[hpsdr] HPSDR / PowerSDR hardware selection

[Michael White]

Hi Eric

Great stuff regarding paging control. I would imagine there must be  
something similar in the Windows API.

Am I right in thinking that Linux uses a co-operative task scheduler?,  
I remember from years ago working on a Unix system that ran a time  
slice system and then depended on co-operative code to release the  
thread early.

I have seen many embedded system boards coming through these days  
using light weight Linux, (like uClinux),, but as I understand it,  
unix cannot be made pre-emptive for true real-time purposes. But so  
much time has passed since the days I was playing with Unix it could  
be that there is branch that can act as an RTOS.

I know the Analog Devices Blackfin processor is running uClinux as a  
viable OS for DSP,. That  could be a really good open source platform  
for Sasquatch with all the free toolchains.

Glenn is looking at dsPic, but I am not sure if that chip has an open  
RTOS. I know there is a commercial one available.

Michael



On 25 May 2008, at 16:17, Eric Blossom wrote:

> On Sun, May 25, 2008 at 02:28:26PM +0100, Michael White wrote:
>> ***** High Performance Software Defined Radio Discussion List *****
>>
>> I totally agree Glenn.
>>
>> To me this is a problem with these type of OS we can only really  
>> guess what
>> is going on under the hood. It is so difficult to properly engineer  
>> a real
>> time system using Windows or even Linux, because the guts of the  
>> system is
>> inaccessible  (to most people),  and getting a setup that has a low
>> probability of buffer overrun is something of a black art.
>
> Speaking about most Unix and all Linux systems, getting rid of page
> faults in your own code is trivial.  There is a system call that will
> lock all of the relevant pages into memory.  See man mlock.
>
> Eric


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