diff --git a/LDP/howto/linuxdoc/SRM-HOWTO.sgml b/LDP/howto/linuxdoc/SRM-HOWTO.sgml deleted file mode 100644 index d9ac52d8..00000000 --- a/LDP/howto/linuxdoc/SRM-HOWTO.sgml +++ /dev/null @@ -1,1139 +0,0 @@ - - -
- -SRM Firmware Howto - - -, -and - - -v0.6.1, 5 March 2000 - -This document describes how to boot Linux/Alpha using the SRM console, -which is the console firmware also used to boot Compaq Tru64 Unix -(also known as Digital Unix and OSF/1) and OpenVMS. - - - - -About this manual - -Who should read this manual -

-You should read this manual if you are installing Linux on a new -Alpha system that can only boot from the SRM console, or if you are -installing Linux on an older Alpha system that can use the SRM console -and wish to use SRM to boot your Linux installation. -

-

-Because SRM is the only way to boot Linux on modern Alpha systems, -and because it provides the proper operating environment for Unix and -Unix-like operating systems (such as Linux), it is the recommended way -of booting Linux on Alpha when available. -

-

-Sometimes, it is preferable to use the ARC, ARCSBIOS, or AlphaBIOS -console, such as if you have a machine for which SRM is not available, -if you wish to dual-boot with Windows NT without switching consoles, -or if you have hardware that is not supported by SRM. On these -machines, you will typically use MILO to boot Linux. For more -information, refer to the MILO Howto, available from -. -

- - -Conventions -

-Throughout this manual, we will use the following conventions for -commands to be entered by the user: -

-

-SRM console commands will be shown with the characteristic SRM -'>>>' prompt, like this: On multiprocessor machines, you -will see 'P00>' instead, or possibly some other number depending on -which processor SRM is running. - ->>> boot dva0 -fi linux.gz -fl "root=/dev/fd0 load_ramdisk=1" - -

-

-Unix commands will be shown with the '#' command prompt if they are -to be run as root, or '$' if they are to be run by a normal user, -like this: - -# swriteboot -f3 /dev/sda /boot/bootlx - -

-

-Aboot commands will be shown with the 'aboot>' command prompt, like -this: - -aboot> b 6/boot/vmlinuz root=/dev/hda6 - -

- - - -What is SRM? -

-SRM console is used by Alpha systems as -Unix-style boot firmware. Tru64 Unix and OpenVMS depend on it and -Linux can boot from it. You can recognize SRM console as a blue screen -with a prompt that is presented to you on power-up. -

- -Getting to SRM -

-Most Alpha systems have both the SRM and ARC/AlphaBIOS console in -their firmware. On one of these machines, if your machine starts up -with ARC/AlphaBIOS by default, you can switch to SRM through the -"Console Selection" option in the Advanced CMOS Setup menu. To make -the change permanent, you should set the os_type environment -variable in SRM to "OpenVMS" or "Unix", like this: - ->>> set os_type Unix - -

-

-Either one will work to boot Linux. However, if you intend to -dual-boot OpenVMS on this machine, you must set os_type to -"OpenVMS". Conversely, to return to ARC/AlphaBIOS, you can set -os_type to "NT". -

-

-Some older systems may not have both SRM and ARC in firmware as -shipped. On these systems, you will have to upgrade your firmware. -See for the -latest firmware updates and instructions. -

-

-A few older systems (primarily evaluation boards such as the 164SX -and 164LX) are "half-flash" systems, whose firmware can hold SRM or -AlphaBIOS, but not both. If you have one of these machines, you will -have to reflash your firmware with the SRM console using the AlphaBIOS -firmware update utility. Again, see - for firmware -images and instructions. If you wish to return to AlphaBIOS on these -machines, you may rerun the firmware update utility from a floppy in -SRM using the fwupdate command. You can also start AlphaBIOS -from a floppy using the arc command. -

- - -Using the SRM console -

-The SRM console works very much like a Unix or OpenVMS shell. It -views your NVRAM and devices as a pseudo-filesystem. You can see this -if you use the ls command. Also, it contains a fairly large set -of diagnostic, setup, and debugging utilities, the details of which -are beyond the scope of this document. As in the Unix shell, you can -pipe the output of one command to the input of another, and there is a -more command that works not unlike the Unix one. To get a full -listing of available commands, run: - ->>> help | more - -

-

-As well, SRM has environment variables, a number of which are -pre-defined and correspond to locations in NVRAM. You can view the -entire list of environment variables and their values with the -show command (there are quite a few of them, so you will probably -want to pipe its output to more). You can also show variables -matching a "glob" pattern - for example, show boot* will show all -the variables starting in "boot". -

