Re: embedding filesystems in core image (Re: moving ata initialisation to a command)

[Bean]

On Dec 22, 2007 4:54 AM, Robert Millan <address@hidden> wrote:
> On Fri, Dec 21, 2007 at 07:04:05PM +0100, Robert Millan wrote:
> > > >
> > > > I'd prefer to support embedding filesystems in core.img instead.  This
> > > > solves the problem for every situation instead of just PC boot media
> > > > (e.g. LinuxBIOS ELF payload image).
> > >
> > > Agreed, I would like to see such feature.  Also for stuff like
> > > diskless boot.
> > >
> > > What I had in mind was the following.  We could perhaps make it
> > > possible to add all files using grub-mkimage, not only modules.  When
> > > you add modules, those will be loaded automatically.  All other files
> > > will be ignored.
> > >
> > > Another filesystem module has to be written.  It scans over these
> > > files and will make them available.  This can be simple and elegant.
> > > I do not like the idea of adding a diskimage or so.  Are you
> > > interested in working on this?
> >
> > Well, I already have an almost-working implementation.  I guess I'll have to
> > defend it then! :-P
> >
> > Really, it's clean and elegant.  Very simple and flexible.  Once I get the
> > address detection right, that is..
>
> Please have a look at the attached patch.  This allows adding an arbitrary
> number of files.  No extra filesystem module is needed, since any of the
> supported filesystems can be used with this feature:
>
>   genisoimage -o filesystem_image -r stuff
>   grub-mkimage -o core.img -m filesystem_image
>

Yes, i think this concept is great, and i just think of an improvement
for the module. we can add support for a raw file system which store
files compactly,  so that very little space is wasted on file system
structure, for example, this is a possible implementation:

OFFSET_TO_NEXT_ITEM
FILE1_NAME_LEN
FILE1_NAME
FILE1_DATA
OFFSET_TO_NEXT_ITEM
FILE2_NAME_LEN
FILE2_NAME
FILE2_DATA

This is useful in situation where the size of core.img is limited, like bootrom.

-- 
Bean