On Fri, May 16, 2014 at 09:29:39PM +0800, Chen Jie wrote:
> >> -#ifdef CONFIG_CPU_MIPSR2
> >> +#if defined(CONFIG_CPU_MIPSR2) || defined(CONFIG_CPU_LOONGSON3)
> >
> > Is there some reason CPU_LOONGSON3 can't select CPU_MIPSR2?
>
> Loongson 3a is not fully mips32r2 compatible, but Loongson 3b is.
Interesting, I was led to believe that the 3A was MIPS64r2 compliant
(and thus by nature MIPS32r2 compliant) with the one difference with
other implementations being how it handles Status.FR=0 (appearing as
16x64b registers rather than the 32x32b registers of other CPUs). Are
there any other ways in which Loongson 3A is not MIPS64r2/MIPS32r2
compliant?
If not then wouldn't it make more sense to select CPU_MIPSR2 & then
special case any FPU differences? That would get you all the R2 bits of
the kernel with minimal #ifdef-ery.
Thanks,
Paul
Attachment:
signature.asc
Description: Digital signature
