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B.2. Preparations and General Procedure for Installation
There are many different Alpha systems, each requiring different installation methods. Because different Linux kernels are compiled to meet these variations in CPU and system designs, you should identify your Alpha hardware in case the generic kernel doesn't work properly. In the Linux kernel the different Alpha systems are mostly known by their engineering code name. Provided you know the official system name you can usually find the codename. On such resource for looking up these names is the system type table available at http://www.linuxalpha.org/docs/systypes.txt.
Before you install an operating system, you must know the machine's graphics options and audio components, system memory, CPU class, disk-drive interfaces and sizes, existing operating systems/filesystems (if any), and attached peripherals, especially any CD-ROM drive and floppy drives. Some Alpha systems require firmware configuration changes and even actual hardware changes to complete a Linux installation.
B.2.1. Potential Incompatibilities and Hardware Problems
Which Linux distribution you choose to install may depend on the hardware you have and any other operating systems that you run on it. After you gather your hardware information, you can determine which distribution best suits your needs. You can always build any source packages from other installations once you have a bootable system. Here are a few examples of hardware factors that dictate your choice of distribution or method of installation:
-
Some Alpha systems require setting jumpers to load Linux and install it as a native, firmware-bootable operating system.
-
If your system has no floppy disk drive, you may not be able to install the Linux distribution you want on your system, because of firmware constraints in supporting filesystems and devices on systems that do not have floppy disk devices. We recommend that you install or attach a floppy drive to your system. If your system's floppy drive simply "died," it's very inexpensive to replace.[68]
[68]Even the extra-thin 3.5 inch floppy used in the older Multia and Alphabook 1 "systems" can be replaced with a standard laptop drive. On newer Alpha systems hardware, most hardware is interchangeable with standard OEM PC hardware.
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If your Linux installation shares the computer with another operating system (installed on different hard-disk partitions or different hard disks), different versions of Linux offer different levels of filesystem and utility compatibility with co-resident operating systems. For example, if you want to run Tru64 Unix (Digital Unix, or DU) on your system as well as the Debian Linux Alpha distribution, their default disk filesystem, partitioning, and labeling would conflict. Likewise, if you apply BSD-style disk labeling from Linux, that partition will not be accepted as valid by DU. If you want to set up Linux co-resident with another operating system on an Alpha system, the safest way is to partition the disk from within that operating system and define the partition for Linux to be installed to.
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The Linux fdisk utility fails to label DOSFS filesystems so that SRM and other firmware utilities can access them. Therefore, as a general rule, format your MS-DOS diskettes for configuring your system using MS-DOS or Windows NT (or buy preformatted MS-DOS diskettes).
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The first time you install Linux on older machines (especially UDB/Multias), your installation may fail if your system's internal battery is not charged. Reports of motherboards shipped from a vendor with a dead battery are common. Some systems have a rechargeable battery that nevertheless will not recharge on a powered-up system if the battery is discharged when the system is turned on. For instance, the monitor will not work, and firmware changes that you need to complete a self-booting installation will not be saved.
B.2.2. Installation Choices
Once you have gathered your hardware data and selected your Linux distribution, choose your installation method. Alpha systems vary more than typical PC systems (having been engineered to be used as everything from basic display terminals to supercomputers), so you should evaluate your hardware and choose the booting method you will use with your Linux distribution. Otherwise, you may find that you cannot complete the installation as you expected, or that Linux will be difficult to boot without rebuilding the installation.
If you add a CD-ROM drive to your system to install Linux, check your hardware documentation and Linux package documentation to make sure that the CD-ROM will be recognized natively in the BIOS or that SRM will support that drive. Most standard SCSI CD-ROM and IDE drives connected to an onboard controller are recognized and supported by SRM. But IDE CD-ROMs attached to add-in PCI IDE controllers will most likely not be seen by SRM.
Although network installation of Linux (storing the files on one machine and downloading them over the network to the machine where you want Linux to run) is possible, major distributions have had persistent problems supporting this capability. We are not going to describe the technique. We assume you are installing Linux on a stand-alone Alpha system. You can configure it for network use later.
Configuring and setting booting behavior on some older Alpha systems requires changing jumper settings on the motherboard or changing system data stored in nonvolatile RAM, or both. You may need to change jumper settings initially for installation and again afterward to configure the system.
Even a routine AlphaLinux installation procedure is more complex than a Linux installation on the usual Intel PC. While the Intel PC provides the system hardware interface in the onboard BIOS, Alpha systems require that the system bootstrap itself by defining and loading a firmware interface before loading the operating system. The various ways this is done are the subject of the following section.
B.2.2.1. Firmware options
Each Alpha contains at least one firmware program stored in system ROM or flash ROM that provides a configuration-program execution environment to set up hardware configurations, specify boot options, and perform other system maintenance tasks. This firmware is the usual starting point for installing Linux. Types of firmware include:
- System Reference Maintenance (SRM)
-
Available on systems set up for Tru64 Unix or Open VMS. The only
exceptions are systems based around the UX motherboard, which have
their own ARC BIOS firmware and the Digtal XL series, for which SRM
was never released. SRM is the best environment for installing Linux,
and the one we concentrate on in this appendix. The SRM is described
in an online manual at
ftp://ftp.digital.com/pub/Digital/info/semiconductor/literature/srmcons.pdf.[69]
[69]SRM console firmware for Multia, AlphaStation, AlphaServer, AlphaPC164, and AXPpcisystems is available at ftp://gatekeeper.dec.com or http//ftp.digital.com/pub/DEC/Alpha/firmware.
- Alpha Reference Console (ARC)
- Available on older systems set up for Windows NT. It offers a simple, menu-driven console interface for managing the system's hardware.
