RE: remote serial protocol - gdbserver

["Raja Saleru" <iap_sraja at access dot co dot jp>]

Hi, please find the session.

------------------------------------------------------------------------
-------------------------------------------
[root@prism gdbserver_test]# sh-elf-gdb GdbServer_Test
GNU gdb 6.0
Copyright 2003 Free Software Foundation, Inc.
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are
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Type "show copying" to see the conditions.
There is absolutely no warranty for GDB.  Type "show warranty" for
details.
This GDB was configured as "--host=i686-pc-linux-gnu --target=sh-elf"...
Sending packet: $Hc-1#09...Ack
Packet received: OK
Sending packet: $qC#b4...Ack
Packet received: QC2
Sending packet: $qOffsets#4b...Ack
Packet received: Text=8c5e8354;Data=8c5e9368;Bss=8c5ea37c
Sending packet: $?#3f...Ack
Packet received: T0510:54835e8c;0e:00000000;0f:7466658c;
Sending packet: $m0,4#fd...Ack
Packet received: 8867658c
__entry (param=0x8c656788) at crt0.c:26
26      {
(gdb) b main
Breakpoint 1 at 0x8c5e83d4: file GdbServer_Test.c, line 38.
(gdb) c
Continuing.
Sending packet: $Z0,8c5e83d4,2#4c...Ack
Packet received:
Packet Z0 (software-breakpoint) is NOT supported
Sending packet: $m8c5e83d4,2#03...Ack
Packet received: 04d1
Sending packet: $X8c5e83d4,0:#26...Ack
Packet received:
binary downloading NOT suppported by target
Sending packet: $M8c5e83d4,2:20c3#15...Ack
Packet received: OK
Sending packet: $Hc0#db...Ack
Packet received: OK
Sending packet: $c#63...Ack
Packet received: T0510:d4835e8c;0e:9866658c;0f:ac835e8c;
Sending packet: $m8c5e83c8,2#06...Ack
Packet received: e62f
Sending packet: $m8c5e83ca,2#2f...Ack
Packet received: 224f
Sending packet: $m8c5e83cc,2#31...Ack
Packet received: f87f
Sending packet: $m8c5e83ce,2#33...Ack
Packet received: f36e
Sending packet: $m8c6566a4,4#d4...Ack
Packet received: b066658c
Sending packet: $m8c5e83c8,2#06...Ack
Packet received: e62f
Sending packet: $m8c5e83ca,2#2f...Ack
Packet received: 224f
Sending packet: $m8c5e83cc,2#31...Ack
Packet received: f87f
Sending packet: $m8c5e83ce,2#33...Ack
Packet received: f36e
Sending packet: $m8c6566a4,4#d4...Ack
Packet received: b066658c
Sending packet: $m8c6566a0,4#d0...Ack
Packet received: ac835e8c
Sending packet: $M8c5e83d4,2:04d1#16...Ack
Packet received: OK

