463 lines
18 KiB
HTML
463 lines
18 KiB
HTML
|
<!DOCTYPE html>
|
||
|
|
<html lang="en" class="sidebar-visible no-js light">
|
||
|
|
|
||
|
|
<head>
|
||
|
|
<meta charset="utf-8">
|
||
|
|
<title>Hitch Hiker Linux</title>
|
||
|
|
<meta content="text/html; charset=utf-8" http-equiv="Content-Type">
|
||
|
|
<meta name="description" content="">
|
||
|
|
<meta name="viewport" content="width=device-width, initial-scale=1">
|
||
|
|
<meta name="theme-color" content="#ffffff" />
|
||
|
|
|
||
|
|
<link rel="icon" href="/favicon.svg">
|
||
|
|
<link rel="shortcut icon" href="/favicon.png">
|
||
|
|
|
||
|
|
<link rel="stylesheet" href="/handbook/css/variables.css">
|
||
|
|
<link rel="stylesheet" href="/handbook/css/general.css">
|
||
|
|
<link rel="stylesheet" href="/handbook/css/chrome.css">
|
||
|
|
|
||
|
|
<link rel="stylesheet" href="/handbook/css/print.css" media="print">
|
||
|
|
|
||
|
|
<!-- Fonts -->
|
||
|
|
<link rel="stylesheet" href="/handbook/FontAwesome/css/font-awesome.css">
|
||
|
|
|
||
|
|
<link rel="stylesheet" href="/handbook/fonts/fonts.css">
|
||
|
|
|
||
|
|
<!-- Highlight.js Stylesheets -->
|
||
|
|
<link rel="stylesheet" href="/handbook/highlight.css">
|
||
|
|
<link rel="stylesheet" href="/handbook/tomorrow-night.css">
|
||
|
|
<link rel="stylesheet" href="/handbook/ayu-highlight.css">
|
||
|
|
|
||
|
|
<!-- Custom Stylesheets -->
|
||
|
|
<link rel="stylesheet" href="/hhl.css">
|
||
|
|
|
||
|
|
</head>
|
||
|
|
|
||
|
|
<body>
|
||
|
|
<!-- Provide site root to javascript -->
|
||
|
|
<script type="text/javascript">
|
||
|
|
var path_to_root = "/handbook";
|
||
|
|
var default_theme = window.matchMedia("(prefers-color-scheme: dark)").matches ? "navy" : "light";
|
||
|
|
</script>
|
||
|
|
|
||
|
|
<!-- Work around some values being stored in localStorage wrapped in quotes -->
|
||
|
|
<script type="text/javascript">
|
||
|
|
try {
|
||
|
|
var theme = localStorage.getItem('mdbook-theme');
|
||
|
|
var sidebar = localStorage.getItem('mdbook-sidebar');
|
||
|
|
|
||
|
|
if (theme.startsWith('"') && theme.endsWith('"')) {
|
||
|
|
localStorage.setItem('mdbook-theme', theme.slice(1, theme.length - 1));
|
||
|
|
}
|
||
|
|
|
||
|
|
if (sidebar.startsWith('"') && sidebar.endsWith('"')) {
|
||
|
|
localStorage.setItem('mdbook-sidebar', sidebar.slice(1, sidebar.length - 1));
|
||
|
|
}
|
||
|
|
} catch (e) { }
|
||
|
|
</script>
|
||
|
|
|
||
|
|
<!-- Set the theme before any content is loaded, prevents flash -->
|
||
|
|
<script type="text/javascript">
|
||
|
|
var theme;
|
||
|
|
try { theme = localStorage.getItem('mdbook-theme'); } catch(e) { }
|
||
|
|
if (theme === null || theme === undefined) { theme = default_theme; }
|
||
|
|
var html = document.querySelector('html');
|
||
|
|
html.classList.remove('no-js')
|
||
|
|
html.classList.remove('light')
|
||
|
|
html.classList.add(theme);
|
||
|
|
html.classList.add('js');
|
||
|
|
</script>
|
||
|
|
|
||
|
|
<!-- Hide / unhide sidebar before it is displayed -->
|
||
|
|
<script type="text/javascript">
|
||
|
|
var html = document.querySelector('html');
|
||
|
|
var sidebar = 'hidden';
|
||
|
|
if (document.body.clientWidth >= 1080) {
|
||
|
|
try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
