Call for SPARCengine 1e BSP

[Joel Sherrill <joel@OARcorp.com>]

Ivan Galkin wrote:
> 
> Regarding MVME167 as a better match for our long-suffering sun4e sparc - 
> I agree.
> 
> However, we have been playing with an Intel Rtems target for some months 
> already, for a different project. Building a host bsp environment #3 for 
> motorola... our setup today is confusing enough, and we really don't 
> know how steep the Power PC curve is going to be.

If you don't know the PowerPC and have to debug in detail, it is a
bit to learn.

> RTEMS support of VME in motorolas is a strong point, though.
> 
> As for the second-hand boards, our hard-earned experience tells us not 
> to get on that route without documentation and a ready to use BSP. It 
> took us a couple of  months and triple the cost of the board to get docs 
> for our sparcengine 1e.

Motorola seems to be quite good about having their documentation 
available on-line.  You should be able to download mvme167 documentation
right now easily.

OTOH any board with a Marvell part is IMO underdocumented.  They have a
policy that requires an NDA before documentation can be received.  And 
this is for parts that appear on common VMEBus boards including a few
Motorola ones.

--joel

> Cheers for now.
> E1
> 
> Joel Sherrill <joel at OARcorp.com> wrote:
> 
>> Ivan Galkin wrote:
>>
>>>
>>> Jiri, many thanks for these important clarifications.
>>> I only wish we knew that this sparc v7 board won't work a month ago.
>>> We do need VME to control our VME hardware and sync to its timing.
>>> I don't think we are going to spend $18K on a TSC695 starter kit. 
>>> Does not sound right.
>>> MiThOS will work on sun4e, but their development is defunct, and they 
>>> never wrote a VME driver.
>>> We are leaning towards scratching the idea and moving to an intel vme 
>>> board. This will mean different bsp, vme, endian, CPU speed. But its 
>>> better than sun4e, apparently.
>>> Something like vp101 by ArcTechnico. This brings another question - 
>>> do we order a linux VME driver from ActTechnico, hoping that we can 
>>> make it work in Rtems? Another option in a VxWorks vme driver.
>>
>>
>>
>> Depending on what your CPU desire is, the Motorola PowerPC VMEBus boards
>> have an active RTEMS user community.
>>
>> If you are trying to do this on the cheap, then a used MVME162 or
>> MVME167 might make a nice option.
>>
>> The x86 VMEbus boards should work as well but you would probably have to
>> adapt the VMEbus driver.
>>
>> --joel
>>
>>> Thanks again,
>>> Ivan
>>>
>>>
>>>
>>> Jiri Gaisler wrote:
>>>
>>>>
>>>> Since you asked, here my view on the topic ...
>>>>
>>>> The ERC32 is not very similar to the Fujitsu MB86901A
>>>> processor used in the Sparcengine 1e. The integer
>>>> pipeline implements the same SPARC V7 instruction set,
>>>> but the memory hierarchy is completely different.
>>>> MB86901A has a cache, an MMU, and DRAM main memory.
>>>> ERC32 has no cache, no MMU and executes directly
>>>> from 0-waitstate external static RAM. The peripherals
>>>> (uart, timers, irq ctrl, I/O) are completely different.
>>>> I also believe that the MB86901A has 7  register
>>>> windows while ERC32 (based on Cypress 601) has 8.
>>>>
>>>> It should be possible to develop an SS 1E bsp, but
>>>> all low level code (drivers and init) will becdifferent
>>>> from ERC32. So the only RTEMS part you really can
>>>> reuse is the general SPARC support. The complete
>>>> bsp and associated drivers must be written from
>>>> scratch. This means that you need detailed
>>>> data sheets with register definitions, address
>>>> allocation and interrupt routing. Unless you
>>>> have that, it will be very difficult (impossible?).
>>>>
>>>> If you really want some cheap SPARC hardware,
>>>> why not get a low-cost FPGA board (~ $500) and
>>>> put a LEON3 on it. There is a stable RTEMS bsp
>>>> for it (yes, I will soon merge it in to the main tree)
>>>> and the VHDL code and development tools are free.
>>>> OK, there is no VME but do you really need that?
>>>>
>>>> An other aspect is that we have today announced
>>>> the availability of LEON3FT parts on the Actel
>>>> RTAX2000 radiation-hardened FPGA devices. There
>>>> will be various pre-programmed LEON3FT devices
>>>> with 1553, CAN-2.0 and Spacewire available, as well
>>>> as netlists if you want to make you own FPGA config.
>>>> Performance is 20 - 30 MHz, on par or better than ERC32,
>>>> but with only ~ 0.5W power consumption. For software
>>>> development, you can use cheap Xilinx/ALtera boards
>>>> or a commercial grade AX2000 device (~ $250).
>>>> Debugging is also significantly easier than ERC32,
>>>> you have a real on-chip debug support unit, with
>>>> single-stepping, tracing and memory/register access.
>>>>
>>>> Jiri.
>>>
>>>
>>>
>>>
>>
>>


-- 
Joel Sherrill, Ph.D.             Director of Research & Development
joel at OARcorp.com                 On-Line Applications Research
Ask me about RTEMS: a free RTOS  Huntsville AL 35805
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