I’m research about rtems qdp smp V6 gr712, gr740 but, I wanted to test in an SMP environment with an emulator that supports RTEMS QDP SMP, but only one CPU core could be specified.
I used qemu-system-sparc on rtems/bin
I thought it might be because gr712 is dual core, so I tried it on gr740 and used the emulator on the rtems general distribution, but the same problem occurred.
Oh, it seems like the qemu path is not inside rtems. I tried sparc-rtems6-sis, but it only has one core, so I tried qemu, and it seems like the same problem occurred.
QEMU 6.2.1 is from 2021. Like I mentioned above, if I found the right patch above, SMP support for SPARC has been added 2024. So I think you need a newer QEMU. From the release history, I would expect that you need at least a version 9.0.0.
If your distribution doesn’t provide a current QEMU, you can just build one from the sources. Usually QEMU works quite stable in the development versions so I would just use the latest git version.
I would start with reading the SCF. It contains a section with examples which run on SIS. The SIS is included in the package. This simulator supports four processors for the GR740. The LEON3 support for Qemu is not really maintained. TSIM provided by Gaisler is also an option.