On 20.08.2008 16:37, Stefan Reinauer wrote:
Carl-Daniel Hailfinger wrote:
v3 can't use global variables in stage1 or initram. Same applies to static local variables. See the bug below.
Ideas for fixes? The generic variable infrastructure would be one option.
Just call smbus_init() prior to calling smbus_read_byte() the first time. The variable infrastructure might be a nice idea for some things, but I think in cases as simple as this, we should not rely on it.
Agreed.
By the way, the new section checker has better output: CHECK initram (non-empty .data sections) /sources/tmptrees/corebootv3-check_illegal_global_vars/build/coreboot.initram_partiallylinked.o: first_time.3526 make: *** [/sources/tmptrees/corebootv3-check_illegal_global_vars/build/coreboot.initram] Error 1
Is there a method to change variables in your "variable infrastructure" across cpus? If so, it could be useful for semaphores / locking. But I don't think that's possible since the stuff is in cache, right?
It strongly depends on the processor. Some processors share their CAR area contents, some don't. If CAR is shared, locking and updating is possible. If CAR is not shared, we need a global register for locking and a sort of syscall mechanism which allows APs to tell the BSP about memory writes/reads.
Regards, Carl-Daniel