When booting manually from OF, you'll see some output lines on screen. There are two important lines that tell you the boot stage. This can be demonstrated well with the load and go commands. Problems after that stage are MorphOS related, and if the MorphOS boot image doesn't appear soon, then MorphOS might not have found a device or image to boot from, or there might be driver or compatibility issues.
MorphOS reset keys Ctrl-Lcmd-Rcmd, Fn-alt-alt also work at this stage even if there are any other problems halting the boot process. A shorter, and usual, way to boot is to use the boot command, which combines both load and go commands.
Several boot arguments can be given to the boot. Without arguments MorphOS boots a device that is bootable and has the highest boot priority set. Note that this only applies to partitions that contain a MorphOS compatible bootable filesystem. The HDConfig tool can be used to set partitions bootable and alter their boot priorities, but usually it's unnecessary to change these settings. The arguments can be given in a longer or shorter, in parenthesis format.
MorphOS documentation's usual advice is to boot the machine with the c key pressed, but that method can sometimes be unreliable for one reason or another, so you might end up in a situation where a boot image has been loaded from a HD and the actual system from a CD, which results in an error if the boot image and the CD aren't from the same MorphOS version.
A more reliable way is to boot into the Startup Manager menu on Macs by holding the alt option key at boot, and select the CD from that graphical boot menu. Pressing the F12 key in the menu will eject the CD. As well as the previously mentioned methods, there are other ways to boot a CD from the Open Firmware prompt. As you can see, there are several different boot images for different architectures. The blessed directory is marked with an asterisk. The system would most likely boot from the CD even without this argument, because of the previously mentioned boot priorities.
If you can't access your FAT formatted USB stick, refer to the official guide on how to re-format it in a compatible way. Some Macs can be more picky about the format than others, and the same stick, that works in G4 Macs, might not work in a G5 Mac, etc. If you still have issues with USB stick detection in OF or can't format the stick properly, this section of the tutorial provides some alternative methods to get a system booted.
The firmware is not part of Mac OS X, but it plays an important role in the operation of the machine, and is useful in debugging. Hence, we discuss it here.
Apple and Sun are two prominent computer system makers that use implementations of Open Firmware in their systems Sun's trademark is called OpenBoot. Device drivers that are required during system startup are also implemented similarly. Such drivers usually exist in the expansion ROM of expansion cards that are needed before the operating system has loaded.
You can enter Open Firmware by pressing the key combination cmd-opt-O-F just as you power on a Macintosh. The cmd key is the one with the Apple logo, and the opt option key is the same as the alt key. You should see a welcome message and some other verbiage, and should be dropped into a prompt like the following:. You can continue booting the machine by typing mac-boot , or shut it down by typing shut-down.
Even though this Forth "shell" supports reasonable for a BIOS command line editing you can use ctrl-a to go to the beginning of a line, ctrl-e to go to the end, ctrl-u to erase a line, the up-arrow key for history, etc. Here is the command sequence to do this everything is typed at the Open Firmware prompt, unless stated otherwise :. In the examples on this page, if you see ok , remember that it is printed by Open Firmware and you are not supposed to type it in it's not a valid Open Firmware word anyway. If your Mac's Open Firmware includes the telnet package, you would see:. Note that current at least G4 and above Apple computers come with Ethernet ports that are auto-sensing and self-configuring, so you do not need a cross-over cable to connect it directly to another computer no hub is required, etc.
The following command gives you information about installed RAM:. The two pairs of numbers against reg are specify the starting address and size of the chips. The second chip starts at 0x MB and has a size MB. If you need to reduce the installed RAM size as seen by Mac OS X for any reason, without actually having to remove a RAM stick or you want to simulate an arbitrary size that's less than the total installed RAM , you can actually delete the reg entry using the delete-property command, and specify your own reg.
Referring to the previous example of the MB PowerBook, the following command essentially disables the second RAM stick note that this change is not written to NVRAM - it is transient - once you reboot, the other chip will be detected and used as before :. It must be kept in mind though that the reg properties can change from machine to machine, or more likely with architectural changes for example, the format changed with the PowerMac G5.
A less adventurous and more appropriate way to limit visible RAM is to use the maxmem boot argument, such as at the shell prompt:. The following command sequence shows you various information on the machine's CPU s :. The rest of the output contains various cache sizes, the processor's graphics capabilities Altivec, support for certain instructions, The following command lists files in the root directory of the disk partition referred to by the "alias" hd.
The following command expands the alias hd , and gives you the complete path of the device in the tree type devalias by itself to see a list of current aliases, along with what they refer to :. You can load a file kernel using the load command, and boot it using the boot command. As stated earlier, mac-boot and shut-down are predefined to boot the machine normally, or shut it down, respectively. You can get and set variables options using the printenv and setenv commands.
Executed at startup, this script will temporarily force the system to report that a faster processor is installed, allowing the Leopard installer to successfully complete its minimum system requirements check. This allows Leopard to be installed from unmodified installation media or another bootable device.
LeopardAssist handles the interaction with Open Firmware, specifying the target processor speed, the number of physical processors in the system, the desired boot device and any additional startup flags to simplify the installation and configuration process.
Accessing Open Firmware; Determining The USB Drive; Using The Device Alias; Booting The USB Drive; To Boot The Hard Disk. Original Author. Contributing. On NewWorlds, you can also use an OpenFirmware command to boot from the “Booting NewWorld Macs from OpenFirmware” for booting from the hard disk, to use the Open Firmware prompt, since Open Firmware does not search USB.
Insert or connect your OS X Leopard installation media, ensure you are logged in as an Administrator and follow the prompts in LeopardAssist to prepare the system for installation. LeopardAssist has been tested across many different systems and hardware configurations, however it is impossible to accurately test every different possible combination of hardware and software.
While all changes made by LeopardAssist are designed to be reversible, the software can not be guaranteed to function correctly across all configurations and is provided on an as-is basis. Any questions related to the use, care and maintenance of your PowerPC based Mac and the installation of OS X Leopard can be directed to one of these communities. In addition, further information about LeopardAssist can be found on the LeopardAssist SourceForge site leopardassist. Complete Rewrite with extensive under-the-hood improvements and optimisations.
Redesigned interface and icon. Limited customisation of startup options now available on G5 systems.