RE: Gdb stubs for embedded targets

["Atul Talesara" <atul dot talesara at nevisnetworks dot com>]

comments inline ...

Hi,
Wanted to know about the following

1.) Are the gdb stubs written only for communication
over the serial port ? Are there stubs that can
communicate via tcp/ip
[Atul Talesara] Stubs are *not* written only for
communication.  They are written to *take* commands
from the GDB running on remote host and *execute*
them, viz. read/write mem/regs, single step, etc.
Mechanism of communication serial or TCP depends
on what is available to stub on the remote target.

2.) Are gdb stubs only dependant on the processor
architecture ? Are they dependant on the OS that runs
on the target
[Atul Talesara] Typically yes.  Since stub runs as
a part of exception handler on the remote target,
the only part that depends on OS is exception
handling, i.e. arranging for OS to transfer control
to stub on SIGTRAP.  Memory read/write might also
depend on OS.

3.) Any place where i can find more info that is more
comprehensive than the gnu manuals
[Atul Talesara] [1] Explains what GDB expects of stub
on the remote target and [2] details the remote serial
protocol that GDB uses to communicate to remote target.

[1] http://www.objsw.com/docs/gdb_104.html#SEC105
[2]
http://www.redhat.com/docs/manuals/enterprise/RHEL-3-Manual/gdb/remote-p
rotocol.html

Hope this helps.

cheers,
Atul P Talesara
----------------------------------------------------------
Hold fast to dreams for if dreams die,
Life is a broken-winged bird that cannot fly.
                                        - Langston Hughes 
----------------------------------------------------------