Re: [Qemu-devel] gdb for sparc64?

[Mark Cave-Ayland]

Artyom Tarasenko wrote:

> Does any gdb version work with current qemu-system-sparc64 ?
>
> I tried 7.1 and 6.8 with --target=sparc64-linux and --target=sparc64
> And result seems to be pretty much the same:
>
> GNU gdb 6.8
> Copyright (C) 2008 Free Software Foundation, Inc.
> License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
> This is free software: you are free to change and redistribute it.
> There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
> and "show warranty" for details.
> This GDB was configured as "--host=x86_64-unknown-linux-gnu
> --target=sparc64-linux".
> (gdb) target remote :1234
> Remote debugging using :1234
> [New Thread 1]
> Remote 'g' packet reply is too long:
> 0000000000000000000000000000000000000000080000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
000000000000000000000000000000000000000001fff0000020000001fff00000240000000000003507000000000000000000000000000000000000000000000000
> (gdb)
>
> Regards,
> Artyom Tarasenko

Hi Artyom,

In order to use gdb with OpenBIOS on SPARC64, you need to build gdb with 
--target=sparc64-linux and then point it towards a 64-bit image with 
"file" in order to prevent the "Remote 'g' packet reply" error, e.g.

address@hidden:~/src/openbios/openbios-devel$ sparc64-linux-gdb
GNU gdb 6.8
Copyright (C) 2008 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later 
<http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
and "show warranty" for details.
This GDB was configured as "--host=x86_64-unknown-linux-gnu 
--target=sparc64-linux".
(gdb) target remote :1234
Remote debugging using :1234
[New Thread 1]
Remote 'g' packet reply is too long: 
000000000000000000000000000000000000000008000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
0000000000000000000000000000000000000001fff0000020000001fff00000240000000000003507000000000000000000000000000000000000000000000000
(gdb) file obj-sparc64/openbios-builtin.elf.nostrip
Reading symbols from 
/home/build/src/openbios/openbios-devel/obj-sparc64/openbios-builtin.elf.nostrip...done.
(gdb) target remote :1234
Remote debugging using :1234
[New Thread 1]
0x000001fff0000020 in ?? ()
(gdb) cont
Continuing.

...and then off you go. I don't know whether this is a bug/feature in 
the QEMU gdb stubs or just GDB itself.


HTH,

Mark.

--
Mark Cave-Ayland - Senior Technical Architect
PostgreSQL - PostGIS
Sirius Corporation plc - control through freedom
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