-

-Environment variables are categorized as either read-only, -warm non-volatile, or cold non-volatile. The full listing -of pre-defined variables is detailed in the Alpha Architecture -Reference Manual. The most useful pre-defined environment variables -for the purposes of booting Linux are bootdef_dev, -boot_file, boot_flags, and -auto_action, all of which are cold non-volatile. -

-

-To set environment variables, use the set command, like this: - ->>> set bootdef_def dka0 - -

-

-If you set an undefined variable, it will be created for you, however -it will not persist across reboots. -

-

-The bootdef_dev variable specifies the device (using -VMS naming conventions - see for an -explanation of these) which will be booted from if no device is -specified on the boot command line, or in an automatic boot. -The boot_file variable contains the filename to be -loaded by the secondary bootloader, while boot_flags -contains any extra flags. auto_action specifies the -action which the console should take on power-up. By default, it is -set to HALT, meaning that the machine will start up in the -SRM console. Once you have configured your bootloader and the -boot-related variables, you can set it to BOOT in order to -boot automatically on power-up. -

-

-Finally, two helpful console keystrokes you should know are -Control-C, which, as in the shell, halts a command in progress (such -as an automatic boot), and Control-P, which if issued from the aboot -prompt (or other secondary bootloader) will halt the bootloader and -return you to the SRM console. -

- - -How Does SRM Boot an OS? -

-All versions of SRM can boot from SCSI disks and the versions for -recent platforms, such as the Noname or AlphaStations can boot from -floppy disks as well. Network booting via bootp is supported. -Note that older SRM versions (notably the one for the Jensen) -cannot boot from floppy disks. Booting from IDE devices -is supported on newer platforms (DS20, DS10, DP264, UP2000 etc..). -

-

-Booting Linux with SRM is a two step process: first, SRM loads and -transfers control to the secondary bootstrap loader. Then the -secondary bootstrap loader sets up the environment for Linux, reads -the kernel image from a disk filesystem and finally transfers control to Linux. -

-

-Currently, there are two secondary bootstrap loaders for Linux: -the raw loader that comes with the Linux kernel and aboot -which is distributed separately. These two loaders are described in -more detail below. -

- - -Loading The Secondary Bootstrap Loader -

-SRM knows nothing about filesystems or disk-partitions. It simply -expects that the secondary bootstrap loader occupies a consecutive -range of physical disk sector, starting from a given offset. The -information on the size of the secondary bootstrap loader and the -offset of its first disk sector is stored in the first 512 byte -sector. Specifically, the long integer at offset 480 stores the -size of the secondary bootstrap loader (in 512-byte blocks) and -the long at offset 488 gives the sector number at which the -secondary bootstrap loader starts. The first sector also stores a -flag-word at offset 496 which is always 0 and a checksum at offset -504. The checksum is simply the sum of the first 63 long integers in -the first sector. -

-

-If the checksum in the first sector is correct, SRM goes ahead and -reads the size sectors starting from the sector given in the -sector number field and places them in virtual memory at -address 0x20000000. If the reading completes successfully, -SRM performs a jump to address 0x20000000. -

- - - -The Raw Loader -

-The sources for this loader can be found in directory -arch/alpha/boot of the Linux kernel source -distribution. It loads the Linux kernel by reading -START_SIZE bytes starting at disk offset -BOOT_SIZE+512 (also in bytes). The constants -START_SIZE and BOOT_SIZE are defined in -linux/include/asm-alpha/system.h. START_SIZE -must be at least as big as the kernel image (i.e., the size of the -.text, .data, and .bss segments). Similarly, -BOOT_SIZE must be at least as big as the image of the raw -bootstrap loader. Both constants should be an integer multiple of the -sector size, which is 512 bytes. The default values are currently 2MB -for START_SIZE and 16KB for BOOT_SIZE. Note -that if you want to boot from a 1.44MB floppy disk, you have to reduce -START_SIZE to 1400KB and make sure that the kernel you -want to boot is no bigger than that. -

-

-To build a raw loader, simply type make rawboot in the top -directory of your linux source tree (typically -/usr/src/linux). This should produce the following files in -arch/alpha/boot: -

-

- -tools/lxboot:

The first -sector on the disk. It contains the offset and size of -the next file in the format described above.

-tools/bootlx:

The raw boot loader that -will load the file below.

-vmlinux.nh:

The raw kernel image consisting of -the .text, .data, and .bss segments of the -object file in /usr/src/linux/vmlinux. The -extension .nh indicates that this file has no object-file -header.