Sending packet: $m8c656698,4#b0...Ack
Packet received: 02000000
Sending packet: $m8c65669c,4#db...Ack
Packet received: a866658c
Breakpoint 1, main (argc=2, argv=0x8c6566a8) at GdbServer_Test.c:38
38          Application();
(gdb) l
33
34      extern void Application();
35
36      int main(int argc, char **argv)
37      {
38          Application();
39
40          return 0;
41      }
42
(gdb) s
Sending packet: $Hc2#dd...Ack
Packet received: OK
Sending packet: $s#73...Ack
Packet received: T0510:d6835e8c;0e:9866658c;0f:ac835e8c;
Sending packet: $m8c5e83d4,2#03...Ack
Packet received: 04d1
Sending packet: $M8c5e83d4,2:20c3#15...Ack
Packet received: OK
Sending packet: $Hc0#db...Ack
Packet received: OK
Sending packet: $s#73...Ack
Packet received: T0510:10845e8c;0e:9866658c;0f:da835e8c;
Sending packet: $m8c5e841c,2#00...Ack
Packet received: 67d1
Sending packet: $M8c5e841c,2:20c3#12...Ack
Packet received: OK
Sending packet: $c#63...Ack
Packet received: T0510:1c845e8c;0e:1466658c;0f:da835e8c;
Sending packet: $M8c5e841c,2:67d1#1c...Ack
Packet received: OK
Sending packet: $m8c5e8410,2#cd...Ack
Packet received: 862f
Sending packet: $m8c5e8412,2#cf...Ack
Packet received: 962f
Sending packet: $m8c5e8414,2#d1...Ack
Packet received: e62f
Sending packet: $m8c5e8416,2#d3...Ack
Packet received: 224f
Sending packet: $m8c5e8418,2#d5...Ack
Packet received: 8c7f
Sending packet: $m8c5e841a,2#fe...Ack
Packet received: f36e
Sending packet: $m8c65668c,4#da...Ack
Packet received: 9866658c
Sending packet: $m8c5e8410,2#cd...Ack
Packet received: 862f
Sending packet: $m8c5e8412,2#cf...Ack
Packet received: 962f
Sending packet: $m8c5e8414,2#d1...Ack
Packet received: e62f
Sending packet: $m8c5e8416,2#d3...Ack
Packet received: 224f
Sending packet: $m8c5e8418,2#d5...Ack
Packet received: 8c7f
Sending packet: $m8c5e841a,2#fe...Ack
Packet received: f36e
Sending packet: $m8c65668c,4#da...Ack
Packet received: 9866658c
Sending packet: $m8c656688,4#af...Ack
Packet received: da835e8c
Sending packet: $M8c5e83d4,2:04d1#16...Ack
Packet received: OK
Application () at application.c:58
58              mmUserPrint(" Enter Root task\n");
(gdb) l
53              T_RFLG pk_rflg;
54              T_RVER pk_rver;
55
56              INT     err;
57
58              mmUserPrint(" Enter Root task\n");
59
60              /* o[WQ?*/
61              err = tk_ref_ver( &pk_rver );
62              if( err != E_OK)
(gdb) n
Sending packet: $m8c5e83d4,2#03...Ack
Packet received: 04d1
Sending packet: $M8c5e83d4,2:20c3#15...Ack
Packet received: OK
Sending packet: $s#73...Ack
Packet received: T0510:1e845e8c;0e:1466658c;0f:da835e8c;
Sending packet: $s#73...Ack
Packet received: T0510:20845e8c;0e:1466658c;0f:da835e8c;
Sending packet: $s#73...Ack
Packet received: T0510:22845e8c;0e:1466658c;0f:da835e8c;
Sending packet: $s#73...Ack
Packet received: T0510:2874008c;0e:1466658c;0f:26845e8c;
Sending packet: $Hg2#e1...Ack
Packet received: OK
Sending packet: $g#67...Ack
Packet received:
000000002874008ca866658c00000000b0935e8ca866658c000000000000000000000000
00000000000000000000000000000000000000001466658c26845e8c2874008c00000000
0000008c0000000000000000000000000000006008000000000000000000000004000000
000000002e000000040000000000000000000000487d0000180000001600000004000000
040000000c00000039000000080000000300000000000000c81200000000000000000000
0000000004000000000000003e000000010000000000000000000000c812000030000000
000000000000000001000000000000004c000000
Sending packet: $m0,2#fb...Ack
------------------------------------- <1>
Packet received: b0935e8c
Sending packet: $M0,2:20c3#0d...Ack
------------------------------------- <2>
Packet received: OK
Sending packet: $c#63...Ack
Packet received: T0510:2874008c;0e:1466658c;0f:26845e8c;

Program received signal SIGTRAP, Trace/breakpoint trap.
Sending packet: $M0,2:b093#13...Ack
------------------------------------- <3>
Packet received: OK
Sending packet: $M8c5e83d4,2:04d1#16...Ack	
Packet received: OK
0x8c007428 in ?? ()
(gdb)
------------------------------------------------------------------------
--------------------------------------------------------------

here after the next command you can find the memory read and write
operation with zero address.
I would like to know more on this.

- Raja S




-----Original Message-----
From: gdb-owner@sources.redhat.com [mailto:gdb-owner@sources.redhat.com]
On Behalf Of Andrew Cagney
Sent: Friday, October 10, 2003 11:28 AM
To: saleru.raja@iap-online.com
Cc: gdb@sources.redhat.com
Subject: Re: remote serial protocol - gdbserver


> Hi,
> I have a querry related to remote serial protocl.
> 
> I have been ported gdbserver on RTOS (micro itron) running on SH3 
> processor. while debugging the remote application with "next" user 
> command from gdb,
> 
> Gdb send the following packets to gdbserver
> 
>          m0,2#fb
>          M0,2:20c3#0d
>   
>          simmilary for Z packet with zero address.
> 
> Here if the address is zero, what does it mean ? for example in this 
> packet "M0,2:20c3#0d" where the TRAP instruction should be write ? 
> where the data should be read from or write into ?
> 
> The solution for this querry will be greatly appreciated.

Can you post a gdb session with "set debug remote 1" enabled?

A wild guess is that it's trying to set a breakpoint at the return 
address of the function it's trying to NEXT over, only its getting that 
return address wrong.

Andrew