* Starting a kernel out of a running kernel...
@ 2007-01-15 23:53 Volker Jung
2007-01-16 8:11 ` Jan C. Kleinsorge
2007-01-16 14:18 ` Brian Sammon
0 siblings, 2 replies; 3+ messages in thread
From: Volker Jung @ 2007-01-15 23:53 UTC (permalink / raw)
To: grub-devel
Hello,
is there a solution for starting a new Linux kernel out of a running Linux
kernel using GRUB or a changed GRUB? First I thought I could use LILO. But LILO
runs in real mode, not having any idea about protected mode. GRUB runs in
protected mode itself - in order to boot an OS it has to switch back to real
mode or to prepare the protected mode control registers of the CPU to start the
OS. So GRUB may be able to pass control from one kernel to the other.
The idea: Instead of using GRUBs abilities to do various things inside a shell
one could use it to boot a complete Linux. Then one can do everything one wants
and afterwards one could start the desired system WITHOUT rebooting.
Perhaps this sounds crazy but there is a problem where this idea would be
helpful: So you could implement a read only failsafe system that starts again
whenever you reset your remote server and out of this system (remotely
controlled via SSH or similar) you could start the desired system WITHOUT having
to reboot which would again start the failsafe system which isn't the thing one
wants. You can call this "GRUB with a fully featured OS"...
In LILO this behaviour could be implemented using the -R option - but this
assumes a read write medium...
Any suggestions?
Thanks in advance
Volker
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: Starting a kernel out of a running kernel...
2007-01-15 23:53 Starting a kernel out of a running kernel Volker Jung
@ 2007-01-16 8:11 ` Jan C. Kleinsorge
2007-01-16 14:18 ` Brian Sammon
1 sibling, 0 replies; 3+ messages in thread
From: Jan C. Kleinsorge @ 2007-01-16 8:11 UTC (permalink / raw)
To: The development of GRUB 2
Volker Jung wrote:
> Hello,
>
> is there a solution for starting a new Linux kernel out of a running
> Linux kernel using GRUB or a changed GRUB? First I thought I could use
> LILO. But LILO runs in real mode, not having any idea about protected
> mode. GRUB runs in protected mode itself - in order to boot an OS it
> has to switch back to real mode or to prepare the protected mode
> control registers of the CPU to start the OS. So GRUB may be able to
> pass control from one kernel to the other.
>
> The idea: Instead of using GRUBs abilities to do various things inside
> a shell one could use it to boot a complete Linux. Then one can do
> everything one wants and afterwards one could start the desired system
> WITHOUT rebooting.
>
> Perhaps this sounds crazy but there is a problem where this idea would
> be helpful: So you could implement a read only failsafe system that
> starts again whenever you reset your remote server and out of this
> system (remotely controlled via SSH or similar) you could start the
> desired system WITHOUT having to reboot which would again start the
> failsafe system which isn't the thing one wants. You can call this
> "GRUB with a fully featured OS"...
>
> In LILO this behaviour could be implemented using the -R option - but
> this assumes a read write medium...
>
> Any suggestions?
That is not possible. 'Protected Mode' clearly denotes some form of
protection. Unless you grant the software extra privileges (that is,
write kernel-code)
it's virtually impossible. Apropos 'virtually': Use some virtualization
technology instead and you never will have to reboot any machine again,
ever.
>
> Thanks in advance
> Volker
>
>
> _______________________________________________
> Grub-devel mailing list
> Grub-devel@gnu.org
> http://lists.gnu.org/mailman/listinfo/grub-devel
>
-jan
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: Starting a kernel out of a running kernel...
2007-01-15 23:53 Starting a kernel out of a running kernel Volker Jung
2007-01-16 8:11 ` Jan C. Kleinsorge
@ 2007-01-16 14:18 ` Brian Sammon
1 sibling, 0 replies; 3+ messages in thread
From: Brian Sammon @ 2007-01-16 14:18 UTC (permalink / raw)
To: The development of GRUB 2
> is there a solution for starting a new Linux kernel out of a running Linux
> kernel using GRUB or a changed GRUB? First I thought I could use LILO. But LILO
It's not based on grub, but "kexec"/"kboot" does that sort of thing:
http://www.xmission.com/~ebiederm/files/kexec/README
http://lists.osdl.org/mailman/listinfo/fastboot/
http://kboot.sourceforge.net/
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2007-01-16 14:18 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2007-01-15 23:53 Starting a kernel out of a running kernel Volker Jung
2007-01-16 8:11 ` Jan C. Kleinsorge
2007-01-16 14:18 ` Brian Sammon
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.