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Re:BOOM Open Source RISC-V Core Runs on Amazon EC2 F1 Instances by patrickg_zill on Thursday December 13, 2018 @11:40AM (#18673659)
What FPGA do you need to use for this cpu otherwise? I would think that it would be a lot cheaper to have one locally if you were still developing or testing out your application or code.
Re:BOOM Open Source RISC-V Core Runs on Amazon EC2 F1 Instances by _chris_ on Thursday December 13, 2018 @11:49AM (#18673746)
Unless you cut out floating point and superscalar, it requires a fairly large FPGA, on the order of >$1000. So you'd have to put it to serious use to break even with using AWS.

The other advantage of AWS is scale-out once you want to get benchmark data and not wait forever (or to simulate warehouse scale computers). In the past, maintaining our own FPGA cluster was a nightmare.

Re:BOOM Open Source RISC-V Core Runs on Amazon EC2 F1 Instances by tverbeure on Thursday December 13, 2018 @12:28PM (#18674123)
I haven't tried BOOM specifically, but if you're interested in a large FPGA that can be acquired very cheaply, you should look into the Pano Logic G2 thin client. They used to be available in bulk for $3 a piece, but those have now all been snapped up by hobbyists.

But you can still get them for $20 or so on eBay.

They have a Spartan-6 LX150 (DVI version, revB) or Spartan-6 LX100 (DVI version, revC), which are really huge FPGAs. It's by far the best deal in town if you're interested in that kind of stuff.

Google for "github panologic-g2" to find up-to-date proceedings about the reverse engineering effort.

Right now, the FPGA is up and running and outputting an image over DVI.

Do you have any idea about how many FFs are needed for a BOOM CPU?

Re:BOOM Open Source RISC-V Core Runs on Amazon EC2 F1 Instances by 4ad on Thursday December 13, 2018 @01:01PM (#18674457)
I don't know anything about FPGAs, are all FPGAs compatible? Assuming this fits on an FPGA, does it work on every FPGA?
Re:BOOM Open Source RISC-V Core Runs on Amazon EC2 F1 Instances by _chris_ on Thursday December 13, 2018 @01:04PM (#18674488)
No, the IO plumbing and infrastructure are different. FPGAs are a total pain because each platform is different. :'(
Re:BOOM Open Source RISC-V Core Runs on Amazon EC2 F1 Instances by _chris_ on Thursday December 13, 2018 @12:36PM (#18674221)
I don't remember numbers (and resources aren't always apples-to-apples), but it's bigger than a Zedboard and 60% of a zc706 I believe. It's a ton of wires is the big issue I suspect.
Re:BOOM Open Source RISC-V Core Runs on Amazon EC2 F1 Instances by tverbeure on Thursday December 13, 2018 @01:00PM (#18674446)
Ok. The FPGA in a ZC706 is about double the size of the Spartan-6 LX150.

That's a lot of logic!

Re:BOOM Open Source RISC-V Core Runs on Amazon EC2 F1 Instances by strmpnk on Thursday December 13, 2018 @02:52PM (#18675417)
For this specific RISC-V variant, it seems like it requires relative expensive FPGAs. There are some other RSIC-V cores that you can play with which run on small and cheap FPGAs. I’ve played with the picorv/picosoc project on a TinyFPGA BX and those are easy to find (recently sold out at some shops but crowdsupply still has some of you can’t wait a month for the next batch of boards) and cheap.

There are also a lot of new FPGA dev boards with good community support for folks looking at getting their feet wet, like the icebreaker (crowdsupply) and alchitry (Kickstarter).