Re: [ECOS] Problem with GDB over /dev/ttyS0

[Jonathan Larmour <jlarmour at redhat dot com>]

jyl087@netscape.net wrote:
> 
> Hi,
> 
> Help..., I'm can't connect to my remote EDB7312 via the serial GDB
> interface. The host is Linux 7.2, running GDB 5.1.1. The target is
> the latest eCos, running on a EDB7312 board with RedBoot installed
> in Flash.
> 
> The strange thing is that I can connect to the remote host via TCP:9000.
> Also, I can "cu" and "minicom" connect to the target to talk to the
> Redboot prompt. I can even connect to the target via /dev/ttyS0 when
> running Angel in the ROM and using "target rdi"!  However, when I
> use "target remote /dev/ttyS0", gdb just hangs. Also hangs when I use
> the Insight GUI. I've made sure to use "set remotebaud 38400" to match
> the setup of my board.

If you use minicom and type something like:
++$g#67

do you see anything?
 
> Another odd thing... when the gdb is hung after issuing the "target
> remote" command, I can open another xterm window and "cu -l /dev/ttyS0 dir" and get the port. This obviously means that gdb hasn't even
> opened the serial port.
> 
> Any ideas on what I'm doing wrong?

Do you have read/write access to /dev/ttyS0? Perhaps GDB isn't reporting an
error.
 
> Also, another oddity about eCos. I can download a test program via the
> remote/TCP connection and execute it normally. However, when I download
> my test program using the RedBoot monitor and TFTP, I get a different
> result. Using a terminal emulator connected direcly to the board, I
> type "load..." and then "jump start"... The test program runs very
> slooooowly.   What's different about running the target directly from
> the hardware vs. over GDB?

Perhaps the port you are using isn't complete e.g. code sometimes requests
delays sometimes, and if the port didn't set things up right for the clock
speed, this might cause your problems.

Jifl
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