[coreboot] LZMA support in SeaBIOS

Kevin O'Connor kevin at koconnor.net
Wed Apr 29 04:24:39 CEST 2009

Hi Patrick,

On Tue, Apr 28, 2009 at 01:25:42PM +0200, Patrick Georgi wrote:
> Quite simple: There will be a generic header for everything that
> doesn't require special handling. And that header comes with a
> compression field, too.

I look at CBFS as a tool for storing named files in flash.  I don't
see a requirement to handle any files special, and as such I see the
concept of special vs normal files as unnecessary complexity.  It
looks like we view things differently.

> As for special handling:
> Payloads are stored in SELF format, and thus "special"
> Stages are internal to coreboot. Whatever helps coreboot is fine here.
> Option ROMs contain the vid/did as fields for faster retrieval.

I view all of the above as files to be stored in flash.  Clearly, SELF
is a better storage format than elf for coreboot purposes.  However, I
view a SELF file as just another file to be stored in CBFS.  Same
thing for Stages and Option ROMs.

> Once we go the "use filenames to select" route, we're awfully close
> to the PRECOMPRESSED_PAYLOAD mess in coreboot-v2 configuration. I'd
> like to avoid that by keeping all matter related to compression
> within cbfs.

I can see an advantage of moving compression into CBFS.  The cost is
having CBFS know when to compress/not compress a given file.  I guess
I'm not sold on that cost.


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