Translations by Walter Cheuk

Booting the Installation System

Booting the Installer on &arch-title;

Console firmware is stored in a flash ROM and started when an Alpha system is powered up or reset. There are two different console specifications used on Alpha systems, and hence two classes of console firmware available:

<emphasis>SRM console</emphasis>, based on the Alpha Console Subsystem specification, which provides an operating environment for OpenVMS, Tru64 UNIX, and Linux operating systems.

<emphasis>ARC, AlphaBIOS, or ARCSBIOS console</emphasis>, based on the Advanced RISC Computing (ARC) specification, which provides an operating environment for Windows NT.

ARC requires that you use an MS-DOS partition table (as created by <command>cfdisk</command>) for the boot disk. Therefore MS-DOS partition tables are the <quote>native</quote> partition format when booting from ARC. In fact, since AlphaBIOS contains a disk partitioning utility, you may prefer to partition your disks from the firmware menus before installing Linux.

Conversely, SRM is <emphasis>incompatible</emphasis><footnote> <para> Specifically, the bootsector format required by the Console Subsystem Specification conflicts with the placement of the DOS partition table. </para> </footnote> with MS-DOS partition tables. Since Tru64 Unix uses the BSD disklabel format, this is the <quote>native</quote> partition format for SRM installations.

GNU/Linux is the only operating system on Alpha that can be booted from both console types, but &debian; &release; only supports booting on SRM-based systems. If you have an Alpha for which no version of SRM is available, if you will be dual-booting the system with Windows NT, or if your boot device requires ARC console support for BIOS initialization, you will not be able to use the &debian; &release; installer. You can still run &debian; &release; on such systems by using other install media; for instance, you can install Debian woody with MILO and upgrade.

Because <command>MILO</command> is not available for any of the Alpha systems currently in production (as of February 2000), and because it is no longer necessary to buy an OpenVMS or Tru64 Unix license to have SRM firmware on your older Alpha, it is recommended that you use SRM when possible.

The following table summarizes available and supported system type/console combinations (see <xref linkend="alpha-cpus"/> for the system type names). The word <quote>ARC</quote> below denotes any of the ARC-compliant consoles.

ARC or SRM

ARC (see motherboard manual) or SRM

Generally, none of these consoles can boot Linux directly, so the assistance of an intermediary bootloader is required. For the SRM console, <command>aboot</command>, a small, platform-independent bootloader, is used. See the (unfortunately outdated) <ulink url="&url-srm-howto;">SRM HOWTO</ulink> for more information on <command>aboot</command>.

The following paragraphs are from the woody install manual, and are included here for reference; they may be useful to someone at a later date when Debian supports MILO-based installs again.

Generally, none of these consoles can boot Linux directly, so the assistance of an intermediary bootloader is required. There are two mainstream Linux loaders: <command>MILO</command> and <command>aboot</command>.

<command>MILO</command> is itself a console, which replaces ARC or SRM in memory. <command>MILO</command> can be booted from both ARC and SRM and is the only way to bootstrap Linux from the ARC console. <command>MILO</command> is platform-specific (a different <command>MILO</command> is needed for each system type) and exist only for those systems, for which ARC support is shown in the table above. See also the (unfortunately outdated) <ulink url="&url-milo-howto;">MILO HOWTO</ulink>.

<command>aboot</command> is a small, platform-independent bootloader, which runs from SRM only. See the (also unfortunately outdated) <ulink url="&url-srm-howto;">SRM HOWTO</ulink> for more information on <command>aboot</command>.

Thus, three scenarios are generally possible, depending on the system's console firmware and whether or not <command>MILO</command> is available: <informalexample><screen> SRM -&gt; aboot SRM -&gt; MILO ARC -&gt; MILO </screen></informalexample> Because <command>MILO</command> is not available for any of the Alpha systems currently in production (as of February 2000), and because it is no longer necessary to buy an OpenVMS or Tru64 Unix license to have SRM firmware on your older Alpha, it is recommended that you use SRM and <command>aboot</command> on new installations of GNU/Linux, unless you wish to dual-boot with Windows NT.

The majority of AlphaServers and all current server and workstation products contain both SRM and AlphaBIOS in their firmware. For <quote>half-flash</quote> machines such as the various evaluation boards, it is possible to switch from one version to another by reflashing the firmware. Also, once SRM is installed, it is possible to run ARC/AlphaBIOS from a floppy disk (using the <command>arc</command> command). For the reasons mentioned above, we recommend switching to SRM before installing &debian;.

As on other architectures, you should install the newest available revision of the firmware<footnote> <para> Except on Jensen, where Linux is not supported on firmware versions newer than 1.7 &mdash; see <ulink url="&url-jensen-howto;"></ulink> for more information. </para> </footnote> before installing &debian;. For Alpha, firmware updates can be obtained from <ulink url="&url-alpha-firmware;">Alpha Firmware Updates</ulink>.

Booting with TFTP

If you wish to use a serial console, you <emphasis>must</emphasis> pass the <userinput>console=</userinput> parameter to the kernel. This can be done using the <userinput>-flags</userinput> argument to the SRM <userinput>boot</userinput> command. The serial ports are named the same as their corresponding files in <userinput>/dev</userinput>. Also, when specifying additional kernel parameters, you must repeat certain default options that are needed by the &d-i; images. For example, to boot from <userinput>ewa0</userinput> and use a console on the first serial port, you would type:

Booting from CD-ROM with the SRM Console

Booting from CD-ROM with the ARC or AlphaBIOS Console

Booting from Floppies with the SRM Console

Booting from Floppies with the ARC or AlphaBIOS Console

Booting with MILO