Re: Testers on PowerMac needed - overwriting the boot-device in NVRAM

[Julio Herrero <debian@jherrero.org>]

El vie, 25-03-2022 a las 08:43 +0100, John Paul Adrian Glaubitz
escribió:
> Hello!
> 
> I would like to ask users running Debian on a real PowerMac machine
> (G3, G4, G5 etc)
> to help me verify a theory on the boot mechanism. In particular, the
> question is
> whether we can skip setting the boot-device in NVRAM in the grub-
> installer script
> which causes incompatibilities with the PowerMac emulation in QEMU
> [1].
> 
> According to Apple's documentation [2], Open Firmware will
> automatically search for
> available operating systems, so there is no need to explicitly set
> the path to
> the boot device.
> 
> To verify this, I set the boot device on my iBook G4 to NULL and
> checked whether the
> machine would still boot which turns out to be true. However, before
> I change the
> code in grub-installer, I want to make sure it won't break any other
> PowerMacs.
> 
> So, if you would like to help, please try the following.
> 
> As root, run:
> 
> root@ibook-g4:~# nvram --print-config=boot-device
> /pci@f4000000/ata-6@d/@0:2,\\:txbi
> root@ibook-g4:~# nvram --update-config boot-device=""
> root@ibook-g4:~# nvram --print-config=boot-device
> root@ibook-g4:~# reboot
> 
> If your machine still comes up after changing "boot-device" to zero,
> we know that
> it's safe to drop the NVRAM part from the grub-installer script for
> PowerMacs.
> 
> This will fix the remaining compatibility with QEMU.
> 
> Thanks,
> Adrian

Hi,

Powerbook G4

cpu             : 7447/7457, altivec supported
clock           : 1249.999000MHz
revision        : 1.1 (pvr 8002 0101)
bogomips        : 60.23

timebase        : 18432000
platform        : PowerMac
model           : PowerBook5,2
machine         : PowerBook5,2
motherboard     : PowerBook5,2 MacRISC3 Power Macintosh
detected as     : 287 (PowerBook G4 15")
pmac flags      : 0000001a
L2 cache        : 512K unified
pmac-generation : NewWorld
Memory          : 512 MB

normal bootup after reboot. 


> 
> > [1] https://lists.debian.org/debian-powerpc/2022/03/msg00029.html
> > [2]
> > https://opensource.apple.com/source/bless/bless-37/README.BOOTING
>