|
||
|
|
sidebar = sidebar || 'visible';
|
||
|
|
}
|
||
|
|
html.classList.remove('sidebar-visible');
|
||
|
|
html.classList.add("sidebar-" + sidebar);
|
||
|
|
</script>
|
||
|
|
|
||
|
|
<nav id="sidebar" class="sidebar" aria-label="Table of contents">
|
||
|
|
<div class="sidebar-scrollbox">
|
||
|
|
<ol class="chapter">
|
||
|
|
<li class="chapter-item affix ">
|
||
|
|
<a href="/">Home</a>
|
||
|
|
</li>
|
||
|
|
<li class="chapter-item affix ">
|
||
|
|
<a href="/news/">News</a>
|
||
|
|
</li>
|
||
|
|
<li class="chapter-item affix ">
|
||
|
|
<a href="/about/">About</a>
|
||
|
|
</li>
|
||
|
|
<li class="chapter-item affix ">
|
||
|
|
<a href="/pub/">Download</a>
|
||
|
|
</li>
|
||
|
|
<li class="chapter-item affix ">
|
||
|
|
<a href="https://git.hitchhiker-linux.org">Source</a>
|
||
|
|
</li>
|
||
|
|
<li class="spacer"></li>
|
||
|
|
<li class="chapter-item affix ">
|
||
|
|
<a href="/handbook/">Handbook</a>
|
||
|
|
</li>
|
||
|
|
</ol>
|
||
|
|
</div>
|
||
|
|
<div id="sidebar-resize-handle" class="sidebar-resize-handle"></div>
|
||
|
|
</nav>
|
||
|
|
<div id="page-wrapper" class="page-wrapper">
|
||
|
|
<div class="page">
|
||
|
|
<div id="menu-bar-hover-placeholder"></div>
|
||
|
|
<div id="menu-bar" class="menu-bar sticky bordered">
|
||
|
|
<div class="left-buttons">
|
||
|
|
<button id="sidebar-toggle" class="icon-button" type="button" title="Toggle Table of Contents" aria-label="Toggle Table of Contents" aria-controls="sidebar">
|
||
|
|
<i class="fa fa-bars"></i>
|
||
|
|
</button>
|
||
|
|
<button id="theme-toggle" class="icon-button" type="button" title="Change theme" aria-label="Change theme" aria-haspopup="true" aria-expanded="false" aria-controls="theme-list">
|
||
|
|
<i class="fa fa-paint-brush"></i>
|
||
|
|
</button>
|
||
|
|
<ul id="theme-list" class="theme-popup" aria-label="Themes" role="menu">
|
||
|
|
<li role="none"><button role="menuitem" class="theme" id="light">Light (default)</button></li>
|
||
|
|
<li role="none"><button role="menuitem" class="theme" id="rust">Rust</button></li>
|
||
|
|
<li role="none"><button role="menuitem" class="theme" id="coal">Coal</button></li>
|
||
|
|
<li role="none"><button role="menuitem" class="theme" id="navy">Navy</button></li>
|
||
|
|
<li role="none"><button role="menuitem" class="theme" id="ayu">Ayu</button></li>
|
||
|
|
</ul>
|
||
|
|
</div>
|
||
|
|
<h1 class="menu-title">
|
||
|
|
Hitch Hiker Linux
|
||
|
|
</h1>
|
||
|
|
</div>
|
||
|
|
|
||
|
|
<!-- Apply ARIA attributes after the sidebar and the sidebar toggle button are added to the DOM -->
|
||
|
|
<script type="text/javascript">
|
||
|
|
document.getElementById('sidebar-toggle').setAttribute('aria-expanded', sidebar === 'visible');
|
||
|
|
document.getElementById('sidebar').setAttribute('aria-hidden', sidebar !== 'visible');
|
||
|
|
Array.from(document.querySelectorAll('#sidebar a')).forEach(function(link) {
|
||
|
|
link.setAttribute('tabIndex', sidebar === 'visible' ? 0 : -1);
|
||
|
|
});
|
||
|
|
</script>
|
||
|
|
<div id="content" class="content">
|
||
|
|
<main>
|
||
|
|
|
||
|
|
<h1><a class="header" href="#recent" id="recent">Compiling for aarch64/riscv64 from qemu user mode chroot</a></h1>
|
||
|
