[coreboot] SELF/ELF/LAR

[Myles Watson]

On Wed, Apr 16, 2008 at 4:41 AM, Corey Osgood <corey.osgood at gmail.com> wrote:
> On Tue, Apr 15, 2008 at 12:14 PM, Myles Watson <mylesgw at gmail.com> wrote:
>
> >
> >
> > >
> > > Code isn't interesting anyway; design / architecture is the problem
> > > here.
> > >
> >
> > Agreed.
> >
> >
> > > > We are all professionals - we can come to a consensus.  Right now,
> > > > we're trying to figure out if we can make ELF perform the way we need
> > > > it to perform.  If we can be satisfied that it can, then we move on.
> > > > If we cannot be satisfied, then the core team will have to make a
> > > > decision to move on to another alternative, and then we can debate the
> > > > details of SELF or something similar.
> > >
> > > I agree.
> > >
> > > So, what exactly *do* we need here, and *why*?
> > >
> >
> > I think a discussion of where we are and where we want to go would be
> > helpful.  Feel free to correct my status summary.
> >
> > Right now:
> > 1. LAR format supports inclusion of:
> >        a. bootblock
> >                1. Can be copied out, but only re-used in same size ROM
> file
> >        b. ELF segments (multiple segments with one entry point, from an
> > ELF)
> >                1. Can't be extracted without losing entry point
>
> This is something I don't understand, and probably would need a deeper
> understanding of elf to understand, but maybe someone can explain it in a
> nutshell. LAR parses the elf, extracts and manipulates the segments, and in
> the process moves the entry point, right? But LAR has to have some sort of
> entry point. So why can't we re-extract those segments, in LAR's new order,
> and generate an elf header with LAR's entry point? So the elf file isn't a
> binary equal to the original, but it runs just like it?
>
> The other option, in my simple mind, would be to have LAR work like a
> one-way archiver. If you want the LARchive's payload, LAR doesn't actually
> extract the payload, it hands you a LARchive of just the payload, which can
> then be added to another LARchive. Could that work?
>

This is only part of the problem.  It would be easy to do, but there's
not consensus about what format to use for the extracted file.

Myles