Subject: Resolving bootfloopy-big size limit
To: None <port-i386@netbsd.org>
From: Julio M. Merino Vidal <jmmv84@gmail.com>
List: port-i386
Date: 11/11/2006 16:16:56
Hello,

[ Please CC me any replies. ]

The bootfloppy-big installation disk image is every now and then
giving problems due to its size limit.  This is set to 2.88MB to allow
its use in El-Torito floppy disk emulation bootable ISO images.

The limit prevents the addition of new features (such as full LFS
support).  But it also causes build failures from time to time due to
the addition of non-optional features that keep enlarging e.g. the
kernel.

We now have the ability to build bootable ISO images that use
El-Torito hard disk emulation, hence not having any size constraints.
The problem is that we cannot take advantage of them due to the limit
in bootfloppy-big.  I see several solution:

1) Remove the bootfloppy-big image altogether.  This won't happen
   because people still wants it (think netbooting).

2) Remove the size constraints in bootfloppy-big.  This prevents using
   the image with El-Torito but still allows its use in other situations
   (as mentioned in the previous point).  Then, this image could be
   usable for the "new" ISO images.  Seems to be the cleanest
   approach.

3) Add a new ramdisk (say ramdisk-full) that does not have any
   corresponding floppy disk image.  This could be used exclusively for
   the new bootable CDs.  This may seem the best approach because
   it is the most conservative, but this is also its biggest problem.  It
   will only delay a real solution because, eventually, it will overflow
   again (as we have been seeing for a long time).  But it may be the
   safest to use now that 4.0 is around the corner.

I'd rather go with 2 provided that we ship the bootable CDs as built
by "distrib/i386/cdroms/installcd".  Note that the resulting ISO also
includes tiny CD images that can be used to burn custom CDs (e.g. for
serial console installation).  The only problem with these is that
they cannot be extended to include also the installation sets... can
they?

Comments?

Note that if we want to enable LFS usage for root file systems in 4.0
(something that'd be a good selling point) we must fix this issue.
Full LFS support overflows the disk images by a good amount (100kb
IIRC) and is not easily fixable otherwise.

Also note that wherever I said bootfloppy-big I meant bootfloppy-big
and bootfloppy-laptop-big.

Thanks.

-- 
Julio M. Merino Vidal <jmmv84@gmail.com>
The Julipedia - http://julipedia.blogspot.com/