|
<p class="subtitle"><strong>2021-01-28</strong></p>
|
||
|
|
<p>This is a novel approach that I've been experimenting with lately, to do some
|
||
|
|
legwork towards supporting architectures for which I either don't have physical
|
||
|
|
hardware or else the hardware is limited in capability so much as to make native
|
||
|
|
compilation impractical.</p>
|
||
|
|
<span id="continue-reading"></span>
|
||
|
|
<p>Qemu, in addition to running full virtual machines, also has what is known as
|
||
|
|
"user mode emulation". In a nutshell, when using qemu in this way one is able to
|
||
|
|
run binaries for another architecture without creating virtual hardware or a
|
||
|
|
virtual kernel. In this case, qemu just acts as a translation layer, translating
|
||
|
|
instructions designed for one ISA to instructions that can be executed on the
|
||
|
|
host processor. By not running a virtual kernel on virtual hardware, there is
|
||
|
|
actually a huge savings of system resources.</p>
|
||
|
|
<p>Setting this up, while not trivial, is surprisingly straightforward. First, a
|
||
|
|
suitable root filesystem must be created. Qemu must be compiled statically, and
|
||
|
|
the static binary copied into the chroot filesystem. Then, by using binfmt-misc,
|
||
|
|
one can register this qemu executable as the program interpreter for binaries of
|
||
|
|
the guest architecture. In this way it is actually possible to set up a functional
|
||
|
|
chroot on a well spec'ed X86_64 machine running Risc-V binaries. There is a bit
|
||
|
|
more to getting this to work, but suffice to say that it does in fact work,
|
||
|
|
within the normal limitations of a chroot.</p>
|
||
|
|
<p>While running foreign binaries does incur some performance penalty, this method
|
||
|
|
is actually proving to be a significant improvement over, say, compiling for
|
||
|
|
aarch64 on a Raspberry Pi 4, as I have four times the memory and a significantly
|
||
|
|
faster processor with twice the number of cores available. And it has the benefit
|
||
|
|
of not requiring a cross compiler. Instead, one is running a native compiler via
|
||
|
|
an emulation layer. But this eliminates many of the pain points of cross compiling.
|
||
|
|
It's a neat trick.</p>
|
||
|
|
<p>So what does this mean for HitchHiker? It means that work is now well underway
|
||
|
|
towards running HitchHiker on a BeagleV when they become widely available later
|
||
|
|
this year. I have been eagerly waiting to dip toes into Risc-V as soon as an
|
||
|
|
affordable option was available, and it looks like said option is now on the
|
||
|
|
horizon.</p>
|
||
|
|
|
||
|
|
|
||
|
|
<hr>
|
||
|
|
<p class="subtitle"><strong>Tags for this post:</strong></p>
|
||
|
|
|
||
|
|
<a class="tags" href="/tags/arm/">Arm</a>
|
||
|
|
|
||
|
|
<a class="tags" href="/tags/porting/">Porting</a>
|
||
|
|
|
||
|
|
<a class="tags" href="/tags/riscv/">RiscV</a>
|
||
|
|
|
||
|
|
<a class="tags" href="/tags/qemu/">Qemu</a>
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
</main>
|
||
|
|
</div>
|
||
|
|
</div>
|
||
|
|
</div>
|
||
|
|
<script>
|
||
|
|
(function themes() {
|
||
|
|
var html = document.querySelector('html');
|
||
|
|
