I am glad that I have finally made the grub2 multiboot for ppc working.
It is based on Hollis' earlier work
(http://lists.gnu.org/archive/html/grub-devel/2005-06/msg00049.html) .
Hollis' hello world example works for my building environment and
system, which is Mandrake Linux (2.6.11) on Power Mac G4. A patch is
attached for grub 1.92 release. The patch also includes the
util/powerpc/ieee1275/grub-install.in file, which is missed in 1.92
release (but in cvs checkout). I have trouble to create the patch by
cvs diff, so to apply it, you may have to use "patch -p1" under the
grub2 folder.
grub2 is really great and it is very easy to write a module that loads a kernel and jump to it for run.
As in x86 and sparc, the multiboot strap is basically not the real
kernel, but a loader to load ramdisk and initializer of system before
exitto unix module. Here comes several choices about the system
initialization:
1. should the multiboot strap trust the multiboot_info passed from
grub? x86 multiboot only use the cmdline of it and multiboot is
changing as from grub developers. If use it, it may save some
coding efforts.
2. if multiboot strap collect system information by itself, should it
use GRUB ieee1275 functions or Solaris's own code(mainly in
psm/promif/ieee1275, but would have to port to ppc). Using Grub2's code
saves efforts to port Solaris code.
3. grub2 network is not available (Marco planned to work on it on Feb
as posted from grub wiki), shall we port the solaris network stack
(src/stand/lib) for grub or wait?
4. Finally, should the boot strap be independent from Grub? so that it can be loaded by other loaders, such as yaboot?
5. Does a user allowed to get back to open firmware prompt (like sparc
Stop + A key), or grub prompt after system is up? this feature may be
used for file system synchronization or core dumping after system hang.
(this does not matter in current stage, doe it :)
In summary, what is the role the grub should play in booing and system
initialization, only as a loader, or a loader and system utilities that
help system booting and other purpose? In Solaris x86, I only found the
cmdline of multiboot_info is used by the multiboot strap.
Thanks for reading through this and hope that some of them are important and worthwhile to discuss.
Noah Yan
ppcmtp1.92.patch