Booting from the network is only required in certain cases. Booting from the network is very
usefull when you have unsupported I/O devices, diskless systems, or systems with broken hardware.
Network booting is detailed below.
4.3.1. Preparing to boot from network
Booting from the network involves two machines: the boot server
and the boot client, the latter being the PA-RISC system you are
trying to start up, and the former, the machine that will serve over the network
the files which the client needs.
The rest of this section will extensively deal with setting up the boot
server since this is probably the trickiest part.
You will need a lifimage to perform a network boot.
See Section 3.2 to learn how to create one.
You can also use the one from
Debian Installer.
Needless to say, all server-side setup is meant to be performed by the
super-user, also known as root.
4.3.2. rboot or bootp?
All 'recent' machines can boot using
BOOTP, starting from 715/100,
715/120, and 712s. Older ones, mostly early 715s,
710s and 725s need RBOOT.
To use BOOTP you have to enable
the
IP: Kernel level autoconfiguration->IP: BOOTP support
within the 'Networking options'
section of the kernel configuration, if you want to use a
home-made kernel. See Chapter 5
for details.
Please note that though Section 4.3.3 deals with
RBOOT only, two different implementations of the
BOOTP protocol are detailed in Section 4.3.4
and Section 4.3.5. We detail these two because
we can, but if you need to use the BOOTP
protocol, you will have to choose one.
If you don't know which BOOTP implementation to use,
go for the dhcp one, it is much easier to deal with.
4.3.3. Using rboot
4.3.3.1. Obtaining rbootd
If you have an old machine that requires rboot
to boot over network, use the following procedure to set up and
configure a boot server, and boot using the PA-RISC/Linux kernel.
Old machines, including the Scorpio 715s, use the
RBOOT protocol. You need rbootd
to handle their boot requests. Look for it in your favorite distribution
archive (assuming you will be servicing boot requests from a Linux box).
Here are two ways of getting the rboot daemon:
If you are using a Debian-powered server (which you really should be doing ;o),
you're almost done. Run from a command shell:
[user@machine ~/dir]>apt-getinstall rbootd
If you can't find any rbootd package for your system
(which is very possible since it is a very old netboot protocol), you can find
its source in the Debian archive:
rbootd.
You will have to build it from source.
4.3.3.2. Configuring rbootd
As we already said, to boot a RBOOT-aware system, you need
a separate machine with rbootd
installed (this is the 'boot server') on which you will store the
PA-RISC/Linux kernel lifimage that you want to use to boot
your PA-RISC system with.
Once the rbootd server software is installed,
read the following to configure it to work with your PA-RISC system:
In /etc/rbootd.conf you will have to add a line like:
ethernet_addr bootfile
Replace bootfile with the name of your
PA-RISC/Linux kernel image, usually 'lifimage'.
Now get the Ethernet address of your PA-RISC system by typing
lanaddress at the
'BOOT_ADMIN>' prompt
(see Section 2.1.2.3).
It will return a number like
080009-7004b6. Take note of this number.
In /etc/rbootd.conf on your boot server, the
Ethernet address has to be colon-delimited. That means you will have to modify
the number you just obtained so that every set of two characters (after removing the
'-') is separated by a colon. For example:
080009-7004b6 becomes
08:00:09:70:04:b6.
Add the colon delimited Ethernet address to
/etc/rbootd.conf on your boot server. The
resulting file will look something like this:
# ethernet addr boot file comments
08:00:09:87:e4:8f lifimage_715 # PA/Linux kernel for 715/33
08:00:09:70:04:b6 lifimage_720 # PA/Linux kernel for 720
This rbootd.conf example contains the Ethernet
addresses and boot file names for two different machines.
Once you have changed the configuration file, restart
rbootd.
By default, rbootd assumes that bootfiles are located
in /var/lib/rbootd/. Therefore,
you will have to put your bootable kernel image in that directory, or,
if you really hate that directory for some reason, you can rebuild
rbootd to use a different directory.
The easiest thing, of course, is just to drop your kernel images in
the default directory!
4.3.4. Using dhcp/tftp
We will see here how to setup a DHCP server
to handle BOOTP requests (since PA-RISC box use
BOOTP, unless they need RBOOT,
as mentioned above).
Debian users will just have to install the packages using the
following commands, executed as root:
[user@machine ~/dir]>apt-getinstall dhcp tftpd
If you need rpm packages (for the ISC dhcp server), the best
way is to go to http://rpmfind.net/.
