+.reveal .slides section .fragment.fade-semi-out.visible {
+    opacity: 0.5;
+    visibility: inherit;
+}
+
+.reveal ul.os {
+    margin-left: 0;
+    padding-left: 0;
+}
+
+.reveal ul.os-good {
+    list-style: none;
+    margin-left: 0;
+    padding-left: 0;
+}
+
+.reveal ul.os-good li::before {
+    content: "✔️ ";
+    font-family: "sans-serif";
+}
+
+.reveal ul.os-bad {
+    list-style: none;
+    margin-left: 0;
+    padding-left: 0;
+}
+
+.reveal ul.os-bad li::before {
+    content: "❌ ";
+    font-family: "sans-serif";
+}
+
+.reveal blockquote.os-quote::before {
+    content: "“";
+    left: 20%;
+    position: absolute;
+    top: -30px;
+    font-size: 50pt;
+}
+
+.reveal blockquote.os-quote::after {
+    content: "”";
+    left: 70%;
+    position: absolute;
+    bottom: -60px;
+    font-size: 50pt;
+}
+
+/*********************************************
+  * NAVIGATION CONTROLS
+  *********************************************/
+
+.reveal .controls {
+    color: #42affa;
+}
+
+/*********************************************
+  * PROGRESS BAR
+  *********************************************/
+
+.reveal .progress {
+    background: rgba(0, 0, 0, 0.2);
+    color: #42affa;
+}
+
+.reveal .progress span {
+    -webkit-transition: width 800ms cubic-bezier(0.26, 0.86, 0.44, 0.985);
+    -moz-transition: width 800ms cubic-bezier(0.26, 0.86, 0.44, 0.985);
+    transition: width 800ms cubic-bezier(0.26, 0.86, 0.44, 0.985);
+}
+
+/*********************************************
+  * PRINT BACKGROUND
+  *********************************************/
+
+@media print {
+    .backgrounds {
+        background-color: #222;
+    }
+}
+
+.boldblue {
+    font-weight: bold;
+    color: blue;
+}
+
+.white50bg {
+    background: rgba(255, 255, 255, 0.5);
+}
+
+.bg50 {
+    background: rgba(0, 177, 197, 0.3);
+}

img/Untitled.svg

@@ -0,0 +1,21 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
+<svg width="100%" height="100%" viewBox="0 0 2120 3225" version="1.1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" xml:space="preserve" xmlns:serif="http://www.serif.com/" style="fill-rule:evenodd;clip-rule:evenodd;stroke-linejoin:bevel;stroke-miterlimit:1.5;">
+    <g id="Artboard1" transform="matrix(1,0,0,1,20,0)">
+        <rect x="-20" y="0" width="2120" height="3225" style="fill:none;"/>
+        <g transform="matrix(1,0,0,1,-20,0)">
+            <g transform="matrix(1.80723,0,0,2.15789,-1144.88,-2190.79)">
+                <rect x="675" y="1050" width="1079" height="1425" style="fill:rgb(229,229,229);"/>
+            </g>
+            <path d="M2025,3150L2025,75" style="fill:none;stroke:rgb(167,167,167);stroke-width:31.48px;"/>
+            <path d="M75,3150L2025,3150" style="fill:none;stroke:rgb(167,167,167);stroke-width:31.48px;"/>
+            <path d="M2025,75L75,75L75,3150" style="fill:rgb(229,229,229);stroke:black;stroke-width:31.48px;stroke-linecap:round;stroke-linejoin:round;"/>
+            <g transform="matrix(24.5625,0,0,24.5625,-6084.94,-6109.5)">
+                <use xlink:href="#_Image1" x="255" y="255" width="16px" height="18px"/>
+            </g>
+        </g>
+    </g>
+    <defs>
+        <image id="_Image1" width="16px" height="18px" xlink:href="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABAAAAASCAYAAABSO15qAAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA+UlEQVQ4ja1SO4oCQRB9tUwgCxobjIl3MNrEWzQIjan5YOIV7AIz48WormA0mTDRHmJPsMEiAzImdtP2ZxzYfdBQXcV79bq6gH9CN+RUVdWFxDcvpgEHoUjhX0Qk6uCjaRoYYwCgY2YKHTxB1xq61smaMcY5SQroWmO0fgcAKKVcnplBRCAiMDN6HVw/f6OciEBEgMc8sgKn5QntsUV7bC0hiyJX8Imrw4eLb5fShukhznebpGC5nyTzkcBsfE6KfG9/bHf7/vwvhCK3SxmS8w4yIm4Tw2WLhjj9WvhXgrcHKUQCIgKlVGT11Zr3Fvs4RZCIOv+hwTDcAf1BWOiGHoqWAAAAAElFTkSuQmCC"/>
+    </defs>
+</svg>

img/missing-image.svg

@@ -0,0 +1,81 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
