Re: Running Linux on FPGA

From: Jan Engelhardt
Date: Sun Jan 21 2007 - 16:33:14 EST



On Jan 21 2007 00:14, Ralf Baechle wrote:
>On Sat, Jan 20, 2007 at 11:42:37PM +0000, sathesh babu wrote:
>
>> I am trying to run Linux-2.6.18.2 ( with preemption enable)
>> kernel on FPGA board which has MIPS24KE processor runs at 12
>> MHZ. Programmed the timer to give interrupt at every 10msec. I
>> am seeing some inconsistence behavior during boot up processor.
>> Some times it stops after "NET: Registered protocol family 17"
>> and "VFS: Mounted root (jffs2 filesystem).". Could some give
>> some pointers why the behavior is random. Is it OK to program
>> the timer to 10 msec? or should it be more.
>
>The overhead of timer interrupts at this low clockrate is
>significant so I recommend to minimize the timer interrupt rate as
>far as possible. This is really a tradeoff between latency and
>overhead and matters much less on hardcores which run at hundreds of
>MHz.

Hm I've been running 2.6.13 on a 10/20 MHz (switchable) i386 @ 100 Hz
before without any hangs during boot or operation.


-`J'
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