[arch-general] Change kernel version or module dir at bootprompt?
gerhard.brauer at web.de
Sat Dec 1 08:07:14 EST 2007
* Xavier <shiningxc at gmail.com> schrieb am [01.12.07 11:11]:
Oh, i miss Jame's mail, so in answer you.
> On Sat, Dec 01, 2007 at 05:05:46PM +1100, James Rayner wrote:
> > the kernel version is also embedded into the individual modules, so you'd
> > have to modify the kernel and every module. You might be able to do some
> > ugly sed trickery, but I really discourage it -- you're asking for
> > trouble.. and it probably won't work.
Are you sure? Ay, yes is see: 2.6.23-ARCH SMP preempt mod_unload 686
Ok, this is a "neutral" entry, but changing KERN_VER is not possible, i
> > Why would you want to do something like this anyway?
As others say: for a quick backup before a kernel-update.
For myself i have a own "rescue" kernel on all important machines. But
the only way to have such is to build a whole kernel.
I thought about an less time expensive method.
First thougt myself was for ex. add a VAR to pacman.conf BackupKernel =
yes|no and then add something like pre-install/update to
> But it's still a problem. There was a request for a fallback kernel, but it
> was apparently rejected :
I must read this.
After James comment about the vermagic entries i mentioned about a
"hack" in initrd-hooks to bypass this problem.
Ex: we have /lib/modules/kernel26-ARCH which is real 126.96.36.199-1.
One woul like to test the new kernel from testing.
At the moment testing-kernel overwrites the stock arch kernel.
But if (maybe a script):
- Backup kernel and initrd-iamge
- copy /lib/modules/kernel26-ARCH to a backup in /lib/modules
- Have a bootloader entry for backup kernel with a parameter
Then a hook in initrd.img check useoldkernel and do:
- mv /lib/modules/kernel26-ARCH to something similar
- do a symlink or mv from backup module dir to
I don't know if this could be done in the initrd-image. But if, we have
AFAIK no problem with vermagic in the "new" module dir.
You see, i puzzle a little round that "problem" ;-)
Don't drink and root!
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