Re: Various size of (Project) ideas for NetBSD and pkgsrc

[Yann Sionneau <yann.sionneau%gmail.com@localhost>]

Le 29/09/13 20:41, Ryo ONODERA a écrit :
> Hi,
>
> From: Yann Sionneau <yann.sionneau%gmail.com@localhost>, Date: Sun, 29 Sep 2013 
> 19:37:14 +0200
>
> > Hi Ryo,
> >
> > Le 29/09/13 03:09, Ryo ONODERA a écrit :
> > > Hi,
> > >
> > >
> > > (8) Porting NetBSD to some FPGA CPU board
> > > OpenCores' OpenRISC 1200, Xilinx's MicloBlaze, Altera NIOS II is
> > > available for FPGA board.
> > > At least OpenRISC 1200 and MicroBlaze have Linux support.
> > > Supporting these architecture is interesting for NetBSD.
> > > (I have no idea about NetBSD/nios2 status.)
> > I am in the process of adding support for LatticeMico32 (LM32)
> > architecture to NetBSD 6 kernel.
> > Last year a MMU (memory management unit) has been added to the LM32
> > softcore which makes it able to run Linux or NetBSD.
> > LM32 already had a uCLinux (noMMU) working port.
> > This year I started the project to port NetBSD 6 kernel on MMU-enabled
> > LM32 CPU in general and on the Milkymist open source System-on-Chip in
> > particular.
> >
> > Today I had my first result on this project:
> > http://pastebin.com/MJgB6Y05
> >
> > -> NetBSD 6 kernel immediately panics and dies. Even though this might
> > -> seem like a poor result, there have been a lot of work behind it.
> > This is a first step which looks very promising :) (at least console
> > driver works ;))
> Great work!
> I am not kernel developer, but I want to know the following questions.
>
> How about status of NetBSD current?
> According to NetBSD development process, porting to current is essential,
> if I understand correctly.
Sorry I was using wrong term by saying "NetBSD 6" maybe.
My work is based on "-current"
But it's been several months since I last merged back into current so 
I'm a bit outdated I guess...

But I don't think the kernel as changed so much that it would take more 
than a few hours to sort out how to merge correctly my branch with 
NetBSD-current :)
> And how about bus support?
> According to MiklyMist wiki, MilkyMist uses wishbone like bus, and
> I understand correctly, wishbone or similar bus support are not
> implemented in current NetBSD.
Wishbone is the "on-chip" bus used in the System-on-Chip.
It's totally transparent to the software.
Basically all of the cores in the system-on-chip have a set of registers 
which are memory mapped.
So there is no need for a "bus support", or maybe something trivial like 
mapping those registers to virtual memory once and then use the mapping 
in the respective drivers of the different cores connected to the 
wishbone bus.
Here is a block diagram of the Milkymist SoC: 
https://en.wikipedia.org/wiki/File:Milkymist_architecture.svg
> > The Milkymist System-on-Chip runs on various FPGAs (Spartan 3, Spartan
> > 6, Virtex 4 etc) from various FPGA vendors (Xilinx, Lattice, Altera)
> > It has been ported on numerous boards (Milkymist One, ML401, De0-nano,
> > Nexys3 etc...)
> > It uses LatticeMico32 (open source softcore) as it's CPU softcore.
> >
> > If you want more information about Milkymist and it's NetBSD porting
> > work status do not hesitate to e-mail me or the Milkymist mailing list
> > :)
> I think FAGA based hardware needs setup of hardware, so
> NetBSD developer should write CPU softcore etc to FPGA chip.
> Maybe developers not familiar with this kind of works.
>
> For example, MilkyMist for DE0 namo is attractive for me.
> It is low price FPGA hardware.
> But I am completely newbie to FPGA device, and I cannot imagine
> what is needed to start MilkyMist on DE0 nano.
You need:

- The hardware
- A Windows or Linux PC (don't know about BSD support, maybe with the 
linux syscall compatibility layer?)
- The IDE for the FPGA vendor installed, for the DE0 it's the Altera IDE 
-> Quartus II Web Edition Software (free of charge)
- Clone the source code over there: 
https://github.com/Florent-Kermarrec/milkymist-ng-de0nano
- Clone its dependencies (Migen and Mibuild from this github account: 
https://github.com/milkymist/)
- Install Migen, Mibuild (python setup.py install, that's all)
- cd milkymist-ng-de0nano && make

Then use whatever software your board needs to push the FPGA bitstream 
(the design file that tells the FPGA how to behave) in the FPGA.

And there you are, you get a minimalistic Milkymist-ng system-on-chip 
with LatticeMico32 core, uart console, memory mapped GPIOs, SDRAM 
controller.