The dhcp package can do much more than a simple bootp daemon.
Nevertheless, it is also known to be much easier to configure.
If you really want to try regular bootp, skip
this and go to Section 4.3.5.
4.3.4.2. Configuring dhcp/tftp
Here are the instructions to set up dhcp on your
boot server. To keep this explanation simple, we will assume that
you want to assign a fixed IP to your box, without DNS update. Your
subnet will be 192.168.1.0/24, with optional:
gateway at 192.168.1.1, domain name
foo.com and DNS at 192.168.1.4.
Feel free to replace these values with those which would suit your
needs in the next sections.
This section is dedicated to Debian users.
For others distributions, it should be similar though
there may be some differences like default directories.
Edit /etc/inetd.conf on your boot
server to add the following line, if it doesn't already exist:
Here, /tftpboot/
is being used as tftpd server's root (this is where you will put the
lifimage file). You can choose another
directory if you want. According to man tftpd,
this is the usual default directory.
When this is done, reload inetd with:
/etc/init.d/inetd reload. Non-Debian users can also
issue a killall -HUP inetd.
According to man 5 dhcpd.conf, edit the
/etc/dhcpd.conf file to contain something like:
You have to fill in the [hostname],
[mac address],
[ip address],
[boot filename] and
[root path] fields with the
appropriate information, where:
[hostname]
is the name of the PA-RISC system.
[mac address]
is the colon-delimited ethernet address of the PA-RISC system, which
can be obtained by typing lanaddress at the
'BOOT_ADMIN>' prompt
(see Section 2.1.2.3).
[ip address]
is the IP address you wish to assign to the PA-RISC system.
[boot filename]
is the name of the bootable kernel image you want to boot your system with.
[root path]
is the path to the NFS root filesystem exported by the server.
Additionally, if the tftp server you want to use is not the same as the one
running the dhcp server, you can add next-server
[ip address];, replacing
[ip address] with the actual IP of the tftp
server, to the dhcp configuration.
You'll end up with something like this for each box
you want to netboot:
You'll have been warned! This daemon is far more obfuscated
in its configuration.
4.3.5.2. Configuring bootp/tftp
Follow these instructions to use the bootp
daemon on your boot server:
This section is dedicated to Debian users.
For others distributions, it should be similar though
there may be some differences like default directories.
Edit /etc/inetd.conf on your boot server
to add the following lines, if they don't already exist:
Here, /tftpboot/ is being
used as tftpd server's root (this is where you will put the
lifimage file). You can choose another directory
if you want. According to man tftpd, this
is the usual default directory.
When this is done, reload inetd with:
/etc/init.d/inetd reload. Non-Debian users can also issue
a killall -HUP inetd.
According to man 5 bootptab, edit the
/etc/bootptab file to contain:
You have to fill in the [hostname],
[mac address],
[ip address] and
[root path]
fields with the appropriate information, where:
[hostname] is the name
of the PA-RISC system.
[mac address] is the
NOT-delimited ethernet address of the PA-RISC system, which can be obtained
by typing lanaddress at the
'BOOT_ADMIN>' prompt
(see Section 2.1.2.3).
[ip address] is the
IP address you wish to assign to the PA-RISC system.
[boot filename] is the
name of the bootable kernel image you want to boot your system with.
[root path] is the
path to the NFS root filesystem exported by the server.
To conclude with the developers' way to boot the
kernel, this section will tell you how to actually boot your
system from a network server. But it tends to be less and less used.
Most users will prefer to stick to Section 4.2 once
their system is properly setup.
Here we are. We assume that you've done everything outlined
above, your network boot server is on the same physical subnet as
your PA-RISC machine, you've got a bootable PA/Linux kernel lifimage
on your boot server, and you're willing to give it a try.
If everything is ready (including you!), the following procedure
will introduce you to the joy of network booting your PA box into Linux.
Fire up your PA-RISC system.
Watch your PA-RISC box starting up. When the following message
appears during the PA-RISC machine's boot process, press
and hold the Esc key:
Searching for Potential Boot Devices.
To terminate search, press and hold the ESCAPE key.
If needed, select 'a) Enter Boot Administration
mode' from the menu. This brings up the
'BOOT_ADMIN>' prompt.
Type the following at the prompt: boot lan.
Watch your PA-RISC system magically becoming a PA/Linux system.
Ta dah!
Of course your are supposed to run only one boot server
at a time on your network, in order to avoid conflicts...