+<svg width="100%" height="100%" viewBox="0 0 2120 3225" version="1.1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" xml:space="preserve" xmlns:serif="http://www.serif.com/" style="fill-rule:evenodd;clip-rule:evenodd;stroke-linejoin:bevel;stroke-miterlimit:1.5;">
+    <g id="Artboard1" transform="matrix(1,0,0,1,20,0)">
+        <rect x="-20" y="0" width="2120" height="3225" style="fill:none;"/>
+        <g transform="matrix(1,0,0,1,-20,0)">
+            <g transform="matrix(1.80723,0,0,2.15789,-1144.88,-2190.79)">
+                <rect x="675" y="1050" width="1079" height="1425" style="fill:rgb(229,229,229);"/>
+            </g>
+            <path d="M2025,3150L2025,75" style="fill:none;stroke:rgb(167,167,167);stroke-width:31.48px;"/>
+            <path d="M75,3150L2025,3150" style="fill:none;stroke:rgb(167,167,167);stroke-width:31.48px;"/>
+            <path d="M2025,75L75,75L75,3150" style="fill:rgb(229,229,229);stroke:black;stroke-width:31.48px;stroke-linecap:round;stroke-linejoin:round;"/>
+            <g transform="matrix(21.4375,0,0,21.4375,253.125,257)">
+                <g>
+                    <path d="M2,2L11,2L11,4L12,4L12,9L9,9L9,11L8,11L8,12L4,12L4,14L2,14L2,2Z" style="fill:rgb(169,169,169);"/>
+                    <path d="M11,11L12,11L12,14L9,14L9,13L11,13L11,11Z" style="fill:rgb(169,169,169);"/>
+                </g>
+                <g>
+                    <rect x="10" y="2" width="3" height="2" style="fill:white;"/>
+                    <path d="M10,0L10,4L11,4L11,2L12,2L12,1L11,1L11,0L10,0Z" style="fill:rgb(115,115,115);"/>
+                    <g transform="matrix(1,0,0,1,-11,-2)">
+                        <rect x="23" y="4" width="1" height="1" style="fill:rgb(115,115,115);"/>
+                    </g>
+                    <g transform="matrix(1,0,0,1,-10,-1)">
+                        <rect x="23" y="4" width="1" height="1" style="fill:rgb(115,115,115);"/>
+                    </g>
+                </g>
+                <g>
+                    <g transform="matrix(3,0,0,2,-66,3)">
+                        <rect x="23" y="4" width="1" height="1"/>
+                    </g>
+                    <g transform="matrix(2,0,0,1,-41,7)">
+                        <rect x="23" y="4" width="1" height="1" style="fill:rgb(203,35,17);"/>
+                    </g>
+                    <g transform="matrix(2,0,0,1,-42,6)">
+                        <rect x="23" y="4" width="1" height="1" style="fill:rgb(203,35,17);"/>
+                    </g>
+                    <g transform="matrix(2,0,0,1,-43,5)">
+                        <rect x="23" y="4" width="1" height="1" style="fill:rgb(203,35,17);"/>
+                    </g>
+                    <g transform="matrix(1,0,0,2,-20,0)">
+                        <rect x="23" y="4" width="1" height="1" style="fill:rgb(203,35,17);"/>
+                    </g>
+                    <path d="M3,9L3,12L6,12L6,11L5,11L5,10L4,10L4,9L3,9" style="fill:rgb(232,48,203);"/>
+                </g>
+                <g>
+                    <g transform="matrix(2,0,0,2,-41,-3)">
+                        <rect x="23" y="4" width="1" height="1"/>
+                    </g>
+                    <g transform="matrix(2,0,0,2,-40,-4)">
+                        <rect x="23" y="4" width="1" height="1"/>
+                    </g>
+                    <path d="M4,4L4,6L7,6L7,3L5,3L5,4L4,4" style="fill:rgb(6,105,6);"/>
+                    <g transform="matrix(1,0,0,1,-18,1.77636e-15)">
+                        <rect x="23" y="4" width="1" height="1" style="fill:rgb(14,200,16);"/>
+                    </g>
+                </g>
+                <g>
+                    <g transform="matrix(2,0,0,2,-38,1)">
+                        <rect x="23" y="4" width="1" height="1"/>
