* madhu.kiran@soc-soft.com madhu.kiran@soc-soft.com [040722 11:08]:
We need FCode Evaluator information. We are confused from thespec about how to develop FCode evaluator for particular target hard ware. Please share with us any documentation regarding FCode evaluator.
There is several information available: * IEEE 1275-1994 Open Firmware Core specification. Find more information at http://www.openbios.org/docs/1275.html * SUN provides some fine books on fcode programming, ie. "Writing FCode 3.x Programs" which is also available as PDF on the SUN website
But there is no need to develop a new FCode evaluator, since quite some exist already.. See unstable/forth/device/feval.fs:byte-load in the OpenBIOS bitkeeper tree or get tar balls at http://www.openbios.org/snapshots/
According OpenBIOS software, kernel developed both in C andForth. WE understand that C language used for generic Kernel, Forth is for Open Firmware specification interfaces. How did you compile both together to put on target? ( If u compile C code separately for target by using cross compiler and FCode translated through the evaluator how link form between these at run time)
On target you have two choices, either you use the "builtin image" which contains the forth dictionary within the kernel image, or you can choose to read a dictionary at a fixed address in flash. The dictionary contains all of the Open Firmare interface code including the fcode evaluator, and the ans forth implementation. It is created by the forth kernel itself during compilation.
Cross compilation in OpenBIOS is untested, and needs a bit of work. Currently you have to bootstrap at least on a machine with equal bitwidth (32/64) and endianess (big/little endian)
Stefan