The time to complete the ELF transition has come.

More to the point, progress has stopped and there is no sign of things getting going and finishing off the remaining rough edges without a bit more of a shove.

Please read this through carefully before getting out the flamethrowers or starting a reply.

There are some known problems and rough edges still. They are not getting fixed because not enough of the developers are using it. Note that people installing 3.0-RELEASE get ELF by default, and 3.0.1 will have an ELF kernel too. We need to get the remaining developers (kicking and screaming if necessary) onto the bandwagon or the current outstanding problems are going to be present in 3.0.1 as well.

The state of the ELF world today is that just about everything important works for just about everybody.

Specifically:

• The userland builds, installs and runs "just fine" as ELF, and has done so for a long time (I believe over a year).
• a.out binaries and libraries work unmodified. There is no need to toss out /usr/local/bin. The libraries get moved to /usr/local/lib/aout so there are no naming conflicts and the ldconfig paths can handle this.
• The kernel builds and runs as an ELF file.
• /boot/loader can load static aout and elf kernels, as well as do KLD preloading for ELF. a.out and ELF kernels have had KLD enabled in them for over a month.
• The new bootblocks default to /boot/loader, but there are some problems for some people still. This needs to be fixed, and either the new bootblocks need fixing or the old bootblocks need a cutdown and modified to fire up /boot/loader by default.
• The new bootblocks can load an a.out and ELF /kernel directly without /boot/loader. (handy if you happen to break it or want to revert to /boot/loader.old :-).
• KLD's work and are a superset of LKM's. You can build a.out and ELF KLD modules. You can load a.out KLD's on an ELF kernel and ELF KLD's on an a.out kernel without noticing the difference.

In all, we're about as ready as we're ever going to be without getting more people bashing at the code.

However, the problems and risks:

• OLD bootblocks apparently cannot load /boot/loader. We do not yet know why. We need to know why and preferably what to change in /boot/loader's headers to make it work. This seems to affect only systems installed with 2.0.x, 2.1.x and early 2.2.x bootblocks that have never had them upgraded.
• 'make aout-to-elf' is known to have a few bumps when coming from some versions of 2.2.x and some -current builds from the last few months. There are other ways of ELF bootstrapping if building the source proves too difficult or takes too much space. I personally have upgraded two machines by installing a new binary bindist and then doing a normal 'make world' on the now ELF system to clean up the loose ends and bring it up to date. I didn't have a.out binaries to worry about though.
• currently existing a.out LKM's will be truely dead. This may be a problem for the one known 3rd party binary LKM, namely OSS. (No, we don't have something against sound drivers, in spite of what it looks like :-).
• A 'make install' by an unwary -current user could install an ELF /kernel and strand themselves if they have got OLD bootblocks that cannot load /boot/loader, or if they do not know to just type "/boot/loader" at the boot: prompt to get out of the jam.

The plan:

January 6 becomes The Day. (E2-day? E-squared day? :-)

On that day, 'make world' to build an a.out would will be blocked. Not destroyed, not removed, just blocked. I would like it to be sufficiently crippled so that it isn't too hard to get going again in an emergency or if somebody is really badly affected. Perhaps something like:

On the same day, the default kernel format would get changed to ELF.. People can do an

Barring any really major showstoppers, this will go ahead in the early hours of January 6 (in the USA) and later in the day for the rest of the world due to timezone differences.

What you can do right now:

• Test the /boot/loader on your system from the boot: prompt to make sure it loads up and doesn't crash or reboot on the spot.
• Prepare some emergency boot floppies now, in case. Get the 3.0 boot and fixit floppies from CD or from ftp.freebsd.org in /pub/FreeBSD/3.0-RELEASE/floppies/
• You might try downloading this gzipped dd image, gunzip it, and write it to a formatted floppy: gunzip newboot.dd.gz dd if=newboot.dd of=/dev/rfd0 bs=18k This is a 1.44MB floppy, with the new bootblocks and /boot/loader. It also has a GENERIC kernel.gz, so you can see it loading plain .gz files as well.
• If you are feeling like a little more fun, try building new floppy with the new bootblocks, new boot loader and see that it works with your kernel on your system. To do this:
  • get a formatted floppy ready
  • disklabel -Brw -b /boot/boot1 -s /boot/boot2 /dev/rfd0.1440 fd1440
  • newfs -T fd1440 /dev/rfd0.1440
  • mount /dev/fd0.1440 /mnt
  • mkdir /mnt/boot
  • cp /boot/loader /mnt/boot/loader
  • cp /kernel /mnt/kernel
  • touch /mnt/boot/boot.conf
  • umount /mnt
  And try it out. Display the "twiddle" character and then pause for about three seconds. If you press a key on the keyboard, the stage2 loader will pause and give you the usual boot: prompt. Anyway, It should initiate /boot/loader a few seconds later, and the 3rd stage loader should start. It should say "starting /kernel in 10 seconds" and do a countdown. If this works and it loads the kernel from floppy, then you are clear. (Yes, the kernel is expected to panic since it doesn't have a real rootfs or /sbin/init). You can abort the autostart and have a play around. You can do things like: set currdev=disk1s1a (hard disk root) load /kernel (your real kernel) boot -s (start in single user).
• You can also try typing "/kernel" at the first boot: prompt.
• You may also like to try building an ELF kernel cd compile/FOO; make KERNFORMAT=elf depend; make KERNFORMAT=elf and copy that somewhere that you can try it out.
• If you are happy that the new bootblocks work, update your bootblocks on your hard disk. MAKE SURE YOU HAVE A FALLBACK IF YOU GET STRANDED! Ideally have the sysinstall boot/fixit floppy handy at all times.
• Also, have a peek at Robert Nordier's page on the new bootblocks.

This is what a successful boot looks like using the new bootblocks and /boot/loader. (Yes, this loader and kernel is a little old, but it shows just how long this stuff has been sitting in limbo)

Note the 'preloaded elf kernel' bit. This is the in-kernel linker (KLD) finding itself in the tables that the /boot/loader prepared for it.

Finally.. Try a

Note that on a pre-3.0 system, the 'make aout-to-elf' and 'make aout-to-elf-install' scripts require that you manually convert your kernel config to 3.0 level and place it as src/sys/i386/conf/GENERICupgrade. Copy the plain GENERIC and start from that if necessary. WARNING: The ELF upgrade process WILL ask to reboot your machine at the end!

Note that aout-to-elf will not install an ELF kernel for you! Just do one thing at a time, ie: get an ELF binary world running. Once you've got that sorted out, then try building an updated ELF kernel.

If you need to make comments or ask questions, please send mail to the current@FreeBSD.org mailing list. Both success and failure reports are welcome.