+                    </g>
+                    <g transform="matrix(2,0,0,2,-37,1.77636e-15)">
+                        <rect x="23" y="4" width="1" height="1"/>
+                    </g>
+                    <g transform="matrix(2,0,0,2,-36,-1)">
+                        <rect x="23" y="4" width="1" height="1"/>
+                    </g>
+                    <path d="M8,7L11,7L11,9L10,9L10,10L8,10L8,7L11,7" style="fill:rgb(3,57,228);"/>
+                    <g transform="matrix(1,0,0,1,-14,4)">
+                        <rect x="23" y="4" width="1" height="1" style="fill:rgb(31,196,242);"/>
+                    </g>
+                </g>
+                <g>
+                    <path d="M10,4L10,5L13,5L13,7L14,7L14,4L10,4Z"/>
+                    <path d="M13,9L14,9L14,16L8,16L8,15L13,15L13,9"/>
+                    <path d="M2,16L0,16L0,0L10,0L10,1L1,1L1,15L2,15L2,16Z"/>
+                </g>
+            </g>
+        </g>
+    </g>
+</svg>

index.html

@@ -0,0 +1,666 @@
+<!doctype html>
+<html>
+
+<head>
+    <meta charset="utf-8">
+
+    <title>Xous: Rust Semantics in your OS</title>
+
+    <meta name="description" content="Overview of Xous, a microkernel with Rust semantics">
+    <meta name="author" content="Sean &quot;xobs&quot; Cross">
+
+    <meta name="apple-mobile-web-app-capable" content="yes">
+    <meta name="apple-mobile-web-app-status-bar-style" content="black-translucent">
+
+    <meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=no">
+
+    <link rel="stylesheet" href="css/reveal.css">
+    <link rel="stylesheet" href="css/theme/fossasia2020.css" id="theme">
+
+    <!-- Theme used for syntax highlighting of code -->
+    <link rel="stylesheet" href="lib/css/zenburn.css">
+
+    <!-- Printing and PDF exports -->
+    <script>
+        var link = document.createElement('link');
+        link.rel = 'stylesheet';
+        link.type = 'text/css';
+        link.href = window.location.search.match(/print-pdf/gi) ? 'css/print/pdf.css' : 'css/print/paper.css';
+        document.getElementsByTagName('head')[0].appendChild(link);
+    </script>
+
+    <!--[if lt IE 9]>
+        <script src="lib/js/html5shiv.js"></script>
+        <![endif]-->
+</head>
+
+<body>
+
+    <!-- Start of main presentation -->
+    <div class="reveal">
+        <div class="footer">
+            <a class="url" href="https://p.xobs.io/fa20-bt/">p.xobs.io/fa20-bt</a>
+            <span class="theme">Who’s Watching</span><span class="hashtag"> | #LCA2020</span><span class="twitter"> |
+                @linuxconfau</span>
+        </div>
+        <div class="commentary"></div>
+        <div class="slides">
+            <section data-background-image="css/theme/lca2019-title-bg-transparent.svg">
+                <h2 style="background-color: transparent;">Betrusted: Being Secure</h2>
+                <h5 style="background-color: transparent;">That's no Blackberry, it's a chat client!</h5>
+                <p align="right" style="margin-bottom: 0px; margin-top: 0px; line-height: 1;">
+                    <small>Sean Cross - <a href="https://xobs.io/">https://xobs.io/</a> - @xobs</small>
+                </p>
+            </section>
+
+            <section>
+                <h3>Betrusted: A Security Chip with I/O</h3>
+                <p>
+                    <img data-src="img/bt-quarter2-shrunk.jpg" width="90%">
+                </p>
+            </section>
+
+            <section>
+                <section>
+                    <h2>Xous: Why another kernel?</h2>
+                    <aside class="notes">
+                        A big question that gets asked is -- why another kernel? Why don't we just
+                        put Linux on it and be done with it? Or something else like Minix, TockOS,
+                        or FreeRTOS?
