Re: [ECOS] Speed up TFTP download time in RedBoot

[Andrew Lunn <andrew at lunn dot ch>]

On Mon, Mar 19, 2012 at 06:05:36PM +0200, Elad Yosef wrote:
> Hi,
> I'm trying to speed up the TFTP download time in the Redboot.
> I have tried to change the following params;
> 
> CYGNUM_REDBOOT_NETWORKING_MAX_PKTBUF - had no effect
> CYGNUM_REDBOOT_GETC_BUFFER - I have increased it to 10K but still no improvement
> CYGNUM_IO_ETH_DRIVERS_NUM_PKT - had no effect
> 
> My ETH RX ring has 12 buffer each has 770 bytes (9240 in total)
> 
> Am I missing something?

TFTP uses a very simple UDP protocol without any windows. Each
received packet is ACKed before the next is sent. So the size of the
buffers makes no difference, so long as it can hold one frame. You are
only likely to get speedup if you are suffering from packet loss. The
retries are quite slow, so the effect of loosing a packet is quite
big. So make sure you have a reliable network.

You might also want to look at using http instead. I don't know how
good the TCP implementation is in redboot, it might support some
windowing so speeding up the transfer.

	  Andrew


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