Re: [PATCH 2/2] target/m68k: fix gdb for m68xxx

["Alex Bennée" <alex.bennee@linaro.org>]

Laurent Vivier <laurent@vivier.eu> writes:

> Le 28/04/2020 à 19:17, KONRAD Frederic a écrit :
>> Currently "cf-core.xml" is sent to GDB when using any m68k flavor.  Thing is
>> it uses the "org.gnu.gdb.coldfire.core" feature name and gdb 8.3 then expects
>> a coldfire FPU instead of the default m68881 FPU.
>> 
>> This is not OK because the m68881 floats registers are 96 bits wide so it
>> crashes GDB with the following error message:
>> 
>> (gdb) target remote localhost:7960
>> Remote debugging using localhost:7960
>> warning: Register "fp0" has an unsupported size (96 bits)
>> warning: Register "fp1" has an unsupported size (96 bits)
>> ...
>> Remote 'g' packet reply is too long (expected 148 bytes, got 180 bytes):    \
>>   00000000000[...]0000
>> 
>> With this patch: qemu-system-m68k -M none -cpu m68020 -s -S
>> 
>> (gdb) tar rem :1234
>> Remote debugging using :1234
>> warning: No executable has been specified and target does not support
>> determining executable automatically.  Try using the "file" command.
>> 0x00000000 in ?? ()
>> (gdb) p $fp0
>> $1 = nan(0xffffffffffffffff)
>> 
>> Signed-off-by: KONRAD Frederic <frederic.konrad@adacore.com>
>> ---
>>  configure             |  2 +-
>>  gdb-xml/m68k-core.xml | 29 ++++++++++++++++++++++++++++
>>  target/m68k/cpu.c     | 52 ++++++++++++++++++++++++++++++++++++---------------
>>  3 files changed, 67 insertions(+), 16 deletions(-)
>>  create mode 100644 gdb-xml/m68k-core.xml
>
> Reviewed-by: Laurent Vivier <laurent@vivier.eu>

Are you going to take this through your tree or do you want me to add it
to my small pile of gdbstub fixes?

-- 
Alex Bennée