+                    </aside>
+                </section>
+
+
+                <section>
+                    <h2>Betrusted Goals</h2>
+                    <ol style="width: 100%;">
+                        <li>&lt;=4 MiB RAM</li>
+                        <li>Safe language</li>
+                        <li>Process Isolation</li>
+                    </ol>
+                    <ul style="text-align: left; width: 100%;" class="os-good">
+                        <li class="fragment">Microkernel</li>
+                        <li class="fragment">Auditable by one person</li>
+                    </ul>
+                    <aside class="notes">
+                        With Betrusted, we wanted to reduce the code footprint. This will allow
+                        us to run with less RAM -- ideally 4 MiB or less. We also wanted to have
+                        a full MMU, which is somewhat unusual in the embedded microcontroller
+                        space, where a more limited Memory Protection Unit is preferred.
+
+                        Whereas the Linux kernel is huge, not to mention all of the support libraries
+                        required to run a system, we would like the Betrusted system to be auditable
+                        by one person. Lowering the memory footprint helps in this regard, as the
+                        less RAM we have, the less code we must have.
+
+                        Additionally, we would like to have the operating system written in a safe
+                        systems language to protect us from common programming errors involving
+                        memory and concurrency.
+
+                        Even so, we would like to have full process isolation, so even if one process
+                        is compromised, attackers will have a harder time boring through the system
+                        to gain a more complete takeover. This allows us to have legacy software
+                        written in non-safe languages, in case we need to take third-party code such
+                        as font renderers from legacy systems.
+
+                        As a result, we would like Betrusted to run a Microkernel-style operating
+                        system, with "servers" that provide features such as the display,
+                        keyboard, and even basic task switching. These should all run in
+                        userspace with the bare minimum permissions required to get the job done.
+                    </aside>
+                </section>
+
+                <section>
+                    <h2>Microkernels</h2>
+                    <img data-src="img/Annotation 2020-01-16 111040.png">
+                    <div style="font-size: 12pt;">FlexSC: Flexible System Call Scheduling with Exception-Less System
+                        Calls</div>
+                    <aside class="notes">
+                        Microkernels minimize the amount of code in each section. Everything from
+                        the user-facing software to drivers run in userspace, with only memory
+                        management and top-level exception dispatch taking place within the kernel.
+
+                        By having a microkernel, individuals can contribute to servers, and be
+                        responsible for their own section. This is not just one person working
+                        on it, it enables lots of people to work on it together.
+                    </aside>
+                </section>
+
+                <section>
+                    <h2>Too Many Cooks</h2>
+                    <table>
+                        <tr>
+                            <td style="width: 500px;">
+                                <img data-src="img/code_ownership_effects_bugs.svg">
+                            </td>
+                            <td>
+                                <blockquote class="os-quote" style="font-size: 24pt;">if there is one primary
+                                    contributor, <strong>the chances for a file to be buggy decreases
+                                        significantly</strong></blockquote>
+                            </td>
+                        </tr>
+                        <tr>
+                            <td colspan="2">Source: <a
+                                    href="https://docs.microsoft.com/en-us/azure/devops/learn/devops-at-microsoft/code-ownership-software-quality">Microsoft
+                                    Research</a></td>
+                        </tr>
+                    </table>
+                    <aside class="notes">
+                        According to a Microsoft research paper analyzing the failures of Windows Vista,
+                        the number one predictor for code quality is the number of people who work on
+                        a module. If one person works on the project, then the number of bugs goes down.
