Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

FPGA x86 Processor

code.google.com

Post reply on HN
Print view View original

11–20 of 39 posts

Re: FPGA x86 Processor

#11

Post by djcapelis »

raverbashing wrote: post #3

Good luck, this is very, very hard Why? Having tested an x86 processor from a 3rd party manufacturer (not the big ones, and not even the 2nd league) - Bios. Including ACPI stuff. So Windows XP would boot, with linux some would boot, some would work but with instabilities, some would not boot - Minor incompatibilities and every nook and cranny of the x86 spec. - Drivers for everything your board does different - The x…

OS bringup doesn't seem to be part of the goal. It looks like he's just going to run code directly from memory to test it without worrying about needing to get an OS running on it first.

Re: FPGA x86 Processor

#12

Post by ori_b »

daeken wrote: post #5

My god, the ability to use this for tracing code makes me more excited than anything I've seen in a while. The debugging facilities on x86 are, well, limited to the point of being damn near useless. I may spend some time hacking solid trace functionality into this, if it ends up being an open core.

I like the project, but for tracing code, you could probably do better with Bochs. Bochs lets you set breakpoints at certain addresses and CPU states, for example.

If bochs doesn't do enough, it would probably be easier to hack it up to do what you need.

Re: FPGA x86 Processor

#13

Post by djcapelis »

daeken wrote: post #5

My god, the ability to use this for tracing code makes me more excited than anything I've seen in a while. The debugging facilities on x86 are, well, limited to the point of being damn near useless. I may spend some time hacking solid trace functionality into this, if it ends up being an open core.

There are already several open x86 cores. You're not likely to find these as useful for modern code though, since most people are finally using x86_64 these days and a lot of the instructions being used (and a lot of the processor characteristics of modern chips, from SMT to the trace cache) are very different in modern Intel chips.

You might try instrumenting bochs, which might both run your code faster, require less hardware and give you more accurate results. In many ways, bochs is much better built for the type of thing you want.

Re: FPGA x86 Processor

#15

Post by neurotech1 »

Actively developing a x86 FPGA project isn't easy. The ML403 boards originally sold for $495 each. Most SoC/Processor development requires large FPGAs and the boards cost even more.

Re: FPGA x86 Processor

#16

Post by ChuckMcM »

This is awesome. One of the running bets I've had is how many chapters of Hennesy [1] you can implement in an FPGA. Early on it was hard to do more than basic RISC architectures, the 6502 Etc. Then you could do the Z80 which was a good cisc variant that had some excellent code tests. The 8086 and 68000 make for good follow on targets. At some point we should be able to do a VAX, its sort of a local maximum of CISCyness.

[1] http://www.amazon.com/Computer-Architecture-Quantitative-App...

Re: FPGA x86 Processor

#17

Post by hmottestad »

hmottestad wrote: post #4

EE? Extended Essay at the IB? That's only supposed to be 4000 words. A project like this could turn into a book.

Apparently at -1 I guess there are stupid questions in this world. Thanks for the replies though guys, didn't know EE stood for that. Electrical engineering doesn't involve any FPGA's in Norway.

Re: FPGA x86 Processor

#18

Post by jbangert »

This is awesome! Maybe one day we can extend it to more modern members of the x86 family (286,386) that introduced more opcodes (hence producing the complicated ISA encoding that x86 has) and operating modes (unreal mode, protected mode, SMM, ... )

Re: FPGA x86 Processor

#19

Post by edwintorok »

raverbashing wrote: post #3

Good luck, this is very, very hard Why? Having tested an x86 processor from a 3rd party manufacturer (not the big ones, and not even the 2nd league) - Bios. Including ACPI stuff. So Windows XP would boot, with linux some would boot, some would work but with instabilities, some would not boot - Minor incompatibilities and every nook and cranny of the x86 spec. - Drivers for everything your board does different - The x…

It looks like he only wants to emulate 8086, so ACPI and booting Windows/Linux are not a possibility.

Not saying that its simple to implement an 8086, but it should be significantly easier than implementing an 80386/80486 (which is what one would expect today as a minimum when referring to it as x86).

Re: FPGA x86 Processor

#20

Post by derleth »

ChuckMcM wrote: post #16

This is awesome. One of the running bets I've had is how many chapters of Hennesy [1] you can implement in an FPGA. Early on it was hard to do more than basic RISC architectures, the 6502 Etc. Then you could do the Z80 which was a good cisc variant that had some excellent code tests. The 8086 and 68000 make for good follow on targets. At some point we should be able to do a VAX, its sort of a local maximum of CISCyne…

> At some point we should be able to do a VAX

You mean a processor where all of the complex opcodes are implemented in loadable microcode?

Post reply on HN