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84 lines
3.1 KiB
HTML
84 lines
3.1 KiB
HTML
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<blockquote>
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<h2 class="c6">About EtherBoot</h2>
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<p class="c7">Etherboot is a software package for creating ROM
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images that can download code over an Ethernet network to be
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executed on an x86 computer. Many network adapters have a socket
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where a ROM chip can be installed. Etherboot is code that can be
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put in such a ROM. Etherboot is normally used for for booting PCs
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diskless. This is useful in various situations, for example:</p>
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<ul class="c11">
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<li>An X-terminal.</li>
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<li>Clusters of compute servers.</li>
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<li>Routers.</li>
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<li>Various kinds of remote servers, e.g. a tape drive server that
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can be accessed with the RMT protocol.</li>
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<li>Machines doing tasks in environments unfriendly to disks.</li>
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<li>A user platform where remote partitions are mounted over the
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network and you are willing to accept the lower speed compared to
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disk.</li>
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<li>Maintaining software for a cluster of equally configured
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workstations centrally.</li>
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</ul>
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<p class="c7">Etherboot can boot computers faster than from a disk
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because there are no delays in spinning up disks, etc. A moment's
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calculation will show that even with a 10Mbit Ethernet, sending a
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500kB kernel will take only a couple of seconds typically. With
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100Mbit Ethernet it gets even better.</p>
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<p class="c7">Compared to booting from solid-state devices, e.g.
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Flash disks, Etherboot has the advantage of centralising software
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adminstration, the tradeoff being the dependence on a server. This
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can be partly alleviated by providing redundant servers.</p>
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<p class="c7">Etherboot can work with RAM disks, NFS filesystems,
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or even local disks, if desired. It's a component technology and
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can be combined with other technologies to do things the way you
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want.</p>
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<p class="c7">Etherboot is usually used to load Linux, FreeBSD or
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DOS. However the protocol and boot file formats are general, so
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there is no reason why it could not be used to load arbitrary
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images to a PC, including other OSes.</p>
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<p class="c7">Etherboot is Open Source under the GNU General Public
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License Version 2 (GPL2).</p>
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<p class="c7">The components needed by Etherboot are</p>
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<ul class="c11">
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<li>A bootstrap loader, usually in an EPROM on a network card, or
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installed in the flash BIOS, but could be put anywhere in the
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address space the BIOS probes in. For testing this could be put on
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a floppy disk or a hard disk partition. Some configurations may
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even be always run from a floppy disk (e.g. temporary testing
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setups or pedagogic uses).</li>
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<li>A DHCP or bootp server, for returning an IP address and other
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information when sent a MAC (Ethernet card) address.</li>
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<li>A tftp server, for sending the kernel images and other files
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required in the boot process. Alternatively, Etherboot can boot
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from an NFS mount.</li>
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<li>A Linux or FreeBSD kernel.</li>
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<li>Optionally, a NFS server, for providing the disk partitions
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that will be mounted if Linux or FreeBSD is being booted.</li>
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<li>Optionally, a RAM disk contained in the loaded image. This can
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be the initial RAM disk if desired.</li>
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<li>Software tools for building the download image, and tools for
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debugging.</li>
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</ul>
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</blockquote>
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