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Re: Performing installer tests on PowerMac with USB sticks

Thanks for all the information you are providing.

Despite my efforts I still am not able to boot my eMac G4 (Apple
PowerMac6,4) by USB.

After reading your email I was able to see that with a USB stick
inserted at boot a disk device indeed shows up in the device tree
(visible by using the command "dev / ls"), but I am still not able to
list its files by using the command "dir".

By the way, the USB stick contains a dd'ed debian ISO image and it is
possible to browse its files on a PowerMac G5 (PowerMac11,2).

I think I am using the correct OF path, derived by looking at the device
tree and by comparison with the working path on the G5.

I can confirm it has OpenFirmware 3 as shown by the following command on OF:

0 > dev /openprom
0 > .properties
name		openprom
device_type	BootROM
model		OpenFirmware 3
boot-syntax	00000001

This is not the first time I bang my head against OF and USB boot.
Eventually I ended up using NetBoot for a G3 and this G4 (which was not
easy anyway especially on the G3).

For what is worth, I think that a developer in need to test several CD
images without burning them should consider investing in a FireWire HD.
As far as I know booting from FireWire should be much easier, but I
never tried it.


Il 30/04/19 21:56, Linux User #330250 ha scritto:
> Am 30.04.19 um 12:54 schrieb John Paul Adrian Glaubitz:
>> Hello! I have dug out one of my iBook G4s now so I can perform
>> installer tests on the PowerMac target. While the machine has a
>> built-in optical drive, I would avoid having to burn CDs for every
>> installation test run (even when using CD-RWs), so I was wondering how
>> well booting from USB sticks works on these machines. Does anyone have
>> experience creating bootable USB media for PowerMacs to install
>> Debian? Adrian
> Despite what others said, it should really work with every Macintosh
> that has the NewWorld bootrom and thus at least Open Firmware 3.0, i.e.
> starting with the iMac "Bondi" 1998 and the PowerBook G3 "Lombard" 1999.
> And, it's all already written down in a nice way.[1] Don't read on when
> you are happy with this official guide.
> Or read this:
> * http://hints.macworld.com/article.php?story=20060301112336384
> * https://lists.debian.org/debian-powerpc/2012/08/msg00042.html
> *
> https://sites.google.com/site/shawnhcorey/howto-boot-apple-powerpcs-from-a-usb-drive-in-open-firmware
> The long read: I wanted to share my own experience as well...
> Apple did not provide an easy way, like holding a key for this kind of
> boot selection. The possible keys are, a selection[2]:
> * c – boot from CD-ROM (or any other /internal/ optical drive)
> * d – forces boot from first hard disk drive (like it normally would anyway)
> * n – network boot, looks for suitable BOOTP or TFTP network boot source
> * r – (PowerBooks) resets stored screen size to internal default
> * t – target disk mode
> * mouse button held down – forces eject for media in internal optical drive
> * option – shows Open Firmware boot selection
> Sadly, Apple decided to include FireWire in the automatic search for
> bootable volumes but to leave out USB. The capability is there
> nonetheless, only that there is no key for it to press and hold, like in
> easy, quick and comfortable...
> The solution is to enter the Open Firmware (OF) command prompt by
> holding Option + Command + O + F until you can read the Open Firmware
> greeter on your monitor. Then you need to find the device and load the
> boot file from there. In essence it is the manual way of what the other
> options do for you automatically.
> The syntax is like this:
>> boot <dev>:<partition>,<file>
> Examples for <dev>:
> 1) /pci@f4000000/ata-6@d/disk@0
> 2) /pci@f2000000/mac-io@17/ata-3@20000/disk@0
> 3) bridge/ACARD,6280M@4/@2
> Only, on most Macs there are aliases for this long and complicated
> device paths. So, for example, all of those above could be just:
> 1) hd (is set to the faster first HDD, should be the same as ultra0)