- -

-

- The concatenation of these three files should be written to the -disk from which you want to boot. For example, to boot from a floppy, -insert an empty floppy disk in, say, /dev/fd0 and then type: - -# cat tools/lxboot tools/bootlx vmlinux >/dev/fd0 - -

-

-You can then shutdown the system and boot from the floppy by -issuing the command boot dva0. -

- - -The aboot Loader -

-When using the SRM firmware, aboot is the preferred way of -booting Linux. It supports: -

-

- - direct booting from various filesystems (ext2, ISO9660, and -UFS, the DEC Unix filesystem) - listing directories and following symbolic links on ext2 (version 0.6 and later) - booting of executable object files (both ELF and ECOFF) - booting compressed kernels - network booting (using bootp) - partition tables in DEC Unix format (which is -compatible with BSD Unix partition tables) - interactive booting and default configurations for -SRM consoles that cannot pass long option strings - -

- -Getting and Building aboot -

-The latest sources for aboot are available in . -The description in this manual applies to aboot version 0.6 -or newer. Please note that many distributions ship aboot with them so -downloading aboot from this directory is probably unnessesary. -

Once you downloaded and extracted the latest tar file, take a -look at the README and INSTALL files for -installation hints. In particular, be sure to adjust the variables in -Makefile and in include/config.h to match your -environment. Normally, you won't need to change anything when -building under Linux, but it is always a good idea to double check. -If you're satisfied with the configuration, simply type make -to build it (if you're not building under Linux, be advised that -aboot requires GNU make). -

-

-After running make, the aboot directory should contain the -following files: -

-

- -aboot

This is the actual aboot executable (either an -ECOFF or ELF object file).

-bootlx

Same as above, but it contains only the text, data -and bss segments---that is, this file is not an object file.

-sdisklabel/writeboot

Utility to install aboot on a -hard disk.

-tools/e2writeboot

Utility to install aboot on an ext2 -filesystem (usually used for floppies only).

-tools/isomarkboot

Utility to install aboot on a iso9660 -filesystem (used by CD-ROM distributors).

-tools/abootconf

Utility to configure an installed aboot.

- -

- - -Floppy Installation -

The bootloader can be installed on a floppy using the -e2writeboot command (note: this can't be done on a Jensen since -its firmware does not support booting from floppy). This command -requires that the disk is not overly fragmented as it needs to find -enough contiguous file blocks to store the entire aboot image -(currently about 90KB). If e2writeboot fails because of this, -reformat the floppy and try again (e.g., with fdformat(1)). For -example, the following steps install aboot on floppy disk -assuming the floppy is in drive /dev/fd0: - -# fdformat /dev/fd0 -# mke2fs /dev/fd0 -# e2writeboot /dev/fd0 bootlx - -

- - -Harddisk Installation -

-Since the e2writeboot command may fail on highly fragmented -disks and since reformatting a harddisk is not without pain, it is -generally safer to install aboot on a harddisk using the -swriteboot command. swriteboot requires that the first few -sectors are reserved for booting purposes. We suggest that the disk -be partitioned such that the first partition starts at an offset of -2048 sectors. This leaves 1MB of space for storing aboot. On -a properly partitioned disk, it is then possible to install aboot -as follows (assuming the disk is /dev/sda): - -# swriteboot /dev/sda bootlx - -

-

-On systems where partition c in the entire disk it will be -necessary to 'force' the write of aboot. In this case use the -f -flag followed by the partition number (in the case of partition c -this is 3): - -# swriteboot /dev/sda bootlx -f3 - -

-

On a Jensen, you will want to leave some more space, since you need to -write a kernel to this place, too---2MB should be sufficient when -using compressed kernels. Use swriteboot as described in Section - to write bootlx together with the Linux -kernel. -

- - -CD-ROM Installation -

To make a CD-ROM bootable by SRM, simply build aboot as -described above. Then, make sure that the bootlx file is present -on the iso9660 filesystem (e.g., copy bootlx to the directory -that is the filesystem master, then run mkisofs on that -directory). After that, all that remains to be done is to mark the -filesystem as SRM bootable. This is achieved with a command of the -form: - -# isomarkboot filesystem bootlx - -

-

-The command above assumes that filesystem is a file containing -the iso9660 filesystem and that bootlx has been copied into the -root directory of that filesystem. That's it! -

