Linux capable free/GPL SOFT CPU for XC3S500E?

Hi All,

I'm looking for a possibility to run Linux (may be a ucLinux) on a XC3S500E containing CPU and some custom peripherials. The hardware platform should be a Spartan3E Starter Kit (rev. D), or something like this.

I have found the almost ready to use solution here:

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but it is MicroBlaze based, which is not acceptable for me due to licensing terms (which are even worse for the Ethernet MAC controller). Has anybody tried to use the aeMB clone with the free OpenCores Ethernet MAC controller with the MicroBlaze ucLinux?

The OpenRisc and LEON3 seem to be too big for XC3S500E (or at least I was not able to trim them sufficiently for this FPGA).

The most preferable solution seem to be a CPU which has a standard instruction set (e.g. Plasma, which is MIPS I compatible), because in this case the toolchain is well supported.

However I could not find any information if it is possible to run Linux on the Plasma (or mips789) SOFT CPU. Has anybody any experience in that subject?

There is an ideal solution announced on the OpenCores:

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But it is only an idea (Development status :: alpha)

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TIA & Regards,
Wojtek Zabolotny
Reply to
Wojciech Zabolotny
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here:

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OpenCores:

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linux should run nicely on MIPS arch, but not sure about Plasma, well also interested in the same as you Antti

Reply to
Antti

You can try

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and their Manik CPU It seems to be small enough to fit into the XCS500E with several peripherals. Here is startup description for Spartan-3 Starter Kit
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Vit

Reply to
mares.vit

Antti a écrit :

Hi,

I was also considering trying to port uCLinux on the Plasma CPU, but I quickly gave up (too complicated for me ;)), however I found an interesting page regarding the porting on uCLInux to MIPS arch.

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Hope it can help.

Steven

>
Reply to
Steven Derrien

When I checked Manik CPU a few months ago, I couldn't find any information regarding its licensing. I have sent a question to niktech about it, but have never received any answer. Without clear license allowing me to use it, I will not risk basing my laboratory on this design, even though it seems to be very nice...

Wojtek

Reply to
Wojciech Zabolotny

To get some response it needed some investigation to get the right email :-) When you search this forum for Niktech+Manik you can find Sandeep Dutta name The right email was snipped-for-privacy@niktech.com

He sent me answers to several questions >>> Did you try to port uClinux to Manik? No we have not yet started porting uCLinux, we do have plans to port it. >>> What is the licence of Manik CPU core and other IP cores? The licensing scheme is very simple, you can use the core in your product for free, you cannot re-sell the core itself, you are not obligated to give out the source of any derived work. Consider it being a GPL with expection that if you instantiate this core in your design it does by itself make the resulting work covered by GPL. >>> Will you put it to opencores.org? Currently we ave no plans to put it into opencores. Sandeep

Regards Vit

Reply to
mares.vit

It looks out much better, but anyway it would be nice to have the license terms included in the sources. Additionally the above statement seem to me to be self-contradictory. I'm not a native english speaker, so maybe I've misunderstood something, but it seems to me that it should be either: version 1 a) "you are not obligated to give out the source of any derived work" b) "Consider it being a GPL with eception that if you instantiate this core in your design it does NOT by itself make the resulting work covered by GPL."

or:

version 2 a) "you are (deleted not) obligated to give out the source of any derived work" b) "Consider it being a GPL with eception that if you instantiate this core in your design it does by itself make the resulting work covered by GPL."

The version two is less probable, because it would be the standard GPL, so no exception is needed at all.

BTW is the author of the MANIK the same Sandeep Dutta who originated the SDCC compiler

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In this case we owe MAAAAANY THANKS to him for all his open source contributions ;-).

--
Wojtek
Reply to
Wojciech Zabolotny

You might be interested in looking at the Lattice Mico32 as well. It is also open source and I know that people have used it on Xilinx devices.

/Andreas

Reply to
Andreas Ehliar

I think he is the SDCC original author. Vit

Reply to
mares.vit

here:

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OpenCores:

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Linux will run on a soft CPU, including ones that fit into the XC3S500. There are uClinux ports for both the MicroBlaze and NIOS.

A point to mention is that uClinux runs without a memory manager. There just aren't enough gates to fit one in an FPGA.

If you can't find an open-source port to MicroBlaze or NIOS, look for an ARM7 port. An ARM7 is an ARM9 with the memory manager removed.

Hope that helps, G.

Reply to
ghelbig

Yes, I know, however I'm looking for an open solution, which I could both give away to students, and to use in some research applications. So the problem is that the cores should be open source and with permissive (preferrably free or even GPL) license.

Well, however the only freely available synthesizable ARM7 implementation is the nnARM, which after its disappearance from OpenCores in 2001 is still available in many mirrors (just google for sARM_tb.zip ;-) ), but AFAIK it is not safe to use due to legal issues (and is not complete as well).

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Thanks and regards,
Wojtek
Reply to
Wojciech Zabolotny

here:

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OpenCores:

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Linux will run on a soft CPU, including ones that fit into the XC3S500. There are uClinux ports for both the MicroBlaze and NIOS.

A point to mention is that uClinux runs without a memory manager. There just aren't enough gates to fit one in an FPGA.

If you can't find an open-source port to MicroBlaze or NIOS, look for an ARM7 port. An ARM7 is an ARM9 with the memory manager removed.

Hope that helps, G.

Reply to
ghelbig

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