Are there processors where that CPU_ADDR_BITS_MASK cannot be reliably retrieved from CPUID? What is the harm in using a value that is too small for the CAR setup? In other words could we use the least common value for any CPU instead of having a different setting on each different chip?
Thanks, wt On Sun, Oct 3, 2010 at 5:14 PM, Scott Duplichan <[email protected]> wrote: > ] > ]But note that the current form is also a bit dangerous. It hardcodes 40bits > ]for K8 and 48bits for Fam10h here unconditionally. I don't know if this > ]assumption is always correct for all CPUs. Using the correct per-CPU > ]CONFIG_CPU_ADDR_BITS_MASK would definately be safer (if this mechanism > ]can work here at all). Are we sure there are no K8 systems that support > ]CPUs with bits != 40? Are we sure there are no Fam10h CPUs with > ]bits != 48 (and that there never will be in the future)? > > Getting this info from cpuid is the way to go (It is reliable on AMD > systems). Hard-coding is next best. It is fixed per family: > > 0Fh 40 > 10h 48 > 11h 40 > 12h 40 > 13h (no product) > 14h 36 > 15h 48 > > Hopefully AMD will start supplying coreboot-ready support code, which > will allow coreboot to run exactly the same reference code as every > other AMD BIOS. > > Thanks, > Scott > > ]Uwe. > ]-- > ]http://hermann-uwe.de | http://sigrok.org > ]http://randomprojects.org | http://unmaintained-free-software.org > > > > -- > coreboot mailing list: [email protected] > http://www.coreboot.org/mailman/listinfo/coreboot > -- coreboot mailing list: [email protected] http://www.coreboot.org/mailman/listinfo/coreboot
