Want a FPGA Board For Your Raspberry Pi Or Beagle Bone?

New submitter hamster_nz writes "Hot topics for the maker community are things such as embedded vision, Bitcoin mining, autonomous vehicle control, Arduino, Open Hardware, software defined radio, small ARM/Linux boards and reconfigurable computing. A current Kickstarter project, LOGi FPGA, is touching all these bases. Funding has been reached after just a day, and Kicktraq currently has it projected to reach over $133,000. As a long time FPGA enthusiast I'm very interested to see what will happen when a thousand keen users get together to explore programmable logic."

Re:Spartan-6 LX9 MicroBoard

[NixieBunny]

MicroBlaze doesn't provide anywhere near the CPU processing power that a Raspberry Pi provides. This project looks like a fine way to get some hardware acceleration on the standard open hacker computer platforms. You know, with Linux!

Re:Spartan 6 LX9?

[hamster_nz]

You missed out Saanlima's Pipistrello [saanlima.com]. A nice Spartan LX45 board, with PMODs, HDMI and other goodies.

Re:ZedBoard, SoCKIT

[Pinhedd]

I have both the Zedboard and the SoCKit

The SoCKit is definitely the beefier of the two, as the Altera Cyclone V SX series FPGAs are far more powerful than their Zynq-7000 series counterparts.

However, the SoCKit has the most obnoxiously bad documentation that I've ever seen. The reference material from Arrow is extremely thin yet somehow still manages to have spelling mistakes in it that would prevent it from functioning if certain functions were enabled. Terasic's material "works" but Terasic does not include any documentation on the HPS whatsoever, just a prebuilt image and some C code to go with it.

I've spent the better part of the past 3 weeks just figuring everything out on my own. Altera's documentation is rock solid, but that only covers the FPGA itself, not the peripherals. Today was spent figuring out how the various clock sources are connected to the FPGA. Despite offering the exact same board in the exact same configuration, Arrow and Terasic provide conflicting and equally useless documentation. Sometime in the next couple of days I'm going to go probing at it with my scope.

The silver lining though is that I've been documenting that I've done, so I should be able to compile a very comprehensive and updated getting started guide in the near future. The ones on the RocketBoards wiki just don't cut it.

The Zedboard is accompanied by much superior documentation. The board design isn't as nice, but it's not as irritating to work with.

Re:ZedBoard, SoCKIT

[Pinhedd]

I haven't found any hardware errata yet, just a truckload of missing, poorly written, or conflicting documentation. I'll provide you with a rough workflow that I've followed to get started. Feel free to ask me any questions.

Step1: Grab the Arrow lab material from the following link and work through them on Quartus 13.1. They're written for Quartus 13.0sp1 but they can be followed on Quartus 13.1 without issue. The only additional step is upgrading the IP cores from those packaged with 13.0sp1 to those packaged with 13.1; this will be done automatically when the sopc is opened in Qsys

http://www.arrownac.com/solutions/sockit/files/SoCKIT_Materials.zip [arrownac.com]

Working through the hardware side will get you a usable sof file to program the FPGA. Working through the software side will get you a usable preloader. Although the SoCKit is heavily based off of Altera's reference development kit (GHRD) the preloader is different in large part due to slightly different SDRAM specifications. Attempting to use the preloader included in Altera's SoCEDS will not work.

The programming stage of the documentation is a bit flawed. The reference configuration assumes a single JTAG device, but there can be more. At a minimum there will be one for the HPS, but a bank of two dipswitches on the board can enable JTAG for the HPS itself and any devices connected via HSMC. Just use autodetect to pick up all JTAG devices and program the SOF file to the FPGA device, it's very clear as to which is which.

Next, grab the github repositories for the linux-socfpga (kernel), poky-socfpga (base filesystem), and u-boot-socfpga (bootloader). Grab the latest version tagged with '-rel'. I used the following:

kernel: socfpga-3.9-rel

u-boot: socfpga_v2013.01.01-rel

poky: danny-altera-rel

The wiki on rocketboards can be followed to install the dependencies and begin compilation. I can verify that everything builds nicely on CentOS 6.5 without much fuss, Ubuntu is extremely problematic so I would avoid it.

If you look at the SD Card image that ships with the SoCKit you'll notice that it has a FAT filesystem with two files on it, socfpga.dtb and uImage. These are the device-tree-blob, and linux-kernel-image respectively. The kernel is in a u-boot image format, which is simply a zImage with an additional header. The bootloader that ships with Terasic's SD card image uses an early 2012 version of u-boot and does not support booting directly from a zImage. Support for this (bootz command) is present in the 2013.01.01 release of u-boot so it is no longer necessary to attach the additional header to the kernel image. Just configure and compile the kernel as a zImage as they do in the wiki.

