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

[Laurent Vivier <laurent@vivier.eu>]

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>