Re: Easy trick to reduce kernel footprint

[Christian Leber <christian@leber.de>]

On Mon, Jun 06, 2005 at 12:35:28AM +0200, Willy Tarreau wrote:

> saves 23 kB (2%) on the overall image without touching any code. The LZMA
> implementation could save 145 kB (12%), but would require a different
> extraction code (I've already seen patches to bring LZMA support on 2.4).

The patch for 2.4 is here:
http://www.zelow.no/floppyfw/download/Development/Patches/kernel/040-lzma-vmlinuz.diff
and it actually works.

My not working patch is here:
http://debian.christian-leber.de/kernel_lzma/lzma_image.patch
you have to apply the patch from the other mail before.
(or here: http://debian.christian-leber.de/kernel_lzma/lzma_ramdisk.patch)

If you just want to see how it doesn't work, here is a kernel image to
see it failing in qemu, basically it just decompresses again and again.
http://debian.christian-leber.de/kernel_lzma/bzImage

The decompression works correctly(checksum), i think the problem is the address
where the decompressed kernel image should be, i just can't get out how
this piece of code is supposed to work.

Therefore it could be a small problem only.


Another minor problem of lzma is that you need slightly more memory than
with gzip. (at least when you can't have the output in a continuous
piece of memory)
On the plus side is also that the lzma decompression code itself is
smaller and doesn't have such a ugly "interface".


Christian Leber

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