multiprocessing (was: Re: [microblaze-uclinux] FPGA apps?)

[Matthew Rubenstein <email@xxxxxxxxxxxx>]

On Fri, 2004-04-02 at 00:09, Greg Ungerer wrote:
> Hi Matthew,
> 
> Matthew Rubenstein wrote:
> > 	Where are the apps? Linux on FPGA is a means to an end, not an end in
> > itself: familiar development environment for new FPGA tools. Is there an
> > archive of apps that run under MicroBlaze? With MicroBlaze omitting
> > fork() in favor of vfork() (inherited from uCLinux, with no MMU), even
> > the ancient Unix multitasking patterns are unavailable.
> 
> I don't understand what you mean here. uClinux supports true
> multitasking, using vfork doesn't preclude this. It does
> preclude the child running in the parents context, but there
> is ways around this, and in many typical embedded applications
> it is just not a problem in practice.

	Using fork() is a very common technique for multitasking; vfork()'s
omission of the parent's page tables and access to other volatile data
does not allow its use in simple porting of existing source code to
uCLinux. But that's an opportunity: the FPGA parallelism is a much
better infrastructure than the  roundrobin multitasking simulated by
MMUs in other *nixes. And without the distraction of fork(), true
multiprocessing will underlie the ported MB/uCL apps. This is a virtue,
born of necessity, of the MB/uCL platform, which makes it superior to
both other uCLinux and even MMU *nix platforms.


> Regards
> Greg
> 
> 
> 
> ------------------------------------------------------------------------
> Greg Ungerer  --  Chief Software Dude       EMAIL:     gerg@snapgear.com
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-- 


(C) Matthew Rubenstein

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