Re: kexec: Clearing registers just before jumping into purgatory

Richard Weinberger
2013-10-11T16:42:58Z

On Fri, Oct 11, 2013 at 6:39 PM, Matthew Garrett <mjg59@srcf.ucam.org> wrote:
> On Fri, Oct 11, 2013 at 06:33:23PM +0200, Richard Weinberger wrote:
>> On Fri, Oct 11, 2013 at 5:48 PM, Matthew Garrett <mjg59@srcf.ucam.org> wrote:
>> > On Fri, Oct 11, 2013 at 11:44:50AM -0400, Vivek Goyal wrote:
>> >
>> >> Just Curious. How is it useful. IOW, what's your use case of booting a new
>> >> kernel and then jumping back.
>> >
>> > I'm kexecing into a kernel with a modified /dev/mem, modifying the
>> > original kernel and then jumping back into it.
>>
>> How do you update the original kernel?
>
> It's still in RAM, so the same way you'd modify any other arbitrary
> physical address?

So, you have a tool like ksplice which patches the kernel in RAM?

--
Thanks,
//richard