Re: Tool for blessing HFS+ filesystems required
On 2/3/21 12:16 PM, Linux User #330250 wrote:
> Which file systems are supported by Open Firmware?
>
> Keeping in mind that there are significant differences from OldWorld
> (Open Firmware prior to version 3) to NewWorld (Open Firmware starting
> with version 3) Macs, every Mac does support booting from a HFS volume.
> But not all variants of HFS+ are supported by Open Firmware. E.g. if I
> remember correctly, case sensitive variants (HFSX) and software-RAID
> configurations don't work.
>
> https://opensource.apple.com/source/bless/bless-37/README.BOOTING
The installation CDs already HFS+. So if your machine is able to boot them,
it will be able to use HFS+ for the boot partition.
> BUT in the next section "New World booting from HFS+":
> * New World machines (with OF 3.0+) support HFS+, ISO9660, and FAT.
>
> This doesn't really make sense, because it means that also FAT(16)
> partitions would be able to hold an OF bootloader. I don't think FAT
> supports blessing, so – even IF FAT was supported – I doubt that OF
> would automatically find the correct bootloader on it...
You could FAT-format and then store the bootloader path in NVRAM. You
wouldn't see the boot option in the boot menu, however.
> My guess is, that, should FAT actually be supported, it would be some
> kind of bootinfo file.
> http://www.nmia.com/~svspire/open-firmware.html
> hd:8,\\bootinfo.txt
> Tells the machine to use the file bootinfo.txt in the System folder on
> disk partition 8 as boot instructions
>
> A bootinfo file looks like an XML file, with some instructions on what
> to boot. See e.g. https://flylib.com/books/en/3.126.1.47/1/
>
> And /MAYBE/ there is a default filename always looked for by Open
> Firmware... It that bootinfo file includes an os-badge, it sould even
> pop up in the graphical boot selection ("OS picker", the one you get
> when holding the Alt key i.e. Option key after the chime; see also:
> https://flylib.com/books/en/3.126.1.46/1/).
>
>
> My point being: In theory we could even use a FAT partition to boot
> Linux on a PowerMac. In practice I think that HFS is the best option –
> not HFS+, not FAT.
>
>
> In order to create a new HFS partition I would simply use older versions
> of mkfs.hfs.
mkfs.hfs no longer supports Legacy HFS [1].
> BUT, one "bug" of this has always been, even with an older version of
> the Apple diskdev_cmds, that the option "-h hfs" was always needed.
> Therefor, those two command do the same to create an HFS+ volume:
> * mkfs.hfsplus /dev/sdxn
> * mkfs.hfs /dev/sdxn
> And these always create a "legacy" HFS volume:
> * mkfs.hfs -h hfs /dev/sdxn
> * mkfs.hfsplus -h hfs /dev/sdxn
>
> In other words, the symlink mkfs.hfs doesn't make it create a HFS
> volume, and the symlink mkfs.hfsplus doesn't make it create a HFS+
> volume, it solely depends on the "-h hfs" commandline option, or not.
No, they don't. Again, Apple removed Legacy HFS support from mkfs.hfs.
If someone actually wants to step up and help me, then please wipe
up a patch to bring HFS Legacy support back to hfsprogs.
Adrian
> [1] https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=973911
--
.''`. John Paul Adrian Glaubitz
: :' : Debian Developer - glaubitz@debian.org
`. `' Freie Universitaet Berlin - glaubitz@physik.fu-berlin.de
`- GPG: 62FF 8A75 84E0 2956 9546 0006 7426 3B37 F5B5 F913
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