Re: [Qemu-devel] [PATCH] Add multi-boot kernel loading support

[Kevin Wolf <kwolf@suse.de>]

Rene Rebe schrieb:
>>> I think I noticed the same with the GRUB example kernel. I'll
>>> take a look at some later hour.
>>>
>>> Is your kernel something you can share for testing?
>>
>> Sure. I tried it with with several homebrew kernels from
>> http://lowlevel.brainsware.org/wiki/index.php/Kategorie:Betriebssystem
>> (page is in German) - to be precise it was tyndur, meinOS, Xantorix and
>> lightOS. Links to the sources and/or binaries for each one are in the
>> respective Wiki articles.
>>
>> I could also send you a tarball with all of them off-list if you like.
> 
> From reading the last mails I thought you would have your own kernel.

Well, I didn't say that I'm not involved in one of these. tyndur is the
one, even if the broken multiboot patch proved that there is room for
improvement in the error handling. (*cough* Triple fault... ;-))

> I now have the mmap, memory sizes (kB, not Bytes) fixed and some
> other comments from the list taken into account (ARRAY_SIZE, etc.).
> 
>  
> http://svn.exactcode.de/t2/trunk/package/emulators/kvm/09-qemu-multiboot.patch
> 
> 
> As I did not yet feel like extracting all the kernels and their modules
> from the cited disk / floppy images so it's not yet tested with those
> "homebrew" kernels.

Looks much better now. Not all systems complete the boot (I would
suspect the OSes to be buggy here though), but no horrible crashes any more.

Well, except that with the lightOS kernel I still managed to get a qemu
segfault in the fread in pc.c:939 when loading a module, and other
modules failed to load ("read error on multiboot module abc (0 != x)").
Interestingly the same modules are loaded without any problem if I use a
different kernel. I guess we'd better fix that before committing.

Kevin