Introduction (hp700-specific), Diskless NetBSD HOW-TO

Client hardware requirements

• Unsupported models

  All of the Series 700 workstations are capable of running diskless.

  However, some models of Series 700 workstations are not supported by NetBSD. These unsupported models include, but are not limited to, the newer machines that use the bootp and tftp protocols to load the boot program.

  Even when a model is supported by NetBSD, that does not imply that all the features of that model are supported (i.e., the keyboard and screen on all models). You should check the hp700 port page for hardware compatibility issues.

• Which Ethernet devices are supported

  Any single built-in Intel Ethernet will support netbooting. NetBSD refers to this single built-in Ethernet as ie0.

• Model Differences in Netboot Protocols

  Most older Series 700 workstations (with PA-7000 (PCXS), PA-7100 (PCXT), PA-7150 (PCXT)) use the RMP (Remote Maintenance Protocol) to netboot. Specifically, they use the rboot protocol to retrieve their boot program. The following list of RMP-only Series 700 workstations is probably complete, but has not been tested:

  • 705
  • 710
  • 715/33, 715/50, 715/75
  • 720
  • 725/50, 725/75
  • 730
  • 735/99, 735/124
  • 745i
  • 747i
  • 750
  • 755/99, 755/125

  Newer Series 700 workstations use bootp and tftp to retrieve their boot program. The following list of BOOTP-only Series 700 workstations is probably complete, but has not been tested:

  • 712
  • 715/64, 715/80, 715/100, 715/100XC
  • 725/64, 725/100
  • newer models, such as the B, C, and J class systems

Setting up the client hardware

• Selecting the correct Ethernet media

  All hp700 machines ship with ethernet. Some models may have two ethernet media types built into the motherboard. You may only use one at a time. Unfortunately, there doesn't appear to be an easy way of determining which is active. You might try attaching a transceiver to the AUI port, as it should only be powered if that port is selected.

  If the wrong type of network is selected, you will need to change the ethernet port. For models 720 and 730, you will need to remove the motherboard to access the jumper. Be sure to use static-prevention measures, as you could easily fry your motherboard from carelessness. If you are uncomfortable with this, ask a friend who is aware of these issues. There is a block of 8 jumpers at the rear of the motherboard, labeled AUI/Thin. You will need to put the jumpers in the position necessary for your type of ethernet.

• Determining your Ethernet hardware address

  You will need to determine the Ethernet hardware address of your workstation. This is sometimes also known as the "link level address" or MAC address. It is a twelve digit hexadecimal number (i.e. it uses 0-9 and A-F for each digit). For example, 08:00:09:49:15:19 is the Ethernet address of my workstation. AFAIK, all older HP workstations start with 08:00:09:XX:XX:XX.

  The easiest way to determine your Ethernet address is to reboot your workstation. While it is Searching for Potential Boot Devices, hit the Escape key until you reach a menu with the option to Enter Boot Administration mode. Select this option, and type in lan_addr (see the FAQ for help).

  BOOT_ADMIN> lan_addr
  LAN Station Address:  080009-491519
  

• Default boot device order

  The order in which the firmware searches for bootable devices depends on your model. In general, it will try to boot off a locally attached hard drive or CD-ROM before checking the network. See the entry in the FAQ.

• Overriding the default boot device order

  If the Ethernet device has a lower boot device priority than your hard drive(s), you'll need to enter the Boot Administration mode of the firmware. On any Series 700 machine, the procedure is the same:

  1. Power on your workstation
  2. Wait until the firmware finishes checking your hardware (this may take over one minute before anything shows up on screen)
  3. Wait until it prints the following:

     Selecting a system to boot.

  4. Hit the Escape key, and wait for it to print the following:

     Searching for Potential Boot Devices.

  5. Hit the Escape key, and you should next see a short menu, one option of which should be:

     Enter Boot Administration Mode

  6. Select this option, which should put you at the following prompt:

     BOOT_ADMIN>

  7. Type boot lan and hit Return. The boot program will then be loaded.

  See the FAQ for more help.

How is the kernel loaded? or How do I boot a different kernel?

The file that you want to have rbootd or tftpd serve to your client is called SYSNBSD. Uncompress the SYSNBSD.gz found under the installation/lifboot directory of the snapshot. This file is large because it contains the kernel that your machine will boot and run.

This is because the NetBSD/hp700 boot program only knows how to use the firmware to load a kernel from the very same Logical Interchange Format (LIF) volume that contained the boot program. This is why every time you recompile the kernel, you need to use the mkboot program to rebuild the LIF volume served by rbootd or tftpd. Otherwise, you'll just load the old kernel the next time you reboot.

For example, to rebuild the LIF volume /usr/mdec/rbootd/SYSNBSD from the kernel in /usr/obj/sys/arch/hp700/compile/GENERIC, you might do:

cd /usr/obj/sys/arch/hp700/compile/GENERIC
ln -sf /usr/obj/sys/arch/hp700/stand/boot/boot ./boot
mkboot -v boot netbsd /usr/mdec/rbootd/SYSNBSD

Note that this assumes that you have a suitable mkboot program, compiled for the host, in your PATH. mkboot is found under sys/arch/hp700/stand/mkboot and should be compilable on any NetBSD host.

How the Boot ROM starts loading from a diskless server (older models)

HP intended for older Series 700 machines (and Series 300/400 models) to entirely use the RMP (Remote Maintenance Protocol) for all things diskless (including filesystem). To keep things simple, the NetBSD folks have only implemented the bootstrapping procedure (known as rbootd), wherein the Boot ROM gets the initial bootloader. Here's what happens when you power on your hp700:

1. The Boot ROM runs through a bunch of hardware checks
2. The Boot ROM checks for the bootloader in various places (see above)
3. When it gets to checking the ethernet, it will broadcast an RMP Boot Request packet
4. If it gets a response, it will send another request (this time asking for the name(s) of the bootloaders on that server)
5. If the user selects that device to boot, the server will send the bootloader to the client using RMP
6. The Boot ROM will transfer control to the bootloader and it will load the kernel from the same location as the bootloader.
7. The bootloader will transfer control to the kernel, and the kernel will start looking for the root filesystem (usually assumed to be a NFS mount).
8. The kernel sends a BOOTP request looking for the machine's IP address and the location of the root filesystem, so you will need a BOOTP daemon on your NFS server.

How the Boot ROM starts loading from a diskless server (newer models)

HP finally got smart and started using the standard technique of BOOTP/TFTP to locate a bootloader and kernel. The DHCP server in BOOTP-compatible mode can be used instead of the BOOTP daemon. Here's what happens when you power on your hp700:

1. The Boot ROM runs through a bunch of hardware checks
2. The Boot ROM checks for the bootloader in various places (see above)
3. When it gets to checking the ethernet, it will broadcast a BOOTP discovery packet
4. If it gets a response, it will send another request (this time asking for the name of the bootloaders on that server)
5. If the user selects that device to boot, the Boot ROM will download the bootloader using TFTP.
6. The Boot ROM will transfer control to the bootloader and it will load the kernel from the same server using NFS.
7. The bootloader will transfer control to the kernel, and the kernel will start looking for the root filesystem (usually assumed to be a NFS mount).
8. The kernel sends a BOOTP request looking for the machine's IP address and the location of the root filesystem.

Begin setting things up (suggested order):

1. rbootd (for earlier models)
2. dhcpd (in BOOTP-compatible mode) or bootpd
3. tftpd (for later models)
4. nfs
5. client filesystem
6. finishing up

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