Grub commands to boot USB and/or CD on open firmware

[fluidhd]

Hi,

I have a ppc Mac where open firmware never seems to do quite what I want it to

For instance I can get it to boot from CD, but only after removing all the hd's

I can never get it to boot from USB

And sometimes keyboards that are A ok, suddenly have buttons that either don't work or start becoming a randomly remapped button

I can however get to a grub command line

If I wanted to use grub to boot from either USB or CD on a ppc Mac, what would those commands look like?

Thanks 👍

 

[ifrit05]

You can usually force OF to boot a CD by typing boot cd:,\\:tbxi. USB is a little more complicated, pre-G5 PowerMacs do not have a dedicated alias assigned to USB devices so you will need to figure out where they are in the device tree manually.

Using devalias and dev / ls will report a list of all aliases in the system and devices in the tree respectfully. Look for any usb@/disk@ in the tree and make a note of those.

Then try (for example) boot /pci@f2000000/usb@1b,1/disk@1:,\\tbxi. NOTE: the numbers after the @ symbol can and will be different depending on the system and disk used.

 

[fluidhd]

Thanks,

I'll see if I can get that to work,

the last time I tried to boot from USB, the biggest problem was that for the command I needed to enter, the buttons on the keyboard I needed to press , would either not work, or suddenly become a different button

 

[ifrit05]

Thanks,

I'll see if I can get that to work,

the last time I tried to boot from USB, the biggest problem was that for the command I needed to enter, the buttons on the keyboard I needed to press , would either not work, or suddenly become a different button

In OF? I have issues sometimes with wireless keyboards, try using a wired one if so.

 

[fluidhd]

In OF? I have issues sometimes with wireless keyboards, try using a wired one if so.

yep, this was with a A1243 and a Trust usb keyboard

 

[dextructor]

First of all you never discussed what specific model of PPC that you have in the Opening Post. That make things a lot easy for many of us to properly help you better

This topic was already discussed many times on the forum, so I hope that the only variable it's the wrong key press. So let's begin:

1) If you have a tower model, you don't have an integrated keyboard, so all the inputs are from USB ports (pretty obvious, but let's continue). So try to disconnect all other things from the USB ports (even the USB ports on the Apple Keyboard) and change the USB ports to see the if behavior persist. (turn off the computer before change ports, power on and enter the OpenFirmware to properly test). If it's a notebook I don't know if the integrated keyboard maybe interfering and if it's possible to disconnect without triggering some issues, but the rest of the folks can help with that knowledge.

2) The OpenFirmware (as any other BIOS or similar) will have an hierarchy to follow, and if you have a HDD with a valid initialization for OS (any kind of valid O.S. for those Macs) will boot, and latter will try other things, like Optical Disks (I don't remember if the Network boot enter without intervention, but that's possible on the "boot selector"). But if I remember correctly even if you have a proper formatted USB device with an valid OS to boot from it and remove all other bootable options "to force OpenFirmware" to automatically boot... That's not gonna happen.

I'll not enter the discussion of USB booting because that that's a pretty exhausted topic on this forum, of many ways, methods etc.