On 5/5/19 4:24 PM, Mark Cave-Ayland wrote:
> Right, these graft points are unnecessary - if you look at the BootX file on 
> the ISO
> then it's simply a pointer to /boot/grub/powerpc-ieee1275/grub.chrp which is a
> bootinfo file containing this:
> 
> <BOOT-SCRIPT>
> boot &device;:&partition;,\System\Library\CoreServices\grub.elf
> </BOOT-SCRIPT>
> 
> and from above this is simply a link to /boot/grub/powerpc.elf, which is also
> different to the bootinfo file that already exists at \ppc\bootinfo.txt which 
> would
> be picked up by CHRP machines by default. It feels like we're just going 
> around in
> circles.

So everyone who has been creating bootable PowerPC ISOs for Debian stable 
releases
and GRUB has been doing it all wrong? I have a hard time believing that. Given 
the
fact that the OpenFirmware implementation in PowerMacs seems to be non-standard 
which
we can also see with grub-ofpathname not printing proper OpenFirmware paths, I 
tend
to believe it's better to follow the common practice for creating these images.

Referencing specs doesn't convince me really because specs don't necessarily
mean that the firmware properly implements them. If WINE developers implemented
the Win32 API according to spec, the compatibility of WINE for real world 
applications
would be much worse.

> To summarise again:
> 
> - Mac machines locate the TBXI filetype in the blessed directory
> - CHRP machines as defined by the specification look at \ppc\bootinfo.txt
> 
> I really can't see why we can't just bless \ppc, set the \ppc\bootinfo.txt 
> file type
> to TBXI and then both Mac and CHRP work with only one copy of each file 
> instead of
> having all these aliases and graftpoints?

Because Apple's OpenFirmware is not 100% compliant with the spec and I would 
rather
have images that work on every PowerMac than something that is valid according 
to
a specification that no user really cares about in the end.

Thanks,
Adrian

-- 
 .''`.  John Paul Adrian Glaubitz
: :' :  Debian Developer - [email protected]
`. `'   Freie Universitaet Berlin - [email protected]
  `-    GPG: 62FF 8A75 84E0 2956 9546  0006 7426 3B37 F5B5 F913

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