- - -Building the Linux Kernel -

-A bootable Linux kernel can be built with the following steps. -During the make config, be sure to answer "yes" to the question -whether you want to boot the kernel via SRM (for certain platforms -this is automatically selected). Note that if you build a generic -kernel (by selecting "Generic" as the alpha system type), the kernel -is able to guess whether it is running under SRM or not. - -# cd /usr/src/linux -# make config -# make dep -# make boot -# make modules (if applicable) -# make modules_install (if applicable) - -

-

-The last command will build the file -arch/alpha/boot/vmlinux.gz which can then be copied to the -disk from which you want to boot from. In our floppy disk example -above, this would entail: - -# mount /dev/fd0 /mnt -# cp arch/alpha/boot/vmlinux.gz /mnt -# umount /mnt - -

- - -Booting Linux -

With the SRM firmware and aboot installed, Linux is generally -booted with a command of the form: - -boot devicename -fi filename --fl flags - -

- -

-The filename and flags arguments are optional. If -they are not specified, SRM uses the default values stored in -environment variables BOOTDEF_DEV , -BOOT_OSFILE and BOOT_OSFLAGS. The -syntax and meaning of these two arguments is described in more detail -below. To list the current values of these variables type show -boot* at the SRM command prompt. This will also show a -boot_dev variable (among others), this variable is read only -and needs to be changed via the bootdef_dev variable. -

- -Device Naming -

-This corresponds to the device from which SRM will attempt to boot. Examples include: -

-

- -dva0

- First floppy drive, /dev/fd0 under Linux

-dqa0

- Primary IDE cdrom or hard disk as Master, /dev/hda under Linux

-dqa1

- Primary IDE cdrom or hard disk as Slave, /dev/hdb under Linux

-dka0

- SCSI disk on first bus, Device 0, /dev/sda under Linux

-ewa0

- First Ethernet Device, /dev/eth0 under Linux

- -

-

-For example to boot from the disk at SCSI id 6, you would enter: - ->>> boot dka600 - -

-

-To list the devices currently installed in the system type show -dev at the SRM command line. In contrast to Linux device naming, the -partition number on a disk device is not given as part of the -device name (you may see extra numbers after the device names when -running show dev - these correspond to things like PCI bus and -device numbers and are not useful to the user). Remember, as -mentioned in , that SRM knows nothing -about partitions or disklabels - it merely reads a boot block and -secondary bootstrap from sectors on a disk. Therefore, the partition -number is given as part of the boot filename. -

- - -Boot Filename -

-The filename argument takes the form: - -[n/]filename - -

-

-n is a single digit in the range 1..8 that gives the partition -number from which to boot from. filename is the path of the file -you want boot. For example to boot a kernel named vmlinux.gz from the second partition of SCSI -device 6, you would enter: - ->>> boot dka600 -file 2/vmlinux.gz - -

-

Or to boot from floppy drive 0, you'd enter: - ->>> boot dva0 -file vmlinux.gz - -

-

-If a disk has no partition table, aboot pretends the disk -contains one ext2 partition starting at the first diskblock. -This allows booting from floppy disks. -

-

-As a special case, partition number 0 is used to request booting -from a disk that does not (yet) contain a file system. When -specifying "partition" number 0, aboot assumes that the Linux -kernel is stored right behind the aboot image. Such a layout -can be achieved with the swriteboot command. For example, to -setup a filesystem-less boot from /dev/sda, one could use -the command: - -# swriteboot /dev/sda bootlx vmlinux.gz - -

-

-Booting a system in this way is not normally necessary. The -reason this feature exists is to make it possible to get Linux -installed on a systems that can't boot from a floppy disk (e.g., the -Jensen). -

- - -Boot Flags -

-A number of bootflags can be specified. The syntax is: - --flags "options..." - -

-

-Where "options..." is any combination the following options (separated -by blanks). There are many more bootoptions, depending on what -drivers your kernel has installed. The options listed below are -therefore just examples to illustrate the general idea: -

-

- -load_ramdisk=1 -

Copy root file system from a (floppy) disk to the RAM disk -before starting the system. The RAM disk will be used in -lieu of the root device. This is useful to bootstrap Linux -on a system with only one floppy drive. -

-floppy=str -

Sets floppy configuration to str. -

-root=dev -

Select device dev as the root-file -system. The device can be specified as a major/minor hex number (e.g., -0x802 for /dev/sda2) or one of a few canonical names (e.g., -/dev/fd0, /dev/sda2). -

-single -

Boot system in single user mode. -

kgdb

Enable kernel-gdb (works only if CONFIG_KGDB is -enabled; a second Alpha system needs to be connected over the serial -port in order to make this work) -

- -

-

-Some SRM implementations (e.g., the one for the Jensen) are -handicapped and allow only short option strings (e.g., at most 8 -characters). In such a case, aboot can be booted with the -single-character boot flag "i". With this flag, aboot will -enter interactive mode -

