Re: U5 firmware password?

[Jochen Kunz <jkunz%unixag-kl.fh-kl.de@localhost>]

On Wed, 12 Aug 2009 01:12:55 -0400 (EDT)
der Mouse <mouse%Rodents-Montreal.ORG@localhost> wrote:

> You can netboot FORTH and FCode?
Yes.

>  How?
Just like any other executable.

> That is, what would I need to set up? Presumably reverse ARP as always;
Yes, or DHCP. (You can do "boot net:dhcp".)

> do I just drop FORTH code, or an FCode blob, in the TFTP area where
> I would normally boot the booter
Yes. I have done this with PPC machines to hack the PROM password. The
FORTH scripts needs to start with (printf(3)) "\\ \n". Example from one
of my scripts:
$ hexdump -C of-tree.forth | head -2 
00000000  5c 20 0a 70 72 69 6e 74  65 6e 76 0a 64 65 76 20  |\ .printenv.dev |
00000010  2f 0a 6c 73 0a 2e 70 72  6f 70 65 72 74 69 65 73  |/.ls..properties|

An other way is to remove the NVRAM chip and plug it into a SS20 or
Ultra1. It needs to be a machine that is different from the PCI-Ultra
era, but uses the same chip type. If you power on that other machine
with the U5 NVRAM in it it will complain about an invalid checksum and
drop to the OPB. There you can do "set-defaults". Then move the chip
back to the U5. It will again complain about an invalid checksun,
"set-defaults" and you are done. The MAC address and host-ID are save
and will not be affected. I did this several times.
-- 


tschüß,
       Jochen

Homepage: http://www.unixag-kl.fh-kl.de/~jkunz/