Re: [regression?] 2.6.26 floppy boot failure with kernel packed using 'upx'

["H. Peter Anvin" <hpa@zytor.com>]

Linus Torvalds wrote:
> 
> On Thu, 10 Jul 2008, Frans Pop wrote:
>> Important factor here is that we "pack" the kernel using upx [1] (in order
>> to fit everything on a floppy). The original (unpacked) kernel after this
>> commit boots fine, only a packed version fails.
>> We have tried upx versions 2.01, 3.01 and 3.03, all with same result.
> 
> Ok, I do not consider this to be a regression. 
> 
> Clearly UPX is expecting a very specific kernel format, and clearly UPX 
> just needs to be updated for the changes.
> 
> That said, if some UPX person can explain what it is that UPX needs, maybe 
> we can add some format markers into the kernel (and perhaps some extra 
> header info) so that future format changes are transparent or at least 
> break in obvious ways.
> 

The issue with UPX is that UPX actually wants to replace the kernel 
decompressor, which also does other tasks (relocation and ELF parsing) 
in recent kernels.

	-hpa