- - -Using aboot interactively -

-As of version 0.6, aboot supports a simple command-oriented -interactive mode. Note that this is different from the prompt -which previous versions issued when booted with the "i" flag, or after -failing to load a kernel. You can get a summary of the available -commands by typing "h" or "?" at the prompt: - ->>> boot dka0 -fl i -aboot> ? - h, ? Display this message - q Halt the system and return to SRM - p 1-8 Look in partition for configuration/kernel - l List pre-configured kernels - d

List directory in current filesystem - b Boot kernel in (- for raw boot) - with arguments - 0-9 Boot pre-configuration 0-9 (list with 'l') -aboot> b 3/vmlinux.gz root=/dev/sda3 single - -

- - -The aboot.conf configuration file -

-Since booting in that manner quickly becomes tedious, aboot -allows to define short-hands for frequently used command lines. In -particular, a single digit option (0-9) requests that aboot uses -the corresponding option string stored in file -/etc/aboot.conf. A sample aboot.conf is shown below: - -# -# aboot default configurations -# -0:3/vmlinux.gz root=/dev/sda3 -1:3/vmlinux.gz root=/dev/sda3 single -2:3/vmlinux.new.gz root=/dev/sda3 -3:3/vmlinux root=/dev/sda3 -8:- root=/dev/sda3 # fs-less boot of raw kernel -9:0/vmlinux.gz root=/dev/sda3 # fs-less boot of (compressed) ECOFF kernel -- - -

-

With this configuration file, the command - ->>> boot dka0 -fl 1 - -corresponds exactly to the boot command shown above. -

-

-Finally, at the aboot prompt, it is possible to enter one of the -single character flags ("0"-"9") to get the same effect as if that -flag had been specified in the boot command line. As noted in the -help text cited above, you can also list the available default -configurations with the "l" command. -

- -Selecting the Partition of /etc/aboot.conf -

-When installed on a harddisk, aboot needs to know what -partition to search for the /etc/aboot.conf file. A newly -compiled aboot will search the second partition (e.g., -/dev/sda2). Since it would be inconvenient to have to -recompile aboot just to change the partition number, -abootconf allows to directly modify an installed aboot. -Specifically, if you want to change aboot to use the third -partition on disk /dev/sda, you'd use the command: - -# abootconf /dev/sda 3 - -

-

-You can verify the current setting by simply omitting the partition -number. That is: abootconf /dev/sda will print the currently -selected partition number. Note that aboot does have to be -installed already for this command to succeed. As of version 0.6, -swriteboot will preserve the existing configuration when -installing a new aboot on a hard disk. -

Since aboot version 0.5, it is also possible to select the -aboot.conf partition via the boot command line. This can be -done with a command line of the form a:b -where a -is the partition that holds /etc/aboot.conf and b is a -single-letter option as described above (0-9, i, or -h). For example, if you type boot -fl "3:h" dka100 the -system boots from SCSI ID 1, loads /etc/aboot.conf from the -third partition, prints its contents on the screen and waits for you -to enter the boot options. -

- - - - - -Booting Over the Network -

-Three steps are necessary before Linux can be booted via -a network. First you need an Ethernet adapter that is supported by SRM. -Most version of SRM support the DE500 series of cards, with newer -versions (5.6 and later) also supporting the Intel EtherExpress/Pro series -of cards. -Second, you need to set the SRM environment variables to -enable booting via the bootp protocol and third you need to setup -another machine as the your boot server. Enabling bootp in SRM is -usually done by setting the ewa0_protocol (DE500 cards) or eia0_protocol (Intel cards) variable to bootp. - ->>> set ewa0_protocol bootp - Setting up the boot server is obviously dependent on -what operating system that machine is running, but typically it -involves starting the program bootpd in the background after -configuring the /etc/bootptab file. The bootptab file -has one entry describing each client that is allowed to boot from -the server. For example, if you want to boot the machine -myhost.cs.arizona.edu, then an entry of the following form would -be needed: - -myhost.cs.arizona.edu:\ - :hd=/remote/:bf=vmlinux.bootp:\ - :ht=ethernet:ha=08012B1C51F8:hn:vm=rfc1048:\ - :ip=192.12.69.254:bs=auto: - -

-

-This entry assumes that the machine's Ethernet address is -08012B1C51F8 and that its IP address is 192.12.69.254. The -Ethernet address can be found with the show device command of the -SRM console or, if Linux is running, with the ifconfig command. -The entry also defines that if the client does not specify otherwise, -the file that will be booted is vmlinux.bootp in directory -/remote. For more information on configuring bootpd, -please refer to its man page. -

