help about debugging embedded linux by GDB target remote debugging

["agan" <sharegan@sh.t2-design.com>]

hi,
    I want to use GDB for mips , to remote debugging  vmlinux(embedded linux
for mips) , I have builded vmlinux by adding gdb_stub.c for mips , add
set_debug_traps() , and breakpoint() function into vmlinux top, and
configure  debuging vmlinuc kernel by GDB  remote serial line.
    but I cannot get remote serila connection by typing 'target mips
/dev/ttyS0' or 'target remote /dev/ttyS0'  ; what the matter that I face is
the same as the attach mail archive"Problem on gdb (insight) under cgywin!
".
    please help me find tha matter. tks a lot.

    my debugging environment:
host:
        cpu arch: x86, os: linux (redhat 6.2) ,
        run  gdb: for target MIPS target ( configure  --target=mips-elf )
target:
        cpu arch: mips, os:wince 3.0( pocket pc) ,
        i download the vmlinux into the pocket pc, and start to run it.

matter:
        gdb cannot connect vmlinux(gdb_stubs) by serial line.


best regards.
agan shao











----------------------------------------------------------------------------
------------------

attach file ( get from GDB maillist :
                    Date: Wed, 18 Apr 2001 10:08:40 -0400 )

<Obvious question:
<To use GDB this way you must be running the GDB stub on your target
<board. Are you running the stub?

<What are you running on the 68K target?

<Also if this is an embedded target then are you sure that the
<console_output is being piped through the GDB stub?

<At 10:13 AM 4/18/01 +0800, you wrote:
>Hi:
>     I've build insight under cygwin for my m68k target.
>     I have some problems.
>
>     1.First I execute m68k-coff-gdb.
>        and open a m68k-coff image, but a error occur
>         => Error loading "...../test.coff"
>             bad offset (0x12264) in compilation unit header(offset 0x0+6)
>         The test.coff is workable when running in target.
>         So I have no idea about why GDB don't accept the coff image?
>
>    2.Using File->target setting,I set target using
Remote/serial,57600,com2.
>       and Run->connect to target.
>       After a long time,there is a message->"connected successfully".
>       But When I ececute a "console_output" command at the target,
>       sending a string like "Hello,Insight" to insight.
>       I think I should see this string at the console window?
>       But nothing there.Do I make any mistake?
>
>    3.I try another method.
>       I open insight and use console window to connect to target.
>       (gdb)target remote com2
>       After long time,the message appear."Ignoring packet
error....continue"
>       Why?
>
>    4.Because I only see baud setting and com port selection in insight.
>       But I set following configuration in target's uart:
>       =>baudrate 57600,8-bits data,1 stop-bit,no parity.
>       How do I make sure  inshgt on the host can recognize this
>configuration at the target?
>
>    5.I've see a message at the ecos-discuss mailing list about ignoring
>packet error
>       The author said he wired up the connector at the PC end to connect
>RTS&CTS,DSR&DTR,
>       and permanently enable DCD.Then it works fine?
>       What did he mean? Do I need a special serial line?Or I can use
common
>serial line that buy from store.
>
>Thank very much!
>B.R.
>