var themeToggleButton = document.getElementById('theme-toggle');
|
||
|
|
var themePopup = document.getElementById('theme-list');
|
||
|
|
var themeColorMetaTag = document.querySelector('meta[name="theme-color"]');
|
||
|
|
var stylesheets = {
|
||
|
|
ayuHighlight: document.querySelector("[href$='ayu-highlight.css']"),
|
||
|
|
tomorrowNight: document.querySelector("[href$='tomorrow-night.css']"),
|
||
|
|
highlight: document.querySelector("[href$='highlight.css']"),
|
||
|
|
};
|
||
|
|
|
||
|
|
function showThemes() {
|
||
|
|
themePopup.style.display = 'block';
|
||
|
|
themeToggleButton.setAttribute('aria-expanded', true);
|
||
|
|
themePopup.querySelector("button#" + get_theme()).focus();
|
||
|
|
}
|
||
|
|
|
||
|
|
function hideThemes() {
|
||
|
|
themePopup.style.display = 'none';
|
||
|
|
themeToggleButton.setAttribute('aria-expanded', false);
|
||
|
|
themeToggleButton.focus();
|
||
|
|
}
|
||
|
|
|
||
|
|
function get_theme() {
|
||
|
|
var theme;
|
||
|
|
try { theme = localStorage.getItem('mdbook-theme'); } catch (e) { }
|
||
|
|
if (theme === null || theme === undefined) {
|
||
|
|
return default_theme;
|
||
|
|
} else {
|
||
|
|
return theme;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
function set_theme(theme, store = true) {
|
||
|
|
let ace_theme;
|
||
|
|
|
||
|
|
if (theme == 'coal' || theme == 'navy') {
|
||
|
|
stylesheets.ayuHighlight.disabled = true;
|
||
|
|
stylesheets.tomorrowNight.disabled = false;
|
||
|
|
stylesheets.highlight.disabled = true;
|
||
|
|
|
||
|
|
ace_theme = "ace/theme/tomorrow_night";
|
||
|
|
} else if (theme == 'ayu') {
|
||
|
|
stylesheets.ayuHighlight.disabled = false;
|
||
|
|
stylesheets.tomorrowNight.disabled = true;
|
||
|
|
stylesheets.highlight.disabled = true;
|
||
|
|
ace_theme = "ace/theme/tomorrow_night";
|
||
|
|
} else {
|
||
|
|
stylesheets.ayuHighlight.disabled = true;
|
||
|
|
stylesheets.tomorrowNight.disabled = true;
|
||
|
|
stylesheets.highlight.disabled = false;
|
||
|
|
ace_theme = "ace/theme/dawn";
|
||
|
|
}
|
||
|
|
|
||
|
|
setTimeout(function () {
|
||
|
|
themeColorMetaTag.content = getComputedStyle(document.body).backgroundColor;
|
||
|
|
}, 1);
|
||
|
|
|
||
|
|
if (window.ace && window.editors) {
|
||
|
|
window.editors.forEach(function (editor) {
|
||
|
|
editor.setTheme(ace_theme);
|
||
|
|
});
|
||
|
|
}
|
||
|
|
|
||
|
|
var previousTheme = get_theme();
|
||
|
|
|
||
|
|
if (store) {
|
||
|
|
try { localStorage.setItem('mdbook-theme', theme); } catch (e) { }
|
||
|
|
}
|
||
|
|
|
||
|
|
html.classList.remove(previousTheme);
|
||
|
|
html.classList.add(theme);
|
||
|
|
}
|
||
|
|
|
||
|
|
// Set theme
|
||
|
|
var theme = get_theme();
|
||
|
|
|
||
|
|
set_theme(theme, false);
|
||
|
|
|
||
|
|
themeToggleButton.addEventListener('click', function () {
|
||
|
|
if (themePopup.style.display === 'block') {
|
||
|
|
hideThemes();
|
||
|
|
} else {
|
||
|
|
showThemes();
|
||
|
|
}
|
||
|
|
});
|
||
|
|
|
||
|
|
themePopup.addEventListener('click', function (e) {
|
||
|
|
var theme = e.target.id || e.target.parentElement.id;
|
||
|
|
set_theme(theme);
|
||
|
|
});
|
||
|
|
|
||
|
|
themePopup.addEventListener('focusout', function(e) {
|
||
|
|
// e.relatedTarget is null in Safari and Firefox on macOS (see workaround below)
