Hi all, I have not clear which hardware support should an embedded CPU provide to make it possible for an OS (like Linux) to support Symmetric Multi-Processing. Is it a matter of special signal lines, interrupts, or what else? And then, is there any standard approach supported by the Linux kernel, or every CPU vendor implements its own protocol, that then has to be incorporated into the kernel sources? Around the net I've found a lot of documents about Intel micros (the solution seems to be the Advanced Programmable Interrupt Controller, a.k.a. APIC), but nothing about MIPS or PowerPC. Cheers, Fabrizio -- ============================================ Fabrizio Fazzino - fabrizio at fazzino.it Fazzino.IT - http://www.fazzino.it ============================================

* Fabrizio Fazzino (fabrizio at fazzino.it) wrote:

in order for all CPU's to work in unified memory space you'd need cache
coherency protocol (so that they both agree what is the 'current' data) and
some sort of atomic / locking operation (typic test and exchange or
decrement and test ...) so that you can implement (spin) locks.

best regards,
p.