A simple BIOS is provided, accessible from the UART.
> And I want to know performance information about FPGA board.
I don't own this board, but you cannot seriously expect big fast FPGA 
for a very small amount of money.
Those small dev boards usually feature the little children of the given 
FPGA family, which in some way is great because it's usually the only 
FPGAs supported by the Free of charge version of the IDE (this is true 
for Xilinx and Altera at least, dunno for Lattice or Actel)
> Microsoft Windows PC is needed?
No Microsoft Windows PC needed, you can use only Linux if you want.
For some boards however, it's only possible to push the bitstream (FPGA 
design file) to the board from Windows, only because sometimes there is 
no Linux software for that. That could be what decides you to buy a 
board and not to buy another.
>   Additional hardware?
There is no RS-232 connector on the De0-nano.
And I don't think USB blaster port can be used as a USB-uart.
A quick look at Mibuild (kind of python library acting as abstraction 
layer between a FPGA board and the Migen framework) indicates that the 
port of milkymist-ng to the De0-nano is using GPIOs D3 and C3 of the 
board as rx and tx for the UART.
Which means you need to hook some 3V3 TTL->RS-232 converter up to the 
GPIO expansion header of the De0-nano in order to connect any PC to the 
uart of the System-on-Chip running on the De0 board.

Another way of doing this, would be to use an arduino if you have one, 
and do a little program that acts as a bridge between the board and your 
PC like this : [De0-nano] rx tx GPIO <-> digital input of Arduino 
[arduino board] USB uart <-> Computer

> Writing how to setup hardware is needed, and it may be
> another NetBSD project idea or homework for MilkyMist people.
>
> By the way, what is your target? MilkyMist SoC? MilkyMist-ng?
For now my target is Milkymist SoC, because it's been heavily tested and 
works very well.
I know the SoC design is very solid and does not have any surprise.
However, Milkymist-ng seems to become stable nowadays, and it's very 
portable and getting more and more easy to deal with since it's written 
in Python by using the fantastic Migen framework :)

Anyway, Milkymist legacy or Milkymist-ng, from a software point of view 
it's very very similar.
Only the addresses of the different cores changed.
As long as you just want to support framebuffer, ethernet, gpio, timer, 
uart that's really pretty much nothing to change to kernel code to have 
it run on one or the other.
> And How to get the hardware that is exactly as same as yours?
I have a Milkymist One (http://milkymist.org/3/mmone.html) board which 
can be tricky to get your hands on since Sharism has stopped operations.
However, you can use the awesome work Michael Walle did by adding 
support for Milkymist SoC (legacy one) to Qemu :)

To be honest, I am mostly testing using Qemu those days since it's very 
convenient during development.
No power supply, no hardware to carry, to USB cables etc etc.
Just your NetBSD kernel, your GDB and your Qemu in your terminal :)

Another NetBSD developer is interested by the NetBSD/Milkymist project, 
he owns a Nexy 3 FPGA board ( 
http://www.digilentinc.com/Products/Detail.cfm?Prod=NEXYS3 ). I quickly 
ported Milkymist-ng SoC on his board ( 
https://github.com/fallen/nexys3-milkymist-ng ) so that he could run a 
simple BIOS on his board :) His board is more expensive though... BUT it 
has a USB-UART ;)
> This question is how to start NetBSD/milkymist question.
> What hardware/software should I buy to follow your work?
You don't need any hardware, at all. That's the beauty of having support 
for the Milkymist SoC in Qemu!
But if you really want to play with hardware (which is pretty cool 
indeed :)) you can buy a cheap De0-nano and a TTL->RS-232 converter!
You could definitely try my NetBSD kernel work on this board, since it 
has 32 MB of SDRAM.
> And I have noticed some open source SPARC CPU sotfcore is available for
> FPGA board (T1, S1, LEON, etc.).
You have S1, LEON, aeMB (open source clone of MicroBlaze), OpenRISC and 
a lot more
If you want to know why Milkymist project chosed LM32 core instead of 
another, you can check out the master thesis Sébastien did, there is a 
short comparison between those cores: 
http://milkymist.org/3/thesis/thesis.pdf page 23 of the PDF file.
> > FYI MicroBlaze CPU is not open source, even though there are a few
> > open source clones out there (aeMB and others)
> > Nios II is not open source neither.
> > OpenRISC is open source and has a MMU and a Linux port, it's a nice
> > project as well :)
> I am not sticky to open source hardware.
> Of course, if CPU softcore is open source, I am more happy.
> And do not forget NetBSD/emips.
Indeed that's a very nice project :)
Too bad boards listed in http://www.netbsd.org/ports/emips/ are starting 
to be getting very old.
And very hard to source.
> > All of this being said, I agree with you that having NetBSD running on
> > FPGA would be a really cool achievement, especially on OpenSource
> > hardware (PCB and FPGA design) which allows for deep understanding of
> > hardware, digital design and low level software as well as tweaking
> > the CPU (cache size, TLB size, instructions, pipeline configuration
> > etc).
> Thanks for your information.
>
> I think the following idea is shown in this thread by you and me.
>
> (a) Porting NetBSD to MilkyMist SoC/MilkyMist-ng open source hardware (status: 
> in progress)
> (b) Porting NetBSD to OpenRISC 1200 (target board is not specified)
> (c) Porting NetBSD to MIcroBlaze (target board is not specified)
> (d) Porting NetBSD to FPGA board with SPARC CPU softcore (target CPU and board 
> is not specified)
> (e) Writing how to start NetBSD/milkymist with a certain board (target board 
> should be specified)
You mean write a tutoriel about how to synthetize Milkymist SoC, put it 
in a board, compile NetBSD kernel and then get it to run on the SoC?
That would be nice indeed :) But first I need to finish the kernel work, 
and there is still a lot of work to be done!
> Thank you.
You're welcome :)

--
Yann Sionneau