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[[!meta copyright="Copyright © 2015 Free Software Foundation,
Inc."]]
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document under the terms of the GNU Free Documentation License, Version 1.2 or
any later version published by the Free Software Foundation; with no Invariant
Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license
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This provides an quick overview of how the GNU/Hurd system starts, and thus how
it is structured.
# Grub
The GNU/Hurd system uses multiboot, and thus usually booted from grub, which
loads into memory the GNU Mach kernel, the ext2fs server (see later), and the
exec server (see later). It then gives hand to GNU Mach, passing the latter as
payloads.
# GNU Mach
GNU Mach initializes a basic console, and tasks, memory management and
interprocess communication. It also initializes drivers for disk. It then
creates two tasks for the ext2fs and exec servers.
# ext2fs
ext2fs is given as a parameter the name of the device of the root filesystem. It
opens it through the GNU Mach disk driver, and mounts the filesystem found on
it. When it is ready, it can start booting the system by starting the "startup",
"proc", and "auth" servers. It does so by using the "exec" server already loaded
by GNU Mach: "exec" handles loading the binaries of the three new servers, just
like it will handle loading binaries in the GNU/Hurd system in general. ext2fs
then gives hand to "startup".
# proc
Proc knows about processes: what pid they have, passing signals, managing tty
sessions, etc.
# auth
Auth knows about identities: uid, gid, etc.
# startup
"startup" is the real system starting point: it basically runs /sbin/init, at
which point we end up with the standard Unix boot up.
# netdde / pfinet
At some point of the boot process, networking will have to be configured. This
is done by starting "pfinet", the TCP/IP stack, from /servers/socket/2, which
itself starts the network device driver server, "netdde", from /dev/netdde.
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