Re: Loadlin and Squeeze kernel 2.6.32
On Sat, Jul 14, 2012 at 4:14 PM, Camaleón <noelamac@gmail.com> wrote:
> On Sat, 14 Jul 2012 15:31:36 -0400, Tom H wrote:
>> On Sat, Jul 14, 2012 at 9:26 AM, Camaleón <noelamac@gmail.com> wrote:
>>>>> AFAIK this calls for block list based installation of GRUB 2 which is
>>>>> not recommended cause it introduces the same issues than map file in
>>>>> LILO.
>>> I don't know what you mean here. Installing GRUB in the first sector of
>>> a partition instead the MBR has been always possible (also documented)
>>> and nothing to be avoided "per se". Can you expand this?
>> When you install grub1/grub2 to a PBR, you cannot embed stage
>> 1.5/core.img in the gap between the first sector and the start of a
>> partition as you would do when you install grub1/grub2 to an MBR. The
>> stage 1/boot.img then has to use block lists to load stage 2/core.img.
> And what are the drawbacks for that?
>
> Reading from GRUB's legacy documentation¹, I see none listed. However,
> GRUB2 manual² does not even mention the possibility of installing GRUB2
> into the first boot sector of a partition, maybe something has changed
> between the two versions :-?
Nothing's changed except that you have to use the "--force" option to
install grub2 into a PBR. The drawback, according to grub, is that you
have to use block lists rather than use an intermediate step (grub1's
stage 1.5 or grub2's core.img) that understands filesystems.
>>>> Cameleon: You can choose to install grub2 to a PBR by refusing to
>>>> install it to the MBR. d-i'll prompt you to provide a device - and it
>>>> accepts a partition.
>>>
>>> Yes, I know.
>>>
>>> But AFAICT, installing nothing in the MBR (e.g., from a low level
>>> formatted hard disk) is not the same than having "generic boot code"
>>> here.
>>
>> I've never heard of "generic boot code". I don't see why SUSE uses it;
>> it must be unnecessary since none of the other distributions that I've
>> used use it.
>>
>> Are you sure about the "generic boot code"?
>
> Yes :-)
>
> I've been installing several (open)SUSEs since many years and this option
> has been always there. Let me search to grab some docs... okay, here it
> is³ the official paper. The option comes from the installer, when you
> first select to install GRUB you can then cherry pick some advanced
> options like the usuals (set bootable flag, etc...) and this one:
>
> ***
> Write Generic Boot Code to MBR
> Replaces the current MBR with generic, operating system independent code.
> ***
>
> Why this option? I can't tell and I don't know (because I have not directly
> tested) if there's any difference between choosing this and installing no
> bootloader at all. To be sincere, I don't know if by selecting no bootloader
> you can boot at all, I mean, directly from your hard disk with no other helpers
> :-?
>
> ¹http://www.gnu.org/software/grub/manual/legacy/grub.html#Installing-GRUB-natively
> ²http://www.gnu.org/software/grub/manual/grub.html#Installing-GRUB-using-grub_002dinstall
> ³http://doc.opensuse.org/documentation/html/openSUSE/opensuse-reference/cha.grub.html#sec.boot.yast2.config.advanced
Thanks for the info and the links. You've misunderstood me. I didn't
say that Linux could boot without a bootloader. I said that I didn't
understand the purpose of the "Generic Boot Code" since other
distributions don't use it when installing grub to a PBR.
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