How to view or modify the HostID in a SUN SPARC server from openboot or solaris environment

Openboot (ok prompt)

1. To view

ok banner

example output

........
..... memory installed, Serial #10573911.

Ethernet address 8:0:20:a1

:58:57, Host ID: 80a15857

ok .idprom

e.g.

Format/Type: 1 80 Ethernet: 8 0 20 a1 58 57 Date: 0

Serial: a1 58 57 Checksum: a9

byte(s)	contents
`0`	always 01 - format/version number
`1`	first byte of hostid (machine type)
`2-7`	6 byte ethernet address (first three bytes should be 08,00,20)
`8-b`	date of manufacture (usually all 0s, doesn't really matter)
`c`	second byte of hostid
`d`	third byte of hostid
`e`	fourth byte of hostid
`f`	IDPROM checksum - bitwise xor of bytes 0-e

2. To modify

a. First set the XOR checksum to an invalid value
ok 57 f mkp (write value 57 into byte location f of the idprom)

b. Example to set the MAC address/hostid
ok 8 0 20 a1 58 57 c3cd91 mkpl <Control-D> <Control-R>
where host ID is the last 3 bytes c3cd91

Solaris

1. To view

# prtconf -vp | grep idprom

idprom: 01800800.20a15857.00000000.a15857a9.00000000.00000000.00000000.0000 0000

2. To modify

not possible ?

References

[1] http://www.euroboxtec.co.uk/docs/sun_hostid.pdf

[2] http://www.squirrel.com/squirrel/sun-nvram-hostid.faq.html