- AlphaBIOS
- A replacement for ARC that attempts to make OS installation on Alpha systems more uniform and automatic, such as OS installation on an Intel-architectured PC. It offers a graphical user interface.
Firmware programs are small and efficient. Alpha system ROMs typically include space to hold several of them, along with other essential programs, such as debugging and diagnostic tools (which should not be overwritten).
To load Linux, many Alpha installations in the past used Milo, mainly because the SRM console used to boot Tru64 Unix and OpenVMS was not easily available for many machines. The standard firmware was initially loaded by accessing a system console when the system was booted and instructing it to load Milo from a diskette. Then a current Milo miniloader image was loaded from diskette, and it in turn was told to load the Linux kernel from the CD-ROM or boot diskette.
By now, Compaq has made the SRM console available for almost all the Alpha machines (one exception being the XL series). Since SRM is much more readily available now, it is the preferred way of booting Linux. Milo is still available and still being updated for those that do not have this option. While you can get by using a slightly old Red Hat Milo for your hardware with the latest Red Hat Linux, the best solution is to change over to SRM console when it is available and supported by your hardware.
Once Linux is installed, many systems provide a flash-RAM management utility (FMU) to allow you to "blow" a Milo image into system nonvolatile RAM. Other such utilities may come with your purchase of a commercial OS release or a developer package. Some are distributed on an EPROM chip that you install. Because ARC and AlphaBIOS firmware provide a graphical interface environment, they take more space, and you will find at most one of them on a standard system.
Booting Linux can be made as automatic as booting MS-DOS or Windows. We do not recommend that you use an FMU, because booting from an SRM console is just as efficient. In this appendix, we focus on an SRM and aboot because they work on all significant Alpha platforms and offer the most consistent and predictable results. You will learn about other installation options as you review your resource materials.
In many cases, it won't matter whether you have an old or a new version of your firmware. In fact, some users advise you not to update firmware unless you know you need to do so. In other words, you can upgrade firmware if Linux fails to install properly on your system. Indeed, some Linux installations require some systems to be "downgraded" to an earlier firmware version to succeed.
But generally, we recommend using the most recent version of your firmware to install Linux, especially if you use AlphaBIOS. Follow your hardware manual's directions for upgrading firmware. You can get firmware upgrades from http://ftp.digital.com/pub/DEC/Alpha/firmware/.
B.2.2.2. Features and limitations of SRM
The SRM console can load data from IDE/ATAPI, SCSI, or floppy drives, and can use a system's native SCSI drive controller to access a recognized SCSI device for booting. SRM can read a floppy drive. It can access MS-DOS-format filesystems (but not those created by Linux fdisk), BSD-labeled UFS filesystems (but not BSD-style filesystems labeled by Linux), and ISO9660 filesystems.
The SRM console allows you to boot the system by transferring control to the secondary bootstrap loader that it loads blindly. SRM knows little about disk partitions or filesystems and treats disk devices as block devices. It reads from the first 512-byte sector of the storage device. This sector should contain a sector address and offset from which SRM can begin reading the size of data block. SRM goes to that location and loads contiguous data into memory. The data should be an image file of the secondary loader that boots the system.
Alpha systems usually have two secondary loaders: the "raw" loader from the Linux kernel and the separate aboot utility. The aboot utility is more flexible than the raw loader and is installed by default with most distributions. However, you can also use the SRM console to load the Milo loader. Some machines do not currently have a MILO available (DS20), so, in those cases, using SRM and aboot is mandatory.
When you use SRM and aboot to boot Linux, the first partition of the disk should start at cylinder number 2. This leaves room at the beginning of the disk to install aboot. The SRM Howto at http://www.linuxalpha.org/faq/srm.html provides more information about SRM and aboot.
B.2.2.3. Features and limitations of ARC Firmware
This firmware is severely limited. It knows how to access files only in MS-DOS, HPFS, and ISO9660 filesystems. When accessing files in MS-DOS or ISO9660, the system recognizes only 8.3 filenames.
B.2.2.4. Features and limitations of AlphaBIOS Firmware
AlphaBIOS firmware is no longer in active development (the last version being 5.70). If your system has AlphaBIOS, install the latest AlphaBIOS firmware update before installing Linux. AlphaBIOS knows how to access files only in MS-DOS and ISO9660 filesystems. Like ARC, when accessing files, the system recognizes only 8.3 filenames.
B.2.2.5. Features and limitations of Milo Miniloader
The Milo miniloader does not know how to boot itself from disk. Before Milo can load Linux, Milo itself must be loaded either from system flash memory or from disk using an operating system loader (OSloader) developed for Alpha systems, such as Windows NT Alpha's boot manager. Linux distributions provide linload.exe.
When Milo is on disk, it is bootstrap-loaded by a ARC, AlphaBIOS, or SRM console after you use linload.exe. linload.exe knows MS-DOS (FAT) filesystems, but does not recognize HPFS or VMS filesystems. Milo is apparently limited to MS-DOS, ISO9660, and ext2 filesystems when it has been loaded by linload.exe.
Milo can read ext2 filesystems by default and can load operating system images in ISO9660 or MS-DOS (FAT) formats using a command-line option. Milo should be able to load compressed kernel image files made using gzip, if given the full filename (e.g., vmlinux.gz), but we have found that at least some Milo distributions cannot process such files, at least not when loaded from ISO9660 or MS-DOS filesystems. MILO is also available only for certain platforms. A chart listing these systems is available at http://www.linuxalpha.org/docs/systypes.txt. For more information, go to http://www.linuxalpha.org/faq/milo.html.
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| B. Installing Linux on Digital/Compaq Alpha Systems |  | B.3. Installing Linux |
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