autodetect kernel argument "reboot=warm"

[Piero Ottuzzi]

Hi there,

I have a dual boot (WinXP-Kubuntu Edgy) HP nc8430 laptop: if I reboot from WinXP the BIOS startup screen is disappearing faster than after a reboot from Kubuntu.

As a net result you can see that a reboot from WinXP is faster than a reboot from KubuntuLinux.
I read somewhere (don't remember where) you can tell the BIOS this is a warm reboot and that everything was already checked and working fine: maybe this is the difference between the two OSes.

Bye
Piero

[Freddy Martinez (freddymartinez9)]

I'm not sure what you mean by "the BIOS startup screen is disappearing faster than after a reboot from Kubuntu."

Let me know so I can help you further.

[Andrew Ash (ash211)]

I think Piero means the time during which the BIOS runs the POST check, or whatever that's called. I've never heard of such a "warm reboot" but I have noticed a difference between the two OSes on my Dell 8400 and Inspiron B130.

What we really need is more information about whatever feature of the BIOS this is.

I'm guessing it's a kernel issue, seeing as that's where hardware detection and usability tends to be.

[Piero Ottuzzi (ottuzzi)]

Hi there,

sorry if I was not very clear: Andrew stated it clearly... I was meaning exactly what he explained clearer.

As per [1]: "A soft reboot (also known as a warm reboot) is restarting a computer under software control, without removing power or (directly) triggering a reset line."

Bye
Piero

[1]:http://en.wikipedia.org/wiki/Booting

[Piero Ottuzzi (ottuzzi)]

After googleing around I found [1]:

"The `reboot=' Argument

This option controls the type of reboot that Linux will do when it resets the computer (typically via /sbin/init handling a Control-Alt-Delete). The default as of v2.0 kernels is to do a `cold' reboot (i.e. full reset, BIOS does memory check, etc.) instead of a `warm' reboot (i.e. no full reset, no memory check). It was changed to be cold by default since that tends to work on cheap/broken hardware that fails to reboot when a warm reboot is requested. To get the old behaviour (i.e. warm reboots) use reboot=w or in fact any word that starts with w will work.

Other accepted options are `c', `b', `h', and `s', for cold, bios, hard, and SMP respectively. The `s' takes an optional digit to specify which CPU should handle the reboot. Options can be combined where it makes sense, i.e. reboot=b,s2"

Bye
Piero
[1]: http://tldp.org/HOWTO/BootPrompt-HOWTO-3.html

[Andrew Ash (ash211)]

Thanks for that info Piero. I'm going to test that on my machine and see how much of a difference it makes.

It would be great if the options in /boot/grub/menu.lst could be detected to include this option. Since that page says older hardware can't handle warm reboots, it defaults to cold ones. That may make this a wish against grub then, to have whatever writes /boot/grub/menu.lst somehow detect if the hardware can handle a warm reboot.

Either way, I'm marking this a confirmed wishlist.

[Andrew Ash (ash211)]

Yes, it does make reboots faster. I'm changing the name of this bug to attract more attention.

[Brian Murray (brian-murray)]

I am assigning this bug to the 'ubuntu-kernel-team' per their bug policy. For future reference you can learn more about their bug policy at https://wiki.ubuntu.com/KernelTeamBugPolicies .

[Sergio Zanchetta (primes2h)]

The 18 month support period for Edgy Eft 6.10 has reached it's end of life. As a result, we are closing the linux-source-2.6.17 Edgy Eft kernel task.

[Sergio Zanchetta (primes2h)]

Hardy Heron 8.04 was recently released. It would be helpful if you could test the new release and verify if this is still an issue - http://www.ubuntu.com/getubuntu/download . You should be able to test your bug using the LiveCD. Please let us know your results. Thanks.

[gkrnours (couesl)]

I've tested it with an Vaio VGN-CR31S, some reboot from my KDE4.1,
some other from my Windows Vista. From the both OSes, the BIOS startup
screen disappear after less than two second, probably one, if what I
see is a BIOS startup screen (But I don't see anything else, so...)

So, I suppose this bug has been correted with the 8.04 release, or
wasn't a problem with my computer.

[Jonathan Thomas (echidnaman)]

Glad to hear it. We can close this as fixed .
Thanks for your bug report and for your contribution to Ubuntu.

[Sergio Zanchetta (primes2h)]

According to previouses comments, I think this bug is not related to VAIO computer.
Better wait a response from whom reported first this bug.
in the meanwhile I put it as Invalid.

[gkrnours (couesl)]

I thonk too that this bug is not related to VAIO computer.
I could try to test on my father computer, or someone else in my
family, but I've no CD to burn the Hardy Heron live-cd.
I couldn't help more for a while.

2008/7/17, Sergio Zanchetta <email address hidden>:
> According to previouses comments, I think this bug is not related to VAIO
> computer.
> Better wait a response from whom reported first this bug.
> in the meanwhile I put it as Invalid.
>
> ** Changed in: linux (Ubuntu)
> Status: Fix Released => Invalid
>
> --
> autodetect kernel argument "reboot=warm"
> https://bugs.launchpad.net/bugs/78693
> You received this bug notification because you are a member of Kubuntu
> Testers, which is a direct subscriber.
>

[Piero Ottuzzi (ottuzzi)]

Hi there,

    the bug is not a bug... it was a feature request; it is not also related to VAIO.
Actually I cannot test it but the report from gkrnours[1] seems to confirm that the feature request was accepted and implemented.

Bye
Piero
[1]https://bugs.launchpad.net/ubuntu/+source/linux-source-2.6.17/+bug/78693/comments/10

[Launchpad Janitor (janitor)]

Per a decision made by the Ubuntu Kernel Team, bugs will longer be assigned to the ubuntu-kernel-team in Launchpad as part of the bug triage process. The ubuntu-kernel-team is being unassigned from this bug report. Refer to https://wiki.ubuntu.com/KernelTeamBugPolicies for more information. Thanks.