大部分都是根据man diskless手册走的，虽然有些地方和手册不一样，但是毕竟是摸索出来的，安装成功了
DISKLESS(8) OpenBSD System Manager's Manual DISKLESS(8)NAME diskless - booting a system over the networkDESCRIPTION The ability to boot a machine over the network is useful for diskless or dataless machines, or as a temporary measure while repairing or re-in- stalling filesystems on a local disk. This file provides a general de- scription of the interactions between a client and its server when a client is booting over the network. The general description is followed by specific instructions for configuring a server for diskless Sun clients.OPERATION When booting a system over the network, there are three phases of inter- action between client and server: 1. The PROM (or stage-1 bootstrap) loads a boot program. 2. The boot program loads a kernel. 3. The kernel does NFS mounts for root and swap. Each of these phases are described in further detail below. In phase 1, the PROM loads a boot program. PROM designs vary widely, so this phase is inherently machine-specific. Sun and Motorola machines use RARP to determine the client's IP address and then use TFTP to download a boot program from whoever sent the RARP reply. HP 300-series machines use the HP Remote Maintenance Protocol to download a boot program. Other machines may load a network boot program either from diskette or using a special PROM on the network card. In phase 2, the boot program loads a kernel. Operation in this phase de- pends on the design of the boot program. The boot program: 2.1 gets the client IP address using RARP. 2.2 gets the client name and server IP address by broadcasting an RPC / BOOTPARAMS / WHOAMI request with the client IP address. 2.3 gets the server path for this client's root using an RPC / BOOTPARAMS / GETFILE request with the client name. 2.4 gets the root file handle by calling mountd(8) with the server path for the client root. 2.5 gets the kernel file handle by calling NFS lookup on the root file handle. 2.6 loads the kernel using NFS read calls on the kernel file handle. 2.7 transfers control to the kernel entry point. In phase 3, the kernel does NFS mounts for root and swap. The kernel re- peats much of the work done by the boot program because there is no stan- dard way for the boot program to pass the information it gathered on to the kernel. The procedure used by the kernel is as follows: 3.1 The kernel finds a boot server using the same procedure as described in steps 2.1 and 2.2 above. 3.2 The kernel gets the NFS file handle for root using the same proce- dure as described in steps 2.3 through 2.5 above. 3.3 The kernel calls the NFS getattr function to get the last-modified time of the root directory, and uses it to check the system clock. 3.4 If the kernel is configured for swap on NFS, it uses the same mecha- nism as for root, but uses the NFS getattr function to determine the size of the swap area.CONFIGURATION Before a client can boot over the network, its server must be configured correctly. This example will demonstrate how a Sun client might be con- figured -- other clients should be similar. Assuming the client's hostname is to be "myclient", 1. Add an entry to /etc/ethers corresponding to the client's Ethernet address: 8:0:20:7:c5:c7 myclient This will be used by rarpd(8). #记得启动rarpd服务 2. Assign an IP address for myclient in your /etc/hosts or DNS database: 192.197.96.12 myclient 3. If booting a Sun or Motorola client, ensure that /etc/inetd.conf is configured to run tftpd(8) in the directory /tftpboot. If booting an HP 300-series machine, ensure that /etc/rbootd.conf is configured properly to transfer the boot program to the client. An entry might look like this: 08:00:09:01:23:E6 SYS_UBOOT # myclient See the rbootd(8) manual page for more information. 4. If booting a Sun or Motorola client, install a copy of the appropri- ate diskless boot loader (such as boot.net from the root directory of the OpenBSD sparc tree) in the /tftpboot directory. Make a link such that the boot program is accessible by a f