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Re: GDB stubs problem



My target is a MIPS R3000 architecture, not x86, so I can't run the Linux's GDB.

I turned on the remote debug in GDB as following:

(gdb) set remotebaud 19200
(gdb) set debug remote 1
(gdb) target remote com1
Remote debugging using com1
Sending packet: $Hc-1#09...Sending packet: $Hc-1#09...Sending packet: $Hc-1#09..
.Sending packet: $Hc-1#09...Timed out.
Timed out.
Timed out.
Ignoring packet error, continuing...
Sending packet: $qC#b4...Sending packet: $qC#b4...Sending packet: $qC#b4...Sendi
ng packet: $qC#b4...Timed out.
Timed out.
Timed out.
Ignoring packet error, continuing...
Sending packet: $qOffsets#4b...Sending packet: $qOffsets#4b...Sending packet: $q
Offsets#4b...Sending packet: $qOffsets#4b...Timed out.
Timed out.
Timed out.
Ignoring packet error, continuing...
Couldn't establish connection to remote target
Malformed response to offset query, timeout
(gdb)

Then I logged every characters came from serial port in function hal_jmr_get_char()
in packages/hal/mips/jmr3904/v1_3_1/src/plf_stub.c. The results show that when
the GDB tried to connect to the target, it sent the following packets:

+$H9$Hc9$Hc9$Hc9---+$4$qC4$qC4$qC4---+$b$qOb$qOb$qOb---+

But according the debug messages shown on GDB's console above, the packets are:

$Hc-1#09$Hc-1#09$Hc-1#09$Hc-1#09$qC#b4$qC#b4$qC#b4$qC#b4
$qOffsets#4b$qOffsets#4b$qOffsets#4b$qOffsets#4b

Why aren't they equal? I guess it's the problem that causes the connection failed.
Could someone help me?

Thanks.

> I've had the same problem.  Are you, by chance, trying to use gdb5.0
> for x86?  If so, try the gdb that comes with your Linux distrubution.
> I found that gdb5.0 didn't work.
> 
> On Mon, May 28, 2001 at 08:13:22PM +0800, xavier wrote:
> > 
> > Hi,
> > 
> > I'm trying GDB stubs support in eCos. I build both gdb_module.img and
> > a test program with GDB stubs included. When the gdb_module.img
> > starts in the target, it sends the following packet:
> > 
> > ++$T0525:a0307a34;1d:80005420;#2
> > 
> > It seems OK. The gdb_module is waiting for a connection. Then I connect
> > GDB to the target. The target receives the following packet:
> > 
> > +$H9$Hc9$Hc9$Hc9---+$4$qC4$qC4$qC4---+$b$qOb$qOb$qOb---+
> > 
> > (gdb)  target remote com1
> > Remote debugging using com1
> > Ignoring packet error, continuing...
> > Ignoring packet error, continuing...
> > Ignoring packet error, continuing...
> > Couldn't establish connection to remote target
> > Malformed response to offset query, timeout
> > (gdb)
> > 
> > I looked into the source code and found that in getpacket() in generic-stubs.c,
> > __add_char_to_packet() expects a '#' character to finish a packet but there is
> > no '#' character sent from GDB. So getpacket() ran forever.
> > 
> > Any suggestion?
> > 
> 


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