Re: Loading code with an Abatron BDI2000

[Shaun Jackman <sjackman at gmail dot com>]

A little searching through GDB's manual turned up "set remote
memory-write-packet-size" and "set download-write-size". On my target
these values defaulted to 336 and 512 respectively. I found that
increasing them to 1025 and 8192 did improve performance somewhat. I
used 1025 because I found the TCP packet size sent by GDB was limited
to 1024 for some reason unknown to me (anyone else know?) and the "+"
acknowledgement was sent in a TCP packet all to its own, but still
counted against the memory-write-packet-size. How can I increase the
TCP packet size to 1460, the TCP MSS, to get more date bytes out of
each packet? Any other thoughts on how else I can improve the transfer
rate?

Cheers,
Shaun

set remote memory-write-packet-size 1025
set remote memory-write-packet-size fixed
set download-write-size 8192

For the curious, a typical transfer between gdb and the BDI2000 is as
follows. The left column is elapsed milliseconds since t0.
0 +
0 $X and 1024 bytes of data
1	ACK the +
3	ACK the $X
14	ACK window update
27	ACK window update
29	+
39	$OK
69 +
70 $X and 1024 bytes of data
... and so forth.

There's quite a gap (30 ms) between the BDI's $OK the gdb's +. Could
this be improved?

On 7/8/05, Shaun Jackman <sjackman@gmail.com> wrote:
> I'm using gdb 6.2.1 to debug an ARM7TDMI with an Abatron BDI2000, a
> device which speaks the gdb remote protocol natively over Ethernet.
> Loading code with gdb is a slower process than I had hoped.
...