Dear "linuxopjemac" I wasn't able to find a email-address therefor I take the forum route to answer this rather technical topic.

I would like to know if new-world PPC based Macs are able to boot from a cd/dvd with only a iso filesystem (instead of hfs/hfs-iso-hybrid)? Manually forcing to boot from CD/DVD revering to yaboot or chrp script from a OpenFirmware prompt is also allowed, as long as it boots a debian/ubuntu/fedora installer without having hfs on the CD/DVD.

A re-writeable cd/dvd a new-world PPC based Mac and some spare time can help solve this question. I think the content from the original debian ppc can be extracted from the iso images and than recreated with mkisofs but without all the apple/hfs related build options. Than (try to) boot it.

I would really like to know this, because I want to create a CD/DVD ISO-UDF bridge so it can contain DVD VIDEO and maybe a mbr hybrid partition table.

Most if not all linux PowerPC distro ISO's prepared by the big Distro's like Debian/Ubuntu/Fedora etc ship on mixed/hybrid isofs/hfs cd-images, but not all PowerPC's are Apple Macs. OpenFirmware is able to boot isofs according to spec, but at this moment I don't have a PPC based Mac to test, so if anyone is willing to try this thanks in advance.

Well Debian ships mult-arch CD's with PPC support.
http://www.debian.org/devel/debian-installer/

I am not sure how they did that, but it seems that it is possible what you want.

Indeed it is possible to mix multi-architecture distro's on to one CD/DVD, but debian uses hfs+iso. I would like to know if you burn or others on this forum a copy of this debian disc content, without the hfs partition will it still boot on the Mac's, even forcing it to boot manually on the CLI in OpenFirmware?

In ISOFS spec there is at the beginning 32K bytes non used space which can be used to put Apple partition table and other needed code like MBR-table to make ISO's for instance directly dd-able to a USB-stick. Debian uses a isofs+hfs hybrid its an option in "mkisofs". If I'm not mistaken the first multi-arch disc like this was brought on Linux Tag a couple of years ago, but I'm just really curious if the Mac's really need the hfs part.

Since I don't own OpenFirmware based new world mac I cannot try booting it from the commandline with a ISO only CD/DVD.

I have never tried it, there is only one way to find it out...

LOL

We'll if I had the hardware laying around, otherwise I end up visiting someone .

I am quite busy so I don't know if I have time for this. Don't you have a friend who has a PPC based Mac to try?

I wasn't able to boot a G3 green/white powermac with only ISO9660 as a filesystem on the CD/DVD. OpenFirmware generated the following error when trying to load yaboot it also doesn't read any files from the CD/DVD at all.


BTW manually booting a yaboot file on a HFS CD only worked when declaring the full path.

Instead of the normal code to boot the CD which in my case booted the internal HD.

Swapping the CD/DVD/HD devices on the IDE / ultra-ATA motherboard connectors makes OpenFirmware identify my cd as cd again instead of HD.

I will also try booting from FAT, and try some other ISO9660 combinations made with mkisofs. Running the following code in OpenFirmware shows that HFS/ISO9660/FAT are supported...

In openfirmware shell I'm able to read/list the files on the ISO9660 CD/DVD with the dir command:



However I still don't know how to boot the yaboot file from this filesystem, because the boot command still gives the same error reported earlier. The Openfirmware version of the old machine is 3.1.1.