-

-Next, build aboot with with the command make netboot. Make -sure the kernel that you want to boot has been built already. By -default, the aboot Makefile uses the kernel in -/usr/src/linux/arch/alpha/boot/vmlinux.gz (edit the -Makefile if you want to use a different path). The result of -make netboot is a file called vmlinux.bootp which contains -aboot and the Linux kernel, ready for network booting. -

-

-Finally, copy vmlinux.bootp to the bootserver's directory. In the -example above, you'd copy it into /remote/vmlinux.bootp. -Next, power up the client machine and boot it, specifying the Ethernet -adapter as the boot device. Typically, SRM calls the first Ethernet -adapter ewa0, so to boot from that device, you'd use the command: - ->>> boot ewa0 - -

-

-The -fi and -fl options can be used as usual. In -particular, you can ask aboot to prompt for Linux kernel -arguments by specifying the option -fl i. -

- - -Partitioning Disks -What is a disklabel? -

-A disk label is a partition table. Unfortunately, there are several -formats the partition table can take, depending on the operating -system. -

-

-DOS partition tables are the standard used by Linux and -Windows. AlphaBIOS systems and every Linux kernel can read DOS -partition tables. Unfortunately, the SRM console's boot sector format -overlaps with parts of the DOS partition table on disk, and therefore -DOS partition tables cannot be used with SRM. -

-

-BSD disklabels are used by several variants of Unix, including -Tru64. SRM's boot block does not conflict with the BSD disklabel (in -fact, the BSD disklabel resides entirely within "reserved" areas of -the first sector), and Linux can use a BSD disklabel, provided that -support for BSD disklabels has been compiled into the kernel. -

-

-To boot from a disk using SRM, a BSD disklabel is required. If the -disk is not a boot disk, the BSD disklabel is not required. A BSD -disklabel can be created using fdisk, the standard Linux disk -partitioning tool. -

- - -Partitioning the Easy Way: a DOS Disklabel -

-The simplest way to partition your disk is to let your Linux installer -do it for you, for example by using Red Hat's disk druid or fdisk. On -Red Hat 6.1, this will produce a valid BSD disklabel, but -only if the disk in question previously contained one. In -most cases, this will produce a DOS disklabel. It will be readable by -Linux, but you will not be able to boot from it via SRM. For this -reason, you will probably want to create a BSD disklabel manually in -order to boot Linux -

- - - -Partitioning with a BSD Disklabel -

- -Start fdisk on the disk you're configuring -Choose to make a BSD disklabel - option 'b' (newer versions of -fdisk will detect existing BSD disklabels and automatically enter -disklabel mode) -You'll notice some things: Partitions are letters instead of -numbers, from a-h Partition 'c' covers the whole of the disk. This is -the convention, don't touch it. While you can see it, note down the -disk parameters as you'll use them more often than with the -DOS-disklabel approach -Creating a new partition uses the same procedure as the -DOS-disklabel approach, except that the partitions are referred to by -letter instead of number. That is, 'n' to make a new partition -followed by the partition letter followed by the starting block -followed by the end block -Setting partition type is slightly different, because the -numbering scheme is different (1 is swap, 8 is ext2). -When you are finished, write ('w') and quit ('q') as normal. - -

-

-There are some important catches that you must be aware of when -partitioning using a BSD disklabel: - -Partition 'a' should start about 1M into the disk: don't start -it at sector 1, try starting at sector 10 (for example). This leaves -plenty of space for writing the boot block (see below) -There is a bug in some versions of fdisk which makes the disk -look one sector bigger than it actually is. The listing when you -create the BSD disklabel is correct. The last sector of partition 'c' -is correct. The default last sector when creating a new partition is -1 sector too big -Always adjust for this extra sector. This bug exists in the -version of fdisk shipped with Red Hat 6.0. Not making an adjustment -for this problem almost always leads to "Access beyond end of device" -errors from the Linux kernel. - -

-

-Once you have made a BSD disklabel, continue the installation. After -installation, you can write a boot block to your disk to make it -bootable from SRM. -

- - - - - - -Sharing a Disk With DEC Unix -

-Unfortunately, DEC Unix doesn't know anything about Linux, so sharing -a single disk between the two OSes is not entirely trivial. However, -it is not a difficult task if you heed the tips in this section. The -section assumes you are using aboot version 0.5 or newer. -

