Using partitions in (Arcnet) device drivers?

[Ian Caddy]

Hi Bill,

Sorry, I didn't mean to scare you...;-)

I wasn't trying to bring into question the reliability of partitions, I 
was just wondering why I didn't see their use in the RTEMS core.  Joel 
has explained that for me.

I was also a bit worried about how I was going to set aside memory for 
the partition and that I wanted to be able to change it size (possibly) 
on startup of the unit from a previously downloaded configuration.

I got my answer for this from Mac Johnson, that we just need to work out 
the size, then alloc the block off the heap, I don't know why but I 
hadn't even thought of using the heap in this way.  It is so simple.... 
I thought I was going to have to set aside a chunk of memory before I 
created the heap or any other region for my partition and then I was 
concerned about being able to change it at a later startup.

Now I can just create the heap as now with the max size and get all my 
partitions from it.  It is so much simpler.

Thanks for the offer of the BSP Bill, but ours is also looking in pretty 
good shape at this stage, I just need to get this last driver completed 
and then we will be ready to port over our old SOS based 68000 
application environment into this lovely open source system.

Talk to you soon,

Ian Caddy


Bill Butler wrote:

>Ian,
>
>EEK!.. I'm currently writing code that I rely on Partitions heavily -- I
>am using the SPxx test code as examples and trust that it works.
>
>Also, Ian, I have a pretty good BSP for the 5307 if you want it. It is
>not 100% complete but it's close. One thing that might be a limitation
>is it does not initialize SDRam, because my code runs in SDram and that
>would kind of be a trick to initial what I'm already relying on :).
>
>If you want it let me know.
>
>
>
>Bill Butler
>Project Lead
>Sr Software Engineer
>AIPCOM Inc
>(972) 644-2328 (x16)
>
>  
>
>>-----Original Message-----
>>From: Ian Caddy [mailto:ianc at microsol.iinet.net.au]
>>Sent: Wednesday, June 26, 2002 12:56 AM
>>To: rtems list
>>Subject: Using partitions in (Arcnet) device drivers?
>>
>>Hi All,
>>
>>We are in the process of putting an arcnet device driver into our
>>    
>>
>RTEMS
>  
>
>>BSP for the Coldfire 5307.
>>
>>By the end of it, we hope to have the Arcnet device driver supporting
>>both the legacy packet interface of an existing product but at the
>>    
>>
>same
>  
>
>>time putting a layer in so we can use IP over the Arcnet also.
>>
>>Our Arcnet is configured to only have 256 byte packets, and we need
>>somewhere to put them when they are received.
>>
>>We have two options available to us, the first is to get the number of
>>buffers required off the heap and then manage them ourselves.
>>
>>The second option is to create partition for the buffers and then let
>>RTEMs manage the buffers for us.
>>
>>We are working on the 4.5.0 release of RTEMs and I did a quick search
>>through the tree and no-one in the RTEMs system seems to use any
>>partitions.  There are some used in the tests.
>>
>>Is there some reason why partitions have not been used, as it looks
>>    
>>
>like
>  
>
>>exactly what we need for this device driver?
>>
>>Also, just a note on the SMC91C111 Ethernet port we were doing.  It is
>>complete now with DMA and working well, but I have been dragged off it
>>for some time.  I still haven't managed to move it into the libchip
>>    
>>
>area
>  
>
>>but it is still on my list of things to do.  I just need to make sure
>>the Arcnet is running also and then I will get back to it.
>>
>>regards,
>>
>>
>>Ian Caddy
>>
>>--
>>
>>ianc at microsol.iinet.net.au
>>Microsol (Aust) Pty Ltd
>>
>>Phone: (+61) 08 9473 6600
>>Fax:   (+61) 08 9473 6699
>>    
>>
>
>
>
>
>  
>

-- 

ianc at microsol.iinet.net.au
Microsol (Aust) Pty Ltd

Phone: (+61) 08 9473 6600
Fax:   (+61) 08 9473 6699