+                    </aside>
+                </section>
+                <section>
+                    <h2>Felix' Rule of Thumb</h2>
+                    <table>
+                        <tr>
+                            <td style="width: 400px;">
+                                <img data-src="img/Cthulhu_sketch_by_Lovecraft.jpg">
+                            </td>
+                            <td>
+                                <blockquote class="os-quote" style="width: 100%; margin-left: 0; margin-right: 0;">
+                                    The largest amount of security-related code that one person can reasonably audit is
+                                    about 64 KiB of binary data
+                                </blockquote>
+                            </td>
+                        </tr>
+                    </table>
+                    <aside class="notes">
+                        A friend of ours named Felix has a rule of thumb: The barrier at which a codebase becomes
+                        too much to reason about for one individual is about 64 KiB. Anything more than this and
+                        it becomes an eldrich horror that morphs and changes when you're not looking at it. As
+                        a result, we would like to keep the core of the system small, so that we can keep it in
+                        our heads as we reason about the system.
+                    </aside>
+                </section>
+
+                <section>
+                    <h2>Principles of Software</h2>
+                    <table width="100%">
+                        <tr>
+                            <td style="text-align: right">
+                                <img width="80%" class="fragment"
+                                    data-src="img/Rust_programming_language_black_logo.svg">
+                            </td>
+                            <td valign="top" width="50%">
+                                <ul style="margin-left: 0px;">
+                                    <li>Safety</li>
+                                    <li>Concurrency</li>
+                                    <li class="fragment fade-semi-out">Speed</li>
+                                    <li class="fragment">Size</li>
+                                </ul>
+                            </td>
+                        </tr>
+                    </table>
+                    <aside class="notes">
+                        The Rust programming language promises the holy trifecta: Safety, Speed,
+                        Concurrency. Pick any three. If you're going to start over on a systems-
+                        level project, choose Rust. There will be a lot of wailing and gnashing
+                        of teeth to begin with, but the end result will be better.
+
+                        When we started Betrusted, we decided that it should primarily use Rust
+                        as the systems language. That way we can be sure that our code is sound.
+                        Additionally, Rust has the ability to produce efficient binaries, and the
+                        efficiency is only going to get better as time progresses.
+
+                        This eliminates non-Rust choices such as Linux or Minix.
+                    </aside>
+                </section>
+
+                <section>
+                    <h2>Rust OS Landscape</h2>
+                    <img class="fragment" data-src="img/os-survey-stale.png">
+                    <aside class="notes">
+                        Having decided to use Rust, we did a survey of Rust-based operating
+                        systems. There are several available, in various states of completeness.
+                        Many projects have long since been abandoned, which is fine because up
+                        until recently you needed to work on Rust nightly to build an OS. The
+                        language underpinnings of these projects has shifted, and so many of them
+                        have been abandoned. A few are still going, and
+                        the two biggest candidates are Redox and Tock.
+                    </aside>
+                </section>
+
+                <section>
+                    <h2>Rust-based OS: Tock</h2>
+                    <table>
+                        <tr>
+                            <td colspan="2" style="text-align: center;">
+                                <img height="250px" data-src="img/os/tockos.svg">
+                            </td>
+                        </tr>
+                        <tr style="font-size: 24pt">
+                            <td>
+                                <ul class="os-good fragment">
+                                    <li>Active Project</li>
+                                    <li>RISC-V Port</li>
+                                    <li>C and Rust Libs</li>
+                                </ul>
+                            </td>
+                            <td>
+                                <ul class="os-bad fragment">
+                                    <li>No MMU Support</li>
+                                    <li>No runtime spawn()</li>
+                                    <li>Limited messaging</li>
+                                </ul>
+                            </td>
+                        </tr>
+                    </table>
+                    <aside class="notes">
+                        Tock is the most obvious choice, since it already has a RISC-V port
+                        and is supported by a well-documented ABI. Tock supports multiple
+                        tasks written in either Rust or C, which is a very nice feature.
