Re: Running Linux on FPGA

[Sunil Naidu]

On 1/21/07, Ralf Baechle <ralf@xxxxxxxxxxxxxx> wrote:
> 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.  For power sensitive
> applications lowering the interrupt rate can also help.  And that's alredy
> pretty much what you need to know, that is a 10ms  timer is fine.

I have worked with FPGA Linux system which is reconfigurable
on-the-fly by the 200Mhz ARM9 CPU running Debian Linux, Altera Cyclone
II FPGA is included on my TS-7300 board. Advantage is, Altera FPGA and
a dedicated high-speed bus between the CPU and FPGA provides a good
design scope to provide many solutions.

Coming to boot up (by an USB 1GB SD card), by doing enough software
tuning bootup to a Linux prompt takes just 1.69 seconds after
power-up. If I remember correctly, SD image will look at the state of
jumper 6 (should be put ON), the full Debian bootup will be bypassed
and the system will instead drop straight to a shell prompt. 1.69
seconds after power-on the serial console prompt is active and 2.41
seconds after power-on the video console is displayed.

This software is based on Debian & has a vendor supplied Linux boot
loader. Currently am working (slowly in free time) to bring the whole
thing to FC6.  Shall post the progres...

>   Ralf

~Akula2
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/