serial port conflicts

serial port conflicts

[Min ZOU]

Hi,

I have implemented a gdb stub for a SH2 target based on "sh-stub.c" from 
GDB-v3.6 source. Now some basic features like step, break, cont, memory 
read/write, etc. are tested successfully.

The gdb stub and gdb on host communicate via remote serial protocol. 
However I have a problem to debug an application program, which accesses 
the same serial port used by gdb, e.g. I/O functions like "putstring()", 
"getchar()", etc. In my case, "putstring()" cannot display any message 
in gdb console, and "getchar()" cannot receive any input.

I guess there is a conflict between gdb and application program to 
access the same serial port. I'd like to hear any advice on solving this 
problem.

Thanks in advance!

-- 
Best Regards,
Min

Re: serial port conflicts

[Ramana Radhakrishnan]

Hi,

> Hi,
> 
> I have implemented a gdb stub for a SH2 target based on "sh-stub.c" from 
> GDB-v3.6 source. Now some basic features like step, break, cont, memory 
> read/write, etc. are tested successfully.
> 
> The gdb stub and gdb on host communicate via remote serial protocol. 
> However I have a problem to debug an application program, which accesses 
> the same serial port used by gdb, e.g. I/O functions like "putstring()", 
> "getchar()", etc. In my case, "putstring()" cannot display any message 
> in gdb console, and "getchar()" cannot receive any input.

1. The IO activities would finally map down into a call to write / read 
/ open etc.  . Modify the write / read / open in your library to take 
care of the File IO extensions in the serial protocol if used with the 
GDB remote protocol.

2. Use 2 different serial ports (if you have them) . One for the console 
output and the other for the remote debugging.  This might be simpler ;-)


HTH
cheers
Ramana

-- 
Ramana Radhakrishnan
GNU Tools
codito ergo sum (www.codito.com)