Sun 2900 Strategy Guide
This guide is intended to explain the process of setting up an operating system (OpenBSD 5.6) on a Sun Fire E2900 machine (such as potassium-nitrate).
Booting an Operating System
The recommended way to load an operating system onto the E2900 is network boot. From any CSC machine, access the management console (telnet potassium-nitrate-alom and enter password), then hit Enter a few times.
- If you see a login prompt, or nothing, push the two keys "#." consecutively to get to the Lights-Out Management console. Then follow the next step.
- If you see a prompt like "lom>", you are at the Lights-Out Management console. Enter "break", then "yes". This suspends the operating system and enters the debugger.
- If you see a prompt like "ok", you are in the debugger and can control the boot sequence.
From the debugger, typing "boot net" causes the following to take place:
- If there is an operating system running, a system reset will be performed.
- The machine performs a reverse-ARP (RARP) lookup to determine its IP address based on its MAC address. The RARP daemon is running on dextrose, and configuration can be changed in /etc/ethers and /etc/hosts.
- The machine then sends a broadcast TFTP GET request for a file whose name corresponds to its IP address encoded as an eight-character string. For example, potassium-nitrate gets the IP address 22.214.171.124, so it asks for the file "8161862D" over TFTP. (Hint: 'printf "%02X%02X%02X%02X\n" 129 97 134 45')
- atftpd doesn't answer broadcast TFTP requests correctly, so you need to find another way. There is a script in dextrose:/root called tftp.py that acts as a very simple TFTP server, and it handles broadcast requests fine.
- This file is loaded into memory and executed.
For OpenBSD/sparc64, this file is "ofwboot" (but renamed or symlinked so the machine can find it).
- ofwboot sends a broadcast BOOTPARAMS request to find out how to load the next part of the installer. The bootparamd software is running on dextrose, and essentially tells the system to mount a certain directory over NFS and then load from there. The NFS mount in question is exported from dextrose.
- ofwboot then asks for a kernel to run. If you are installing OpenBSD (or upgrading), enter "bsd.rd". This is the OpenBSD RAM-disk kernel and contains a minimal environment that can be loaded into memory without a full root filesystem present. The kernel to be loaded is, as mentioned, exported and loaded over NFS.
Following these steps should give you an OpenBSD installation prompt over the management console.