+
+                        However, Tock does not support an MMU. It would be possible to adapt
+                        the MPU interface to work with an MMU, but a lot of design work has
+                        gone into Tock to make it work well with only the standard MPU that
+                        is present on most ARM chips. Using Tock would be asking it to do
+                        something that it's not designed for. Instead, it's better to pick
+                        the right tool for the job.
+
+                        Additionally, the Tock message passing infrastructure assumes only
+                        one server per process, which can limit flexibility.
+                    </aside>
+                </section>
+
+                <section>
+                    <h2>Rust-based OS: Redox</h2>
+                    <table>
+                        <tr>
+                            <td colspan="2" style="text-align: center;">
+                                <img height="250px" data-src="img/os/Redox_logo_2015.svg">
+                            </td>
+                        </tr>
+                        <tr style="font-size: 24pt">
+                            <td>
+                                <ul class="os-good fragment">
+                                    <li>Active Project</li>
+                                    <li>Full Rust stdlib</li>
+                                    <li>Full Userspace</li>
+                                </ul>
+                            </td>
+                            <td>
+                                <ul class="os-bad fragment">
+                                    <li>x86_64 only</li>
+                                    <li>Unix-like</li>
+                                    <li>Desktop-focused</li>
+                                </ul>
+                            </td>
+                        </tr>
+                    </table>
+                    <aside class="notes">
+                        Redox is the other large Rust-based operating system, and is the most
+                        compelling. Redox is currently limited to x86-64 (with a plan to
+                        port it to AArch64), so we would need to port it ourselves to RISC-V.
+
+                        The biggest problem with Redox is its size: It's a full Desktop
+                        operating system, and supporting it on Betrusted would require us to
+                        spend a lot of time cutting it down to just the bare microkernel,
+                        at which point we can start to recreate everything ourselves. The
+                        kernel itself is such a small part of Betrusted. Besides, we would
+                        like the freedom to experiment, to randomize the syscall numbers and
+                        have keepout areas of the screen and add IMEs to the input, which
+                        would quickly introduce incompatibility with Redox.
+
+                        Finally, we would like to be able to use stable Rust for our applications,
+                        which we can almost do with Xous. We're just waiting for either the
+                        "alloc_error_handler" attribute to be stabilized (issue 66740), or
+                        defaulting handle_alloc_error to panic (issue 66741), which would give
+                        us everything we'd need to use alloc on stable Rust.
+
+                        In short, Tock is too small, and Redox is too big.
+                    </aside>
+                </section>
+
+                <section>
+                    <h2>Rust-based OS: Tifflin</h2>
+                    <table>
+                        <tr>
+                            <td colspan="2" style="text-align: center;"><span style="font-size: 168pt">?</span></td>
+                        </tr>
+                        <tr style="font-size: 24pt">
+                            <td>
+                                <ul class="os-good fragment">
+                                    <li>Active Project</li>
+                                    <li>Rust stdlib</li>
+                                    <li>Full Userspace</li>
+                                </ul>
+                            </td>
+                            <td>
+                                <ul class="os-bad fragment">
+                                    <li>nightly only</li>
+                                    <li>Mainly x86_64</li>
+                                    <li>???</li>
+                                </ul>
+                            </td>
+                        </tr>
+                    </table>
+                    <aside class="notes">
+                        Tifflin is a kernel that's been around for a while, but I've
+                        only just learned about. It has a lot of promise, and seems
+                        to be an interesting desktop operating system. I must admit
+                        I don't know much about it, because it's not well-publicised.
+                        However, it does have a rust stdlib, the design of which we
+                        may borrow for Xous. One downside to it is that it requires
+                        the nightly compiler, whereas we want to focus on stable for Xous.
+                    </aside>
+                </section>
+
+                <section>
+                    <h2>Other Alternatives and Inspirations</h2>
+                    <ul>
+                        <li><strong>ChibiOS</strong> - Embedded RTOS</li>
+                        <li><strong>HelenOS</strong> - Everything is a message</li>
+                        <li><strong>Solaris</strong> - Doors</li>
+                        <li><strong>QNX</strong> - Traditional Microkernel</li>
+                    </ul>
+                    <div>Microkernels isolate and make IPC cheap</div>
+                    <aside class="notes">
+                        There are many alternative operating systems. We can draw inspiration
+                        from them, even if we don't use them directly.
