On 10/01/2017 12:47 PM, Frank Scheiner wrote: > I recently stumbled upon [1] which mentions an "8M" limit (either 8 MB or > 8 MiB) for the PReP partition which holds the stage1 binary - most likely > yaboot or > grub - for IBM POWER machines. > > [1]: > https://www.ibm.com/developerworks/community/wikis/home?lang=en#!/wiki/W51a7ffcf4dfd_4b40_9d82_446ebc23c550/page/PowerLinux%20Boot%20howto > > This is also reflected in the current partman recipes for "powerpc-chrp_ibm" > and "powerpc-prep" (and respective ppc64 targets) on [2]: > > Example: > > root/recipes-powerpc-chrp_ibm/atomic > ``` > [...] > 8 1 1 prep > $primary{ } > $bootable{ } > method{ prep } . > [...] > ```
Yes, I know. > So maybe 8 MB/MiB as maximum size for the PReP partition could also be a good > candidate > for the size of the HFS partition on Apple powerpc and ppc64 machines. Well, I assume the PREP partition works differently than Apple's HFS partition. > As mentioned before, I don't know how to mount this PReP partition on my > POWER5 > machine. You don't mount it and debian-installer doesn't either. GRUB takes care of the PREP partition and directly installs into it using the "grub-install" command. > I assumed there is a VFAT FS on this partition, but mounting it as VFAT > doesn't succeed. So maybe there's no FS at all on this partition but just > a stage1 binary. Maybe it's dd'ed directly to this partition - if someone > could shed > some light on this, I'd be grateful. :-) I don't really think we need to dig into what's inside PREP. We only need to figure out why partman in debian-installer isn't flagging the first partition as "PREP". > One other thought: > > It could also be that the size of the partition is not an issue for the > firmware, > but the size of the stage1 binary could be. The original 800 KB limit on Power > Macs could be also to make sure, that the stage1 binary cannot be bigger than > 800 KiB, which was the same size as a Mac 3.5" floppy disk according to > Rogério > Brito on [3]. I don't think this is of our concern either. GRUB knows the limitations and takes care of them. 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