An additional step is missing in the wiki (at least it was last time I looked). The dtb is tightly coupled to the kernel version. Using a dtb from the terasic reference SD image will work for kernel version 3.7, but it will not work for kernel 3.9 or above. The reference one created by Altera's sopc2dts tool is crap and won't work either. However, a working dtb has been included in the linux-socfpga tree under arch/arm/boot/dts/socfpga_cyclone5.dts. This can be compiled to a dtb either through the dtc tool itself, or in-situ by running 'make ARCH=arm dtbs'. This is good enough to get started with, but if you add additional memory mapped devices to your system you will have to modify it by hand and recompile it.

NOTE: the socfpga_cyclone5.dts file exists in the 3.9-rel tree, but has been replaced and expanded in master by one specifically tailored towards the SoCKit. I haven't looked at this yet, it's on my todo list. You may wish to check it out.

OTHER NOTE:The bootloader will look for socfpga.dtb by default. You can change the name of the file that it looks for by tweaking the bootloader environment settings (this is good practice) or you can change the name of the file when you copy it to the filesystem.

Expand the compiled

Do not buy this

[Ditiris]

Short version: I write FPGA code for a living: don't buy this kit. Get a Xilinx MicroZed, Zed, or Altera SoCKIT. It is a revolutionary improvement over what is offered in this kickstarter at a similar price point.

Long version: If you're interested in HDL and coming from the processor world (ARM), consider the Xilinx Zed, MicroZed, or Altera SoCKIT. The Zed is $400 (slightly less with an academic discount), the MicroZed $200, and I believe you can get an Altera SoCKIT board for $100 if you attend the training (if not, it's expensive at $1600). For a hobbyist, I would probably choose the MicroZed since it's the cheapest to buy straight-out at $200, or Zed if you wanted some of the PMod peripherals.

Any of the above boards offer significant advantages over the LOGi FPGA. The Spartan 6 LX9 is disappointing as a choice, as it's a very small, last-generation device. The current SoC offerings from both Altera and Xilinx pair a processor subsystem (PS) (dual Cortex A9) with a programmable logic (PL) subsystem via an array of standard ARM interfaces (AXI). I believe all of the Xilinx/Altera offerings have between 2,000 and 3,000 built-in connections between the PS and PL. This is a tremendous advantage and offers ridiculous amounts of bandwidth between the PS and PL. It allows unprecedented cooperation between the PL and PS that leads to significantly better performance than is possible with a discrete processor and FPGA combination.

The creators point of view

[Anonymous Coward]

Hi all,

i'am one of the co-founder of the project and i just want to address some of your questions/remarks:

Why buying a LOGI-board when you can get a zedboard/sockit ?

The zeboard/sockit are much more powerful than what the LOGI boards can propose and they will run much higher performance applications ... but they lack support from the software community, and are definitely a no go for a beginner. The Beaglebone and Raspberry-pi benefits of a great support from the software community and kernel development community, with our board we try to bridge a gap between the hardware and software community using the beaglebone/raspberry-pi + LOGI as a collaborative platform for the two. Give a kid a zedboard and raspberry-pi and guess which one he will throw to the bin in the end. The idea of stacking boards is to follow the progress of the user and had complexity when its time to.

Why getting a LOGI-board when you can get a DE0/MicroBoard for the same price ?

The computng power of the raspberry/beaglebone processor is far better than what you can get with a NIOS/Blaze and the linux support is great. Moreover you can program the logic from the processor (i did not say design the logic) while a Blaze can't. With the Linux of these boards, you also have access to a ton of software repositories. The LOGI-boards are designed with co-design in mind, when you use Blaze/NIOS you targets both ends of the co-design problem at the same time. With the LOGI-boards you can separate the concerns.
The price problem is also difficult, DE0 and MicroBoards are subsidized by the chip vendors (Altera/Xilinx) so they can be sold for cheap. We are not subsidized so the price you pay is closer to the price you would pay to build your own product.

Thanks for all your comments, and don't hesitate to ask for more information.

Jonathan Piat

Re:Do not buy this

[jpiat]

Hi, i think that you don't see the point of our product. The LOGI don't pretend to be the most powerful most versatile product on earth. We just propose a board to learn co-design with simple starting point. If you give a zedboard or a sockit to a beginner its just like throwing him a brick in the face. What the beaglebone and raspberry-pi propose is a system of capes/extension boards that you can had as you progress or to match your needs. With these two platform you benefit from a much wider community support that the zeboard/sockit and much better support from a wide community of beginners and expert (when zedboard sockit are just expert platforms). Moreover the price you show are for Xilinx/Altera subsidized platforms, if you have a look at open-hardware platforms, our price-point is no higher.