+
+                        For example, both the QNX microkernel and Solaris Doors implementation
+                        allow for one process to pass a message to another, which then inherits
+                        its remaining quantum and runlevel. This prevents priority inversions
+                        and makes syscalls relatively cheap.
+                    </aside>
+                </section>
+            </section>
+
+            <section>
+                <h2>Betrusted Goals</h2>
+                <ul>
+                    <li>&lt;=4 MB RAM</li>
+                    <li>Process Isolation</li>
+                    <li>Safe language</li>
+                    <li class="fragment">Microkernel</li>
+                </ul>
+                <aside class="notes">
+                    With Betrusted, we wanted to reduce the code footprint. This will allow
+                    us to run with less RAM -- ideally 4 MB or less. We also wanted to have
+                    a full MMU, which is somewhat unusual in the embedded microcontroller
+                    space, where a more limited Memory Protection Unit is preferred.
+
+                    We would like to have full process isolation, so even if one process is
+                    compromised, attackers will have a harder time boring through the system
+                    to gain a more complete takeover.
+
+                    Therefore, we would like Betrusted to run a Microkernel-style operating
+                    system, with "servers" that provide features such as the display,
+                    keyboard, and even basic task switching. These should all run in
+                    userspace with the bare minimum permissions required to get the job done.
+
+                    Finally, we would like to have the operating system written in a safe
+                    systems language.
+                </aside>
+            </section>
+
+            <section>
+
+                <section>
+                    <h2 style="margin-top: 25%;">Xous: System Design</h2>
+                    <aside class="notes">
+                        Xous is, currently, very much under development. However, there has
+                        been a lot of planning.
+                    </aside>
+                </section>
+
+                <section>
+                    <h2>Xous: Memory Model</h2>
+                    <table>
+                        <tr>
+                            <td>
+                                <img data-src="img/Library_card.jpg">
+                            </td>
+                            <td height="100%">
+                                <ul class="os">
+                                    <li>Rust Borrow Checker</li>
+                                    <li class="fragment">Message passing</li>
+                                    <li class="fragment" style="font-weight: 500">Inter-process borrowing</li>
+                                    <li class="fragment">Borrow types:
+                                        <ul>
+                                            <li class="fragment">Mutable&nbsp;&nbsp;&nbsp;^ Immutable</li>
+                                            <li class="fragment">No Access | Read Only</li>
+                                        </ul>
+                                    </li>
+                                </ul>
+                                <a style="margin-top: auto; font-size: 12pt;"
+                                    href="https://www.flickr.com/people/9337414@N05">Image CC-BY Tammy</a>
+                            </td>
+                        </tr>
+                    </table>
+                    <aside class="notes">
+                        Xous will base its memory model on the Rust borrow checker. That is,
+                        shared memory will be used for IPC. If one process wishes to get a
+                        response from another, it can pass pages via a mutable borrow. If
+                        a process wishes to share pages across multiple process, then only an
+                        immutable borrow may be made, and the sharing process cannot access
+                        pages until all processes have returned the memory.
+
+                        A process can move memory into another, which for example is how
+                        process spawning works. In such a case, memory is no longer available
+                        in the sending process.
+                    </aside>
+                </section>
+
+                <section>
+                    <h2>Xous: Memory Model</h2>
+                    <ol>
+                        <li class="fragment">Mutable Borrow
+                            <ul>
+                                <li>draw()</li>
+                            </ul>
+                        </li>
+                        <li class="fragment">Immutable Borrow
+                            <ul>
+                                <li>Mapping font database</li>
+                            </ul>
+                        </li>
+                        <li class="fragment">Move
+                            <ul>
+                                <li>Encrypting a string</li>
+                            </ul>
+                        </li>
+                    </ol>
+                </section>
+
+                <section>
+                    <h2>Xous: Interrupts</h2>
+                    <pre><code style="font-size: 23pt; line-height: 1.2em;" class="rust">fn setup_int2() -> xous::Result {
+    let gpio = xous::syscall::map_physical(
+            Some(0xe0000000), None, 4096)?;
+
+    xous::syscall::claim_interrupt(2, |_int_num, gpio| {
+        unsafe {
+          let val = gpio.read_volatile();
+          gpio.write_volatile(val + 1);
+        };
+    }, gpio)
+}</code></pre>
+                    <div class="fragment">All in userspace</div>
+                    <aside class="notes">
+                        Interrupts block the whole system, and follow similar behavior to
+                        memory. That is, each interrupt can only be assigned to a single
+                        handler. This is an example of a server claiming interrupt 2,
+                        and this function will be called to handle that interrupt. It will
+                        be called in Supervisor mode with the process space of this server.
