[OpenBIOS] FCode on an embedded Leon-Sparc system

Rolf Schroedter Rolf at Rolf-Schroedter.de
Tue Sep 19 22:02:46 CEST 2006

Blue Swirl wrote:
>> For a scientific space project I'm thinking about including an FCode
>> interpreter into the onboard software.
>> The target system is a Leon3 processor (Sparc-V8) in FPGA with serial
>> port(s), spacewire and a few other interfaces.
>> I'm able to compile & run bare C applications (gcc cross-compiler), so
>> it seems to me that I don't need a real BIOS.
> So you probably won't need SCSI or floppy drivers or any of the filesystems. 
> These can be disabled by editing config/examples/cross-sparc32_config.xml. 
Thanks, I'll try to disable them.

> What kind of serial port is this, Zilog or PC (16550)?
None of the above, a special serial interface integrated into the processor.
You can simply assume, that  stdin/stdout are connected to the serial 
port at main() startup.
>> Ideally the complete FORTH system should be in the range of 32-40 kBytes...
> That can be difficult to achieve, currently the full build is 150k C code + 
> 100k Forth. I don't know how much of the Forth is needed. Taking out 
> unwanted drivers etc. could help a lot on C side, but down to 30-40k?
Really that large ? I don't have experience with 32-bit Forth'es. 16-Bit 
systems usually have a small footprint.
Okay, I have a 64 KByte PROM, and I forgot that the code could be 
compressed, perhaps a FCode interpreter for ~64 kByte could do it...

Thanks & regards,

Rolf Schroedter
German Aerospace Center
Institute of Planetary Research
D-12489 Berlin, Rutherfordstrasse 2
Tel/Fax:  (+49) (30) 67055-416/384
Email:    Rolf.Schroedter at dlr.de

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