On 10.08.2008 23:36, Segher Boessenkool wrote: >>> Don't APs also need to initialize DRAM? Or can the BSP do this >>> "remotely" ? >> >> APs should do it. >> >> I'm getting a supermicro mainboard with 4 sockets and 128 GB memory, >> and I want that done in parallel :-) > > In principle, the BSP can initialise multiple memory controllers > in parallel as well. Using multiple processors to do it is quite > hard, esp. since you cannot do "normal" SMP stuff because memory > isn't initialised yet; and you get all the "normal" SMP headaches > as well obviously. > > If the memory init needs to access resources that it cannot access > remotely (like, MSRs on x86), you have no choice but to use APs, > of course. This seems to be the case on FAM10h (but not on K8).
The AMD Family 0Fh BKDG says: "The BSP must perform the following tasks: [...] Memory controller initialization on all processor nodes" The AMD Family 10h BKDG is silent on this. Regards, Carl-Daniel -- http://www.hailfinger.org/ -- coreboot mailing list [email protected] http://www.coreboot.org/mailman/listinfo/coreboot