- -Partitioning the disk -

-First and foremost: never use any of the Linux partitioning -programs (minlabel or fdisk) on a disk that is also -used by DEC Unix. The Linux minlabel program uses the same -partition table format as DEC Unix disklabel, but there are -some incompatibilities in the data that minlabel fills in, so -DEC Unix will simply refuse to accept a partition table generated by -minlabel. To setup a Linux ext2 partition under DEC -Unix, you'll have to change the disktab entry for your disk. For the -purpose of this discussion, let's assume that you have an rz26 disk (a -common 1GB drive) on which you want to install Linux. The disktab -entry under DEC Unix v3.2 looks like this (see file -/etc/disktab): - -rz26|RZ26|DEC RZ26 Winchester:\ - :ty=winchester:dt=SCSI:ns#57:nt#14:nc#2570:\ - :oa#0:pa#131072:ba#8192:fa#1024:\ - :ob#131072:pb#262144:bb#8192:fb#1024:\ - :oc#0:pc#2050860:bc#8192:fc#1024:\ - :od#393216:pd#552548:bd#8192:fd#1024:\ - :oe#945764:pe#552548:be#8192:fe#1024:\ - :of#1498312:pf#552548:bf#8192:ff#1024:\ - :og#393216:pg#819200:bg#8192:fg#1024:\ - :oh#1212416:ph#838444:bh#8192:fh#1024: - -

-

-The interesting fields here are o?, and -p?, where ? is a letter in the range -a-h (first through 8-th partition). The o -value gives the starting offset of the partition (in sectors) and the -p value gives the size of the partition (also in sectors). -See disktab(4) for more info. Note that DEC Unix likes to -define overlapping partitions. For the entry above, the partition -layout looks like this (you can verify this by adding up the various -o and p values): - - a b d e f -|---|-------|-----------|-----------|-----------| - - c -|-----------------------------------------------| - - g h - |-----------------|-----------------| - -

-

-DEC Unix insists that partition a starts at offset 0 and that -partition c spans the entire disk. Other than that, you can -setup the partition table any way you like. -

-

-Let's suppose you have DEC Unix using partition g and want to -install Linux on partition h with partition b being a -(largish) swap partition. To get this layout without destroying the -existing DEC Unix partition, you need to set the partition types -explicitly. You can do this by adding a t field for each -partition. In our case, we add the following line to the above -disktab entry. - - :ta=unused:tb=swap:tg=4.2BSD:th=resrvd8: - -

-

-Now why do we mark partition h as "reservd8" instead of "ext2"? -Well, DEC Unix doesn't know about Linux. It so happens that partition -type "ext2" corresponds to a numeric value of 8, and DEC Unix uses the -string "reservd8" for that value. Thus, in DEC Unix speak, "reservd8" -means "ext2". OK, this was the hard part. Now we just need to -install the updated disktab entry on the disk. Let's assume the disk -has SCSI id 5. In this case, we'd do: - -# disklabel -rw /dev/rrz5c rz26 - -

-

-You can verify that everything is all right by reading back the -disklabel with disklabel -r /dev/rrz5c. At this point, you -may want to reboot DEC Unix and make sure the existing DEC Unix -partition is still alive and well. If that is the case, you can shut -down the machine and start with the Linux installation. Be sure to -skip the disk partitioning step during the install. Since we already -installed a good partition table, you should be able to proceed and -select the 8th partition as the Linux root partition and the 2nd -partition as the swap partition. If the disk is, say, the second SCSI -disk in the machine, then the device name for these partitions would -be /dev/sdb8 and /dev/sdb2, respectively (note that -Linux uses letters to name the drives and numbers to name the -partitions, which is exactly reversed from what DEC Unix does; the -Linux scheme makes more sense, of course ;-). -

- - -Installing aboot -

-First big caveat: with the SRM firmware, you can boot one and -only one operating system per disk. For this reason, it is generally -best to have at least two SCSI disks in a machine that you want to -dual-boot between Linux and DEC Unix. Of course, you could also boot -Linux from a floppy if speed doesn't matter or over the network, if -you have a bootp-capable server. But in this section we assume -you want to boot Linux from a disk that contains one or more DEC Unix -partitions. -

-

-Second big caveat: installing aboot on a disk shared with -DEC Unix renders the first and third partition unusable (since those -must have a starting offset of 0). For this reason, we recommend -that you change the size of partition a to something that is just -big enough to hold aboot (1MB should be plenty). -

Once these two caveats are taken care of, installing aboot is -almost as easy as usual: since partition a and c will -overlap with aboot, we need to tell swriteboot that this is -indeed OK. We can do this under Linux with a command line of the -following form (again, assuming we're trying to install aboot on -the second SCSI disk): - -# swriteboot -f1 -f3 /dev/sdb bootlx - -

