Peter Maydell <peter.maydell@linaro.org> writes:
On 27 July 2012 14:37, Anthony Liguori <aliguori@us.ibm.com> wrote:
This command attempts to map to the behavior of -cpu ?. Unfortunately, the output of this command differs wildly across targets.
I've never really understood why so much of the cpu selection logic is deferred to target-*...
It will be fixed as part of the QOM conversion.
To accomodate this, we use a weak symbol to implement a default version of the command that fails with a QERR_NOT_SUPPORTED error code. Targets can then override and implement this command if it makes sense for them.
This is a bit of a weak reason (boom boom!) for requiring a platform specific thing like weak symbols, though, and it's not how we handle similar existing cases (eg see the configure/makefile logic for memory_mapping.c vs memory_mapping-stub.c).
I don't think we have a consistent approach today FWIW. I think using weak symbols is sufficiently compelling that it will become consistent.
If having separate configure/make stuff for each of these things sounds a bit heavyweight, we could just have a target-stubs.c which #includes cpu.h and has a lot of #ifndef TARGET_QUERY_CPUDEFS [stub version] #endif #ifndef TARGET_GET_MEMORY_MAPPING [stub version] #endif
This is pretty hideous. FWIW, weak symbols are supported on OS X as of 10.2. Regards, Anthony Liguori
etc.
-- PMM