Linux-running MIPS CPU available for free to universities – full Verilog code

http://blog.imgtec.com/mips-processors/mipsfpga-opens-up-the-mips-architecture-to-universities-worldwide

by alexvoica • 11 years ago

68 25 11 years ago

blog.imgtec.com

alexvoica7• 11 years ago

The package includes a microAptiv CPU (MIPS32 Release 3) written in Verilog, a getting started guide, and various files for debugging, simulation and synthesis (free SDK, tools from Modelsim and Xilinx, etc.)

cbd1984• 11 years ago

Given that OpenCores has a ton of open-source cores on it already, why does this matter?

http://opencores.org/

alexvoica7• 11 years ago

This matters because you get access to the full Verilog code for a modern CPU and a complete toolchain to boot Linux and write software. This also matters because these two vital elements (hardware and software) are coming straight from the source.

Open cores might get close to an implementation, but usually they break code compatibility or implement older versions of the architecture, which limits your ability to run (or update to) a modern Linux kernel or use a standard toolchain from established providers.

solarexplorer4• 11 years ago

But the reason they break code compatibility or implement older versions of the architecture is that parts of the ISA are patented by MIPS. Other ISAs like OpenRISC, SPARC and RISC-V don't have these limitations.

rasz_pl• 11 years ago

teaching MIPS as the most elegant example of a RISC processor

elegant as in simplified to the bone, but also a market failure compared to not so reduced ARM

You’ve been here for two months, and now you want to give our IP away!

haha, nice try Imagination Technologies, you arent giving anything for free. Later on in the blog post is a mere mention of all the proprietary IP, patents and licenses they are NOT granting/licensing. This is a huge win for Imagination, somehow they managed to convince a ton of universities to base their curriculum on Img proprietary design, this is as big as Nvidia "helping out" with heterogenous computing courses resulting in universities universally (hah) ignoring OpenCL, and exclusively teaching proprietary CUDA.

alexvoica7• 11 years ago

This is not simplified, we include the full RTL and all the building blocks required to run Linux (cache controllers, MMU, debug interface, load/store unit etc.).

We are granting an open license, which means you can see the code. CPU IP usually includes many options (i.e. parameters) that need to be set by design teams before doing any FPGA integration work (synthesis, functional simulation and verification, place and route, etc.). Setting those parameters up requires a lot of expertise which is usually accumulated over years of work in SoC design.

The blog article mentions a case where a university struggled to configure the MIPSfpga CPU because (naturally) IP can be quite complex, especially if you haven’t used it before. So we’ve actually done a lot of work to create a pre-configured, pre-validated version that is easy to use by academics (lecturers, students, etc.) for FPGAs. Of course, we also state in the press release that users can change it but they need to talk to us first to ensure that the changes they make are valid and sensible. The last thing you want is to break a CPU architecture; this will affect not just the behavior of the hardware, but also the toolchain.

ris3• 11 years ago

"We are granting an open license"

I know it's become a bit of a tradition to abuse the word "open" in technology circles, but this is really pushing it a bit far. Even Microsoft didn't have the gall to call its "shared source" initiative "open".

userbinator2• 11 years ago

but also a market failure compared to not so reduced ARM

There are tons of MIPS SoCs out there, mostly in various Chinese devices (the ones which are too cheap for ARM?) so I wouldn't say they failed completely, but in terms of performance or power efficiency MIPS is definitely behind compared to ARM or x86:

http://www.extremetech.com/extreme/188396-the-final-isa-show...

AFAIK all the patents on early x86 have expired, and IMHO that's a far more interesting architecture to study...

http://zet.aluzina.org/index.php/Zet_processor

solarexplorer4• 11 years ago

I disagree. This comparison is extremely unfair because they used a chineese clone instead of the real CPU/compiler from MIPS...

ris3• 11 years ago

"IMHO that's a far more interesting architecture to study"

By interesting do you mean awful? The only reason for clinging on to x86 is maintaining compatibility with old proprietary (almost entirely windows) software.

jeffbush• 11 years ago

Many set top boxes and TVs use MIPS. I don't think it's accurate to call it a failure, although ARM certainly has more volume.

abrowne• 11 years ago

My internet radio, too.

protomyth• 11 years ago

elegant as in simplified to the bone, but also a market failure compared to not so reduced ARM

ah, to have such a failure that gets my chip in embedded use for decades including some game machines and some not too shabby workstations

glabifrons2• 11 years ago

In addition to all of the other examples given, countless SoHo routers (just about everything from the old WRT54G workhorse on up) run MIPS processors.

Edit: Fixed typo.

glabifrons2• 11 years ago

Hopefully, this will get more traction than OpenSPARC did. I was really surprised that one didn't get adopted heavily. It runs Linux (and Solaris and OpenBSD), is multicore, CMT, low power.

Reference:

http://opensparc.net/

http://www.oracle.com/technetwork/systems/opensparc/openspar...

alexvoica7• 11 years ago

There is also the RISC-V ISA (http://riscv.org/) being developed at Berkeley and the lowRISC SoC incorporating a 64-bit RISC-V CPU (http://www.lowrisc.org/) by a team in Cambridge.

ris3• 11 years ago

Hold on - please don't confuse the two. OpenSPARC actually was/is open, comparatively this is highly restricted.

Linux-running MIPS CPU available for free to universities – full Verilog code

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