Re: [PATCH] memdisk + grub-mkrescue

[Pavel Roskin]

Quoting Robert Millan <address@hidden>:

> On Tue, Jan 22, 2008 at 09:55:43AM -0500, Pavel Roskin wrote:
> > >On Mon, Jan 21, 2008 at 09:11:04PM -0500, Pavel Roskin wrote:
> > >>
> > >>I wish I could use it on PowerPC to work around the "claim failed"
> > >>problem, but I'll still need to link "memdisk" and "cpio" with
> > >>grub-mkimage.
> > >
> > >I don't understand.  How would this work around the problem?
> >
> > It would work around the problem if appending modules to kernel.elf
> > with grub-mkimage could be completely avoided.
>
> Ah, I see.  But as you point out, you still need memdisk and cpio.  Maybe we
> could put these two in kernel when we have "grub-mkimage -m" support for ELF,
> but it looks very ugly to me! :-)

I think I'll submit a patch that introduces the gap between the core  
end and the modules.  It's better that nothing.  There was a gap  
before, just much bigger.

> > >>I have a patch for PowerPC, but I think I'll hold it until your patch is
> > >>committed.  I could change my patch to be more in-sync with i386, in
> > >>particular use /boot/grub as the blessed directory.
> > >
> > >Cool!  Could you send it to the list?  I'd like to see if it'll work on
> > >i386-elf targets.
> >
> > OK, attached.  Sorry, this mailer would break the patch otherwise.
>
> Ah, I think I missunderstood.  I thought you implemented "grub-mkimage -m"
> switch.

Sorry, not yet.

> > +# Make GRUB rescue image
> > +# Copyright (C) 1999,2000,2001,2002,2003,2004,2005,2006,2007  Free  
> >  Software Foundation, Inc.
>
> Missing 2008 here.
>
> > +map_file=`mktemp`
> > +cat >${map_file} <<EOF
> > +# EXTN          XLate   CREATOR   TYPE     Comment
> > +grub.img        Raw     'UNIX'    'tbxi'   "bootstrap"
> > +EOF
>
> How standard is this format?  Is this targetted only at one OFW vendor?

The text format is probably specific to genisoimage.  But the  
attributes themselves are used by PowerPC based Apple machines.  Macs  
look for bootloader in the "blessed" directory.  The bootloader should  
have "tbxi" type.

I haven't tried to emulate CHRP and PREP yet.  I know that Fedora  
LiveCD generator uses additional tricks for both.  I think it's  
possible to support them.

> > +genisoimage -hfs -part -no-desktop -r -J -o ${output_image} \
> > + -map ${map_file} -hfs-bless ${boot_dir} ${iso_dir}
>
> Same here.

It's all hfs specific.

> Perhaps this should be mentioned in --help or something?

Maybe.

> In the future we could add --image-type= options for other platforms
> like i386-pc does with floppy/cdrom ?

My Mac has no floppy, but if qemu emulates it correctly, I could try it.

I understand that PREP need some "boot image" that needs to be put on  
the CD, so that's another possible image type.

--
Regards,
Pavel Roskin