|
||
|
|
if (!!e.relatedTarget && !themeToggleButton.contains(e.relatedTarget) && !themePopup.contains(e.relatedTarget)) {
|
||
|
|
hideThemes();
|
||
|
|
}
|
||
|
|
});
|
||
|
|
|
||
|
|
// Should not be needed, but it works around an issue on macOS & iOS: https://github.com/rust-lang/mdBook/issues/628
|
||
|
|
document.addEventListener('click', function(e) {
|
||
|
|
if (themePopup.style.display === 'block' && !themeToggleButton.contains(e.target) && !themePopup.contains(e.target)) {
|
||
|
|
hideThemes();
|
||
|
|
}
|
||
|
|
});
|
||
|
|
|
||
|
|
document.addEventListener('keydown', function (e) {
|
||
|
|
if (e.altKey || e.ctrlKey || e.metaKey || e.shiftKey) { return; }
|
||
|
|
if (!themePopup.contains(e.target)) { return; }
|
||
|
|
|
||
|
|
switch (e.key) {
|
||
|
|
case 'Escape':
|
||
|
|
e.preventDefault();
|
||
|
|
hideThemes();
|
||
|
|
break;
|
||
|
|
case 'ArrowUp':
|
||
|
|
e.preventDefault();
|
||
|
|
var li = document.activeElement.parentElement;
|
||
|
|
if (li && li.previousElementSibling) {
|
||
|
|
li.previousElementSibling.querySelector('button').focus();
|
||
|
|
}
|
||
|
|
break;
|
||
|
|
case 'ArrowDown':
|
||
|
|
e.preventDefault();
|
||
|
|
var li = document.activeElement.parentElement;
|
||
|
|
if (li && li.nextElementSibling) {
|
||
|
|
li.nextElementSibling.querySelector('button').focus();
|
||
|
|
}
|
||
|
|
break;
|
||
|
|
case 'Home':
|
||
|
|
e.preventDefault();
|
||
|
|
themePopup.querySelector('li:first-child button').focus();
|
||
|
|
break;
|
||
|
|
case 'End':
|
||
|
|
e.preventDefault();
|
||
|
|
themePopup.querySelector('li:last-child button').focus();
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
});
|
||
|
|
})();
|
||
|
|
|
||
|
|
(function sidebar() {
|
||
|
|
var html = document.querySelector("html");
|
||
|
|
var sidebar = document.getElementById("sidebar");
|
||
|
|
var sidebarLinks = document.querySelectorAll('#sidebar a');
|
||
|
|
var sidebarToggleButton = document.getElementById("sidebar-toggle");
|
||
|
|
var sidebarResizeHandle = document.getElementById("sidebar-resize-handle");
|
||
|
|
var firstContact = null;
|
||
|
|
|
||
|
|
function showSidebar() {
|
||
|
|
html.classList.remove('sidebar-hidden')
|
||
|
|
html.classList.add('sidebar-visible');
|
||
|
|
Array.from(sidebarLinks).forEach(function (link) {
|
||
|
|
link.setAttribute('tabIndex', 0);
|
||
|
|
});
|
||
|
|
sidebarToggleButton.setAttribute('aria-expanded', true);
|
||
|
|
sidebar.setAttribute('aria-hidden', false);
|
||
|
|
try { localStorage.setItem('mdbook-sidebar', 'visible'); } catch (e) { }
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
var sidebarAnchorToggles = document.querySelectorAll('#sidebar a.toggle');
|
||
|
|
|
||
|
|
function toggleSection(ev) {
|
||
|
|
ev.currentTarget.parentElement.classList.toggle('expanded');
|
||
|
|
}
|
||
|
|
|
||
|
|
Array.from(sidebarAnchorToggles).forEach(function (el) {
|
||
|
|
el.addEventListener('click', toggleSection);
|
||
|
|
});
|
||
|
|
|
||
|
|
function hideSidebar() {
|
||
|
|
html.classList.remove('sidebar-visible')
|
||
|
|
html.classList.add('sidebar-hidden');
|
||
|
|
Array.from(sidebarLinks).forEach(function (link) {
|
||
|
|
