Boot flags and PROM commands

Network boot

The alpha boot PROMs support the bootp and mop network boot protocols. We use bootp to boot spin with bootpd and tftpd running on silk. The TFTP server exports a root filesystem starting with /afs/cs/project. Filenames that you specify to the TFTP server are then resolved against that root. For example, /spin/bershad/spin.boot refers to the file /afs/cs/project/spin/bershad/spin.boot.

On TURBOCHANNEL alphas use the ez0 device for network boots and on PCI alphas use the ewa0 device.

Here are the steps to net boot.

Put a bootable kernel image someplace high into silk's file system. We usually put a symbolic link from your real kernel image (for me, that's /afs/cs/project/spin/bershad/spin/sal/SPIN/spin_kernel.sys). Call the bootable image something short (spin.boot is a good choice). The reason you have to move spin.boot is that the PROM will take only very short path names.
From the BOOT PROM, type:
```
b -fi "/spin/YOU/spin.boot" ez0
```
Wait about 30 seconds as the dots go flying by...

Debug boot

Use the t flag to stop the boot process as soon as ttd debugging is initialized. The t stands for TTD. Use T if you prefer. The -fl must be after the -fi flag.

b -fi "/spin/YOU/spin.boot" -fl t ez0

Interactive boot

Interactive booting lets you specify BOTH an image to run and an initial set of bootflags.

b -fl i

>> "what image you want to run"

   spin_kernel boothowto=0xffffffffff

bershad@cs.washington.edu