Re: booting grub, loading kernels and unloading kernels question

[Marco Gerards]

"Lubomir Kundrak" <address@hidden> writes:

>> "adrian15" <address@hidden> writes:
>>
>>> Can we boot grub
>>> and boot linux
>>> so that
>>> linux don't write on grub reserved memory (let's say first 640k)
>>> And then make an special halt command
>>> that halts linux and boots again grub? (without rebooting)
>
> When we discussed thhis on IRC i expressed an idea of having grub in linux
> kernel format. Then we could use kexec facility to return to grub. But it
> would also need patching linux so that it doesnt't clobber BIOS memory.
> NetBSD takes care not to do so afaik, so if kloader worked on i386 thhis
> could be another option.

I personally don't think it is feasible and worth the effort.

>>
>> GRUB depends on the BIOS to function.  I think linux changes the
>> hardware state too much.  So even if you can return to GRUB, I don't
>> think the hardware state is reliable enough for GRUB or the BIOS to
>> function reliably and properly, if it is possible at all.
>
> Hardware state? What hardware is in question, except disks?

It can be all hardware.  Like how IRQs are routed, which set of
keyboard scancodes are used, video state, etc.

--
Marco