[LinuxBIOS] [PATCH] v3: support LARchives with header-after-data

Stefan Reinauer stepan at coresystems.de
Fri Oct 12 11:55:26 CEST 2007

* Carl-Daniel Hailfinger <c-d.hailfinger.devel.2006 at gmx.net> [071012 00:38]:
> AFAIK not all architectures start executing code at the top of ROM, some
> start at the bottom (low address). 

Are you working on porting LinuxBIOS to such an architecture currently?

> In that case, we can't start the
> archive with a LAR header, but we can end it with one or postfix the
> first archive member with a LAR header.

I think this idea is massively over-engineered and makes things too

Just add a jump into the "bootblock" member of the lar the first thing
before the archive on those architectures that start their execution at
the beginning of flash rather than anywhere in the middle.

This would be a perfectly valid lar, as lar copes with non-lar-data
between the members. It was designed to do that. Lar could even produce
that jump once it supports non-x86 architectures. (Obviously lar's
bootblock handling can never be 100% generic)

Also, the bootblock knows where the lar sits, per design. So it will
never have to scan in any direction, risking to loop indefinitely.

Let's keep things simple so that every idiot can understand it, even 6
months later.


coresystems GmbH • Brahmsstr. 16 • D-79104 Freiburg i. Br.
      Tel.: +49 761 7668825 • Fax: +49 761 7664613
Email: info at coresystems.dehttp://www.coresystems.de/

More information about the coreboot mailing list