Subject: Re: Boot ROM hacking
To: Simon Burge <simonb@NetBSD.ORG>
From: Andrew Gillham <gillhaa@ghost.whirlpool.com>
List: port-i386
Date: 12/22/1999 11:49:19
Simon Burge writes:
>
> Look at minilzo (http://wildsau.idv.uni-linz.ac.at/mfx/lzo.html). On
> an i386:
>
> wincen:~/zz/minilzo.106 49> size minilzo.o testmini
> text data bss dec hex filename
> 4161 8 12 4181 1055 minilzo.o
> 7323 264 197684 205271 321d7 testmini
>
>
> That 4.1k is both the compressor and decompressor! "testmini" is
Awesome! I'll check this out. Perhaps it might be possible to build
a shim package that takes an existing netboot.rom and creates the minilzo
version. :-) I suppose the relocating would need to be fixed up though,
because if the minilzo relocated/decompressed into 9000:0, it wouldn't
work to have start_rom.S relocate again. (unless it checks for it's proper
location? I'll have to look)
> a harness for testing. Modified to read in the first 32k of my
> netboot.com (the balance of the 64k is zeros) I get:
>
> wincen:~/zz/minilzo.106 47> ./testmini
>
> LZO real-time data compression library (v1.06, Nov 29 1999).
> Copyright (C) 1996, 1997, 1998 Markus Franz Xaver Johannes Oberhumer
>
> compressed 65536 bytes into 20896 bytes
> decompressed 20896 bytes back into 65536 bytes
>
> So perhaps this could be worth looking into further...
Definitely!
Thanks for the pointer.
-Andrew
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