Re: boot failed with gzip'ed modules

On Saturday 26 April 2008 14:22:47 you wrote:
> On Friday 25 April 2008 05:20:34 pm David Naylor wrote:
> > Hi,
> >
> > I have a live CD that has a GENERIC kernel and that loads some modules
> > before booting.  They have been gzip'ed to save space however suddenly
> > the booting has stopped.   The kernel loads and then after the first line
> > of the modules to load it stops:
>
> I've seen reports of problems with gzip'd modules on 7.0.  You'll probably
> have to add debugging or look at the diffs between 6.3 and 7.0 of the boot
> code (sys/boot and lib/libstand) to narrow down things to try.  (For
> example, did moving malloc up above 1MB break it somehow.)
I think the break happened to HEAD in the last month, I can easily track down 
the problem... Except I do not know any cvs commands (I just use csup, which 
I don't think is powerful enough in this case), also is there an easy way to 
check the commit history (www.freshbsd.org doesn't allow the commit messages 
to be filtered on a subset of the files...)

Is it only sys/boot and lib/libstand that are involved with loader?  If so, 
unless revision 1.13 to lib/libstand/ntp.c broke it, it is probably that 
sys/boot is the cause.  However sys/boot is rather involved and will take me 
a bit longer to check the commits using cvsweb...

This is not possibly caused by having an amd64 system?  Other then csup from 
about a month ago the only other change I did was switch from i386 to amd64.  
Since the boot loader is i386 in any case I do not think it will have an 
impact.  

>
> > Oh, on an aside.  What is the BTX and why is the bootloader i386 even for
> > an amd64 system (I suspect it is because there is no need for an amd64
> > bootloader [unless kernels and modules suddenly exceed 4GB 8-/ ])?
>
> 1) BTX is a mini-kernel that the boot code uses.  This lets us write the
> boot loader as a 32-bit app in C rather than assembly.
Nice  :-)

> 2) Yes, the amd64 code uses the i386 bootstrap.  amd64 CPUs start up in
> real mode just like i386 and you can't easily call the BIOS from long mode
> anyway, so a different bootstrap for amd64 would be rather gratuitous.
Thought so...

Is there any plan to add bzip2 to loader (i.e. bzip2 modules and kernel) or to 
geom_uzip?  If not is there a good reason why it is avoided or just a case of 
lacking developer interest (or time)?  

Thank you for the quick reply

David