Firmware password ?
The one that is set into the OBP of your computer's systemboard ?
Nope. You'll need to buy a replacement IDPROM.
There's no quick-trick workaround, such as for a PeeCee.
See Chapter #3 in the OBP 4.x Command Reference Manual.
http://docs.sun.com/app/docs/doc/816-1177-10?q=816-1177
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Solaris Operating Environment password for the root user's account ?
Dig out your Solaris installation CD's and then search the forum and search Google.
Keywords will be "solaris root password.".
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Edit:
Though this topic applies to all of Sun's SPARC systems,
Your Sunblade 100 is not a SERVER.
The question would have been better placed in the other forum.
The SB100 a low-end desktop workstation that just runs and runs and runs ...
... served me very well in a past incarnation as a Sun support Engineer.
When I boot up i see:
Type boot, go (continue), or login (command mode)
And whatever I type I see
Firmware password:
I tried to fix it by mounting the disks on Linux machine and was able to crack one of the passwords of users of sysadmin group... but unfortunately now I see:
Boot magic number in disk label
Can't open thee disk label package
Boot device:disk File and args
Bad magic number in disk label
Can't open disk label package
Can't open boor device
I think I messed the instaled system... argh.... any hints?
Could I use disk from another Sun machine (Blade 1400) and boot from another disk and that reset this firmware password?
No.
Your password on the Sunblade 100 has been written to the IDPROM on its systemboard.
It is in FIRMware, not in software.
It has not been written to any place on the disk drives.
Call Sun. Open a support case.
Expect to have to pay for a replacement IDPROM.
This isn't a condition that a warranty or a service contract would cover.
There's no malfunction of hardware or software.
The component design is acting exactly as it is supposed to behave.
(Go read that chapter in the OBP manual link in my first response.)
Then go create a company policy for this circumstance, for the future.