link.setAttribute('tabIndex', -1);
|
||
|
|
});
|
||
|
|
sidebarToggleButton.setAttribute('aria-expanded', false);
|
||
|
|
sidebar.setAttribute('aria-hidden', true);
|
||
|
|
try { localStorage.setItem('mdbook-sidebar', 'hidden'); } catch (e) { }
|
||
|
|
}
|
||
|
|
|
||
|
|
// Toggle sidebar
|
||
|
|
sidebarToggleButton.addEventListener('click', function sidebarToggle() {
|
||
|
|
if (html.classList.contains("sidebar-hidden")) {
|
||
|
|
var current_width = parseInt(
|
||
|
|
document.documentElement.style.getPropertyValue('--sidebar-width'), 10);
|
||
|
|
if (current_width < 150) {
|
||
|
|
document.documentElement.style.setProperty('--sidebar-width', '150px');
|
||
|
|
}
|
||
|
|
showSidebar();
|
||
|
|
} else if (html.classList.contains("sidebar-visible")) {
|
||
|
|
hideSidebar();
|
||
|
|
} else {
|
||
|
|
if (getComputedStyle(sidebar)['transform'] === 'none') {
|
||
|
|
hideSidebar();
|
||
|
|
} else {
|
||
|
|
showSidebar();
|
||
|
|
}
|
||
|
|
}
|
||
|
|
});
|
||
|
|
|
||
|
|
sidebarResizeHandle.addEventListener('mousedown', initResize, false);
|
||
|
|
|
||
|
|
function initResize(e) {
|
||
|
|
window.addEventListener('mousemove', resize, false);
|
||
|
|
window.addEventListener('mouseup', stopResize, false);
|
||
|
|
html.classList.add('sidebar-resizing');
|
||
|
|
}
|
||
|
|
function resize(e) {
|
||
|
|
var pos = (e.clientX - sidebar.offsetLeft);
|
||
|
|
if (pos < 20) {
|
||
|
|
hideSidebar();
|
||
|
|
} else {
|
||
|
|
if (html.classList.contains("sidebar-hidden")) {
|
||
|
|
showSidebar();
|
||
|
|
}
|
||
|
|
pos = Math.min(pos, window.innerWidth - 100);
|
||
|
|
document.documentElement.style.setProperty('--sidebar-width', pos + 'px');
|
||
|
|
}
|
||
|
|
}
|
||
|
|
//on mouseup remove windows functions mousemove & mouseup
|
||
|
|
function stopResize(e) {
|
||
|
|
html.classList.remove('sidebar-resizing');
|
||
|
|
window.removeEventListener('mousemove', resize, false);
|
||
|
|
window.removeEventListener('mouseup', stopResize, false);
|
||
|
|
}
|
||
|
|
|
||
|
|
document.addEventListener('touchstart', function (e) {
|
||
|
|
firstContact = {
|
||
|
|
x: e.touches[0].clientX,
|
||
|
|
time: Date.now()
|
||
|
|
};
|
||
|
|
}, { passive: true });
|
||
|
|
|
||
|
|
document.addEventListener('touchmove', function (e) {
|
||
|
|
if (!firstContact)
|
||
|
|
return;
|
||
|
|
|
||
|
|
var curX = e.touches[0].clientX;
|
||
|
|
var xDiff = curX - firstContact.x,
|
||
|
|
tDiff = Date.now() - firstContact.time;
|
||
|
|
|
||
|
|
if (tDiff < 250 && Math.abs(xDiff) >= 150) {
|
||
|
|
if (xDiff >= 0 && firstContact.x < Math.min(document.body.clientWidth * 0.25, 300))
|
||
|
|
showSidebar();
|
||
|
|
else if (xDiff < 0 && curX < 300)
|
||
|
|
hideSidebar();
|
||
|
|
|
||
|
|
firstContact = null;
|
||
|
|
}
|
||
|
|
}, { passive: true });
|
||
|
|
|
||
|
|
// Scroll sidebar to current active section
|
||
|
|
var activeSection = document.getElementById("sidebar").querySelector(".active");
|
||
|
|
if (activeSection) {
|
||
|
|
// https://developer.mozilla.org/en-US/docs/Web/API/Element/scrollIntoView
|
||
|
|
activeSection.scrollIntoView({ block: 'center' });
|
||
|
|
}
|
||
|
|
})();
|
||
|
|
</script>
|
||
|
|
|
||
|
|
</body>
|
||
|
|
|
||
|
|
</html>
|