[U-Boot] change root password

[U-Boot] change root password

[Nuno Cardoso]

hi,

How can I change root password??

I try this:

1) stop u-boot and add "init=/bin/sh" to the bootargs variable;
2) boot
3) passwd -d root (inside shell)


but this doesn't work!!!! When I reboot the machine, I cannot login with a
new password.

Thanks,
Nuno Cardoso.

[U-Boot] change root password

[Albert ARIBAUD]

Le 04/05/2010 12:48, Nuno Cardoso a ?crit :
> hi,
>
> How can I change root password??
>
> I try this:
>
> 1) stop u-boot and add "init=/bin/sh" to the bootargs variable;
> 2) boot
> 3) passwd -d root (inside shell)
>
>
> but this doesn't work!!!! When I reboot the machine, I cannot login with a
> new password.
>
> Thanks,
> Nuno Cardoso.

This is not a U-boot issue; this is an issue with the operating system 
(at large) to which U-boot transfers control. If you are the designer of 
the OS, then you're basically the boss and you should check why your 
permanent storage does not keep the new password; if you use a 
predesigned OS, turn to the designers for assistance.

Amicalement,
-- 
Albert.

[U-Boot] change root password

[Detlev Zundel]

Hi Nuno,

> How can I change root password??
>
> I try this:
>
> 1) stop u-boot and add "init=/bin/sh" to the bootargs variable;
> 2) boot
> 3) passwd -d root (inside shell)
>
>
> but this doesn't work!!!! When I reboot the machine, I cannot login with a
> new password.

There really is no need to shout.

What do you mean with "new password"?  The -d has deleted the password,
so you should use no password at all.  On the other hand, the "root"
user not having any password may be forbidden by the rest of the
filesystem, so I would rather try to use "passwd root" and set a known
password and try again.

Cheers
  Detlev

-- 
The success of PCs is in large part due to the fact that, by making all
hardware equivalent, good software enabled bad hardware. (Ugly)
                                    -- Rob Pike
--
DENX Software Engineering GmbH,      MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich,  Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-40 Fax: (+49)-8142-66989-80 Email: dzu at denx.de

[U-Boot] change root password

[Nuno Cardoso]

When I change the root password I'm using the command that you specify
"passwd root" and enter a new password. After that, I execute the "exec
init" command in U-Boot shell to boot all the linux system. At login, I put
the new password, but I cannot log!!!!!

After a restart, I stop the u-boot process to start shell (init=/bin/sh) and
cat the /etc/shadow file, and the root password doesn't change (is the old).
What I'm doing wrong?

Thanks,
Nuno Cardoso.

2010/5/4 Detlev Zundel <dzu@denx.de>

> Hi Nuno,
>
> > How can I change root password??
> >
> > I try this:
> >
> > 1) stop u-boot and add "init=/bin/sh" to the bootargs variable;
> > 2) boot
> > 3) passwd -d root (inside shell)
> >
> >
> > but this doesn't work!!!! When I reboot the machine, I cannot login with
> a
> > new password.
>
> There really is no need to shout.
>
> What do you mean with "new password"?  The -d has deleted the password,
> so you should use no password at all.  On the other hand, the "root"
> user not having any password may be forbidden by the rest of the
> filesystem, so I would rather try to use "passwd root" and set a known
> password and try again.
>
> Cheers
>  Detlev
>
> --
> The success of PCs is in large part due to the fact that, by making all
> hardware equivalent, good software enabled bad hardware. (Ugly)
>                                    -- Rob Pike
> --
> DENX Software Engineering GmbH,      MD: Wolfgang Denk & Detlev Zundel
> HRB 165235 Munich,  Office: Kirchenstr.5, D-82194 Groebenzell, Germany
> Phone: (+49)-8142-66989-40 Fax: (+49)-8142-66989-80 Email: dzu at denx.de
>

[U-Boot] change root password

[Wolfgang Denk]

Dear Nuno Cardoso,

In message <x2j3cf2debb1005060055w943eecd4t9a87659b0badf2e@mail.gmail.com> you wrote:
>
> When I change the root password I'm using the command that you specify
> "passwd root" and enter a new password. After that, I execute the "exec
> init" command in U-Boot shell to boot all the linux system. At login, I put
> the new password, but I cannot log!!!!!
> 
> After a restart, I stop the u-boot process to start shell (init=/bin/sh) and
> cat the /etc/shadow file, and the root password doesn't change (is the old).
> What I'm doing wrong?

Probably you are missing a step to write the changes to the password
data back to some persistent storage; when re-booting, you are
re-loading the old, unmodified data.

We don't know your system and it's file system layout. We don't know
if it provides any form of persistent, changable storage for these
data, and where.

When booting with init=/bin/sh the whole system is at your hands -
explore it and find out.

Eventually the data is in a read-only file system and cannot be
changed at all - then you can try to upload the file system image,
undpack it, modify it, repack it and install it on your target. Of
course there is a chance that you brick the system that way, so you
better know exactly what you are doing.

We do not know your systeme. We CANNOT help you.
And all this is off topic here.

Best regards,

Wolfgang Denk

-- 
DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
"There was no difference between  the  behavior  of  a  god  and  the
operations of pure chance..."   - Thomas Pynchon, _Gravity's Rainbow_