-

-The -f1 means that we want to force writing bootlx even -though it overlaps with partition 1. The corresponding applies for -partition 3. -

-

This is it. You should now be able to shutdown the system and boot -Linux from the harddisk. In our example, the SRM command line to do -this would be: - ->>> boot dka5 -fi 8/vmlinux.gz -fl root=/dev/sdb8 - -

- - - -Installation of Distributions -RedHat 6.0 and 6.1 -Installation from the Red Hat 6.0 or 6.1 CD -

-Red Hat have made their distribution CD bootable from SRM console -Please note that through the official RedHat CD-ROM is SRM -bootable, copies made by various other companies may not be -bootable. To start an installation, put the CD in and type -the following: - ->>> boot srm-device -file kernels/generic.gz -flags root=linux-device - -

-

-In the above, the SRM device name and Linux device name for your -CD-ROM drive are needed. For Example if the machine had an IDE cdrom -installed as primary master the command would look like this: - ->>> boot dqa0 -file kernels/generic.gz -flags "root=/dev/hda" - -

-

-See the section on conventions if you don't know what these are. -

- - - -SuSE 6.1 -Installation from the SuSE 6.1 CD -

-The SuSE 6.1 CD is not bootable from SRM console. SuSE have an -alternative approach which involves creating two boot floppies, the -images of which are included on the CD. The boot disks can be created -in various ways, depending on the systems you have available -

-

Writing the boot disks from a linux system -The command to use is dd. From the mount-point of SuSE CD 1, the commands are: - -# dd if=disks/aboot of=/dev/fd0 -# dd if=disks/install of=/dev/fd0 - -

-

-For writing the boot disks from a windows system, the command to use -is rawrite. It is available on the CD. - -D:\tools\> rawrite - -

-

-The program then prompts for input disk image and output disk -drive. Run this command once for each of the disk images as shown -above. -

-

-Starting the SuSE installer from the boot disks -With the floppy disk made from the aboot image in place, type: - ->>> boot dva0 -file vmlinux.gz -flags "root=/dev/fd0 load_ramdisk=1" - -

-

-This will start the kernel, prompt you for the second boot disk, and start the installer -

- - - -SuSE 6.3 - -Installation from the SuSE 6.3 CD -

-The SuSE 6.3 CD-ROM is SRM bootable much like the RedHat 6.0 and 6.1 CD-ROMs. The best way -to start the install from SRM is to use the following command: - ->>> boot srm-device -flags 0 - -

-

-In the above, the SRM device names for your -CD-ROM drive is needed. For Example if the machine had an IDE cdrom -installed as primary master the command would look like this: - ->>> boot dqa0 -flags 0 - -SuSE has added support to aboot to allow it to load initrd files. The above command will from the -CD-ROM drive and use config number 0 from the /etc/aboot.conf file. For other variations -on this refer to the SuSE installation guide. - - - - - -Document History -

-v0.6.1 21 March 2000 Changes from Rich Payne <rdp@alphalinux.org> - - Made the installation hints a new chapter - Added information on Netbooting - Added to the new section on RedHat 6.1 and BSD disklabels - Removed David Mosberger-Tang's name from the authors list - Marked a few of the feature as being in 0.6 only - Added info for SuSE 6.3 and RedHat 6.1 - -

-

-v0.6 3 March 2000 Changes and information from David Huggins-Daines -<dhd@linuxcare.com> - -Moved the notes on MILO vs. SRM to an "About this document" section -Added sections on switching to SRM, and basic SRM usage -Added section on the new interactive use of aboot -Updated the note on DOS partition tables to mention the Red Hat 6.1 -installer's behavior. -Normalized the markup, and codified the conventions used for -user-entered commands. -Corrected the notes on BSD disklabels (SRM does not -read BSD disklabels, it's just that they don't conflict with the boot -block). - -

-

-v0.5.2 5 December 1999 Added comments and information from Stig Telfer -(stig @ alpha-processor.com). - -Added chart on SRM to Linux name mappings -Added RedHat 6.0 and SuSE 6.1 installation information -Added Disk Partitioning Information - -

-

-v0.5.1 (Not Released) 13 November 1999 Took the original 0.5 document and updated several parts: -

-

- -Update information on SRM booting from IDE devices -Fixed URL to aboot source -Update toc page to reflect MILO's future -Included information on bootdef_dev and boot_dev to chapter 3 -Added this section - -

-

-v0.5 17 August 1996 - Original Document by David Mosberger-Tang -

- -
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