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. For example, if you want your email address to be used as the "OEM banner", you should do the following:. You can access get and set these from within Mac OS X via the nvram command line utility.
Top Bottom. After installing the key, upon each power-on, the boot countdown can be interrupted with Esc the upper left key to get to the Forth prompt. The HDConfig tool can be used to set partitions bootable and alter their boot priorities, but usually it's unnecessary to change these settings. But that only worked on one of my Power Mac G5s. I cannot get Fedora or Gentoo to boot this way yet.
To sum up, Open Firmware is a powerful tool for controlling, debugging, and exploring the computer. When an Open Firmware equipped Macintosh all current Apple systems at the time of this writing is powered on, hardware is diagnosed by some POST code and initialized. The first entity to control the CPU thereafter is the firmware. Open Firmware which runs with interrupts disabled builds a device tree, probes slots for devices, queries PCI devices and assigns them address space appropriately, and then looks for the default boot device unless one was specified explicitly.
The following "snag" keys let the user specify a boot device as the system is powered on:. C device referred to by the 'cd' alias, a CD-ROM drive D device referred to by the 'hd' alias, a hard disk drive N device referred to by the 'enet' alias, a network card Z device referred to by the 'zip' alias, a ZIP drive. Essentially, your Mac becomes a fancy external FireWire disk drive. You can also specify the complete pathname of a device, or have the machine boot over the network using TFTP:. If Open Firmware fails to find a boot device, a blinking folder is displayed.
BootX is then executed and Control is then passed to it. BootX can load Mach-O binaries. The "Old World" Macs had various issues with the implementation of Open Firmware, which in turn caused many booting problems for Apple engineers, and even more problems for the PowerPC Linux port.
Now, Apple had access to the firmware's source.
They solved most of the problems either via NVRAM patches, or by integrating required changes into BootX itself in the instances where the changes could not be implemented as patches. The sequence of events when BootX starts executing after being handed control by Open Firmware is described below:. Mac OS X uses a few kinds of "kext" kernel extension caches to speed up loading of kexts.
The cache files are named kernelcache. Mac OS X uses a boot-time optimization effectively a smart readahead called "BootCache" that monitors the pattern of incoming read requests to a block device the boot disk , and sorts the pattern into a "playlist" it also measures the cache hit rate and stores the request pattern into a "history list" for being adaptive in future. Once this is loaded, the cache comes into effect. The effectiveness of BootCache can be gauged from the following: in a recent update to "Panther", a reference to BootCacheControl was broken.
However, another program possibly loginwindow. All Rights Reserved.
The specific assignments vary from implementation to implementation. Load a Forth file over a serial line with TIP and interpret.
Begin executing a previously-loaded binary program, or resume executing an interrupted program. Called automatically by boot. Prepare a loaded program for execution. Called automatically by load and boot. Address where load first places the data it reads from a device. The program image may be moved elsewhere as init-program prepares it for execution. Change the saved value of a register. Use in the form: value to regname.
Continue from a breakpoint. Restrict debugger to the part of the definition after and including the word to be executed next.
This is useful for debugging words with loops in then. Fetch the byte at adr. Return the data and true if the access was successful. Return false if a read access error occurred. Also lpeek, wpeek. Store the byte to adr. Return true if the access was successful. Return false if a write access error occurred. Also lpoke, wpoke.
Allocate and map size bytes of available memory; return the virtual address. After "dev usb0" I'm asked to enter the password. I appreciate your quick replies! Anything I can do now? Is that significant? Try that with two back-slashes. Tried twice with the corrected code, same deal. It flashes a screen with text but only for a fraction of a second so I can't make out the message.
Elio Elio 1. Sign up or log in Sign up using Google. Sign up using Facebook. Sign up using Email and Password.
Post as a guest Name. Email Required, but never shown.
Featured on Meta. Congratulations to our 29 oldest beta sites - They're now no longer beta! Unicorn Meta Zoo 7: Interview with Nicolas.