> 2) cd (set to internal optical drive, e.g. ide0)
> 3) ide0, ide1 (ATA bus)
> 4) ultra0, ultra1 (UltraATA bus)
> 5) usb0, usb1
> 6) ud0, ud1 – only on later PowerPC-Macs (like the Power Mac G5 or the
> iMac G5, starting around 2003)
> So, to replicate the boot from CD-ROM (holding the "c" key on system
> start-up) from the default partition (automatic), you can use the
> following from the Open Firmware prompt:
>> boot cd:
> To choose a specific partition, with a specific file as the initial
> bootloader:
>> boot cd:2,yaboot
> To use the blessed bootloader on a specific parition, in this example
> partition 3 from the hard disk drive:
>> boot hd:3,\\:tbxi
> The <file> "\\:tbxi" is not a real file, instead OF will look for the
> one file that is blessed on this partition, that is the one file that
> has specific attributes to it. For Mac OS X this will be bootx, for
> Linux normally yaboot or grub2. To my knowledge this only works on a
> partition with HFS.
> So, now we want to boot from USB. First you need to identify the path of
> the USB device you want to boot from. Then you need to know the
> partition number. And, maybe, also the name of the bootloader (or try
> :tbxi).
> To find out what aliases your Mac already has defined, run the following:
>> devalias
> To see the full device tree without aliases:
>> dev /
>> ls
> Other usefull commands in Open Firmware:
> * lsdev
> * .properties
> * devalias, devalias <alias> <device-path>
> * nvalias
> * printenv, printenv <variable>
> * set-env
> * set-default <variable>
> * set-defaults
> * dir <devicepath or alias>:
> * eject cd:
> * mac-boot (will boot the standard)
> * reset-nvram (same as Cmd+Opt+N+V)
> * reset-all (will reboot)
> If you somehow messed up your Open Firmware settings, you can always
> reset/zap the NVRAM and the parameter memory (PRAM):
> * Hold Cmd+Opt+P+R to zap the PRAM
> * Hold Cmd+Opt+N+V to zap the NVRAM
> hold the keys until you hear the startup chime. I always held the keys
> until I heard the chime /again/ and /again/ 3 times in total. It's said
> that it has to be done this way.
> I think that on my Power Mac G5 (PowerMac11,2) from 2005 I was able to
> boot from the USB drive with:
>> boot ht@0,f2000000/pci@4/usb@b/disk@2:2,\\:tbxi
> or
>> boot ht@0/pci@4/usb@b/disk@2:2,\install\yaboot
> I found some notes, this must have been last year or so.
> I just tried 2019-04-24/debian-10.0-powerpc-NETINST-1.iso on my iBook G3
> (original Clamshell, 1999) and it did not boot with:
>> boot usb0/disk@1:2,\\:tbxi
> I got "can't OPEN: cd:,\install\yaboot"
> I then tried
>> boot usb0/disk@1:2,\install\yaboot
> and this worked.
> BTW, in yaboot I get this warning:
>> WARNING: Bootstrap partition type is wrong: "Apple_HFS"
>>           type should be: "Apple_Bootstrap"
> One more note on the USB boot front: I use one of those sticks that can
> be write-protected by a physical slider on the side of the stick. WHEN
> the stick is read-only, OF is unable to access it properly. Not even the
> dir command works. Without write-protection everything works fine with
> the same stick/same data on it.
> For what it's worth, USB booting on a Power Mac is alwayy trial and
> error. Write down what works. I heard that it should be possible to
> define a new devalias somehow... Also, setting boot-device in nvram[4]
> could make the boot selection permanent (until the PRAM is zapped or the
> battery dies).
>> setenv boot-device usb0/disk@1:2,\install\yaboot
> Only, in the case of an external USB pen drive, I would advice against
> it...But I can confirm that this also works!
>> mac-boot
> will then boot from the USB pen drive, as will every restart as long as
> the stick remains plugged in.
> Cheers,
> Linux User #330250
> [1]https://www.debian.org/releases/sarge/powerpc/ch05s01.html.en
> [2]https://whircat.centosprime.com/startup-keys-boot-options/
> [3]https://cdimage.debian.org/cdimage/ports/2019-04-24/debian-10.0-powerpc-NETINST-1.iso
> [4]http://www.macfreek.nl/memory/Open_Firmware

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