[coreboot] v3 patch rm elfboot

Myles Watson mylesgw at gmail.com
Fri Feb 15 20:56:07 CET 2008

Sorry I've been out of the loop.  Here are Stefan's emails and my responses.

As I stated in one of my previous emails, I think that this confusion
of having two places where we parse ELF is enough reason to get rid of
elfboot in v3.

On Fri, Feb 15, 2008 at 12:50 PM, Myles Watson <mylesgw at gmail.com> wrote:
> ron minnich wrote:
>  > per stefan's comment, let's see how much space we save. This is
>  > bootblock space, which could be significant, but can we see a number?
>  >
>  Elfboot still uses bootblock space if it is disabled in Kconfig? That's
>  definitely something we need to fix. That space is tight.

PAYLOAD_NONE doesn't mean no elfboot.  Elfboot is included always so
that if someone adds an ELF to the lar later it will still work.  My
contention is that we should make people preparse the ELF when adding
it to the lar, so that v3 doesn't have to understand ELF.  That
doesn't mean that lar shouldn't.  Just the opposite.

>  ... as long as they do not remove functionality that is still used.
>  Please don't just remove this code. If you don't like to compile it in,
>  create a config option to disable it. (There is such a config option
>  already, so I really don't see the gain)

I didn't see one.

>  I say: NACK.
>  Why?
>  Because with this patch it is no longer possible to unpack a lar.

v3 doesn't unpack a lar.  lar unpacks them.

>  Please don't do stuff like that with levity.
>  Stefan
>  ron minnich wrote:
>  > Stefan, one thing I don't understand, why does removing elfboot make
>  > it so we can't unpack LAR?
>  >
>  >
>  Because the LAR header information is lost, things like the entry point.
>  You unpack it, repack it, and the segments become ordinary files with
>  their lar headers containing bogus information.
>  So either we recreate an ELF file on unpack, or we dump the metadata to
>  a MANIFEST file.
>  Or we forget about lars having the feature to be unpacked. Not sure that
>  its ever needed, except when you want to migrate a payload from one
>  image to another one.

This is a lar problem, not a v3 problem.

>  Stefan.

I hope this clears up some of the confusion.  I'm looking forward to
understanding your concerns better.  I thought this would be an easy


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