[OpenBIOS] OpenBIOS == Open Boot/Firmware?

[Geir Frode Raanes]

On Fri, 27 Feb 1998, Chris Arguin wrote:

As an innocent bystander just entering the show, it appears to me that 
you are trying to reinvent the wheel here.  Have you yet discussed the
possibility of simply implement Open Boot (on Sun) or Open Firmware (on
PowerPCs)?  Same thing.  It's availeable on PCI PowerMacs through a
three-button combo at powerup.  Allows for insertion of device drivers
through interpreted/semicompiled Forth code and U*IX like device trees.


It is an open standard; IEEE 1275-1994.  More important, it *works*. Now.
Probabely the best place to read about it is on the home page of the 
Open Firmware Working Group at;

	http://playground.sun.com/pub/p1275/

But let me quote some highlights from FirmWorks home page:

http://www.cuviello.com/_portfolio/_FirmWorks/technology.powerfeatures.html

---
Open Firmware encodes the drivers in a machine-independent language
called "FCode".  FCode is a byte-coded "intermediate language" for the
Forth programming language.   The same FCode driver can be used on
systems with different processor types.

Open Firmware can debug hardware, operating system software, plug-in
drivers, and even the firmware itself through Interactive Debuggers.

The Open Firmware client interface allows the OS to examine the device
tree, temporarily use Open Firmware device drivers, display progress 
messages on the console device, allocate memory, and utilize other Open
Firmware services.  Usually, after the OS is fully initialized, it assumes
responsibility for most of these tasks, and Open Firmware is no longer 
needed until the machine is rebooted. 

The device interface specifies the full set of FCode primitives guaranteed
to be available to an FCode driver.

A full-featured Open Firmware implementation, including debuggers, network
protocols, selftest diagnostics, drivers for on-board devices, keyboard
maps, graphics device support libraries, fonts, and on-line help, usually
requires between 128K and 256K bytes of ROM space.
---

Oh, by the way - SILO, the SPARC/Linux loader have no problems reading the
ext2fs filesystem and thus first search out 'silo.conf,' reading that and
since find the approriate kernel image.  No need to rerun SILO just
because of an updated 'silo.conf.'  OTOH, SILO itself has to be placed
somewhere/anywhere OpenBoot can find it.  Usually that means sector one
of the first partition, but details may be specified to Open Boot.

Unfortunately, I see a problem in how to lobotomate Open Boot to allow
legacy BIOS services to be implemented.  Perhaps the Quarterdeck Quick
Boot feature with a BIOS image reinsertion when needeed is the way to go.  

--
http://devworld.apple.com/dev/technotes/tn/tn1062.html
http://devworld.apple.com/dev/technotes/tn/tn1044.html
http://www.forth.org/
--


Geir Frode Raanes
Omega Verksted
NTNU, Trondheim
Norway.


---
OpenBIOS -- http://www.linkscape.net/openbios/
openbios-request at linkscape.net   Body: un/subscribe
Problems?  dcinege at psychosis.com