Enabling DragonFly BSD disklabel64 read support

[Radosław Szymczyszyn]

Hello everyone,

I'd like to extend GRUB to be able to read the DragonFly BSD's
disklabel64 format. On my way there, adding support for disklabel32 -
unreadable by GRUB now, but similar to Free/Open/NetBSD disklabel - is
an option, too.

I've already played with GRUB a bit, run its test suite and prepared
some disk images with MBR and FBSD disklabel, DFly disklabel and DFly
disklabel64. I've also extended the build system to build and link
with libgrubmods.a a new module placed in grub-core/partmap/dfly.c.
These changes aren't available anywhere on the net, yet.

One thing I've found lacking in the documentation is the grub-shell's
requirement for xorriso. It's nothing fancy, but the program is used
on a script line whose both outputs are redirected to /dev/null, so
finding out what's missing might not be that straightforward.

On, to my questions:
- Is there any up-to-date git mirror of GRUB available? Learning bzr
isn't a showstopper, but staying with the tool I know would be
preferable.
- The source code includes some grub_dprintf diagnostics, but neither
the tests nor running grub_shell shows any of this output. What's the
proper way of enabling these diagnostic messages?

Thanks in advance.

Regards,
Radosław Szymczyszyn