Re: [patch] set prefix on PPC

[Marco Gerards <metgerards@student.han.nl>]

Hollis Blanchard <hollis@penguinppc.org> writes:

> On Feb 15, 2005, at 3:31 PM, Marco Gerards wrote:
>> Ok.  But the file does not need to be blessed to boot from it.  It's
>> just used so the user can use:
>>
>> boot hd,0
>>
>> instead of:
>>
>> boot hd,0:grubof
>>
>> To me the second sounds good enough.  Or does that cause other
>> problems?
>
> Remember that resetting the PRAM (a rare but not unusual action on
> Macs) will revert to the stock firmware configuration, and if OS X is
> the only blessed OS, the user will find themselves unable to boot into
> Linux without a decent understanding of Open Firmware. Blessing GRUB
> would eliminate this problem*.

This is a good explanation of the problem.  When we have
documentation we should have a text like this in it. :)

> * If OS X is on a lower partition number, the user will still boot
> into OS X after a PRAM reset. However, if the firmware recognizes GRUB
> as a valid kernel, there is a graphical "select boot device" interface
> on newer machines that can be triggered by holding down the Option key
> at startup.

Ok.

>>> Ok. I assume you want to test my patch and review it further, so I
>>> will wait for more comments before committing it.
>>
>> Sure, I will test and review it on both of my PPC systems and review
>> the patch.  I hope you understand that it can take a while. :/
>
> I hope I can talk you into taking a look soon, as this functionality
> is essential if we want to actually *use* GRUB2.

Ok.

> It should be pretty easy to build and see what happens... :) (See my
> patch from earlier today since current CVS doesn't build.)

That's something I could do. :)

>>>> I don't want to add a fancy parser yet.  At the moment we just use a
>>>> single argument.  If more will be used, this code has to be changed.
>>>
>>> And in that case, the format of "bootargs" will have to change
>>> too. It's never too early to think about backwards compatibility,
>>> especially if people are thinking of packaging and distributing a
>>> grub2.deb... :)
>>
>> Huh?  Why would backward compatibility be broken?
>
> If a user installs GRUB now with this bootargs patch, then later if we
> wish to add a debug option with "fancy parser" they will no longer be
> able to boot, as the syntax will change.
>
> Now: "boot grubof hd0,6"
> Later: "boot grubof prefix=hd0,6 debug=all"

I do not like the prefix= syntax.  What I want is:

Now: "boot grubof (hd0,6)"
Later: "boot grubof (hd0,6) --debug=all"

> Users trying to boot with the old syntax will fail.

In my case it will still work. :)

Thanks,
Marco