+                        During the interrupt handler, interrupts are disabled, and after it
+                        returns they will be re-enabled. You can't make any syscalls in
+                        this mode that don't have an "_i" suffix. This will form the
+                        basis of drivers running in userspace using safe code.
+                    </aside>
+                </section>
+
+                <section>
+                    <h2>Xous: Missing Features</h2>
+                    <table style="width: 100%">
+                        <tr>
+                            <td style="width: 300px">
+                                <img data-src="img/missing-image.svg">
+                            </td>
+                            <td>
+                                <ul class="os-bad">
+                                    <li class="fragment">fork()</li>
+                                    <li class="fragment">Filesystem</li>
+                                    <li class="fragment">Scheduler</li>
+                                    <li class="fragment">Threads</li>
+                                    <li class="fragment">Locking primitives</li>
+                                    <li class="fragment">Shared libraries</li>
+                                </ul>
+                            </td>
+                        </tr>
+                    </table>
+                    <aside class="notes">
+                        Xous has no fork(). Instead it will have spawn().
+
+                        Xous has no scheduler. The scheduler will be implemented as a userspace
+                        program, which will request the Timer interrupt and call a kernel function
+                        to preempt the current process.
+
+                        It has no threads. However, there is enough information passed from the
+                        kernel to enable the userspace scheduler to implement threads.
+
+                        Similarly, it has no kernel-level locking primitives. Because memory can't
+                        be shared between processes, there is no need for inter-process locking.
+                        Within a process, threads are available with LLVM intrinsics such as cmpxchg.
+
+                        Shared libraries aren't available at the start, but may come later via
+                        shared immutable borrows from the linker server.
+                    </aside>
+                </section>
+
+                <section>
+                    <h2>Xous: Everything in Userspace</h2>
+                    <ul style="width: 100%;">
+                        <li>Small Kernel</li>
+                        <li>Message Passing</li>
+                        <li>Protected Memory</li>
+                    </ul>
+                    <br />
+                    <br />
+                    <div><strong class="fragment" style="font-size: 40pt;">Understandable by one human</strong></div>
+                    <div><strong class="fragment" style="font-size: 40pt;">Made by many</strong></div>
+                </section>
+            </section>
+
+            <section data-background-image="img/sw/renode.png">
+                <table style="width:100%">
+                    <tr>
+                        <td width="33%" valign="top">
+                            <img class="fragment" data-src="img/os/betrusted.gif" height="100%">
+                        </td>
+                        <td width="10%" align="center">
+                            &nbsp;
+                        </td>
+                        <td width="53%" align="center">
+                            <br />
+                            <br />
+                            <br />
+                            <br />
+                            <ul class="boldblue white50bg">
+                                <li class="fragment">CI</li>
+                                <li class="fragment">Simulation</li>
+                                <li class="fragment">On Target</li>
+                                <li class="fragment">UI Robot</li>
+                            </ul>
+                        </td>
+                    </tr>
+                </table>
+                <aside class="notes">
+                    We plan to support Continuous Integration using Renode<br />
+                    <br />
+                    *.cs (defines simulated hardware)<br />
+                    LiteX -> Lxsocdoc -> SVD -> Renode (annotations register access)<br />
+                    Rust -> ELF (software) <br />
+                    *.repl (defines renode platform, loads *.cs, *.svd, ELF)<br />
+                    *.resc (defines renode script - orchestrates everything)<br />
+
+                    And, as a following pipeline step, running on prototype hardware <br />
+                    Ideally with automated UI testing<br>
+                </aside>
+            </section>
+
+        </div>
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